Mar 21, 2023 | Announcements, News releases
New Study Sheds Light on Ancient Microbial Dark Matter
March 21, 2023
Reno, Nev.
Shared with permission from the University of Nevada, Las Vegas
Omnitrophota
Microbial Dark Matter
Header Photo: Obsidian Pool in Yellowstone National Park. Credit: Bob Lindstrom. Photo in the Public Domain
DRI contributes to international team of scientists that unearths first in-depth look at Omnitrophota, one of the world’s oldest and tiniest
DRI’s Duane Moser, Ph.D., is a coauthor on a new study in Nature Microbiology that offers the first detailed analysis of a globally prominent, but poorly characterized type of bacteria belonging to a group scientists refer to as “microbial dark matter.” Formally described here for the first time as the Omnitrophota, the existence of this phylum of bacteria was first inferred from environmental DNA nearly thirty years ago.
“This paper illuminates the properties and ecological function of a group of ubiquitous, but poorly understood organisms,” said Moser, associate research professor of microbiology.
Moser’s contribution to the study included identifying field sites and collecting samples, as well as developing an understanding of environmental context. His long-standing research relationship with the lead authors of the study meant that collaborative projects over the years led to a number of useful datasets for the analysis.
“The research community has followed the Omnitrophota story since the 1990s, when earlier groundbreaking studies that revealed unexpected diversity within Archaea at Obsidian Pool in Yellowstone National Park were expanded to include bacteria,” Moser says. “In those days, full genomes of uncultivable microorganisms were beyond the reach of available technologies, so a conserved gene that encodes an essential structure shared by all cellular life (the 16S rRNA gene) was used to identify novel life and estimate relatedness between organisms.”
“What scientists found was so different from anything that had been described previously that scientists of the time proposed that Omnitrophota might be a novel phylum within Bacteria (the equivalent of the evolutionary difference between plants and animals). This interpretation has stood the test of time,” Moser continued.
“Over the past several decades, Omnitrophota has been frequently encountered in aquatic and soil samples worldwide. In our own work in springs, mines, and shallow groundwaters, Omnitrophota have often been among the more prominent microbial groups detected. I sometimes wonder if the sheer abundance and evident diversity of this omnipresent group has intimidated researchers from tackling its formal description. This was an ambitious project that required the combined expertise of a strong team of collaborators.”
Brian Hedlund, a microbiologist at the University of Nevada, Las Vegas, and lead author of the study, said “Duane’s knowledge of the geology and hydrology of subsurface environments — and how to sample them meaningfully — was really important for this study.”
Below is the full press release from the University of Nevada, Las Vegas.
LAS VEGAS – March 16, 2023 – Bacteria are literally everywhere – in oceans, in soils, in extreme environments like hot springs, and even alongside and inside other organisms including humans. They’re nearly invisible, yet they play a big role in almost every facet of life on Earth.
Despite their abundance, surprisingly little is known about many microorganisms that have existed for billions of years.
This includes an entire lineage of nano-sized bacteria dubbed Omnitrophota. These bacteria, first discovered based on short fragments of DNA just 25 years ago, are common in many environments around the world but have been poorly understood. Until now.
An international research team produced the first large-scale analysis of more than 400 newly sequenced and existing Omnitrophota genomes, uncovering new details about their biology and behavior. The team’s findings are reported in the March 16 issue of the journal Nature Microbiology.
“We now have the most comprehensive view to date of the biology of an entire phylum of microorganisms and the surprising role they play in the Earth’s ecosystems,” said UNLV microbiologist Brian Hedlund, the study’s corresponding author. “There is a finite number of major lineages of life on our planet, and it’s exciting to learn more about organisms that pre-date plants and animals and have been essentially hidden under our noses.”
The tricky thing with Omnitrophota is that they’re still largely considered microbial dark matter, which means they exist in nature but can’t yet be cultivated as single species in lab studies. Just two species have been microscopically observed, and only very recently.
To present a comprehensive picture of their biology, scientists compared 349 existing and 72 newly mapped genomes of Omnitrophota. This included a review of publicly available data and new samples collected from geothermal environments, freshwater lakes, wastewater, groundwater, and springs located around the world.
The team observed that, in most cases, Omnitrophota measure less than 450 nanometers, which places them among the smallest of all known organisms. They also displayed genetic markers consistent with symbiosis – possibly as predators or parasites of other microorganisms, which suggested they would have high metabolic rates. Indeed, when isotope uptake was measured as a proxy for metabolic activity, Omnitrophota were hyperactive.
“Despite how little we collectively knew about Omnitrophota, they’ve long been cited by microbial ecologists. Our goal was to finally drag this lineage out of the dark,” said Cale Seymour, a recent UNLV master’s graduate and the study’s lead author. “The more we learn about their energy conservation pathways and possible lifestyles, the closer we get to our goal of cultivating them in the lab and bringing them into the light.”
The study, “Hyperactive nanobacteria with host-dependent traits pervade Omnitrophota,” appeared March 16 in the journal Nature Microbiology. Additional collaborating organizations include Bigelow Laboratory for Ocean Sciences, the University of North Alabama, the U.S. Department of Energy’s Joint Genome Institute, Desert Research Institute, Northern Arizona University, Sun Yat-sen University, University of Science and Technology of China, and University of Queensland.
Mar 21, 2023 | Blog, Featured researchers
DRI Student Interns Join Efforts to Improve Drinking Water Access in Ghanaian Communities
March 21, 2023
RENO, NEV.
By Guadalupe Alvarez
DRI Communications Intern
Water Treatment
Sanitation
CIWAS
DRI’s Behind the Science Blog continues with the third installment of our fall 2022 Research Immersion Internship Series
This fall, DRI brought eleven students from Nevada’s community and state colleges to the Las Vegas and Reno campuses for a paid, immersive research experience. Over the course of the 16-week program, students worked under the mentorship of DRI faculty members to learn about the process of using scientific research to solve real-world problems.
Our Behind the Science Blog is highlighting each research team’s accomplishments over a series of five stories. Previous stories covered Tiffany Pereira’s interns as they tracked elusive desert tortoises in the desert of Las Vegas, and Erick Bandala’s student interns on their quest to find solutions for communities struggling with high concentrations of fluorides in their drinking water.
In this story, we highlight the work of two student interns and their research in international Water, Sanitation, & Hygiene (WASH) development issues in Ghana. These students are building on decades of DRI-led research focused on improving access to clean drinking water in Ghanaian communities.
Above: The CIWAS program installs and maintains drinking water wells in Ghanaian communities. Photo credit: DRI.
Student Researchers: Anjali Bhatia and Anida Bouakhasith
Faculty mentor: Braimah Apambire, Ph.D., Director, Center for International Water and Sustainability (CIWAS)
Additional Mentor: Palistha Shrestha/ Research Scientist, Program Manager, CIWAS
As communities all over the Southwest continue to face challenges tied to severe drought, water accessibility is becoming an increasing concern. Here at DRI, research in water sustainability extends to communities far beyond Nevada.
More than 2 billion people lack access to safe drinking water and 3.6 billion people do not have access to safely managed sanitation services. Water contamination and poor hygiene are driving 88% of all diseases in developing countries. To address these needs, the United Nations established the Sustainable Development Goals – a set of 17 goals to improve living conditions of people around the globe. Goal #6 is to ensure availability and sustainable management of water and sanitation for all by 2030. This is an ambitious goal – according to the United Nations, reaching this goal would require quadrupling the current rate of progress.
Constructing water systems is only the first step in managing water sustainability, as many developing countries continue to experience the breakdown of water infrastructure and inadequate water treatment. Access to safe, clean drinking water is an underlying issue in Ghana, where a 2019 World Health Organization (WHO)/UNICEF report found that 32% of people in rural communities lacked access. Under the mentorship of Braimah Apambire, interns Anjali Bhatia and Anida Bouakhasith analyzed the effectiveness of water systems, water quality, and health impacts surrounding water services. Their work highlights the importance of community-centered research to understand the long-term sustainability of water infrastructure.
“Water is an essential part of our everyday lives,” said intern Anjali Bhatia. “In developing countries, access to safe drinking water is a real and current issue and something we are striving to fix. The first step is to know what each community needs and continuing to address those specific needs.”
A map of the districts in Ghana where research was focused: East, North, and Northeast Gonja districts.
Community-Centered Research
During their 16-week internship, Bhatia and Bouakhasith evaluated data collected from the Circuit Rider Program in Northern Ghana. Since 2016, this program has aimed to provide training and materials to Ghanaian communities in order to build their capacity for maintaining functional water systems. By focusing on supporting local technicians with funding and training support, the Circuit Rider Program addresses the main challenges by ensuring that rural water systems are maintained, and water quality is adequately tested.
The interns evaluated data collected from three Ghanaian regions: East, North, and Northeast Gonja districts. An 18-question survey inquiring about water access, quality, and time spent accessing water was distributed to various households throughout the districts. When asked what their main source of water is, 50% of households in East Gonja reported their main source of water was through hand pumps or surface water. In the Northeast district, 65% of households also reported surface water as their main source of water. Surface water — when left untreated — can contain dangerous levels of arsenic, fluoride, microplastics, and other substances linked to the transmission of diseases.
“Surface water can often contain bacteria, parasites, viruses, and other contaminants,” Bhatia said. “It’s often required that the water is treated before it is safe to drink.”
When asked how long it takes to collect their water, the three areas varied. While 50% of Northern Gonja households reported they have at-home access, more than 60% of households across the three districts reported it takes them up to half an hour or more to access water.
Collecting water can involve long and risky journeys. Limited accessibility along with poor sanitation can affect an individual’s well-being and impact other social and economic areas of life. “It puts into perspective how often we take for granted how easily accessible it is to get water. That’s time they could spend doing something else,” said Bhatia.
All three communities were also asked how they would rate the quality of water from the source they are drinking from. While 95% of households in North Gonja evaluated their water quality as good, it was the opposite for Northeast district communities, where 97% of households described their water quality as poor and even “cloudy, salty, and colored,” with a bad smell.
Above Left: Intern Anjali Bhatia presents her research. North Gonja primarily sourced water from boreholes with hand pumps, while most of North East Gonja sourced their water from surface water.
Above Right: Intern Anida Bouakhasith presents her research. Most of North Gonja rated their water quality as “good,” whereas most of Northeast Gonja rated their water quality as “poor.”
Where To Go From Here
All the survey data received from rural communities in Ghana help piece together what is needed to ensure effective water systems. Bhatia and Bouakhasith’s data analysis shows the crucial attention needed towards the water systems already put in place and the potential health impacts on households across the region.
“Getting direct feedback from these communities allows us to see where we need to make changes, what changes need to be made, and with that information we can make those changes,” said Bhatia.
“The internship program is an opportunity to develop important professional and technical skills,” said Braimah Apambire, their faculty mentor. “It helps students become even more passionate about helping others and using science to make a positive impact on the world.”
Mar 10, 2023 | Announcements, News releases
Christine Albano Receives Board of Regents 2023 Rising Researcher Award
March 10, 2023
Reno, Nevada
DRI scientist Christine Albano, Ph.D., is the recipient of the 2023 Rising Researcher Award from the Nevada System of Higher Education (NSHE) Board of Regents
DRI scientist Christine Albano, Ph.D., is the recipient of the 2023 Rising Researcher Award from the Nevada System of Higher Education (NSHE) Board of Regents, in recognition of her outstanding early-career accomplishments and potential for advancing scientific knowledge in the field of earth and environmental sciences.
Dr. Albano is an Assistant Research Professor in DRI’s Division of Hydrologic Sciences, where her work focuses on understanding the impacts of atmospheric rivers and other extreme atmospheric events on the hydrology of landscapes over time.
“I’m incredibly grateful for this award,” Albano said. “I’ve so appreciated the mentorship and support I’ve received from DRI management and colleagues over the past several years. It’s a place where I’ve felt encouraged to do work that I think is interesting and important.”
DRI scientist Christine Albano, Ph.D
Dr. Albano began at DRI as a Ph.D. student and dedicated her dissertation work to improving our understanding of how atmospheric rivers impact water storage and flood risk in the Sierra Nevada and Great Basin regions. She has continued to expand her research interests, using her background in conservation biology and ecology to connect extreme hydrologic events to impacts on ecosystems in new and novel ways. In 2022, she published ground-breaking work quantifying changes in evaporative demand across the U.S. over the last 20 years, and the implications for irrigated agriculture.
Dr. Albano has published 28 peer-reviewed journal articles and reports, with two more in review. She has worked with countless research teams, partners, and stakeholders to complete projects funded by agencies such as the NSF, USDA, U.S. Army Corps of Engineers, and several federal land management agencies. She finds that working with state and federal agencies to develop research approaches that lead to improved conservation and sustainable use of natural resources is the most rewarding aspect of her work.
“Dr. Albano’s innovative research has already made her a leader in her field,” said DRI Vice President for Research Vic Etyemezian, Ph.D. “In addition to publishing her research in high-impact peer-review journals, she brings so much to both DRI and the broader community by communicating her research results with the media and the public.”
In addition to her impressive research portfolio, Albano utilizes her experience working with non-profit conservation organizations to include community stakeholders in the scientific process. She contributes to mentoring the next generation of scientists by serving on the Graduate Program in Hydrologic Sciences faculty and is mentoring her first Ph.D. student. She also teaches advanced climatology in the UNR graduate school and has led workshops teaching the R programming language to undergraduate students at UNR and Salish Kootenay College.
Dr. Albano holds a B.S. in biology with minors in chemistry and environmental studies from Westminster College, and a M.S. in ecology from Colorado State University. Her Ph.D. in hydrology was completed in 2019 under the mentorship of DRI and UNR’s Maureen McCarthy and Michael Dettinger. She continued in DRI’s ecohydrology lab working alongside Justin Huntington for her postdoctoral research and became an Assistant Research Professor in 2020.
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Mar 9, 2023 | Announcements, News releases
First-ever layered lake sediment sample extracted from subglacial Antarctica
March 9, 2023
Golden, Colorado
Shared with permission from the Colorado School of Mines
Subglacial Lakes Antarctica
Header Photo Credit: Matthew Siegfried
Sample gives important details into past dynamics of the Antarctic ice sheet and its cold, dark ecosystems
DRI’s Mark Hausner, Ph.D., is a coauthor on a new study detailing the first layered lake-sediment sample taken from a subglacial lake in Antarctica. Hausner stepped in to assist the project team — dubbed SALSA for Subglacial Antarctic Lakes Scientific Access — after a difficult deployment created challenges in recovering temperature data from their equipment.
“I worked with the team after their return to recover the best temperature data we could,” Hausner says. Although precise temperature observations couldn’t be recovered, Hausner’s expertise with fiber-optic distributed temperature sensing cables enabled him to identify changes in the data that were consistent with other observations.
“Using multiple observation methods really increases your confidence in what you’re seeing,” he says. “In this case, satellite observations, surface geophysics, and the temperature profile through the ice and into the lake all tell the same story of a lake underneath 1 km of ice that’s switching from draining to filling.”
Below is the full press release from the Colorado School of Mines.
Since the discovery 50 years ago of subglacial lakes in Antarctica — some of the least accessible geological features on Earth — scientists have attempted to extract lake bed sediment to learn about the formation, movement, and past conditions of the ice sheet. Now, a team of researchers with the NSF-funded project Subglacial Antarctic Lakes Scientific Access (SALSA) has successfully done so, recovering the first layered sediments from beneath the modern Antarctic ice sheet.
Their findings from analysis of the sediment sample, published March 9 in Geology, give important insight into the larger dynamics of the Antarctic ice sheet and its history, including when the ice sheet was smaller than its current size. Their work adds to the sedimentary record of knowledge of Antarctica and also holds implications for understanding how Antarctica may contribute to global sea level change.
Previous studies of modern subglacial lakes were limited to the timescale of the modern ice sheet due to the challenge of sampling an environment locked beneath thousands of feet of ice. The sediment sample extracted by the SALSA team will allow researchers to better understand subglacial activity across almost two centuries, instead of merely two decades.
“There are places on Earth that we still haven’t explored,” said Matthew Siegfried, assistant professor of geophysics at Colorado School of Mines and a lead author of the paper. “We have now one sample trying to understand an environment that is one and a half times the size of the continental United States. It’s like pulling up a rock in New Orleans and understanding how the Mississippi River and its entire basin has acted for the past 1,000 years.”
The saga of the SALSA team’s quest to explore subglacial lakes is chronicled in “The Lake at the Bottom of the World,” a feature-length documentary film released across multiple streaming platforms on February 28 by the team in partnership with Metamorph Films. The NSF-funded film gives viewers a close look at how the scientists conducted their work amid harsh Antarctic conditions.
‘Like grabbing a package of soup’
Researchers captured the sediment sample on a field expedition in December 2018. They cleanly bored a hole through over 3500 feet of ice over Mercer Subglacial Lake by filling a modified fire hose with sterilized water at nearly 200 °F and aiming it into the ice. They carefully collected sediment cores through a borehole that was constantly freezing back in using a device modified from its typical use in “normal” lakes to fit in a narrow ice borehole.
While researchers knew that even the mere extraction of the sediment from the lake would be a success, the fact that a sample arrived at the lab intact proved even more gratifying.
“We didn’t expect to find this mushy, fragile sediment under the ice sheet,” Siegfried said. “It was basically like grabbing a package of soup, bringing it up 1100 meters to the surface of the ice, shipping it to America, getting it into a CT scanner in Oregon, and somehow maintaining tiny laminations in the sample.”
Previous sediment samples from beneath the modern West Antarctic Ice Sheet have only consisted of a jumbled mixture of marine muds and rocks left behind when glaciers move over the Earth and do not contain a layered history of the region or ice sheet.
“In a 2001 paper published after a decade of subglacial drilling efforts in Antarctica, glaciologist Barclay Kamb somewhat unenthusiastically summarizes that everywhere the project sampled sediments, they found the same uninteresting, sticky, gray mixture,” said Ryan Venturelli, assistant professor of geology and geological engineering at Colorado School of Mines and a lead author on the paper.
“We found that, too. But above that same sticky, gray stuff, we found something different for the first time.”
Understanding subglacial movement
CT imagery of the sample showed a pattern of contrasts that indicated the subglacial lake was filling and draining with water before the scientists’ observational record. This finding offers insight into how long water has been moving under this part of Antarctica — movement that has implications for how the ice sheet moves and contributes to sea level rise. The life cycle of subglacial lakes derived from these contrasts also will enable researchers to better identify how carbon, nutrients and dissolved gasses are transported through the subglacial system to the global ocean.
“We use sediments from normal (subaerial) lakes all the time to build records of regional changes in climate. Subglacial lakes are different, because they are sealed by an overlying ice sheet that shields them from changing seasons and changing climate. Any variation in the subglacial sediment record is driven by changes to the overlying ice sheet and associated water system,” Venturelli said.
“Thanks to satellites that have helped us spy on Antarctica from space since 2003, we have a deep understanding of subglacial lake activity in the modern record, but the sediments we collected as part of SALSA give us an idea of how persistent these features are on a much longer timescale — hundreds of years. It’s our first insight into the life cycle of an active subglacial lake, and that is really exciting,” Venturelli added.
Significance of the sampling effort
The findings shared in Geology come amid more groundbreaking publications from the SALSA team based on the sediment samples they retrieved from Mercer Subglacial Lake. In February, researchers published work in ISME Communications that examined and compared microbial communities in the sediment to other regions under the ice; their work indicated an extensive subglacial ecosystem that is biogeochemically and evolutionarily linked through ice sheet behavior and the transport of microbes, water and sediments. Forthcoming research out soon in AGU Advances, also led by Venturelli, constrains the Antarctic subglacial carbon cycle for the first time and indicates how details of the cycle can be used to estimate how much smaller the West Antarctic Ice Sheet was in the last few thousand years.
“Knowing the dynamics of the ice sheet in the past is critical for predicting how it may respond to changes in the future, but this information has also helped to better understand the connectedness of these ecosystems to processes on the surface and regions beneath deep Antarctic ice that have yet to be explored,” said Brent Christner, a microbiologist at the University of Florida and SALSA Project team member.
Feb 21, 2023 | Announcements, News releases
Arsenic Contaminates Private Drinking Water Wells Across the Western Great Basin
February 21, 2023
RENO, Nevada
Arsenic
Water Wells
Western Great Basin
Above: Researchers test a private well water for traces as metals such as arsenic in Washoe Valley, Nevada.
Credit: Monica Arienzo/DRI.
A New Study Maps Risk of Elevated Arsenic Levels in Groundwater Wells Across Northern Nevada, Northeastern California, and Western Utah
In the arid and drought-stricken western Great Basin, sparse surface water means rural communities often rely on private groundwater wells. Unlike municipal water systems, well water quality in private wells is unregulated, and a new study shows that more than 49 thousand well users across the region may be at risk of exposure to unhealthy levels of arsenic in drinking water.
Led by researchers at DRI and the University of Hawai’i Cancer Center and published February 16th in Environmental Science and Technology, the study used data from groundwater wells across the western Great Basin to build a model to predict the probability of elevated arsenic in groundwater, and the location and number of private well users at risk. According to the study, the Carson Desert basin (including the town of Fallon, Nevada), Carson Valley (Minden and Gardnerville, Nevada), and the Truckee Meadows (Reno), have the highest population of well users at risk. The new study builds on previous research showing that 22% of 174 domestic wells sampled in Northern Nevada had arsenic levels exceeding the EPA guideline.
“What we are finding is that in our region, we have a high probability for elevated arsenic compared to most other regions in the country,” said Daniel Saftner, M.S., a hydrogeologist at DRI and lead author of the study. “And we are seeing that geothermal and tectonic processes that are characteristic of the Great Basin contribute to the high concentrations of naturally occurring arsenic in the region’s groundwater.”
The region’s mountains are also primary sources of arsenic. “As the arsenic-rich volcanic and meta-sedimentary rocks that form the mountains erode, sediment is transported to the valleys below,” says Steve Bacon, Ph.D., DRI geologist and study co-author. Water percolating through the valley floor then carries arsenic into the groundwater. Deeper, older groundwater and geothermal waters tend to have a higher arsenic concentration and can migrate upward along faults and mix with shallow groundwater.
“We really wanted to better understand the unique geologic factors that contribute to high arsenic in this study,” Saftner says. “It’s important for us to think about the role of the environment as it pertains to human health – where we live can influence what our long-term health looks like.”
To train and test the predictive model, the research team used data collected through the Healthy Nevada Project, including water samples from 163 domestic wells primarily located near Reno, Carson City, and Fallon. These data were supplemented with 749 groundwater samples compiled from the USGS National Water Information System. The model uses tectonic, geothermal, geologic, and hydrologic variables to predict the probability of elevated arsenic levels across the region.
Although the U.S. EPA has set an arsenic concentration guideline of 10 µg/L for public drinking water, previous research has shown a range of health effects from long-term exposure to levels above 5 µg/L. Using this concentration as the benchmark, the model and map show that much of the region’s groundwater – particularly in western and central Nevada – is predicted to have more than a 50% probability of elevated arsenic levels.
“Community members can use our arsenic hazard map to see what the risk is at their location, which might motivate them to test their well water,” says Monica Arienzo, Ph.D., associate research professor at DRI and study co-author. “Then, if they have high levels of arsenic or other contaminants, they can take steps to reduce their exposure, such as installing a water treatment system.”
The findings from this study are potentially useful for a range of different applications. “The results can be useful for water utilities or water managers who tap similar shallow aquifers for their water supply,” says Saftner, “as well as irrigation wells that source water from these aquifers.”
The research team plans to use their model to take a closer look at the health impacts of prolonged arsenic exposure. “Through the Healthy Nevada Project, genetic data and health records are paired with environmental data to help determine whether there are associations between the levels of arsenic in a community’s groundwater and specific health outcomes,” stated Joe Grzymski, Ph.D., research professor at DRI and principal investigator of the project.
Map showing the hydrographic basin boundaries and predicted average population density with arsenic ≥5 μg/L in (a) the entire western Great Basin; (b) Truckee Meadows (Reno area), Lemmon Valley, and Cold Spring Valley; (c) Carson Valley (Minden and Gardnerville areas); and (d) Carson Desert (Fallon area).
Predicted probability of arsenic ≥5 μg/L in alluvial aquifers of the western Great Basin, including (a) mean probability of arsenic ≥5 μg/L, (b) 95% confidence upper bound, and (c) 95% confidence lower bound. Bedrock aquifers and lakes are shown in gray and were not included in the arsenic hazard assessment.
More information:
The full study, “Predictions of Arsenic in Domestic Well Water Sourced from Alluvial Aquifers of the Western Great Basin, USA,” is available from Environmental Science and Technology: https://doi.org/10.1021/acs.est.2c07948
Study authors include: DRI researchers Daniel Saftner, Steve Bacon, Monica Arienzo, Erika Robtoy, Karen Schlauch, Iva Neveux, and Joseph Grzymski, as well as Michele Carbone with the University of Hawaii Cancer Center.
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About the University of Hawaiʻi Cancer Center
The University of Hawaiʻi Cancer Center through its various activities, including scientific research and clinical trials, adds more than $57 million to the Oʻahu economy. It is one of only 71 research institutions designated by the National Cancer Institute. An organized research unit within the University of Hawaiʻi at Mānoa, the UH Cancer Center is dedicated to eliminating cancer through research, education, patient care and community outreach with an emphasis on the unique ethnic, cultural, and environmental characteristics of Hawaiʻi and the Pacific. Learn more at https://www.uhcancercenter.org. Like us on Facebook at https://www.facebook.com/UHCancerCenter. Follow us on Twitter @UHCancerCenter.
Jan 19, 2023 | Blog, Featured researchers
DRI Opens Doors to Careers in Scientific Research with Student Internship Program
Jan. 24, 2023
LAS VEGAS, NEV.
Fluoride
Water Treatment
Water Filters
The first in DRI’s Behind the Science Blog coverage of our fall 2022 Research Immersion Internship Series.
This fall, DRI brought eleven students from Nevada’s community and state colleges to the Las Vegas and Reno campuses for a paid, immersive research experience. Over the course of the 16-week program, students worked under the mentorship of DRI faculty members to learn about the process of using scientific research to solve real-world problems. This unique internship program welcomes all students, not only those pursuing majors in science, who are in their first or second year of enrollment at local state and community colleges.
Students for the 2022 fall semester joined from the College of Southern Nevada, Nevada State College, and Truckee Meadows Community College.
“Hands-on experience in science, working directly with experienced mentors, is one of the best ways to help students explore careers in scientific fields, and DRI’s internship program opens up this opportunity to more students across Nevada,” says Meghan Collins, M.S., who leads the internship program. “We’re thrilled to have continued support from MGM Resorts and the Hearst Foundations in order to bring more potential future scientists to DRI.”
The students wrapped up their semester-long internships on Dec. 20 by presenting lightning talks about their research to the DRI community. Their research spanned multiple scientific disciplines, from Nevada’s endangered species, to improving access to drinking water quality in Ghanaian communities, to monitoring Earth’s urban climates from space.
DRI’s Behind the Science Blog will highlight each research team’s accomplishments over a series of five stories.
Applications for fall 2023 internships will open in spring 2023.
In this story, we learn about Erick Bandala’s student interns and their quest to find solutions for communities struggling with a persistent and overlooked problem: the health impacts of high concentrations of fluorides in their drinking water.
Left: Intern Shaezeen Vasani tests the efficacy of three different experimental materials in removing fluoride from water. Right: The experimental set-up in Erick Bandala’s lab.
Student Interns Help Erick Bandala Develop a Water Treatment Prototype for Fluoride Removal
Student Researchers: Jennifer Arostegui, Rocio Cortez, Shaezeen Vasani
Faculty mentor: Erick Bandala, Ph.D., Assistant Research Professor of Environmental Science Additional Mentor: Adam Clurman, Student Worker in the Division of Hydrologic Sciences
Fluoride is largely known as a toothpaste additive – the American Dental Association recommends fluoride toothpastes because they help prevent cavities and strengthen tooth enamel. Many communities around the world add fluoride to their drinking water supply for the same reason. But when people consume too much fluoride – more than the 0.7 parts per million recommended by the U.S. Department of Health and Human Services – a number of health problems can arise.
“Normally, we hear positive news about fluoride – that it has been proven to rebuild and strengthen tooth enamel,” said intern Rocio Cortez. “However, a high concentration can pose a great danger.”
The Risks of Fluoride Over-Consumption
Fluorides are actually compound elements where the element fluorine combines with other substances, usually metals. They naturally occur in Earth’s rocks and soils, following rain and erosion to make their way into watersheds. Nearly all water contains some level of fluorides, but the geologic history of a region can sometimes lead to far higher levels than average.
Once inside the body, fluorides move through the bloodstream and concentrate in areas with higher calcium, including teeth and bones. Persistent exposure to higher levels can cause dental fluorosis, which discolors teeth and increases the risk of tooth decay. However, some communities are exposed to such high levels of fluorides that skeletal fluorosis can occur, which results from the buildup of fluorides in bones. This leads to joint stiffness and pain, brittle bones, and bone fractures.
“At high levels, fluoride starts to replace calcium in the teeth and bones,” said faculty mentor Erick Bandala. “And we have found places – for example, in Ghana – where the fluoride concentration may be as high as 50 milligrams per liter, which is far higher than the guideline of 1.5 milligrams per liter set by the World Health Organization (WHO).”
Closer to home, Bandala’s research team found wells in central Nevada’s Walker Lake Indian Reservation where the fluoride concentration is around 5 milligrams per liter, nearly three times the WHO guideline.
Excess fluoride can be removed from water with the aid of specialized filters and reverse osmosis, but many communities don’t have access to the proper technology, or the expertise needed to maintain it. Recognizing this, Bandala set out to identify inexpensive, readily available materials that can be used as water filters.
“We are developing materials that can remove contaminants from the water using the concept of circular economy,” Bandala said. “This means that we want to use material that for someone is considered a waste and turn it into something that can be used for water treatment.”
Researching Water Filters for Fluoride Removal
For their internship project, the students examined the potential efficacy of three different materials for removing fluorides from water. The first material, calcium hydroxyapatite (or “bone dust”), is derived from cattle bones. The second, sulfuric biochar, is created from pine wood that had been infected by beetles. The third material, phragmites, is a common invasive plant found in wetland areas.
“For our experiments, the materials were under a process called chemisorption,” said intern Jennifer Arostegui. “This process uses high pressure and high temperatures.”
Chemisorption causes new chemical bonds to form, allowing fluorides to bind to the experimental material and be subsequently removed from the water. The students tested various concentrations of each material over the course of approximately 70 different tests. Their results showed that unheated calcium hydroxyapatite was the most effective at filtering fluoride from water, followed by sulfuric biochar and then phragmites.
Another experiment examined each material to determine whether it was hydrophobic (water repelling) or hydrophilic (water attracting) and compared this to their results for fluoride removal. The students found that this wasn’t a critical factor in determining how effectively the experimental materials scrubbed fluoride from the water.
The interns tested how efficiently three different materials removed fluoride from drinking water: calcium hydroxyapatite, sulfuric biochar, and phragmites.
Embracing the Research Experience
The student researchers benefitted from their hands-on experience in the lab as well as immersion in the DRI community. They shared some of their highlights and surprises, as well as how the internship helped guide their future studies and careers.
“This experience was eye opening,” said intern Shaezeen Vasani, a student at the College of Southern Nevada studying physical sciences. “Every day I learned something new and could not wait to come back in to continue my project. Every time I thought I learned everything, something new would be brought to my attention.”
Vasani said she was surprised by the scientific process, especially when experimental results varied from her expectations. “While running tests, our numbers should have been decreasing but instead it was increasing for some of the materials,” she said, referring to the fluoride concentrations with treatment. “We later learned from our mentor that this could be due to the chemical properties in some of the materials and their interaction with our project’s contaminants.”
For intern Arostegui, the highlight of the internship experience was the ability “to actually get involved and introduced to a laboratory outside of school. In our group, we learned how to use a spectrophotometer, use reagents/stock solutions, and weighed/prepped our own samples.”
She says she was surprised to be part of a research team that respected her as a collaborator. “The biggest surprise for me was being referred to as a ‘scientist,’ ‘researcher,’ and even ‘engineer’ by my mentor and colleagues,” she said. “I have only seen myself as a student.”
Arostegui is studying environmental management at the College of Southern Nevada and has a specific interest in water resources and says that the internship encouraged her to continue studying hydrology and geology. “This was such a positive experience to be a part of,” she said. “I am forever grateful.”
Prior to the internship, intern Rocio Cortez had focused her undergraduate studies on business administration. Now, she says her career goals have shifted. “I have put in some thought into pursuing a graduate degree that relates to STEM,” she said. “In addition, it has also made me want to volunteer and look for opportunities similar to this internship.”
“When I first started the internship, I really did not know what to expect,” Cortez said. “Through every step of the way, my teammates and I received guidance and support from our mentor… I would like to thank DRI for having this internship and opening its doors to students outside of STEM.”
Jan 18, 2023 | Announcements, News releases
A Changing Flood Recipe for Las Vegas
January 18, 2022
LAS VEGAS, Nevada
Urbanization
Climate Change
Flooding
Above: Las Vegas after thunder storm with flood water in November 2019. Photo Credit: 4kodiak, iStock.
A new study shows that urbanization and climate change are changing the strength and seasonality of flooding in the Las Vegas region
Las Vegas, with its rapid urbanization and desert landscape, is highly vulnerable to flooding. For this reason, flood managers have built an extensive system of drainage ditches and detention basins to protect the public. Now, a new study shows how intentional engineering and urban development are interacting with climate change to alter the timing and intensity of flood risk.
In a study published Jan. 6 in The Journal of Hydrometeorology, researchers from DRI, the Clark County Regional Flood Control District, the University of Wisconsin- Madison, and Guangdong University of Technology examine Las Vegas’ changing flood regime. Their results show that flood intensity has increased since the mid-20th century, with an abrupt shift occurring in the mid-1990s. Climate change has also shifted flood seasonality, with the storms and their resultant floods now occurring more frequently in winter, in contrast with the historically stronger summer monsoon season.
“When I looked at the data for annual flood peaks, I could see that something is changing,” said Guo Yu, Ph.D., lead author on the new study and hydrologist at DRI. “I wanted to understand the reason for this change as well as the physical mechanisms driving it, because that will help water managers and the public understand whether such a change will continue in the future, given climate and land use changes here.”
Las Vegas is one of the fastest growing metropolitan regions in the country. In 1950, fewer than 35 thousand people resided in the region; by 2020, that number grew to 2.6 million. Like many cities in the arid Southwest, development centers on the valley floor and spreads up into the natural topography of the surrounding mountains. As concrete and pavement replace more porous desert soils, the risk of flooding in human communities rises – catastrophic floods have caused fatalities as recently as 2022. To mitigate this risk, the Clark County Regional Flood Control District constructed a complex series of storm drains and culverts to capture and direct the flow of water away from populated areas and toward Lake Mead.
Over the same period, climate change has led to shifts in seasonal rainfall patterns. The Southwest has two distinct flood seasons: winter floods produced by atmospheric rivers and summer floods linked to the North American monsoon. Since 1950, daily rainfall amounts have increased in winter and decreased in the summer months.
“Historically, people in Las Vegas haven’t paid as much attention to winter floods as to summer floods,” Yu said. “But our research shows that there will be more frequent winter floods happening because of climate change. This is because the warmer sea surface temperatures on the Pacific coast will cause more atmospheric rivers, like what we’re seeing this January in California. And when these are positioned to bypass the Sierra Nevada mountains, they will very likely hit Las Vegas and cause severe winter rainfall and floods.”
The new research demonstrates an overall picture of shifting intensity and seasonality of floods in Las Vegas. The study authors are continuing to refine their understanding of flood risk in the region with an upcoming study, currently under review, that examines changing rainfall patterns in more detail.
“A lot of research focuses on a single driver – either land use or climate – but in Las Vegas, our study shows that both are changing and interacting with each other,” said Yu.
More information:
The full study, The Nonstationary Flood Hydrology of an Urbanizing Arid Watershed, is available from The Journal of Hydrometeorology: https://doi.org/10.1175/JHM-D-22-0117.1
Study authors include: DRI researchers Guo Yu, Julianne Miller, Benjamin J. Hatchett, and Markus Berli; as well as Daniel B. Wright (University of Wisconsin, Madison); Craig McDougall (Clark County Regional Flood Control District); and Zhihua Zhu (Guangdong University of Technology, Guangzhou, China).
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Nov 21, 2022 | Blog, Featured researchers
New research examines the potential impacts of climate change on water quality in tropical reservoirs
NOVEMBER 21, 2022
LAS VEGAS, NEV.
Climate Change
Water Quality
Tropical Reservoirs
Above: The Infiernillo Dam (“Little hell”), also known as Adolfo López Mateos Dam, is an embankment dam on the Balsas River near La Unión, Guerrero, Mexico. It is on the border between the states of Guerrero and Michoacán.
Credit: Arturo Peña Romano Medina, iStock Photo.
A Q&A With Study Author Erick Bandala, Ph.D.
In a new study, DRI’s Erick Bandala, assistant research professor of environmental science, worked with scientists in Mexico to address an important research gap: how will a warming climate alter water quality in tropical reservoirs? With scientists predicting that half of the world’s human population will live in tropical climates by 2050, this knowledge will be critical for adapting to a warming world.
Bandala and his coauthors developed algorithms that can be used to predict changes in water quality under the projected temperature intervals provided by climate change models developed by the Intergovernmental Panel on Climate Change (IPCC).
DRI sat down with Bandala to discuss this study and how it ties into his broader research goals.
DRI: What was the impetus for this research?
Bandala: What we’re trying to do in my lab is create technologies for climate change adaptation. Many people do research on climate change and how it will impact water availability, so there is a lot of information about how water availability will change. But something that we believe is less studied – and that is the focal point of our research – is figuring out how global warming may have an effect on water quality. This is significant because even if you have a lot of water, if the water doesn’t have the proper quality, it cannot be used, or you will need to treat it to make it usable. So, in this study, we looked at water quality parameters in a reservoir in Mexico to predict how they could change over the next 80 years or so.
But we also need to come up with solutions for how to improve the water quality so that people can use it properly without facing the risk of illness. This is what we’re trying to do in my lab. We want to come up with solutions that can help people improve the quality of their drinking water.
DRI: And what kind of solutions are you looking at?
Bandala: Well, I’m very glad that you asked that because we are developing materials that can remove contaminants from the water. And we are using the concept of circular economy, which means we want to use material that for someone is considered a waste, and turn it into something else that can be used for water treatment. For example, we have used crop waste and even plastic waste, and converted them into something that can be used to remove contaminants from water. So, we aren’t only interested in the effect of global warming on contaminants, but also in creating something that can be used for the removal of those pollutants from the water while having a low carbon and environmental footprint.
Figure 1 from the study shows the Adolfo Lopez Mateos Dam (ALMD) and water quality sampling site’s geographical location.
Credit: Erick Bandala/DRI.
DRI: That’s amazing. And how did the international collaboration with your co-authors come about?
Bandala: Well, I believe that science is not an isolated work, and less so now than ever. I think that in many cases the most help is needed in developing countries. You know in my home country of Mexico, they have a saying, “the fleas always go to the skinnier dog.” That’s very true because now many developing countries are suffering the biggest effects of climate change, and I want to help people in these countries deal with all these problems. We are developing processes, technologies, and materials that can be used for helping people in Africa, or Central America, or Asian countries that are facing huge problems with water quality.
DRI: Returning to the study, is there a reason why the study team chose to examine water quality at this particular reservoir, the Adolfo Lopez Mateos Dam in Sinaloa, Mexico?
Bandala: The main reason for choosing that site was because it had reliable water data available – it’s very complicated to get access to a good and reliable data set. Also, many of the models that have been developed in the past are for cold water bodies, and this is a warm one – the differences are significant just because of the increased water temperature in the dam.
DRI: The study showed that there was a temperature threshold where the bacteria in particular really thrived, and then above that temperature, it declined. Why is that?
Bandala: Well, bacteria are living organisms, so they have a preferred temperature range to grow in, just like everyone else. If you go too low or too high, then the reproduction or the growth of the colony will decline because it’s too hot or too cold. Now, we were very interested in microbiological contamination because this is one of the main issues in developing countries like Mexico, where many people are drinking water without the safeguards that are required. And because of that, we have very high mortality, mainly in children five years old or less. So, we wanted to understand how bacterial contamination might change under different climate scenarios.
DRI: What do you think are the biggest implications of this study?
Bandala: Well, I believe the study is probably the first one that I know of where we are really including the effects of global warming and calculating how the water quality in a water body will vary over time. In the past, I have published other papers trying to do the same, but honestly, as you said, it is highly complicated and we just partially achieved that goal. This time, I think we were really good at getting a nice model that will give us some good insight of the actual trends for a warm water body. Most of the studies are made in Canada, the U.S., or Europe, where the temperatures of the water may be in the range from 45 to 60 degrees Fahrenheit. In this case we were about 70 degrees, so it’s a completely different scenario. And that makes them not only challenging, but also interesting to address.
DRI: And do you have any studies that will continue this line of work?
Bandala: Well, we’re planning to use remote sensing to corroborate the information that we created for this paper. So, if that works, it may mean that you don’t need to jump into a big data set, but can simply collect information from satellites for the analysis. Hopefully, that will be the next thing.
Erick Bandala, Ph.D., continues to work in his lab on developing materials that can remove contaminants from water.
Credit: Tommy Gugino/DRI.
Oct 26, 2022 | Announcements, News releases
Elevated Levels of Arsenic and Other Metals Found in Nevada’s Private Wells
October 26, 2022
RENO, Nevada
Water Treatment
Arsenic
Private Wells
Above: Researchers test a private well water for traces as metals such as arsenic in Washoe Valley. Private wells are the primary source of drinking water, serving 182,000 people outside of Nevada’s bustling cities.
Credit: Monica Arienzo/DRI.
Study shows that many household wells need better drinking water treatment and monitoring
Outside of Nevada’s bustling cities, private wells are the primary source of drinking water, serving 182,000 people. Yet some of the tested private wells in Nevada are contaminated with levels of heavy metals that exceed federal, state or health-based guidelines, a new study published in Science of The Total Environment shows. Consuming water contaminated by metals such as arsenic can cause adverse health effects.
Scientists from DRI and the University of Hawaii Cancer Center recruited households with private wells through the Healthy Nevada Project. Households were sent free water testing kits, and participants were notified of their water quality results and recommended actions they could take. More than 170 households participated in the research, with the majority from Northern Nevada around Reno, Carson City and Fallon.
“The goals of the Healthy Nevada project are to understand how genetics, environment, social factors and healthcare interact. We directly engaged our participants to better understand environmental contaminants that may cause adverse health outcomes,” said co-author Joseph Grzymski, Ph.D., research professor at DRI, principal investigator of the Healthy Nevada Project®, and chief scientific officer for Renown Health.
Nearly one-quarter (22%) of the private wells sampled had arsenic that exceeded safe levels determined by the Environmental Protection Agency (EPA) — with levels 80 times higher than the limit in some cases. Elevated levels of uranium, lead, cadmium, and iron were also found.
Monica Arienzo, Ph.D., and Erika Robtoy, undergraduate student at the University of Nevada, Reno collect well water samples in Palomino Valley, Nevada.
Credit: Daniel Saftner/DRI.
“We know from previous research that Nevada’s arid climate and geologic landscape produce these heavy metals in our groundwater,” says Monica Arienzo, Ph.D., an associate research professor at DRI who led the study. “It was important for us to reach out to community members with private wells to see how this is impacting the safety of their drinking water.”
Fewer than half (41%) of the wells sampled used water treatment systems, and some treated water samples still contained arsenic levels over EPA guidelines. Although average levels of heavy metal contaminants were lower in treated water, many homes were unable to reduce contaminants to levels considered safe.
The state leaves private well owners responsible for monitoring their own water quality, and well water testing helps ensure water is safe to drink. This study shows that more frequent testing is needed to ensure Nevada’s rural communities have safe drinking water. This is particularly important as the effects of climate change and population growth alter the chemistry of groundwater, potentially increasing metal concentrations.
“The results emphasize the importance of regular water quality monitoring and treatment systems,” said co-author Daniel Saftner, M.S., assistant research scientist at DRI.
Although the research focused on wells in Nevada, other arid communities in Western states are facing similar risks of water contamination.
More information:
The full study, Naturally Occurring Metals in Unregulated Domestic Wells in Nevada, USA, is available from Science of The Total Environment: https://doi.org/10.1016/j.scitotenv.2022.158277.
This project was funded by an NIH award (#1R01ES030948-01). The Healthy Nevada Project was funded by grants from Renown Health and the Renown Health Foundation. Study authors included Monica M. Arienzo (DRI), Daniel Saftner (DRI), Steven N. Bacon (DRI), Erika Robtoy (DRI), Iva Neveux (DRI), Karen Schlauch (DRI), Michele Carbone (University of Hawaii Cancer Center) and Joseph Grzymski (DRI/Renown Health).
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About Renown Health
Renown Health is Nevada’s largest, not-for-profit integrated healthcare network serving Nevada, Lake Tahoe, and northeast California. With a diverse workforce of more than 6,500 employees, Renown has fostered a longstanding culture of excellence, determination, and innovation. The organization comprises a trauma center, two acute care hospitals, a children’s hospital, a rehabilitation hospital, a medical group and urgent care network, and the locally owned not-for-profit insurance company, Hometown Health. Renown is currently enrolling participants in a community-based genetic population health study, the Healthy Nevada Project®. For more information, visit renown.org.
About the University of Hawaiʻi Cancer Center
The University of Hawaiʻi Cancer Center through its various activities, including scientific research and clinical trials, adds more than $57 million to the Oʻahu economy. It is one of only 71 research institutions designated by the National Cancer Institute. An organized research unit within the University of Hawaiʻi at Mānoa, the UH Cancer Center is dedicated to eliminating cancer through research, education, patient care and community outreach with an emphasis on the unique ethnic, cultural, and environmental characteristics of Hawaiʻi and the Pacific. Learn more at https://www.uhcancercenter.org. Like us on Facebook at https://www.facebook.com/UHCancerCenter. Follow us on Twitter @UHCancerCenter.
Media Contacts:
Renown Public Relations
M: 775.691.7308
E: news@renown.org
Detra Page – DRI
M: 702.591.3786
E: Detra.Page@dri.edu
Sep 14, 2022 | Announcements, News releases
Removing turf-grass saves water. But will it increase urban heat?
September 14, 2022
LAS VEGAS, Nev.
Landscape
Urban Irrigation
Air Temperature
New study examines impacts of three desert landscaping strategies on urban irrigation and air temperatures
As Las Vegas and other Southwestern cities look for ways to reduce water use during a historic drought, the removal of grass lawns and other areas of “nonfunctional turf” has been recommended by the Southern Nevada Water Authority and written into Nevada state law with AB356. But, will this change from turf-grass to other landscaping types result in other unintended climate impacts in urban areas, such as increased air or surface temperatures?
In a new study in the journal Hydrology, a team of scientists from DRI, Arizona State University (ASU), and the University of Nevada, Las Vegas (UNLV), examined the irrigation water requirements of three common types of urban landscapes. Then, they compared air temperature, surface temperature, and wind speed around the three sites to learn how differences in landscape types impact their surrounding environment.
The three landscape types analyzed in the study were a “mesic” tree and turf-grass landscape with water-intensive plants; a “xeric” landscape consisting primarily of desert plants on drip irrigation; and an intermediate “oasis” landscape type with a mix of high-and low water use plants. The sites were located around buildings in an experimental study area at ASU in Phoenix.
As expected, the mesic (tree and turf-grass) landscape showed the highest water consumption rate. However, the mesic site also had the lowest surface and air temperatures, both in the daytime and nighttime, thus creating better conditions for outdoor thermal comfort.
The site with xeric (desert) landscaping had the lowest irrigation water requirement but the highest temperatures. Air temperatures in the xeric landscape plot averaged 3oC (5.4oF) higher than in the other two landscape types.
The oasis landscape, with a mix of high- and low-water use plants, provided the best of both worlds – lower irrigation water requirements than the mesic site but more daytime cooling than the xeric landscape.
“The simple take-home message from what we learned was that xeric (desert) landscaping is not the best long-term solution and neither is mesic (tree-turf),” said the study’s lead author Rubab Saher, Ph.D., Maki postdoctoral research associate at DRI. “An ‘oasis’ style landscape, which contains trees like Acacia or ghost gum, and shrubs like dwarf poinciana, requiring light irrigation, are the best solution, because it conserves water but also contributes to cooling through the evapotranspiration of the plants.”
The study also examined the role of buildings and open sky to understand the effect of shade on the landscape. They found that shade in the narrow space between buildings created shade of comparable temperature to that under a tree in a mesic landscape and are interested in doing follow-up studies to learn more about the impact of building orientation on maximizing summer shade.
“I became interested in this topic because urban irrigation and water efficient landscaping are really important issues in the Western U.S., but haven’t been studied very thoroughly,” said Saher. “People have been applying methods for calculating irrigation from agricultural fields, but urban areas are very different landscapes, and the ways that homeowners irrigate are very unpredictable.”
The authors hope that their findings are helpful to homeowners, city planners, or anyone trying to help conserve water but prevent warming temperatures in arid urban regions.
“Removing turf grass from the landscape is an excellent approach for saving water, but if we remove all the turf grass, the temperature will go up,” Saher said. “For every acre of turf grass removed, we also need to plant native and/or rainfed trees to make arid cities livable in the long run.”
More information:
The full study, Assessing the Microclimate Effects and Irrigation Water Requirements of Mesic, Oasis, and Xeric Landscapes, is available from Hydrology: https://www.mdpi.com/2306-5338/9/6/104
This study was made possible with funding from the University of Nevada, Las Vegas (UNLV), and DRI’s Maki Postdoctoral fellowship. Study authors included Rubab Saher (DRI), Ariane Middel (ASU), Haroon Stephen (UNLV), and Sajjad Ahmad (UNLV).
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About ASU
Arizona State University, ranked No. 1 “Most Innovative School” in the nation by U.S. News & World Report for seven years in succession, has forged the model for a New American University by operating on the principles that learning is a personal and lifelong journey for everyone, and that people thrive on experience and discovery that cannot be bound by traditional academic disciplines. Through innovation and a commitment to educational access, ASU has drawn pioneering researchers to its faculty even as it expands opportunities for qualified students.
About UNLV
UNLV is a doctoral-degree-granting institution of more than 30,000 students and nearly 4,000 faculty and staff that has earned the nation’s highest recognition for both research and community engagement from the Carnegie Foundation for the Advancement of Teaching. UNLV offers a broad range of respected academic programs and is committed to recruiting and retaining top students and faculty, educating the region’s diverse population and workforce, driving economic activity, and creating an academic health center for Southern Nevada. Learn more at unlv.edu.
Media Contacts:
Detra Page
DRI
702.591.3786
Detra.page@dri.edu
David Rozul
ASU
480-965-3779
david.rozul@asu.edu
Cheryl Bella
UNLV
702-895-3965 (o)
702-499-3930 (c)
cheryl.bella@unlv.edu
Sep 7, 2022 | Announcements, News releases
Growing numbers of Native American households in Nevada face plumbing poverty, water quality problems
September 7, 2022
LAS VEGAS, Nev.
Native Americans
Plumbing Poverty
Water Quality
New study analyzes trends, opportunities, and challenges related to water security in Nevada’s Native American communities
A growing number of Native American households in Nevada have no access to indoor plumbing, a condition known as “plumbing poverty,” according to a new study by a team from DRI and the Guinn Center for Policy Priorities.
The study assesses trends and challenges associated with water security (reliable access to a sufficient quantity of safe, clean water) in Native American households and communities of Nevada and also found a concerning increase in the number of Safe Drinking Water Act violations during the last 15 years.
Native American communities in the Western U.S., including Nevada, are particularly vulnerable to water security challenges because of factors including population growth, climate change, drought, and water rights. In rural areas, aging or absent water infrastructure creates additional challenges.
In this study, the research team used U.S. Census microdata on household plumbing characteristics to learn about the access of Native American community members to “complete plumbing facilities,” including piped water (hot and cold), a flush toilet, and a bathtub or shower. They also used water quality reports from the Environmental Protection Agency to learn about drinking water sources and health violations.
According to their results, during the 30-year time period from 1990-2019, an average of 0.67 percent of Native American households in Nevada lacked complete indoor plumbing – higher than the national average of 0.4 percent. Their findings show a consistent increase in the lack of access to plumbing over the last few decades, with more than 20,000 people affected in 2019.
“Previous studies have found that Native American households are more likely to lack complete indoor plumbing than other households in the U.S., and our results show a similar trend here in Nevada,” said lead author Erick Bandala, Ph.D., assistant research professor of environmental science at DRI. “This can create quality of life problems, for example, during the COVID-19 pandemic, when lack of indoor plumbing could have prevented basic health measures like hand-washing.”
Native American community members in Nevada with no access to plumbing from 1990 to 2019.
Credit: Erick Bandala, DRI.
Plumbing poverty may correlate with other types of poverty. Analysis by the study team showed that as the number of people living in a household increased, access to complete plumbing decreased significantly, in agreement with other studies.
Study findings also showed a significant increase in the number of Safe Drinking Water Act violations in water facilities serving Native American Communities in Nevada from 2005 to 2020. The most common health-based violations included presence of volatile organic compounds (VOCs), presence of coliform bacteria, and presence of inorganic chemicals.
“Water accessibility, reliability, and quality are major challenges for Native American communities in Nevada and throughout the Southwest,” said coauthor Maureen McCarthy, Ph.D., research professor of environmental science and director of the Native Climate project at DRI.
Types of Safe Drinking Water Act violations documented by the EPA for public water systems serving Native American communities in Nevada, 2005-2020.
Credit: Erick Bandala, DRI.
The study authors hope that their findings are useful to decision-makers and members of the general public who may not be aware that plumbing poverty and water quality are significant problems in Nevada.
More information:
The full study, “Assessing the effect of extreme heat on workforce health in the southwestern USA,” is available from the International Journal of Environmental Science and Technology: https://www.sciencedirect.com/science/article/pii/S1462901122002179?dgcid=author
This project was funded by the General Frederick West Lander Endowment at DRI. Study authors included Erick Bandala (DRI), Maureen McCarthy (DRI), and Nancy Brune (DRI, formerly of the Guinn Center for Policy Priorities).
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Jul 5, 2022 | Blog, Featured researchers
Meet Victoria Wuest, Graduate Researcher
JULY 5, 2021
LAS VEGAS, NEV.
Above: Graduate researcher Victoria Wuest filters wastewater samples for COVID-19 detection in the BSL-2 lab at DRI in Las Vegas.
Credit: Alison Swallow/DRI.
Victoria Wuest is a graduate research assistant with the Division of Hydrologic Science at DRI in Las Vegas, mentored by Duane Moser, Ph.D. She is a Master’s student in Biological Sciences with a concentration in Ecology and Evolutionary Biology at the University of Nevada, Las Vegas. Learn more about Victoria and her graduate research in this interview with DRI’s Behind the Science blog!
DRI: What brought you to DRI? And who at DRI are you working with?
Wuest: I came to DRI to research environmental DNA (eDNA) in two warm springs of Southern Nevada, working under Duane Moser, Ph.D., and with Ali Saidi-Mehrabad, Ph.D. eDNA is DNA that is released from an organism into the environment, and can come from sources like shed skin, mucus, and feces.
In my previous job, I was monitoring endangered species at the Muddy River, one of the study sites for this research. Also, I had previously worked with many biologists from the U.S. Fish and Wildlife Service and Nevada Department of Wildlife who manage this project and both of its study sites — the springs of the Muddy River and Ash Meadows National Wildlife Refuge. I was familiar with the species, the hydrology of these areas, and the management concerns of these precious resources. I had worked with the fish before and care about their survival. I thought I could make a positive impact with this research.
DRI: What research projects have you worked on during your time at DRI?
Wuest: When I first came to DRI, I had the opportunity to study the ancient eDNA excavated from Mule Springs Rockshelter, NV. This research focused on the migration of peoples throughout the Great Basin using DNA found on quids. Quids are chewed and expectorated plant fibers, which essentially served as an unintentional cheek swab. These samples were haplotyped and dated. Some quids turned out to be older than 3,000 years. This was my first experience working with eDNA and was valuable in teaching me the techniques for my project.
On the project at the Muddy River and Ash Meadows National Wildlife Refuge, I have developed a method and markers for using eDNA for early detection of the invasive red swamp crayfish (Procambarus clarkii) and western mosquitofish (Gambusia affinis). I have also been using eDNA to track the movements of two endangered species, the Moapa dace (Moapa coriacea), and Warm Springs pupfish (Cyprinodon pectoralis nevadensis).
Graduate researcher Victoria Wuest extracts DNA from water samples in the clean lab at DRI in Las Vegas.
Credit: Alison Swallow/DRI.
DRI: What are some of the management concerns at the Muddy River and Ash Meadows project sites?
Wuest: The management of both sites focuses on the recovery of the imperiled species that are endemic to the area. The Moapa dace population has grown from 459 in 2008 to over a thousand. Meanwhile, the Warm Springs pupfish has a very small population of less than 500 individuals. Both species are highly susceptible to disturbances and have very localized distributions. The populations of Moapa dace and Warm Springs pupfish are dependent on the restoration of the streams and removal and monitoring of non-native and invasive species.
Graduate researcher Victoria Wuest samples stream water in Beatty, NV for the detection of western mosquitofish.
DRI: What are your research goals?
Wuest: My goal is to design markers, or specific, single-stranded DNA sequences, to detect red swamp crayfish , western mosquitofish, Moapa dace, and Warm Springs pupfish and publish these novel markers along with the novel sampling method. This method has the potential to be expanded to detect all the species in these systems with the future goal of tracking abundance. As I near the end of my degree program, I am proud that I have made progress towards using eDNA as a monitoring tool for these sites.
DRI: Tell us about yourself. What do you do for fun?
Wuest: Like many ecologists, I enjoy being outdoors—hiking, hammocking, and kayaking. At Northern Arizona University, my alma mater, these activities were a fundamental part of my college experience and part of the reason I chose that university. It is also the reason I chose to pursue biology.
However, lately, when I truly need a break from science, I find myself turning to art. I enjoy refinishing furniture, knitting gifts for my friends and family, propagating plants, sewing, photography, and honestly any craft that allows me to solve problems by being creative. These activities allow me to take a break from my work while still being fulfilling.
Graduate researcher Victoria Wuest samples the mainstem Muddy River, NV for the detection of invasive species and the endangered Moapa dace.
Jun 14, 2022 | Announcements, News releases
Study Explores Uncertainties in Flood Risk Estimates
Hydrology
Climate
Flood Risk
Above: The Truckee River in Reno, Nev. during high flow conditions after a storm in late January, 2016.
Credit: Kelsey Fitzgerald/DRI.
Results show a need to revise existing methods for estimating flood risk
Flood frequency analysis is a technique used to estimate flood risk, providing statistics such as the “100-year flood” or “500-year flood” that are critical to infrastructure design, dam safety analysis, and flood mapping in flood-prone areas. But the method used to calculate these flood frequencies is due for an update, according to a new study by scientists from DRI, University of Wisconsin-Madison, and Colorado State University.
Floods, even in a single watershed, are known to be caused by a variety of sources, including rainfall, snowmelt, or “rain-on-snow” events in which rain falls on existing snowpack. However, flood frequencies have traditionally been estimated under the assumption these flood “drivers,” or root causes, are unimportant.
In a new open-access paper in Geophysical Research Letters, a team led by Guo Yu, Ph.D., of DRI examined the most common drivers (rainfall, snowmelt, and rain-on-snow events) of historic floods for 308 watersheds in the Western U.S., and investigated the impact of different flood types on the resulting flood frequencies.
Their findings showed that most (64 percent) watersheds frequently experienced two or three flood types throughout the study period, and that rainfall-driven floods, including rain-on-snow, tended to be substantially larger than snowmelt floods across watershed sizes.
Further analysis showed that by neglecting the unique roles of each flood type, conventional methods for generating flood frequency estimates tended to result in under-estimation of flood frequency at more than half of sites, especially at the 100-year flood and beyond.
“In practice, the role of different mechanisms has often been ignored in deriving the flood frequencies,” said Yu, a Maki postdoctoral research associate at DRI. “This is partly due to the lack of physics-based understanding of historic floods. In this study, we showed that neglecting such information can result in uncertainties in estimated flood frequencies which are critical for infrastructure.”
The study findings have important implications for estimating flood frequencies into the future, as climate change pushes conditions in snowmelt-dominated watersheds toward increased rainfall.
“How the 100-year flood will evolve in the future due to climate change is one of the most important unanswered questions in water resources management,” said Wright, an associate professor in Civil and Environmental Engineering at University of Wisconsin-Madison. “To answer it, we need to focus on the fundamental science of how the water cycle, including extreme rainstorms and snow dynamics, are and will continue to change in a warming climate.”
The study team hopes that this research is useful to engineers, who rely on accurate estimates of flood frequencies when building bridges and other infrastructure. Although many engineers realize that there is a problem with the conventional way of estimating flood frequencies, this study provides new insights into the level of inaccuracy that results.
“This study shows that taking into account different physical processes can improve flood risk assessment,” said Frances Davenport, Ph.D., postdoctoral research fellow at Colorado State University. “Importantly, this result suggests both a need and opportunity to develop new methods of flood frequency assessment that will more accurately reflect flood risk in a warming climate.”
More information:
The full study, Diverse Physical Processes Drive Upper-Tail Flood Quantiles in the US Mountain West, is available from Geophysical Research Letters: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL098855
This project was funded by the DRI’s Maki Postdoctoral fellowship, U.S. National Science Foundation Hydrologic Sciences Program (award number EAR-1749638), and Stanford University. Study authors included Guo Yu (DRI/University of Wisconsin-Madison), Daniel Wright (University of Wisconsin-Madison), and Frances Davenport (Stanford University and Colorado State University).
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About Colorado State University’s Walter Scott, Jr. College of Engineering
Colorado State is one of the nation’s top public research universities with about 33,000 students and $447 million in annual research funding. The Walter Scott, Jr. College of Engineering at CSU prepares students to solve global challenges to shape a better world through research, education, innovation, and outreach. In addition to a top-ranked graduate program in atmospheric science, the college conducts cutting-edge, interdisciplinary research that provides students hands-on learning in biological, biomedical, chemical, civil, computer, electrical, environmental, mechanical, and systems engineering. The college attracts about $80 million in annual research dollars, placing it in the top tier of public institutions of similar size, and is a campus leader in patents, startups, and technology transfer. For more information, please visit www.engr.colostate.edu.
Jun 1, 2022 | Blog, Featured researchers
Field Notes From a DRI Research Team in Greenland: A Story Map
In May 2022, a team led by scientists from DRI in Reno, Nevada departed for Greenland, where they were joined by ice drilling, Arctic logistics, and mountaineering experts. Together, the team plans to collect a 440 meter-long ice core that will represent 4,000 years of Earth and human history.
For much of their time on the Greenland ice sheet, the team will not have access to the internet or phone service — but they are able to send short text messages back to DRI from a Garmin inReach two-way satellite communicator. You can follow along with their journey on our Story Map, “The Return to Tunu.”
May 23, 2022 | Blog, Featured researchers
Meet Brianda Hernandez Rosales, Graduate Researcher
MAY 23, 2022
LAS VEGAS, NEV.
Hydrology
Hydrogeology
Rainwater
Above: Brianda fly fishing in Northern California where the Klamath River and the Pacific Ocean meet.
Brianda Hernandez Rosales is a graduate research assistant with the Division of Hydrologic Sciences at DRI in Reno. She recently earned her Master’s degree in hydrogeology from the Graduate Program of Hydrologic Sciences at the University of Nevada, Reno (UNR). Learn more about Brianda and her graduate research in this interview with DRI’s Behind the Science blog!
DRI: What brought you to DRI?
Hernandez: I first learned of DRI during my time at Mt. San Antonio College, during a research trip to Capitol Reef National Park. The chief scientist of the park was a hydrogeologist with a degree from the Graduate Program of Hydrologic Sciences at UNR and mentioned his affiliation with DRI. I decided to check out DRI when I had access to the web. I started following the research that was being conducted at DRI and knew that I wanted to somehow make my way to Northern Nevada once I was ready to tackle a graduate degree. Luckily, my research interests aligned with the work of Alexandra Lutz, Ph.D., allowing me to attend UNR and join DRI. It was the best decision I made way back in June 2017 during that hot afternoon overlooking the Capital Reef basin.
DRI: What are you studying?
Hernandez: My focus of study is hydrology/hydrogeology. I am interested in water security issues in the West, particularly in underrepresented communities. Using science to help build climate resiliency among these communities is another interest and passion of mine, as well as science communication.
Brianda Hernandez Rosales is a graduate research assistant with the Division of Hydrologic Sciences at DRI in Reno.
DRI: What research projects are you working on? And who at DRI are you working with?
Hernandez: My graduate research focuses on assessing the feasibility of rainwater harvesting for food production in Peach Springs, AZ on the Hualapai Indian Reservation. Rainwater harvesting is the concentration, collection, and storage of rainwater to be used at a later time. It has been practiced for centuries in arid and semi-arid environments around the world, however, this practice has been overlooked in the United States as a means to ensure water security in rural areas. Rainwater harvesting can be used to diversify water portfolios and attain food security in vulnerable communities.
COVID-19 and supply-chain issues have exposed the need to assess food security in areas that are considered “food deserts” and rainwater harvesting can be a way to combat those issues, particularly in the Southwest, since monsoonal rains are available for capture during the growing season. This project has been inspirational for me because it can be scaled to any degree and applied to any rural community interested in harvesting rainwater to grow food. I’ve learned that this practice can be applied not only in rural communities but across the United States to reduce the strain on other water supplies. On this project, I work alongside Alexandra Lutz, Ph.D., Christine Albano, Ph.D., and Susie Rybarski at DRI.
In addition to my graduate research, I also worked alongside Maureen McCarthy, Ph.D., and Alexandra Lutz, Ph.D., during summer 2021 on providing content for the COVID-19 Toolkit website through Native Waters on Arid Lands (NWAL) project. I researched the impacts on water quality during drought in the West to help inform Tribal Extension agents, tribal ranchers, and farmers as well as tribal members about these looming issues.
Brianda documenting the crops currently grown in the Hualapai Community Garden in Peach Springs, AZ with support from the Federally Recognized Tribal Extension Program (FRTEP) agent for the tribe, Elisabeth Alden.
DRI: What are your short-term and long-term goals while at DRI?
Hernandez: My overall goal at DRI is to conduct good, reputable science that is accessible to everyone. I think having access to great science is important, now more than ever. My short-term goal is to finish my degree in May 2022. My long-term goal is to continue working with folks at DRI and the NWAL team to assist in the important work that is being done to ensure climate resiliency among the communities that need it most.
DRI: Tell us about yourself. What do you do for fun?
Hernandez: Like many people at DRI, I am a lover of the outdoors! You can find me climbing boulders in the Tahoe Basin, Bishop, California, or throughout the West. I also enjoy mountain biking on any dirt, fly fishing at any body of water, and simply just camping with friends in the mountains or the open desert. We live in such a beautiful area here in the West, it’s nice just to explore.
When I am not outside, I enjoy reading books about people who do things outside (e.g., adventure memoirs, anthropology books) or science books. I also enjoy listening to music, eating delicious food, and drinking wine while having great conversations with family and friends.
“Pebble wrestling” in Rocky Mountains National Park.
May 17, 2022 | Announcements, News releases
Farm vehicles are heavy as dinosaurs, jeopardize future food security
Reposted from https://www.slu.se/en/ew-news/2022/5/farm-vehicles-heavy-as-dinosaurs-jeopardize-food-security/.
Farm vehicles are becoming so heavy that they jeopardize future food security in Europe, America and Australia. Larger and more flexible tires have limited the damage on the surface, but below the topsoil, the soil is becoming so compact that its long-term production capacity is threatened. These conclusions are made in a new global study, which also draws parallels to the sauropods, the heaviest animals that ever walked Earth.
The study, which was published in the Proceedings of the National Academy of Sciences (PNAS) yesterday, was conducted by Professor Thomas Keller from the Swedish University of Agricultural Sciences (SLU) and Agroscope in Switzerland, and Professor Dani Or from ETH Zurich in Switzerland and the Desert Research Institute in the USA.
Mechanization has greatly contributed to the success of modern agriculture, with vastly expanded food production capabilities achieved by the higher capacity of farm machinery. However, the increase in capacity has been accompanied by heavier vehicles that increase the risk of subsoil compaction.
While the total weight of laden combine harvesters could be around 4 tonnes in the late 1950s, we can today see modern vehicles weighing 36 tonnes in the fields, and the researchers behind the present study decided to investigate what this development has meant for arable land. The contact stress on the soil surface turned out to have remained constant at a low level during this period, which is due to the fact that the machines have been fitted with ever larger tires that distribute the weight over a larger surface. In the deeper soil layer, the subsoil, on the other hand, soil compaction has increased to levels that jeopardize the soil’s ability to produce food. This also has consequences for the soil’s ability to transport water and provide other important ecosystem services.
“Subsoil compaction by farm vehicles is a very serious problem, since once soils are compacted, they remain damaged for decades. This may be one of the reasons why harvests are no longer increasing and why we are now seeing more floods than before”, says lead author Professor Thomas Keller, from SLU in Sweden and Agriscope in Switzerland.
High risk of compaction in one fifth of the arable land globally
The researchers have also produced a map that shows how the risk of chronic subsoil compaction varies around the world and the risk turned out to be greatest in Europe, North and South America and Australia. Globally, about a fifth of all arable land is estimated to be at risk of far-reaching damage that is very difficult to repair. In other words, the chance that these soils will recover is small.
The risk is presently smaller in Asia and Africa, where the mechanization of agriculture has not reached the same high level yet.
“If the mechanization were to gain momentum in Asia and Africa, however, there is a risk of subsoil compaction also on these continents”, says Thomas Keller.
Vehicle manufacturers must pay more attention to subsoil compaction
To contribute to more sustainable agriculture, vehicle manufacturers need to be more concerned about the risk of subsoil compaction and its negative impact on the soil.
“Above all, the wheel loads of modern farm vehicles need to be reduced in order not to affect the subsoil to the same extent as today. The heavier the machines, the worse for the subsoils”, says Thomas Keller.
Did dinosaurs induce soil compaction?
The researchers also show that the heaviest farm vehicles used in modern agriculture approach the weight of the heaviest dinosaurs, the sauropods. This indicates that the sauropods probably induced soil compaction and affected the soil’s production capacity in the same way as modern farm vehicles.
“No one seemed to have wondered whether dinosaurs induced subsoil compaction, but since the sauropods were as heavy as modern farm vehicles, we thought this was a question that ought to be explored”, says Thomas Keller.
Like humans, sauropods depended on the soils ability to provide food, suggesting that they moved across the landscape in a way that reduced the risk of soil compaction. One possibility is that they restricted their movements to fixed “foraging trails” and grazed plants next to them with the help of their long necks. In this way, they could ensure that the surrounding land continued to produce the plant food they needed.
More information:
The full study, “Farm vehicles approaching weights of sauropods exceed safe mechanical limits for soil functioning,” is available from the Proceedings of the National Academy of Sciences: https://doi.org/10.1073/pnas.2117699119.
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
May 9, 2022 | Announcements, News releases
Extreme Heat
Outdoor Workers
Workforce Health
For Outdoor Workers, Extreme Heat Poses Extreme Danger
Study explores effects of summertime heat waves on workforce health in Las Vegas, Phoenix, and Los Angeles
Working outdoors during periods of extreme heat can cause discomfort, heat stress, or heat illnesses – all growing concerns for people who live and work in Southwestern cities like Las Vegas, where summer temperatures creep higher each year. But, did you know that female outdoor workers are experiencing disproportionate impacts? Or, that more experienced outdoor workers are at higher risk than those with fewer years on the job?
In a new study in the International Journal of Environmental Science and Technology, scientists from DRI, Nevada State College, and the Guinn Center for Policy Priorities explore the growing threat that extreme heat poses to workforce health in three of the hottest cities in North America – Las Vegas, Los Angeles, and Phoenix. Their study results hold important findings for outdoor workers, their employers, and policymakers across the Southwestern U.S.
To assess the relationship between extreme heat and nonfatal workplace heat-related illness, the study compared data on occupational injuries and illnesses for the years 2011-2018 with heat index data from Las Vegas, Los Angeles, and Phoenix. Heat index data combines temperature and humidity as a measure of how people feel the heat.
“We expected to see a correlation between high temperatures and people getting sick – and we found that there was a very clear trend in most cases,” said lead author Erick Bandala, Ph.D., assistant research professor of environmental science at DRI. “Surprisingly, this type of analysis hadn’t been done in the past, and there are some really interesting social implications to what we learned.”
First, the research team analyzed changes in heat index data for the three cities. They found a significant increase in heat index at two of the three locations (Phoenix and Las Vegas) during the study period, with average heat index values for June-Aug climbing from “extreme caution” in 2012 into the “danger” range by 2018. Over the same period, data from the Bureau of Labor and Statistics showed that the number of nonfatal heat-related workplace injuries and illnesses in each of the three states increased steadily, climbing from below the national average in 2011 to above the national average in 2018.
According to new research, the number of heat-related nonfatal workplace injuries in Arizona, California, and Nevada increased between 2011 and 2018. The three states now exceed the U.S. average.
Credit: Erick Bandala/DRI.
“Our data indicate that the increases in heat are happening alongside increases in the number of nonfatal occupational injuries across these three states,” Bandala said. “Every year we are seeing increased heat waves and higher temperatures, and all of the people who work outside in the streets or in gardens or agriculture are exposed to this.”
Next, the study team looked deeper into the data to learn about the number of male and female workers being affected by heat-related workplace injuries. At the beginning of the study in 2011, 26 to 50 percent of the people affected across the three states were female. By 2018, 42 to 86 percent of the people affected were female.
Study authors believe that the reason for this increase may be due to more women entering the outdoor workforce, or it could be related to the vulnerability of women to certain heat-related effects, like hyponatremia — a condition that develops when too much plain water is consumed under high heat conditions and sodium levels in blood get too low.
“As the number of female workers exposed to extreme temperatures increases, there is an increasing need to consider the effect of gender and use different approaches to recommend prevention measures as hormonal factors and cycles that can be exacerbated during exposure to extreme heat,” said study coauthor Kebret Kebede, M.D., associate professor of biology at Nevada State College.
The authors examined other variables, such as the length of an employee’s service with an employer. They found that the number of heat-related injury/illnesses tended to increase as the length of service with the employer increased, and that those with more than five years of service were at greater risk than those with less than one year of service. This may be due to employees with more years of service having a reduced perception of risk, or could be a cumulative effect of years of chronic heat exposure on the well-being of outdoor workers.
New research shows that in Arizona, Nevada and California, the number of heat-related injuries/illnesses tended to increase as length of service with the employer increased.
Credit: Erick Bandala/DRI.
In severe cases, heat-related illness or injury can cause extensive damage to all tissues and organs, disrupting the central nervous system, blood-clotting mechanisms, and liver and kidney functions. In these cases, lengthy recoveries are required. The authors found concerning evidence that heat-related injuries are keeping many outdoor workers away from work for more than 30 days.
“These lengthy recovery times are a significant problem for workers and their families, many of whom are living day-to-day,” Bandala said. “When we have these extreme heat conditions coming every year and a lot of people working outside, we need to know what are the consequences of these problems, and we need the people to know about the risk so that they take proper precautions.”
Authors of a new study on the impacts of extreme heat on workplace health found concerning evidence that heat-related injuries are keeping many outdoor workers away from work for more than 30 days.
Credit: Erick Bandala/DRI.
The study also explored connections between heat-related injuries/illnesses and the number of hours worked, the time of day that the event occurred, and the ethnicities and age groups that were most impacted.
Study authors hope that their results will be useful to policymakers to protect outdoor workers. They also hope that the information will be useful to outdoor workers who need to stay safe during times of extreme heat, and employers who rely on a healthy workforce to keep their businesses operating.
“This study underscores the importance of and the need for the work the Nevada Occupational Safety and Health Administration (OSHA) is doing to adopt a regulation to address heat illness,” stated Nancy Brune, Ph.D., study co-author and senior fellow at the Guinn Center.
“As temperatures continue to rise and heat-related illnesses and deaths continue to rise, the need for public policies to alleviate health and economic impacts is growing,” Bandala said. “I hope to continue doing research on this problem so that we can have a better of understanding of the impacts of extreme heat and how to help the people who are most vulnerable.”
More information:
The full study, “Assessing the effect of extreme heat on workforce health in the southwestern USA,” is available from the International Journal of Environmental Science and Technology: https://link.springer.com/article/10.1007/s13762-022-04180-1
This project was funded by NOAA/IRAP (Grant no. NA18AR4310341) and the National Institute of General Medical Sciences (GM103440) from the National Institutes of Health. Study authors included Erick Bandala (DRI), Nancy Brune (Guinn Center for Policy Priorities), and Kebret Kebede (Nevada State College).
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About Nevada State College
Nevada State College, a four-year public institution, is a member of the Nevada System of Higher Education. Nevada State places a special emphasis on the advancement of a diverse and largely under-served student population. Located on a developing 512-acre campus in the foothills of Henderson, Nevada, the college was established in 2002 as a new tier in the state system between the research universities and the two-year colleges and, as such, is Nevada’s only state college. Nevada State College is one of the fastest-growing colleges in the country and the fastest growing in Nevada. It currently has more than 7,000 students and more than 800 full- and part-time employees. For more information, visit http://nsc.edu.
About the Guinn Center
The Guinn Center is a policy research center, affiliated with the University of Nevada, Reno, with offices in both Las Vegas and Reno. The Guinn Center provides data-driven research and policy analysis. The Guinn Center seeks to identify and advance common-sense policy solutions through research , policy engagement, and strategic partnerships.
Apr 6, 2022 | Announcements, News releases
Atmospheric Thrist
Temperature
Climate
Above: A dry Nevada landscape. New research led by DRI scientists shows that atmospheric thirst is a persistent force in pushing Western landscapes and water supplies toward drought.
Credit: Riccardo Panella/DRI.
New study shows robust increases in atmospheric thirst across much of U.S. during past 40 years
Largest changes centered over Rio Grande region of Southwestern U.S.
Reno, Nev. (April 6, 2022) –In arid Western states, the climate is growing warmer and drier, leading to increased demand for water resources from humans and ecosystems. Now, the atmosphere across much of the U.S. is also demanding a greater share of water than it used to, according to a new study by a team from DRI, University of California, Merced, and Scripps Institution of Oceanography at UC San Diego.
The study was published in the Journal of Hydrometeorology and assessed trends in evaporative demand across the U.S. during a 40-year period from 1980-2020 using five datasets. Evaporative demand, sometimes described as “atmospheric thirst,” is a measure of the potential loss of water from the earth’s surface to the atmosphere based on variables including temperature, humidity, wind speed, and solar radiation.
The team’s findings showed substantial increases in atmospheric thirst across much of the Western U.S. during the past 40 years, with the largest and most robust increases in an area centered around the Rio Grande and Lower Colorado rivers. These regions have experienced changes on the order of two-to-three standard deviations from what was seen during the baseline period of 1980-2000.
“This means that atmospheric thirst conditions in parts of the country are now verging outside of the range that was experienced 20 to 40 years ago, especially in some regions of the Southwest,” said lead author Christine Albano, Ph.D., of DRI. “This is really important to understand, because we know that atmospheric thirst is a persistent force in pushing Western landscapes and water supplies toward drought.”
Figure showing changes in atmospheric thirst, measured in terms of reference evapotranspiration (mm), from 1980-2020. The largest changes are centered over the Rio Grande region of the southwestern U.S.
To learn more about the role that different climate variables play in determining atmospheric thirst, Albano and her colleagues analyzed the relative influences of temperature, wind speed, solar radiation, and humidity. They found that, on average, increases in temperature were responsible for 57 percent of the changes observed in all regions, with humidity (26 percent), wind speed (10 percent), and solar radiation (8 percent) playing lesser roles.
“This study shows the dominant role that warming has played on the increasing evaporative demand and foreshadows the increased water stressors the West faces with continued warming,” said study co-author John Abatzoglou, Ph.D., of University of California, Merced.
For farmers and other water users, increases in atmospheric thirst mean that in the future, more water will be required to meet existing water needs. Some of these changes observed in this study are centered over areas where warming temperatures and lower-than-average precipitation are already creating stress on water supplies.
For example, in the Rio Grande region, the study authors calculated that atmospheric thirst increased by 8 to 15 percent between 1980 and 2020. Holding all else equal and assuming no other changes in management, this means that 8 to 15 percent more water is now required to maintain the same thoroughly-watered crop.
“Our analysis suggests that crops now require more water than they did in the past and can be expected to require more water in the future,” said study co-author Justin Huntington, Ph.D., of DRI.
Other impacts of increased atmospheric thirst include drought, increased forest fire area, and reduced streamflows.
“Our results indicate that, decade by decade, for every drop of precipitation that falls, less and less water is likely to drain into streams, wetlands, aquifers, or other water bodies,” said study co-author Michael Dettinger, Ph.D., of Scripps Institution of Oceanography and DRI. “Resource managers, policy makers, and the public need to be aware of these changes and plan for these impacts now and into the future.”
Members of the team are now developing seasonal to sub-seasonal forecasts of evaporative demand.
“We anticipate these types of forecasts will be important for drought and fire forecasting applications,” said study co-author Dan McEvoy, Ph.D., of DRI.
Additional information:
The full text of the study, A multi-dataset assessment of climatic drivers and uncertainties of recent trends in evaporative demand across the continental U.S., is freely available from the Journal of Hydrometeorology: https://journals.ametsoc.org/view/journals/hydr/23/4/JHM-D-21-0163.1.xml
The study team included Christine Albano (DRI), John Abatzoglou (UC Merced), Daniel McEvoy (DRI), Justin Huntington (DRI), Charles Morton (DRI), Michael Dettinger (Scripps Institution of Oceanography/DRI), and Thomas Ott (DRI).
This research was funded by the Sulo and Aileen Maki Endowment Fund to the Desert Research Institute’s Division of Hydrologic Sciences, the National Oceanic and Atmospheric Administration (NOAA) California-Nevada Climate Applications Program (NA17OAR4310284), NOAA National Integrated Drought Information System California-Nevada Drought Early Warning System (NA20OAR4310253C), the NASA Applied Sciences, Water Resources Program (NNX17AF53G), the U.S. Geological Survey Landsat Science Team (140G0118C0007), and USDA-NIFA project (2021-69012-35916).
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About UC Merced
UC Merced opened in 2005 as the newest member of the University of California system and is the youngest university to earn a Carnegie research classification. The fastest-growing public university in the nation, UC Merced is on the cutting edge of sustainability in campus construction and design and supports high-achieving and dedicated students from the underserved San Joaquin Valley and throughout California. The Merced 2020 Project, a $1.3 billion public-private partnership that is unprecedented in higher education, nearly doubled the physical capacity of the campus with 11 buildings earning Platinum LEED certification.
About Scripps Oceanography
Scripps Institution of Oceanography at the University of California San Diego is one of the world’s most important centers for global earth science research and education. In its second century of discovery, Scripps scientists work to understand and protect the planet, and investigate our oceans, Earth, and atmosphere to find solutions to our greatest environmental challenges. Scripps offers unparalleled education and training for the next generation of scientific and environmental leaders through its undergraduate, master’s and doctoral programs. The institution also operates a fleet of four oceanographic research vessels, and is home to Birch Aquarium at Scripps, the public exploration center that welcomes 500,000 visitors each year.
About UC San Diego
At the University of California San Diego, we embrace a culture of exploration and experimentation. Established in 1960, UC San Diego has been shaped by exceptional scholars who aren’t afraid to look deeper, challenge expectations and redefine conventional wisdom. As one of the top 15 research universities in the world, we are driving innovation and change to advance society, propel economic growth and make our world a better place. Learn more at ucsd.edu.
Mar 24, 2022 | Blog, Featured researchers
Meet Dennis Hallema, Ph.D.
MARCH 24, 2021
LAS VEGAS, NEV.
Data Modeling
Hydrology
Wildfires
Above: Dennis Hallema of DRI studies natural catastrophe impacts, such as the longer-term impacts that wildfires have on flood risk after a fire has passed. The hillside shown here burned in California’s Loyalton Fire during August 2020.
Credit: Kelsey Fitzgerald.
Dennis Hallema, Ph.D., is an assistant research professor of hydrology with the Division of Hydrologic Sciences at DRI in Las Vegas. He specializes in data modeling and natural catastrophe research. Dennis is originally from the Netherlands and holds B.S. and M.S. degrees in Earth Sciences from Utrecht University in the Netherlands, and a Ph.D. in Continental hydrology and society from Montpellier SupAgro in France. A new addition to the DRI community, Dennis started working for DRI remotely from North Carolina in November 2021 and relocated to Las Vegas in March.
DRI: Can you tell us a little bit about your background and what brought you to DRI?
Hallema: I started at DRI in November of last year, so I am still fairly new here. If you had to describe me with two keywords, it would be hydrology and wildfires. I specialize in consulting on natural hazard impacts – not so much the natural hazards themselves, but the longer-term impacts that they have on things like flood risks. My methods are AI (artificial intelligence) focused – so, machine learning. When I applied for this job at DRI, there was really a need for a person who could do research on all of these aspects combined – a person that crossed the bridge between traditional hydrologic modeling and who could also apply newer methods like AI.
My background is in hydrologic modeling and fire science. I first did this work for the USDA Forest Service, where I was a research fellow with the Oak Ridge Institute for Science and Education (ORISE). That was my first big fellowship. I did that job for a few years, and that’s where I really became an expert in wildfire impacts on hydrology. Before that, I worked in Quebec City, Canada, on different jobs in hydrologic modeling of snowy landscapes, so I have experience doing snow modeling as well.
DRI: What are some of the ways that wildfires impact hydrology? Can you give us an example?
Hallema: I have studied this across the whole entire country looking at various regions where fires have an impact on runoff. The higher up you go in mountainous areas, you see very profound impacts. We can divide the impacts into primary perils and secondary perils. In the case of a wildfire, primary perils are the immediate damage. People lose their property, there are health impacts, there can be loss of life.
Secondary perils are what come later, after the fire has passed – the indirect effects that occur from the fire. In many cases, secondary perils are related to hillslope stability. You may remember the mudslides of California a few years ago. The hillslope becomes unstable because the wildfire can remove a large part of the vegetation canopy. After the fire, when the first rainfall event occurs, the soil can often still absorb that. But when the second rain shower comes, and there’s nothing to retain or protect the soil, in case of very severe wildfires, the soil becomes saturated and essentially creates a sliding plane, and that’s when you get mudslides.
Above: Dennis Hallema is an assistant research professor of hydrology with DRI in Las Vegas. In his free time, he enjoys spending time outdoors.
DRI: You recently published new research on wildfire risks to watersheds in Canada. Can you tell us about that?
Hallema: The paper was a review of the mechanisms that are responsible for wildfire impacts on water security and water resources across Canada. We mapped out where data are available, and what types of data are available, as far as wildfire occurrence, severity, streamflow data, and streamflow impacts. Data is often collected with publicly funded projects, so the ideal outcome would be that data should be accessible to other users later on. But this isn’t always the case.
One principle that we advocate for in this paper that I also want to promote in Nevada is the FAIR data principle. That stands for Findability, Accessibility, Interoperability, and Reuse of digital assets. Obstacles to that are data scarcity and data fragmentation. Data scarcity means that there is little data available, and data fragmentation means that the data exist, but they are stored in many different locations. There is a lot of opportunity to improve the depth of data collection and quality of datasets and improve and reduce the fragmentation of data.
DRI: Can you tell us about a project you’re working on here at DRI?
Hallema: I’m working on a project that is sponsored by the United States Army Corps of Engineers (USACE), and one thing that we’re exploring is the effect of rain on snow. This happens in landscapes in northern Nevada when temperatures are around the freezing point, and you get an interesting dynamic of snowmelt and snowfall. My research is really focused on how likely this is to generate a flood, such as a 50-year flood, or a 100-year flood. The way I’m approaching the problem is by looking at the interactions between rain, snow, and rain-on-snow events. I’m researching how these interactions at the land surface really affect the runoff that is generated, how that affects the probability of a flood occurring, and when during the season you see this elevated flood risk. That’s one thing I’m working towards – and in general also providing consulting for institutions like USACE for implementing machine learning and remote sensing technologies into natural hazards impact models, wildfire data modeling, water risk models, and such.
DRI: What do you like to do outside of work?
Hallema: I like to spend a lot of time outdoors. I like to travel, I speak a few languages. I’m lucky that the things I do for work are things that I really enjoy doing. Being outside, collecting data, and doing cool computer stuff when I get back to the office, that’s the fun of my job.
Mar 23, 2022 | Announcements, News releases
Wastewater
COVID-19
Wastewater Surveillance
Above: Waste water samples were collected at the Waste Water Treatment Plant in Pahrump, Nevada.
Agencies collaborate to launch wastewater surveillance dashboard
New dashboard will include COVID-19 concentration data, information about variant testing and more.
Las Vegas, Nev. (March 23, 2022) –
The University of Nevada, Las Vegas (UNLV), Southern Nevada Health District, Southern Nevada Water Authority (SNWA) and Desert Research Institute (DRI) are partnering to detect early increases of SARS-CoV-2 (the virus that causes COVID) and emerging variants in Southern Nevada through wastewater surveillance. The data will be available on a new dashboard that will be updated weekly at http://empower.unlv.edu.
The wastewater surveillance program monitors SARS-CoV-2 concentrations from people who contract COVID-19 (with or without symptoms) and shed genetic material in their stools. During the COVID-19 pandemic, wastewater surveillance has tracked, monitored and provided early awareness of increases in volume of the virus as well as changes to the types of variants of COVID-19. Because people who are infected with the virus that causes COVID-19 can take several days before showing symptoms, the information provided through this surveillance program can assist with informing public health strategy and ongoing planning efforts.
In addition to being an early indicator that cases of COVID-19 may be increasing in a community, wastewater surveillance can also indicate when cases are decreasing, and the surveillance program is not dependent on people seeking testing or health care when they are sick.
“As we move into the next stage of our response to COVID-19, wastewater surveillance is going to be a powerful tool for detecting potential surges in new cases or the presence of new variants in our community. We will be able to alert the public in a timelier manner and support public health mitigation measures that can help slow the spread of the virus,” said Cassius Lockett, Director of Disease Surveillance and Control for the Health District.
Currently, the SARS-CoV-2 concentration in the wastewater of participating community water systems across Southern Nevada is tested as part of this program. Nevada was one of the first states to initiate testing, and this surveillance project represents one of the largest projects of its kind in the U.S.
“The collaboration between our community partners has enabled the collection of one of the largest and most diverse wastewater datasets in the country,” said Edwin Oh, professor and director of the Neurogenetics and Precision Medicine Lab at UNLV. “The daily and weekly analyses of these samples will help keep us one step ahead of emerging pathogens and variants.”
DRI Associate Research Professor Duane Moser collects water waste samples in Pahrump to detect possible increases of SARS-CoV-2 and emerging variants in Southern Nevada.
“DRI is contributing to this collaborative effort by organizing sampling from ten wastewater systems across rural Clark and Nye Counties, substantially expanding the geographic reach of the project and providing time-sensitive epidemiological data that would otherwise be lost,” said DRI Associate Research Professor of Microbiology Duane Moser. The addition of these outlying sites has a great deal to teach us about how quickly and effectively viruses spread from population centers to outlying areas with lower population densities.”
While wastewater surveillance can provide early awareness of increases in cases and potential outbreaks, the data provided cannot directly indicate the number of people who are currently infected with COVID-19. The data collected are not intended to be used as the sole method of measuring the prevalence of COVID-19 in the community. The information will be used along with other data by partner and responding agencies for planning purposes.
More information about wastewater surveillance, and national wastewater surveillance data, is available on the Centers for Disease Control and Prevention website at www.cdc.gov/healthywater/surveillance/wastewater-surveillance/wastewater-surveillance.html.
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
About Southern Nevada Health District
The Southern Nevada Health District serves as the local public health authority for Clark County, Boulder City, Henderson, Las Vegas, Mesquite and North Las Vegas. The agency safeguards the public health of the community’s residents and visitors through innovative programs, regulations, and initiatives focused on protecting and promoting their health and well-being. More information about the Health District, its programs, services, and the regulatory oversight it provides is available at www.SNHD.info. Follow the Health District on Facebook, Twitter, and Instagram.
Jan 12, 2022 | Awards and Honors, Blog
Meet Rishi Parashar, Ph.D. and learn about his research in this Q&A with “DRI’s Behind the Science” Blog.
Rishi Parashar, Ph.D., is an Associate Research Professor of Hydrology with the Division of Hydrologic Sciences at DRI in Reno. He studies the movement of water, contaminants, and other substances through Earth’s subsurface. Originally from India, Rishi holds a B.S. in Civil Engineering from the Indian Institute of Technology in Roorkee, India, and Masters and Ph.D. degrees in Civil Engineering from Purdue University. He has been a member of the DRI community since 2008. In his free time, Rishi enjoys photography, listening to music, and spending time with his wife and three children.
DRI: What do you do at DRI?
Parashar: I study flow and contaminant transport through Earth’s subsurface, which consists of soil as well as rocks. Within rocks you can have fractures, so that is known as fractured media; within soils, there are tiny air or water-filled pores, so they are generally called porous media. My research is largely focused on understanding how water or anything that is mixed into the water – like contaminants, microbes, or heat – flow and disperse through fractured rocks and porous media.
DRI: Why is it important to understand these processes here in Nevada? Can you share an example from your work?
Parashar: When I began at DRI in 2008, I spent a large portion of my first eight or nine years working on problems at the Nevada Test Site, which is now known as the Nevada National Security Site (NNSS). During that time, my work was heavily based on trying to understand how radionuclides might move through fractured rocks. Radionuclides are unstable forms of elements that release radiation as they break down and can have harmful effects on living organisms. So, we were trying to determine how radionuclides that were released into the subsurface after atomic tests might move further by getting into fractured rocks. Understanding how contaminants or water or radionuclides in this case can potentially move through fractured rock is very important in places like the NNSS.
DRI: You recently received a Mid-Career Advancement (MCA) award from the National Science Foundation (NSF) that will allow you to expand your work in some exciting new directions. Can you tell us about your plans?
Parashar: This was the first year that the NSF has offered mid-career awards, which provide time and resources for scientists at the Associate Professor rank to diversify their knowledge by partnering and training with researchers working in complimentary fields. Until now, my research has been mainly focused on understanding flow and transport in fractured rocks and porous media – but one of the major challenges in my field right now is that most computational models are large, computationally heavy, and difficult to scale-up. To take science or modeling of these processes to the next level, I believe that we need to try to combine our work with some of the technological advances that we are seeing in the fields of computer science and applied mathematics.
Some high-fidelity fracture network models cannot be easily scaled up – they allow us to study problems at a small scale, but to apply our models for realistic world problems at a larger scale, we may benefit greatly from tapping into artificial intelligence (AI) or machine learning or quantum computing. With the MCA award, I will be partnering with three collaborators: two are applied mathematicians from the Los Alamos National Laboratory, and the third is a computer scientist from the University of Nevada, Reno with expertise in AI, graph representations of networks, and quantum computing. Together we will explore opportunities of convergence research and see if we can develop more robust computational approaches that would benefit many different areas within the field of hydrology.
DRI: What are some of the applications for your work?
Parashar: The type of modeling I’ve described can help us understand the movement of water, heat, and other quantities of interest through connected networks in the subsurface with applications to geothermal, carbon sequestration, and nuclear waste repositories among others. They can also be useful in studying the transport of viruses and bacteria through porous media, which is important in applications such as water recycling. Here in Nevada, there is interest in treating and cleaning municipal water and reusing it for irrigation and other purposes. One way to clean it is to run it through the ground – but to ensure that the water is being properly cleaned it is important to understand how bacteria and viruses move through the system.
DRI: You are originally from India. How did you end up here at DRI?
Parashar: I came to DRI as a postdoc in 2008. The true story is that in all my life I have only written one job application. In 2008, when I was about to complete my Ph.D., my wife was already well established in the Reno area working for a consulting firm. I wanted to explore opportunities and knew about the good quality of work at DRI. So I approached John Warrick, who was the Division Director at that time, and he informed me about this new position that was about to open. I interviewed in Las Vegas and have stayed here at DRI’s Reno campus ever since.
More information:
https://www.dri.edu/directory/rishi-parashar/
Nov 4, 2021 | News releases, Research findings
Above: Researchers’ ice core drilling camp on Colle Gnifetti in 2015. Two ice cores extracted from this area preserved a continuous one-thousand-year record of European climate and vegetation. Credit: Margit Schwikowski.
Evidence preserved in glaciers provides continuous climate and vegetation records during major historical events
Reposted from AGU – https://news.agu.org/press-release/1000-years-of-glacial-ice-reveal-prosperity-and-peril-in-europe/
RENO, Nev. – Europe’s past prosperity and failure, driven by climate changes, has been revealed using thousand-year-old pollen, spores and charcoal particles fossilized in glacial ice. This first analysis of microfossils preserved in European glaciers unveils earlier-than-expected evidence of air pollution and the roots of modern invasive species problems.
A new study analyzed pollen, spores, charcoal and other pollutants frozen in the Colle Gnifetti glacier on the Swiss and Italian border. The research found changes in the composition of these microfossils corresponded closely with known major events in climate, such as the Little Ice Age and well-established volcanic eruptions.
The work was published in Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.
The industrialization of European society also appeared clearly in the microfossil record and, in some cases, showed up sooner than expected. Pollen from the introduction of non-native crops was found to go back at least 100 years ago and pollution from the burning of fossil fuels shows up in the 18th century, about 100 years earlier than expected.
Existing historical sources such as church records or diaries record conditions during major events like droughts or famines. However, studying data from the glaciers contributes to the understanding of climate and land use surrounding such events, providing non-stop context for them with evidence from a large land area. Precisely identifying the timing of these events can help scientists better understand current climate change.
“The historical sources that were available before, I don’t think [the sources] got the full picture of the environmental context,” said Sandra Brugger, a paleoecologist at the Desert Research Institute in Nevada and lead researcher on the study. “But also, with the ice core, we couldn’t get the full picture until we started collaborating with historians on this. It needs those two sides of the coin.”
Evidence on High
The new study analyzed microfossils frozen in two 82- and 75-meter-long ice cores pulled from the Colle Gnifetti glacier, which are the first two ice cores from the continent of Europe studied for microfossils. Similar studies have sampled ice cores in South America, Central Asia and Greenland, but those regions lack the breadth of written historical records that can be directly correlated with the continuous microfossil data in ice cores.
Over the centuries, wind, rain and snow carried microfossils from European lowlands, the United Kingdom and North Africa to the exposed glacier. Ice in this glacier site dates back tens of thousands of years, and the altitude of Colle Gnifetti — 4,450 meters above sea level — means the ice was likely never subjected to melting, which would mix the layers of samples and create uncertainty in the chronology of the record.
“They can actually pinpoint and identify the relationships between what’s happening on the continent with climatic records inherent in the ice,” said John Birks, a paleoecologist at the University of Bergen who was not associated with the study. “They can develop, in a stronger way, this link between human civilization and change and climate, particularly in the last thousand years or so where conventional pollen analysis is rather weak.”
Evidence of pollution due to fossil fuel combustion also appeared earlier in the chronological record than expected. The researchers found evidence of the early burning of coal in the United Kingdom around 1780, much earlier than the expected onset of industrialization around 1850, which could have implications for global climate change modeling.
The records also showed evidence of pollen from non-native European plants from 100 years ago, showing a long legacy of the existing ecological problems created by invasive species transported across continents through trade.
###
AGU (www.agu.org) supports 130,000 enthusiasts to experts worldwide in Earth and space sciences. Through broad and inclusive partnerships, we advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct.
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Oct 21, 2021 | Announcements, News releases
“What OpenET offers is a way for people to better understand their water usage. Giving farmers and water managers better information is the greatest value of OpenET.” – Denise Moyle, Farmer, Diamond Valley, Nevada
OpenET makes satellite-based data widely accessible to help 17 states develop more resilient water supplies
Reposted from OpenET
SACRAMENTO, CA – OpenET, a new online platform that uses satellites to estimate water consumed by crops and other plants, launched today, making critical data for water management widely available in 17 western states for the first time amid record drought.
OpenET fills a major information gap in water management in the West. Although water is essential to the health of our communities, wildlife, and food supply, access to accurate, timely data on the amount of water used to grow food has been fragmented and often expensive, keeping it out of the hands of many farmers and decision-makers. OpenET allows users to easily view and download this important water data for the current year and previous five years at no charge.
OpenET is providing this data down to the field scale in 17 western states as water supplies become increasingly scarce due to drought, climate change and population growth. The states covered by OpenET are Arizona, California, Colorado, Idaho, Kansas, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Texas, Utah, Washington, and Wyoming.
“OpenET addresses one of the biggest data gaps in water management in the western United States,” said Forrest Melton, program scientist for the NASA Western Water Applications Office. “This easy-to-use online platform provides scientifically robust data that are invaluable for water management at all scales, from an individual agricultural field to an entire river basin.”
“As water supplies become increasingly scarce in arid regions, we need new, innovative tools like OpenET to manage water more precisely and sustainably,” said Robyn Grimm, senior manager, water information systems, at Environmental Defense Fund (EDF). “OpenET provides all farmers, policymakers and communities big and small with the same high-quality data on water use, so that we can all work together from the same playbook to develop more resilient water supplies across the West.”
“OpenET is a powerful application of cloud computing that will make a measurable impact on the ground in the agriculture sector. Google is proud to support such an important new tool to help improve water sustainability in the western United States as we see the impacts of climate change intensify,” said Google Earth Engine developer advocate Tyler Erickson.
“OpenET combines decades of research with advances in technology from just the past five years to make valuable water data much more affordable and accessible to all,” said Justin Huntington, a research professor at Desert Research Institute. “In the future we hope to expand OpenET to other arid regions of the world, such as South America, India and Africa.”
“As someone who has worked on evapotranspiration for more than 40 years, I am thrilled to see multiple, independent models for estimating ET come together on a single, easy-to-navigate platform,” said Richard Allen, a professor of water resources engineering at the University of Idaho. “By putting these water consumption data into the hands of farmers and water managers across the western United States, OpenET will be transformative in helping us manage water more sustainably,” added Ayse Kilic, a professor at the University of Nebraska-Lincoln.
“In some parts of the arid West, more than 70% of irrigation water ends up as evapotranspiration. By automating calculations for this highly important water data, OpenET will enable the USGS and water managers to more easily create water budgets at the watershed scale, which is an essential first step toward proactive water management,” said Gabriel Senay, a scientist with the U.S. Geological Survey.
“Irrigated agriculture is essential to feeding a growing population,” said Martha Anderson, a research scientist with the U.S. Department of Agriculture. “OpenET will be a powerful tool to help our nation’s farmers increase food production under conditions of limited freshwater resources.”
“OpenET has not just transformed access to information on ET, but has also facilitated important advances in the underlying science,” said Josh Fisher, a research scientist with the University of California, Los Angeles. “The collaborative approach used to develop OpenET will accelerate our ability to scale the platform to other regions, and to rapidly incorporate new information from future satellite missions.”
“The development of multi-model tools based on cloud computing, as provided by OpenET, is a paradigm shift, allowing water resources management in sustainable ways, not only in the United States, but also in many agricultural regions of the world, where agriculture and irrigation are increasing rapidly, as in Brazil”, added Anderson Ruhoff, a professor at the Universidade Federal do Rio Grande do Sul in Brazil.
Applications of OpenET data include:
- Informing irrigation management and scheduling to maximize “crop per drop” and reduce costs for water, fertilizer and energy. ET data are being used by E&J Gallo Winery in California and Oregon state legislator and alfalfa farmer Mark Owens to reduce applied irrigation water while sustaining crop yields and quality.
- Enabling water and land managers to develop more accurate water budgets, water trading programs and other innovative programs. Rosedale-Rio Bravo Water Storage District in California’s San Joaquin Valley is using OpenET in its online accounting and trading platform. Salt River Project in Arizona is using OpenET to improve their understanding of the impacts of wildfire and forest management on streamflow and groundwater recharge.
What is evapotranspiration?
The “ET” in OpenET stands for evapotranspiration — the process by which water evaporates from the land surface and transpires, or is released, from plants. ET is a key measure of water consumed by crops and other vegetation that can be used by farmers and water managers to better track water use as well as water saved, for instance, when farmers change crops or invest in new technologies.
Evapotranspiration can be estimated by satellites because the ET process absorbs energy and cools the land surface, and vegetation reflects and absorbs different amounts of visible and near-infrared light depending upon the density and health of the vegetation. These effects are visible to thermal and optical sensors on a satellite. Using sophisticated biophysical models, OpenET combines satellite information with local weather data to accurately estimate ET.
Using publicly available data, OpenET brings together six independent models for estimating evapotranspiration onto a single computing platform, ultimately helping to build broader trust and agreement around this information.
OpenET data has been extensively compared to ground-based measurements collected in agricultural fields and natural landscapes, and tested by a wide variety of organizations through several use cases to ensure the highest accuracy.
Unprecedented public-private partnership
OpenET has been developed through an unprecedented public-private collaboration with input from more than 100 farmers, water managers, and other stakeholders. The project is led by Environmental Defense Fund, NASA, Desert Research Institute, and HabitatSeven. Additional team members include Google, the U.S. Geological Survey, U.S. Department of Agriculture, California State University Monterey Bay, University of Idaho, University of Maryland, University of Nebraska-Lincoln, University of Wisconsin-Madison, UCLA, and Universidade Federal do Rio Grande do Sul in Brazil.
The OpenET project has received funding from the NASA Applied Sciences Program Western Water Applications Office, S. D. Bechtel, Jr. Foundation, Gordon and Betty Moore Foundation, Walton Family Foundation, Water Funder Initiative, Lyda Hill Philanthropies, The Keith Campbell Foundation for the Environment, Delta Water Agencies, and the Windward Fund. In-kind support has been provided by Google Earth Engine and partners in the agricultural and water management communities.
Providing farmers and local water managers free ET data is a core objective of the OpenET project. For-profit entities and other organizations looking for large-scale access to OpenET data will be able to purchase it through an application programming interface (API) expected to launch in 2022. Revenue generated will fund continuing research and development of OpenET data services.
###
Environmental Defense Fund (edf.org), a leading international nonprofit organization, creates transformational solutions to the most serious environmental problems. EDF links science, economics, law and innovative private-sector partnerships. Connect with us on Twitter, Facebook and our Growing Returns blog.
The National Aeronautics and Space Administration (nasa.gov) is a U.S. government agency that leads an innovative program of exploration with commercial and international partners to enable human expansion across the solar system and bring new knowledge and opportunities back to Earth. With its fleet of Earth-observing satellites and instruments, NASA uses the vantage point of space to understand and explore our home planet, improve lives and safeguard our future.
The Desert Research Institute (dri.edu) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education.
Google Earth Engine (earthengine.google.com) is a geospatial processing platform that combines a multi-petabyte catalog of satellite imagery and other geospatial datasets with planetary-scale analysis capabilities. The platform is enabling scientists, developers and decision-makers to make substantive progress on global environmental and sustainability challenges.
Sep 10, 2021 | Announcements, News releases
Second DRI researcher to be recognized with this prestigious award
Reno, Nev. (September 10, 2021) – DRI announced that research professor Michael Dettinger, Ph.D., has been selected by the American Geophysical Union (AGU) to give this year’s Tyndall Lecture at the Fall 2021 AGU meeting. The prestigious Tyndall Lecture Award recognizes outstanding work in advancing understanding of global environmental change. Dettinger is the second DRI researcher to be recognized by AGU since the award’s inception in 2013. World-renown DRI researcher Kelly Redmond, Ph.D., was recognized with the second Tyndall Lecture award in 2014.
“I am deeply honored to be recognized with the Tyndall Lecture and to follow in the footsteps of Dr. Kelly Redmond,” said Dettinger. “I look forward to sharing my research at the Fall 2021 AGU meeting. My lecture will present a history of climate and water studies in the Western U.S. Water resources have not been a focus of previous Tyndall Lectures and with current conditions in the West, the time is right for taking a look at this history.”
Dr. Dettinger joined DRI several years ago following a long (38-year) career with the U.S. Geological Survey that began in Nevada with studies of Las Vegas valley groundwater and the carbonate-rock aquifers of Eastern and Southern Nevada in collaboration with DRI scientists in the early 1980s. His career has since focused on unraveling the complex interactions between water resources, climate variations and change, and ecosystems in the Western U.S. He recently co-edited a book on atmospheric rivers. He is a Fellow of the AGU and a Fellow of the American Association for the Advancement of Science.
“We are proud of Mike’s accomplishments and are honored that he has been awarded DRI’s second Tyndall Lecture Award,” said DRI Executive Director, Division of Hydrologic Sciences Sean McKenna, Ph.D. “Mike has sustained his considerable energy, curiosity and creativity over a long career resulting in ground-breaking insights on global environmental change. His ability to communicate his findings in clear language and his dedication to mentor other researchers is a shining example of what we strive for at DRI.”
The Tyndall History of Global Environmental Change Lecture is presented annually and recognizes outstanding contributions to our understanding of global environmental change. It honors the life and work of Irish physicist John Tyndall, who confirmed the importance of the greenhouse effect in the late 1800s.
###
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Media Contact:
Detra Page
Communications Manager
Detra.page@dri.edu
702.591.3786
Jul 30, 2021 | Announcements, News releases
Reposted news release from the office of Senator Cortez Masto.
Washington, D.C. – U.S. Senator Catherine Cortez Masto (D-Nev.) today introduced legislation to get critical water use data in the hands of farmers, ranchers, and decision-makers for improved water management across the Western U.S. The Open Access Evapotranspiration (OpenET) Act would establish a program under the Department of the Interior (DOI) to use publicly available data from satellites and weather stations to provide estimates of evapotranspiration (ET), a critical measure of the water that is consumed and removed from a water system. ET represents the largest share of water use in most arid environments around the world. Companion legislation is being introduced in the House of Representatives by Congresswoman Susie Lee (D-Nev.-03), Congressman Chris Stewart (R-Utah-02), and Congressman Jared Huffman (D-Calif.-02).
“With Nevada and states across the West facing drought, we need to make it as easy as possible for our communities to conserve water and for farmers and ranchers to effectively manage their water use,” said Senator Cortez Masto. “My legislation will help accomplish that goal by equipping Nevadans with this critical water data. This data will help us protect our water resources and ensure our crops, livestock, and wildlife have water access, and passing this bill would mark a significant step in our plan for a more sustainable future.”
“The West faces a historic drought that demands action and innovation,” said Representative Susie Lee. “All of Nevada is currently in drought, and the entirety of my district, Nevada’s Third District, is in exceptional drought, the highest classification. In order to solve our water crisis, we need to better understand how much water is available and how much water is being used. With this program, we will have credible, transparent and easily accessible data on our consumptive water use so that we can make better water management decisions in Nevada and across the West.”
“Extreme drought fueled by climate change has become a dire challenge in the western United States, and it’s critical for us to operate with the best information and data possible as we manage this increasingly limited resource,” said Representative Huffman. “Knowing key water metrics like evaporation rates is incredibly valuable for folks across all sectors, and I‘m glad to join Representatives Lee and Stewart and Senator Cortez Masto in this bill to help farmers, water utilities, regulators, and governments alike all make well-informed water management decisions.”
“Water is the lifeblood of the American West, and the ongoing drought is taking a toll on everyone,” said Representative Stewart. “It’s absolutely necessary that we get the most use out of the water we already have. That starts with giving states more consistent, accessible, and accurate data. This legislation will allow us to be more prudent with our current resources and plan for the future of our communities.”
“The Nevada Division of Water Resources strongly supports the continued development and public accessibility of OpenET,” said Adam Sullivan, Nevada State Engineer, Nevada Division of Water Resources. “This outstanding program directly benefits water users throughout Nevada and the West who strive to improve efficiency and conserve water. Public access to these data will be increasingly vital to support water users and responsible water management needs into the future.”
“OpenET will allow water managers to assess how much water is being used via a cost-effective and easy-to-use web-based platform, filing a critical data gap in water management across the U.S.,” said Zane Marshall, Director, Water Resources, Southern Nevada Water Authority. “The Authority believes OpenET is a valuable tool for federal, state, and local policymakers and water users.”
“It’s more important than ever to provide consistent, accurate information to water users and water managers to allow them to make the most efficient decisions about water use,” said Desert Research Institute President Kumud Acharya. “OpenET is an innovative approach that provides agricultural water users and water managers access to the same information on consumptive water use. I appreciate the leadership of Nevada Senator Catherine Cortez Masto and Nevada Congresswoman Susie Lee on this important piece of legislation.”
“OpenET has been developed in close collaboration with partners from agriculture, cities, irrigation districts, and other stakeholders across the West,” said Laura Ziemer, Senior Counsel and Water Policy Advisor, Trout Unlimited. “OpenET is a forward-looking tool for supporting TU’s goals of water conservation and meaningful water allocation to promote the sustainability of both agriculture and watershed health.”
The West is facing the devastating impacts of increased drought and a changing climate, and to maximize the benefits of our water supplies, we must know how much water is available and how much is being used. Access to this data has been limited, inconsistent, and expensive, making it difficult for farmers, ranchers, and water managers to use it when making important decisions that could benefit communities. The OpenET program brings together an ensemble of well-established methods to calculate ET at the field-scale across the 17 Western states. Applications of this data include:
- Assisting water users and decision-makers to better manage resources and protect financial viability of farm operations during drought;
- Developing more accurate water budgets and innovative management programs to better promote conservation and sustainability efforts;
- Employing data-driven groundwater management practices and understanding impacts of consumptive water use.
The bill text can be found here.
Senator Cortez Masto has worked to safeguard Nevada’s water and landscapes and the agricultural and outdoor recreation industries that rely on them. Her legislation to combat drought and protect the water supply in western states recently cleared a key Senate committee hurdle, and she is also leading a bipartisan bill to restore Lake Tahoe. She has introduced comprehensive legislation to prevent wildfires, fund state-of-the-art firefighting equipment and programs, and support recovery efforts for communities impacted by fires.
Jul 28, 2021 | Blog, Featured projects
WASH Capacity Building Program Alumni Share Career Impacts
July 28, 2021
RENO, NEV.
By Kelsey Fitzgerald
Water, Sanitation and Hygiene (WASH)
Sustainability
Education
Successful international training program provides education in the field of water, sanitation and hygiene (WASH) and environmental issues.
Alumni from the Desert Research Institute’s WASH Capacity Building Program (WASHCap) recently gathered for an online Zoom panel to share some of the positive impacts that the program has had on their careers in the areas of water, sanitation and hygiene (WASH) across Africa and India.
The WASHCap program is led by DRI’s Center for International Water and Sustainability (CIWAS), in partnership with the University of Nevada, Reno (UNR), Drexel University, and World Vision. Students complete a series of courses on topics related to WASH, some of which are taught online and others in a face-to-face setting in locations such as eSwatini, Ghana and Uganda.
Since launching in 2016, five cohorts of students have graduated from WASHCap program – a total of 133 students from 25 countries. A sixth cohort of 38 students is currently enrolled, and includes for the first time students from Latin America and the Caribbean.
More than 75 WASHCap alumni, friends, colleagues, and students attended the online panel discussion, which featured dynamic and lively dialogue among the current and previous students of the program, and remarks by Margaret Shuler, Senior Vice President of International Programs at World Vision and Jodi Herzik, Interim Vice Provost of Extended Studies at UNR.
WASHCap program alumni Martin Mutisya is currently a program manager for WASH WorldVision in Sudan.
The discussion was moderated by Braimah Apambire, Ph.D., Director of CIWAS at DRI. Several instructors from the WASHCap program including DRI’s Rosemary Carrol, Ph.D., Alan Heyavert, Ph.D., and Erick Bandala, Ph.D., and Drs, Emmanuel Opong, John Akudago and Eleanor Wozei also participated in the discussion, asking program alumni to reflect on ways in which the program has helped them to improve their careers, implement new business plans, understand complex issues related to WASH, network with other professionals, and more.
Martin Mutisya, Program Manager for WASH World Vision Sudan, appreciated the breadth of knowledge that was covered during a course called “Cross-cutting issues in WASH”, which helped him understand issues of gender and social inclusion, and the importance of covering them in WASH plans.
Alexander Pandian from World Vision India said that the WASHCap program helped him to feel more comfortable serving as a technical point person for WASH, and allowed him to help develop the first World Vision country strategy on WASH for India.
Rose Riwa, a hygiene specialist from World Vision in Tanzania, credited the WASHCap program for helping her to understand how WASH integrates with other issues, and for helping her to progress in her career as a leader in WASH in her country.
WASHCap program alumni Pamela Wamalwa is currently a program manager for WASH WorldVision in Kenya.
Pamela Wamalwa of World Vision Kenya said that because of the training she received in conducting research and presenting term papers during the WASHCap program, she now feels more comfortable doing research in her job and presenting her findings at professional conferences.
“During the training, I gained a lot of courage,” Wamalwa said. “Before I was not able to present papers, but during the training, I realized that I can actually do research and present in conferences. It was an experience I couldn’t have gotten if I didn’t attend this program.”
Other panelists spoke to the value of the program in building their knowledge, research skills, presentation skills, confidence, and networks within the WASH sector. Many graduates of the WASHCap program have gone on to lead WASH programs and projects across Africa and India, including many who are now employed by World Vision.
“It was very powerful to hear about the positive impact that this program has had on the careers of so many of our graduates, and to be able to share that message with students who are in the program now,” Apambire said.
###
About DRI
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education.
Jun 30, 2021 | Awards and Honors, Blog
Each year, the Desert Research Institute (DRI) honors the incredible commitment and dedication of our faculty and staff through an award ceremony called the Celebration of Science. This year’s event was held virtually and recognized the winners of this year’s Nevada System of Higher Education Rising Researcher Award, the DRI Medals for Science, Service, and Outstanding Contributions, the Technologist of the Year, as well as internal divisional and milestone service awards.
2021 Award Winners
DRI Science Medal – Xiaoliang Wang, Ph.D.
The DRI Science Medal is given based on scientific achievement that has brought recognition to both the winning scientist and to DRI, through either cumulative or a singular outstanding achievement. This award builds on the history of the Count Alessandro Dandini Medal of Science and the Nazir and Mary Ansari Medal for Excellence in Science, which annually recognized the high scientific accomplishments of a DRI faculty member.
Outstanding Contributions Medal – Tim Brown, Ph.D.
The Outstanding Contributions Medial is given annually to a DRI faculty or staff member for outstanding contributions to the Institution. Evidence of contributions can include establishing new directions for research, securing a large grant, or management of large programs.
Service Medal – Jennifer Schultz
The DRI Service Medal is awarded annually to a faculty or staff member who makes broad impacts across the Institution and throughout our communities, making DRI a better place to work and securing our place as a core research asset.
Technical Employee of the Year – Alison Swallow
The Technical Employee of the Year is awarded annually to a staff member for outstanding contributions to the Institution.
Rising Researcher Award – Daniel McEvoy, Ph.D.
Awarded annually by the Nevada System of Higher Education (NSHE) to a faculty member in recognition of outstanding early-career accomplishments in research.
Division Awards
George Burke Maxey Fellowship – Marc Berghouse
Peter B. Wagner Medal of Excellence – Monica Arienzo, Ph.D.
Jonathan O. Davis Scholarship – Erica Bradley and Hayden Kingrey
General Frederick Lander Scholarship – Pearson Nguyen
Colin Warden Memorial Endowment - Pramod Adhikari
Advisor of the Year award – Alison Murray, Ph.D.
Years of Service Milestones
50 Years of Service
35 Years of Service
30 Years of Service
- Lynn Fenstermaker
- Hans Moosmuller
- Ron Hershey
- Tim Minor
- Peter Ross
25 Years of Service
20 Years of Service
- Yvonne Rumbaugh
- Vicki Hall
- Richard Susfalk
- Lynn Karr
- John Karlas
- Glen Wilson
- David Page
- David Campbell
- Cheryl Collins
- Alison Murray
15 Years of Service
- Steven Bacon
- Sophie Baker
- Maureen King
- Karl Schoen
- Donna Schlemmer
- Derek Kauneckis
- Charles Dolbeare
- Alan Heyvaert
10 Years of Service
- Tatianna Menocal
- Tamara Wall
- Suzanne Hudson
- Robert Read
- Maria Vasquez
- Jeffrey Wedding
- Jason Rada
- Iva Neveux
- Eric Wilcox
- Daniel McEvoy
- Albert Wolff
5 Years of Service
- Xuelian Bai
- William (Jim) Metcalf
- Vinay Amin
- Teresa Wriston
- Rae Yuhas
- Nicole Sund
- Kevin Heintz
- Karen Stewart
- John Goetz
- Joanne Huston
- Erick Bandala Gonzalez
- Bruce Lipp
Congratulations to our faculty and staff who were recognized during this year’s Celebration of Science! Perhaps our Special Guest, NSHE Regent Jason Geddes put it best when he said, “DRI is known here in Nevada and around the world as a place where groundbreaking research is conducted, but the greatest asset that DRI has is its people.”
May 28, 2021 | News releases, Research findings
DRI Ice Core Lab Data Shows Magnitude of Historic Fire Activity in Southern Hemisphere
Ice Cores
Fire Activity
Climate Change
Above: Smoke from human-caused wildfires on the Patagonian steppe are trapped in Antarctic ice.
Credit: Kathy Kasic/Brett Kuxhausen, Montana State University.
A new study in Science Advances features ice core data from the DRI Ice Core Laboratory and research by Nathan Chellman, Ph.D., Monica Arienzo, Ph.D., and Joe McConnell, Ph.D.
Fire emissions in the Southern Hemisphere may have been much higher during pre-industrial times than in the present day, according to new research from an international team of scientists including Nathan Chellman, Ph.D., Monica Arienzo, Ph.D., and Joe McConnell, Ph.D., of the Desert Research Institute (DRI) in Reno.
The study, published today in Science Advances, used new ice core data from DRI’s Ice Core Laboratory to document changes in levels of soot from ancient fires and modern fossil fuel combustion during the years 1750 to 2000. Many of the 14 Antarctic ice cores included in the study were obtained through national and international collaborations, and together comprise an unprecedented long-term record of Southern Hemisphere fire activity that provided the foundation for the modeling effort described in the new paper.
All of the ice cores were analyzed using a specialized method for soot measurements in ice that McConnell and his team pioneered at DRI nearly 15 years ago. This method is now widely used in laboratories around the world.
For more information about the DRI Ice Core Laboratory, please visit: https://www.dri.edu/labs/trace-chemistry-laboratory/. The full news release from Harvard University, A fiery past sheds new light on the future of global climate change, is posted below.
Co-author Dr. Robert Mulvaney from the British Antarctic Arctic Survey drilling the James Ross Island core in the Antarctic Peninsula.
The full text of the paper, Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere, is available from Science Advances: https://advances.sciencemag.org/content/7/22/eabc1379.abstract
A fiery past sheds new light on the future of global climate change
Ice core samples reveal significant smoke aerosols in the pre-industrial Southern Hemisphere
By Leah Burrows, Harvard University
Centuries-old smoke particles preserved in the ice reveal a fiery past in the Southern Hemisphere and shed new light on the future impacts of global climate change, according to new research published in Science Advances.
“Up till now, the magnitude of past fire activity, and thus the amount of smoke in the preindustrial atmosphere, has not been well characterized,” said Pengfei Liu, a former graduate student and postdoctoral fellow at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and first author of the paper. “These results have importance for understanding the evolution of climate change from the 1750s until today, and for predicting future climate.”
One of the biggest uncertainties when it comes to predicting the future impacts of climate change is how fast surface temperatures will rise in response to increases in greenhouse gases. Predicting these temperatures is complicated since it involves the calculation of competing warming and cooling effects in the atmosphere. Greenhouse gases trap heat and warm the planet’s surface while aerosol particles in the atmosphere from volcanoes, fires and other combustion cool the planet by blocking sunlight or seeding cloud cover. Understanding how sensitive surface temperature is to each of these effects and how they interact is critical to predicting the future impact of climate change.
Ancient ice from James Ross Island in the Northern Antarctic Peninsula about to be extracted from the drill barrel.
Many of today’s climate models rely on past levels of greenhouse gasses and aerosols to validate their predictions for the future. But there’s a problem: While pre-industrial levels of greenhouse gasses are well documented, the amount of smoke aerosols in the preindustrial atmosphere is not.
To model smoke in the pre-industrial Southern Hemisphere, the research team looked to Antarctica, where the ice trapped smoke particles emitted from fires in Australia, Africa and South America. Ice core scientists and co-authors of the study, Joseph McConnell and Nathan Chellman from the Desert Research Institute in Nevada, measured soot, a key component of smoke, deposited in an array of 14 ice cores from across the continent, many provided by international collaborators.
“Soot deposited in glacier ice directly reflects past atmospheric concentrations so well-dated ice cores provide the most reliable long-term records,” said McConnell.
What they found was unexpected.
“While most studies have assumed less fire took place in the preindustrial era, the ice cores suggested a much fierier past, at least in the Southern Hemisphere,” said Loretta Mickley, Senior Research Fellow in Chemistry-Climate Interactions at SEAS and senior author of the paper.
To account for these levels of smoke, the researchers ran computer simulations that account for both wildfires and the burning practices of indigenous people.
“The computer simulations of fire show that the atmosphere of the Southern Hemisphere could have been very smoky in the century before the Industrial Revolution. Soot concentrations in the atmosphere were up to four times greater than previous studies suggested. Most of this was caused by widespread and regular burning practiced by indigenous peoples in the pre-colonial period,” said Jed Kaplan, Associate Professor at the University of Hong Kong and co-author of the study.
Drilling ice cores in East Antarctica as part of the Norwegian-U.S. International IPY Scientific Traverse of East Antarctica.
This result agrees with the ice core records that also show that soot was abundant before the start of the industrial era and has remained relatively constant through the 20th century. The modeling suggests that as land-use changes decreased fire activity, emissions from industry increased.
What does this finding mean for future surface temperatures?
By underestimating the cooling effect of smoke particles in the pre-industrial world, climate models might have overestimated the warming effect of carbon dioxide and other greenhouse gasses in order to account for the observed increases in surface temperatures.
“Climate scientists have known that the most recent generation of climate models have been over-estimating surface temperature sensitivity to greenhouse gasses, but we haven’t known why or by how much,” said Liu. “This research offers a possible explanation.”
“Clearly the world is warming but the key question is how fast will it warm as greenhouse gas emissions continue to rise. This research allows us to refine our predictions moving forward,” said Mickley.
The research was co-authored by Yang Li, Monica Arienzo, John Kodros, Jeffrey Pierce, Michael Sigl, Johannes Freitag, Robert Mulvaney, and Mark Curran.
It was funded by the National Science Foundation’s Geosciences Directorate under grants AGS-1702814 and 1702830, with additional support from 0538416, 0538427, and 0839093.
Additional Information:
The full text of the paper, Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere, is available from Science Advances: https://advances.sciencemag.org/content/7/22/eabc1379.abstract
The news release above was reposted with permission from Harvard University: https://www.seas.harvard.edu/news/2021/05/fiery-past-sheds-new-light-future-global-climate-change.
###
About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu
May 25, 2021 | News releases, Research findings
Does Cold Wildfire Smoke Contribute to Water Repellent Soils in Burned Areas?
May 25, 2021
RENO, NEV.
By Kelsey Fitzgerald
Soil Science
Wildfires
Hydrology
Above: After a wildfire, soils in burned areas often become water repellent, leading to increased erosion and flooding after rainfall events. The hillside shown here burned in California’s Loyalton Fire during August 2020.
Credit: Kelsey Fitzgerald/DRI.
A new DRI pilot study finds severe water repellency in sand samples after treatment with both hot and cold smoke.
After a wildfire, soils in burned areas often become water repellent, leading to increased erosion and flooding after rainfall events – a phenomenon that many scientists have attributed to smoke and heat-induced changes in soil chemistry. But this post-fire water repellency may also be caused by wildfire smoke in the absence of heat, according to a new paper from the Desert Research Institute (DRI) in Nevada.
In this pilot study (exploratory research that takes place before a larger-scale study), an interdisciplinary team of scientists led by DRI Associate Research Professor of Atmospheric Science Vera Samburova, Ph.D., exposed samples of clean sand to smoke from burning Jeffrey pine needles and branches in DRI’s combustion chamber, then analyzed the time it took for water droplets placed on the sand surface to be absorbed – a measure of water repellency.
A new pilot study by an interdisciplinary team from DRI exposed samples of clean sand to smoke from burning Jeffrey pine needles and branches, then analyzed the time it took for water droplets placed on the sand surface to be absorbed — a measure of water repellency. After exposure to smoke, water droplets sometimes remained on the sand surface for more than 50 minutes without soaking in.
Credit: Vera Samburova/DRI.
The pilot study investigated the effects of smoke and heat on water repellency of the sand and was the first study to also incorporate an analysis of cold smoke. In the experiments, sand was used in place of soil because it could be cleaned thoroughly and analyzed accurately, and Jeffrey pine for a fuel source because it represents a common wildland fire fuel in the Western U.S.
Before exposure to Jeffrey pine smoke, water droplets placed on the surface of the sand samples were quickly absorbed. But after exposure to smoke, the sand samples showed severe-to-extreme water repellency, in some cases retaining water droplets on the sand surface for more than 50 minutes without soaking in. It made little difference whether or not samples had been exposed to heat and smoke, or just cold smoke.
“The classic explanation for fire-induced water repellency is that it is caused as smoke diffuses under rather hot conditions and settles down into the soils, but our work shows that the smoke does not have to be hot to turn the sand hydrophobic — simply the presence of the chemical substances in the smoke is enough,” Samburova said. “This is something we really need to look deeper into because soil water repellency leads to increases in flooding, erosion, and surface runoff.”
Above, left: Jeffrey pine needles and sticks were used as a fuel source in the new DRI study because Jeffrey pine represents a common wildland fire fuel in the Western U.S.
Credit: Vera Samburova/DRI.
Above, right: Jeffrey pine needles and branches burn inside of the combustion chamber at DRI during a new study that investigated the effects of smoke and heat on water repellent of sand samples.
Credit: Vera Samburova/DRI.
This study built on previously published work by former DRI postdoctoral researcher Rose Shillito, Ph.D., (currently with the U.S. Army Corps of Engineers), Markus Berli, Ph.D., of DRI, and Teamrat Ghezzehei, Ph.D., of University of California, Merced, in which the researchers developed an analytical model for relating soil water repellency to infiltration of water.
“Our earlier paper focused on how fire changes the properties of soils, from a hydrology perspective,” Berli explained. “In our current study, we were interested in learning more about the chemistry behind the process of how soils come to be hydrophobic. We’re bringing together geochemistry and organic geochemistry with soil physics and hydrology to understand the impact of fire-induced water repellency on hydrology.”
The project team is now working on a larger proposal to further investigate questions touched on by this study about the roles of heat and smoke in fire-induced water repellency. Among other things, they would like to know how long soil water repellency lasts after a fire, and gain a better understanding of the detailed processes and mechanisms through which cold smoke affects the soil.
DRI’s combustion chamber, pictured here, is a specialized facility that has been designed and built for the open combustion of solid fuels under controlled conditions. In this experiment, it was used to expose samples of clean sand to Jeffrey pine smoke.
Credit: Kelsey Fitzgerald/DRI.
Gaining a thorough understanding of the process that leads to fire-induced soil water repellency is important because land managers need this information in order to accurately predict where soils are likely to be hydrophobic after a fire, Berli explained.
“We still don’t really understand the processes that lead to this fire-induced soil water repellency,” Berli said. “Depending on what we find, the measures to predict fire-induced water repellency might be different, and this can have a significant impact on how we can predict and prevent flooding or debris flows that happen after a fire.”
“This study was one big step forward, but it highlights the importance of future research on how fires affect soil, because wildfires are affecting thousands and thousands of square kilometers of land each year in the Western U.S., ” Samburova added. “Some of our future goals are to find out how exactly this soil water repellent happens, where it happens and how long it lasts.”
Additional Information:
This study was made possible with support from DRI and the National Science Foundation. Study authors included Vera Samburova, Ph.D., Rose Shillito, Ph.D. (currently with U.S. Army Corps of Engineers), Markus Berli, Ph.D., Andrey Khlystov, Ph.D., and Hans Moosmüller, Ph.D., all from DRI.
The full text of the paper, Effect of Biomass-Burning Emissions on Soil Water Repellency: A Pilot Laboratory Study, is available from Fire: https://www.mdpi.com/2571-6255/4/2/24
###
About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu
May 18, 2021 | News releases, Research findings
Above: DeMMO field team from left to right: Lily Momper, Brittany Kruger, and Caitlin Casar sampling fracture fluids from a DeMMO borehole installation. Credit: Matt Kapust.
Las Vegas, Nev. – Below the Earth’s surface, a zone of life known as the continental deep subsurface is home to large populations of bacteria and archaea, but little is known about how these microbial populations are distributed. To learn whether they are spread evenly across rock surfaces or prefer to colonize specific minerals in the rocks, scientists from Northwestern University and the Desert Research Institute (DRI) went deep inside of a former gold mine in South Dakota and grew biofilms (collections of microorganisms) on rocks. Their results, which published in April in the journal Frontiers in Microbiology, show that the microbes formed “hotspots” around certain minerals in the rocks. Brittany Kruger, Ph.D., Assistant Research Scientist in Biogeochemistry from DRI in Las Vegas, served as field lead for the Northwestern research team at the Sanford Underground Research Facility (SURF), where this study was conducted.
The full text of the paper Rock-Hosted Subsurface Biofilms: Mineral Selectivity Drives Hotspots for Intraterrestrial Life is available from Frontiers in the Environment: https://www.frontiersin.org/articles/10.3389/fmicb.2021.658988/full
The press release below was reposted with permission from Northwestern University in Evanston, IL:
Earth’s crust mineralogy drives hotspots for intraterrestrial life
Northwestern University – Evanston, IL
April 9, 2021 – Below the verdant surface and organic rich soil, life extends kilometers into Earth’s deep rocky crust. The continental deep subsurface is likely one of the largest reservoirs of bacteria and archaea on Earth, many forming biofilms – like a microbial coating of the rock surface. This microbial population survives without light or oxygen and with minimal organic carbon sources, and can get energy by eating or respiring minerals. Distributed throughout the deep subsurface, these biofilms could represent 20-80% of the total bacterial and archaeal biomass in the continental subsurface according to the most recent estimate. But are these microbial populations spread evenly on rock surfaces, or do they prefer to colonize specific minerals in the rocks?
To answer this question, researchers from Northwestern University in Evanston, Illinois, led a study to analyze the growth and distribution of microbial communities in deep continental subsurface settings. This work shows that the host rock mineral composition drives biofilm distribution, producing “hotspots” of microbial life. The study was published in Frontiers in Microbiology.
Hotspots of microbial life
To realize this study, the researchers went 1.5 kilometers below the surface in the Deep Mine Microbial Observatory (DeMMO), housed within a former gold mine now known as the Sanford Underground Research Facility (SURF), located in Lead, South Dakota. There, below-ground, the researchers cultivated biofilms on native rocks rich in iron and sulfur-bearing minerals. After six months, the researchers analyzed the microbial composition and physical characteristics of newly grown biofilms, as well as its distributions using microscopy, spectroscopy and spatial modeling approaches.
The spatial analyses conducted by the researchers revealed hotspots where the biofilm was denser. These hotspots correlate with iron-rich mineral grains in the rocks, highlighting some mineral preferences for biofilm colonization. “Our results demonstrate the strong spatial dependence of biofilm colonization on minerals in rock surfaces. We think that this spatial dependence is due to microbes getting their energy from the minerals they colonize,” explains Caitlin Casar, first author of the study.
Future research
Altogether, these results demonstrate that host rock mineralogy is a key driver of biofilm distribution, which could help improve estimates of the microbial distribution of the Earth’s deep continental subsurface. But leading intraterrestrial studies could also inform other topics. “Our findings could inform the contribution of biofilms to global nutrient cycles, and also have astrobiological implications as these findings provide insight into biomass distributions in a Mars analog system” says Caitlin Casar.
Indeed, extraterrestrial life could exist in similar subsurface environments where the microorganisms are protected from both radiation and extreme temperatures. Mars, for example, has an iron and sulfur-rich composition similar to DeMMO’s rock formations, which we now know are capable of driving the formation of microbial hotspots below-ground.
May 11, 2021 | Blog, Featured researchers
Meet Natasha Sushenko, Graduate Researcher
May 11, 2021
LAS VEGAS, NEV.
By Kaylynn Perez
Environmental Microbiology
Pathogenic Bacteria
Space
Natasha Sushenko is a graduate research assistant with the Division of Hydrologic Sciences at the Desert Research Institute (DRI) in Las Vegas. She is a Master’s student in Biological Sciences in the School of Life Sciences at the University of Nevada, Las Vegas (UNLV), and is co-mentored by Duane Moser, Ph.D., of DRI and Brian Hedlund, Ph.D., of UNLV. Funding for Natasha’s position is provided by the NASA EPSCOR Rapid Response Research Program. Learn more about Natasha and her graduate research in this interview with DRI’s Behind the Science Blog!
Natasha Sushenko processes samples using a biosafety cabinet in the Environmental Microbiology Lab at the Desert Research Institute in December of 2020 during a SARS-CoV-2 wastewater monitoring study. Sushenko is a graduate research assistant with the Division of Hydrologic Sciences at DRI in Las Vegas.
DRI: What brought you to DRI?
Sushenko: Dr. Duane Moser spoke in my undergraduate Microbial Ecology class at UNLV, and I was really interested in how his lab studies the deep biosphere, the zone of life that exists far below Earth’s surface. His lab does fascinating research on “microbial dark matter,” yet-to-be-classified microorganisms that live under extreme conditions within the deep biosphere and are difficult to culture in the lab. We kept in touch, and even though I considered leaving Las Vegas to do my graduate studies, the opportunities that he and DRI offered were too good to pass up.
What research projects are you working on? And who at DRI are you working with?
Sushenko: I work in Dr. Moser’s Environmental Microbiology Lab here at DRI. We completed a COVID-19 wastewater monitoring study this winter, but my main research project is a NASA collaboration with the Jet Propulsion Laboratory (JPL). They sent our lab strains of a pathogen (disease-causing bacterium) called Klebsiella pneumoniae that were isolated from the International Space Station (ISS). This microbe is a common cause of hospital-borne pneumonia and other infections, but in this case, it was found living on surfaces on the ISS, including on their space toilet. This pathogen is of particular concern to NASA because it has appeared in multiple samples across several years of microbiome monitoring, and it is growing more prevalent over time. While no astronauts on the space station have gotten sick, future human spaceflight to Mars and beyond may require astronauts to go on trips lasting years before returning to Earth. Because of this, NASA wants to know how pathogens like K. pneumoniae respond and adapt to living in space.
Our goal is to study how this pathogen’s virulence, or ability to cause severe illness, and its resistance to antimicrobial drugs and cleaners changes when exposed to the stresses of microgravity. Microgravity is the condition in space where people or objects appear to be weightless. This is something we can study here on Earth, at DRI, with a machine that simulates microgravity.
Above, left: Natasha Sushenko processes samples using a biosafety cabinet in the Environmental Microbiology Lab at the Desert Research Institute in December of 2020 during a SARS-CoV-2 wastewater monitoring study.
Above, right: Natasha Sushenko performs field chemistries on deep borehole samples in the Funeral Mountains near Death Valley on 28-April, 2021. Here Natasha is using a Hach Colorimeter to measure dissolved oxygen, iron, sulfate, and sulfide to test whether increased rates of pumping from a deep well facilitated collection of deeper samples from a geologic fracture zone. Natasha contributed to the DRI-led portion of an NSF-funded collaboration with Bigelow Lab in ME and others focused on applying cutting-edge genomic approaches to the oceans, marine crustal fluids, and the continental subsurface.
DRI: What are your short-term and long-term goals while at DRI?
Sushenko: Right now, I’m on the master’s degree plan, but I’m considering changing to Ph.D. track to continue working on my project to completion and beyond. The issue of the microbiome of the built environment in closed systems like spacecraft will only become more important as agencies and companies explore travel to the moon and Mars. You don’t get opportunities to work with NASA at every institution, and I’m excited that DRI gives me this opportunity.
DRI: Tell us about yourself. What do you do for fun?
The pandemic has cramped a lot of my favorite hobbies, but usually, I love to travel to visit friends, go camping, hike, and just being outside with others. This past year I’ve instead spent more time hanging out with my dog, gardening (indoors and outdoors), and baking.
In her free time, Natasha enjoys hiking and being outside in beautiful areas like the Desolation Wilderness in California.
Mar 25, 2021 | Blog, Featured researchers
Meet Nathan Chellman, Ph.D.
Ice Cores
Climate Change
Environment
Meet DRI scientist Nathan Chellman and learn about his work in the Ice Core Laboratory in this interview with DRI’s Behind the Science Blog.
Nathan Chellman, Ph.D., is a postdoctoral fellow with the Division of Hydrologic Sciences at the Desert Research Institute (DRI) in Reno, Nev. He specializes in the collection, processing and analysis of ice cores — cylindrical samples of ice drilled from glaciers and ice sheets around the world. Nathan grew up in Reno, and holds a B.Sc. in Geology/Biology from Brown University, and M.S. and Ph.D. degrees in Hydrology from the University of Nevada, Reno. He first worked at DRI as a high school intern in 2008, then later returned to DRI during and after college to work with Joe McConnell in the Ice Core Lab. He received his helicopter private pilot license in 2014 and volunteered as an EMT while he was an undergraduate. In his free time, Nathan enjoys running, skiing, and backpacking in the Sierras and central Nevada.
Nathan Chellman, Ph.D., is a postdoctoral fellow with the Division of Hydrologic Sciences at the Desert Research Institute in Reno.
DRI: What do you do here at DRI?
Chellman: I work in the Ice Core Lab, where we do analyses and measurements on snow and ice from polar and alpine regions to learn about how the environment has changed over the past several centuries and millennia. I also do some work with tree rings and sediment cores from areas a little closer to home, like the Rocky Mountains, primarily looking at pollution and climate reconstructions.
DRI: What does an ice core look like, and how do you collect one?
Chellman: An ice core is a long, narrow cylinder of ice. To recover an ice core from an ice sheet or a glacier we use an ice core drill, which is a hollow tube with sharp cutters at one end and a big motor at the top. The motor spins the hollow tube, the cutters cut the ice away, and the ice core then ends up in the center of the hollow tube. You send the ice core drill down through the ice about 1 meter (3 feet) at a time, bring up the entire drill with an ice core inside, push the ice core out of the hollow drill section, send the drill back down the borehole, and then repeat that until you’re the whole way through the ice feature. For polar ice cores, we sometimes drill down hundreds of meters. So, we end up with hundreds or thousands of those meter-long sections back-to-back that represent a whole profile through the ice.
Above, left: Researchers process an ice core sample collected from a glacier in Greenland. Above, right: Closeup of an ice core drill.
Credit: Michaeol Sigl (left photo); Nathan Chellman/DRI (right photo).
DRI: What can you learn from all of these samples of ice? Can you tell us about one of your projects?
Chellman: One of my favorite projects right now is a study on some really old ice patches in Wyoming. These ice patches are about the size of a football field or smaller, so they are too small to be glaciers. They look just like little remnant snow patches that you might see in the Sierra Nevada if you go out hiking in the late summer. However, they’re not snowdrifts, they’re actual ice – and some of these ice patches are turning out to be thousands and thousands of years old.
I was invited to join the project by a group of archaeologists and climate scientists who were interested in looking at how old the ice patches were, and studying the organic debris inside of them and the artifacts that were melting out around the edges. They didn’t know what to do with the ice itself, but since we specialize in measuring ice chemistry, I volunteered to go to their field site when they were drilling through a shallow ice patch and bring some ice back to DRI. Those samples ended up being a very nice record of ice chemistry. The ice patch turned out to be 10,000 years old at the bottom, with about 30 organic layers cutting through the ice.
Normally in an ice core project, if you have dirt and organic layers in your ice core you’ve done something terribly wrong. In this case, the dirt was the key to unlocking how old the ice patch was, since the age of the organic material can be accurately dated. It turned out that the chemistry of the ice was really interesting as well, and preserved some climate information going back over ten thousand years. You can see distinct warm and cold periods that paralleled lake sediment records from nearby, and also some anthropological records of population. So, that suggested that people living in the area were affected by the general climate conditions as indicated by the ice patch chemistry.
Above, left: Nathan Chellman carries ice coring equipment to an alpine ice patch, where he and his colleagues are using ice core records from an isolated ice patch to learn about ancient climate in the region. Above, right: Chellman holds an ice core sample collected from an alpine ice patch.
Credit: Monica Arienzo/DRI.
DRI: Have you ever been part of a polar drilling operation?
Chellman: Yes, in 2013 I was in northeastern Greenland. That year we recovered a 212-meter ice core, which went back about 1,700 years. It took about two weeks working normal 8- or 10-hour days – but as you drill deeper and deeper into the ice, it takes longer and longer for the drill to go up and down the borehole. On the first day you can go about 20 meters in a day, and the next day you can go a little less, and by the end you’re only drilling 6 to 10 meters per day because it takes so long for the drill to go up and down the hole.
The first day was terrifying. The plane landed out in the middle of the ice sheet, hundreds of miles from any other camps or bases. The pilot dropped us and our gear out in the snow, and then took off and left. Help was a few days away at best, so we had to just get working and get camp set up before everything blew away, because it’s always windy there. There were no buildings, no infrastructure, just us and our camping gear. We had personal sleeping tents (we each used two sleeping bags!), a kitchen tent, and a science tent, as well as plenty of food, Coleman stoves for cooking, and the ice core drill.
DRI: What were the working conditions like in Greenland?
Chellman: The strangest part about working in Greenland during the summer is that it’s never night. The sun never completely goes down, even at night. The sun goes low on the horizon and it gets colder, but it’s never actually dark. It’s a little disorienting at first. You have to sleep with eye covers or pull your hat down over your eyes so you can pretend like you’re in a little bit of darkness.
It was also really cold. Between -25 and -35C (-13 to -31F) at night, and anywhere between -5 and -15C (23F to 5F) during the day. When it’s that cold, it’s really interesting because you have to consider that everything is going to be frozen. Your toothpaste is going to be frozen, if you leave your water in a mug it’s going to be frozen. It requires some adaptations from a lifestyle perspective to make sure what you need isn’t going to be a total block of ice.
In 2013, Chellman and his colleagues traveled to northeastern Greenland to collect a 212-meter ice core that went back 1,700 years. Their field camp is pictured here.
Credit: Nathan Chellman/DRI.
DRI: Do you have any plans to return?
Chellman: We were supposed to go back last year to that same place in Greenland and get an ice core that was twice as long, but that was postponed. We’re rescheduling for this spring, but everything is still very much up in the air. If we go, we’ll be gathering data for a study that is trying to understand pollution from ancient societies. For example, we will be looking to see if we can detect Bronze Age pollution from 2,000-3,000 years ago in the ice. The pollution would have been caused by mining and smelting of metals.
DRI: It sounds like you have a very exciting job. What do you like best about what you do?
Chellman: One of my favorite things is actually being in the lab and making the measurements, and taking all the time to make sure everything is running right, and that the analytical system and all the instruments are making high-quality measurements. When you’re analyzing ice cores, you have to be consistent day to day and week to week, since sometimes it can take a month or two to analyze all the samples from an ice core. But it’s really fun to get in the groove in the lab, run long days, and generate really consistent, nice datasets. There’s a lot of troubleshooting involved, but once the system is running smoothly, it’s really amazing to be able to generate unique, one-of-a-kind data that can be trusted to inform really big picture questions.
Additional Information:
For more information on Nathan Chellman and his research, please visit: https://www.dri.edu/directory/nathan-chellman/
For more information on the DRI Ice Core Laboratory, please visit: https://www.dri.edu/labs/trace-chemistry-laboratory/
DRI scientist Nathan Chellman.
Credit: Nathan Chellman/DRI.
Feb 22, 2021 | News releases, Research findings
Traditional hydrologic models may misidentify snow as rain, new citizen science data shows
Weather Forecasting
Climate
Citizen Science
Tahoe Rain or Snow weather spotters help reduce inaccuracies in estimating precipitation
Normally, we think of the freezing point of water as 32°F – but in the world of weather forecasting and hydrologic prediction, that isn’t always the case. In the Lake Tahoe region of the Sierra Nevada, the shift from snow to rain during winter storms may actually occur at temperatures closer to 39.5°F, according to new research from the Desert Research Institute (DRI), Lynker Technologies, and citizen scientists from the Tahoe Rain or Snow project.
The new paper, which published this month in Frontiers in Earth Science, used data collected by 200 volunteer weather spotters to identify the temperature cutoff between rain and snow in winter storms that occurred during the 2020 season. Their results have implications for the accuracy of water resources management, weather forecasting, and more.
“Scientists use a temperature threshold to determine where and when a storm will transition from rain to snow, but if that threshold is off, it can affect our predictions of flooding, snow accumulation, and even avalanche formation,” said Keith Jennings, Ph.D., Water Resources Scientist at Lynker Technologies and one of the lead authors on the study.
From a backcountry area near Lake Tahoe, Desert Research Institute scientist Monica Arienzo collects field data from her smartphone for the Tahoe Rain or Snow project. January 2021.
Previous studies have found that thresholds used are particularly problematic in the Sierra Nevada, where a significant proportion of winter precipitation falls near 32°F. When the temperature is near freezing, weather forecasts and hydrologic models have difficulty correctly predicting whether it will be raining or snowing.
Tahoe Rain or Snow was launched in 2019 to take on the challenge of enhancing the prediction of snow accumulation and rainfall that may lead to flooding by making real-time observations of winter weather. The team is comprised of two scientists, one education specialist, and about 200 volunteer weather spotters from the Lake Tahoe and western slope regions of the Sierra Nevada and Truckee Meadows.
“Tahoe Rain or Snow harnesses the power of hundreds of local volunteers. The real-time observations that they share with scientists add an incredible amount of value to the study of hydrology and clarify crucial gaps left by weather models,” said Meghan Collins, M.S., Education Program Manager for DRI and another lead author on the paper.
Above: Desert Research Institute scientist Meghan Collins collects data from her smartphone for the Tahoe Rain or Snow project using the Citizen Science Tahoe app during January 2021.
Credit: DRI (left) and Keith Jennings/Lynker Techologies (right)
In 2020, these citizen scientists submitted over 1,000 timestamped, geotagged observations of precipitation phases through the Citizen Science Tahoe mobile phone app.
Ground-based observations submitted by the Tahoe Rain or Snow team in 2020 showed that a much warmer temperature threshold of 39.5°F for splitting precipitation into rain and snow may be more accurate for our mountain region. In contrast, a 32°F rain-snow temperature threshold would have vastly overpredicted rainfall, leading to pronounced underestimates of snow accumulation. Such model errors can lead to issues in water resources management, travel planning, and avalanche risk prediction.
“Tahoe Rain or Snow citizen scientists across our region open a door to improve our understanding of winter storms”, said Monica Arienzo, Ph.D., Assistant Research Professor of Hydrology at DRI and another lead author on the paper. “Growing our team of volunteer scientists is important given that climate change is causing the proportion of precipitation falling as snow to decrease, and they help enhance the predictions of precipitation that we rely on in the Sierra Nevada and Truckee Meadows.”
Tahoe Rain or Snow is continuing in 2021. To join, text WINTER to 877-909-0798. You will find out how to download the Citizen Science Tahoe app and receive alerts as to good times to send weather observations. Tahoe Rain or Snow particularly needs observations from sparsely populated, remote, or backcountry areas of the Sierra Nevada.
Desert Research Institute scientist Monica Arienzo collects field data from her smartphone for the Tahoe Rain or Snow project. January 2021.
Additional Information:
This study was funded by Nevada NASA EPSCoR Grant 20-23, 19-40.
The full text of the study “Enhancing Engagement of Citizen Scientists to Monitor Precipitation Phase” is available from Frontiers in Environmental Science: https://www.frontiersin.org/articles/10.3389/feart.2021.617594/full
To learn more about the Tahoe Rain or Snow project, please visit: https://www.dri.edu/project/tahoe-rain-or-snow/
###
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Lynker Technologies delivers innovative solutions to support global environmental sustainability and economic prosperity as a trusted partner to governments, communities, research institutions, and industry. We are passionate about what we do and the high value we provide to water resources management, hydrologic science, and conservation across the US and beyond. For more information, please visit https://www.lynker.com/.
Feb 1, 2021 | News releases, Research findings
Photo caption: A monsoon rain event in the East River watershed of Colorado, a pristine, high elevation, snow-dominated headwater basin of the Colorado River. Credit: Xavier Fane.
New study holds implications for future water supply in the Colorado River Basin
Las Vegas, Nev. (Monday, Feb. 1, 2021) – In the summer of 2019, Desert Research Institute (DRI) scientist Rosemary Carroll, Ph.D., waited for the arrival of the North American Monsoon, which normally brings a needed dose of summer moisture to the area where she lives in Crested Butte, Colo. – but for the fourth year in a row, the rains never really came.
“2019 had just a horrendous monsoon,” Carroll said. “Just the weakest monsoon. And we’d had a few years of weak monsoons before that, which had really gotten me wondering, how important is the monsoon to late summer streamflow here in the Upper Colorado River basin? And how do monsoons influence the following year’s streamflow?”
Working in partnership with colleagues David Gochis, Ph.D., of the National Center for Atmospheric Research and Kenneth Williams, Ph.D., of Lawrence Berkeley National Laboratory, Carroll set out to explore the importance of monsoon rain in streamflow generation in a Colorado River headwater basin.
The team’s findings, which are published in a new paper in Geophysical Research Letters, point to both the importance of monsoon rains in maintaining the Upper Colorado River’s water supply and the diminishing ability of monsoons to replenish summer streamflow in a warmer future with less snow accumulation.
Their study focuses on the East River watershed, a pristine, high elevation, snow-dominated headwater basin of the Colorado River and part of the Watershed Function Scientific Focus Area (SFA) program that is exploring how disturbances in mountain systems – such as floods, drought, changing snowpack and earlier snowmelt – impact the downstream delivery of water, nutrients, carbon, and metals.
Using a hydrologic model and multiple decades of climate data from the East River watershed, Carroll and her colleagues found that monsoon rains normally deliver about 18 percent of the basin’s water and produce about 10 percent of the annual streamflow, with streamflow generated primarily in the higher elevations of the basin.
“The amount of streamflow produced by monsoons, while not geographically extensive, is actually somewhat substantial,” Carroll said. “It was larger than I thought it would be. That doesn’t mean all of that water gets to a reservoir – some likely is used by riparian vegetation or irrigation, but it still does go to meet some need within the basin.”
Desert Research Institute scientist Rosemary Carroll measures stream discharge in the East River, Colorado. Credit: Kenneth H. Williams.
Next, the team explored the ability of these summer rains to produce streamflow during cool years with high snow accumulation, and during warm years with less snow accumulation. During cool years with more snow, soil moisture levels were higher going into summer, and greater streamflow was generated by the monsoon rains. During warmer years with low snowpack, dry soils absorbed much of the monsoonal rains, and less runoff made it to the streams.
“You can think of the soil zone as a sponge that needs to fill up before it can allow water to move through it,” Carroll said. “So, if it’s already depleted because you had low snowpack, the monsoon then has to fill it back up, and that decreases the amount of water you actually get in the river.”
As the climate warms, snowpack in the Rocky Mountains and other mountain systems is expected to decline, leading to reduced streamflow. Rising temperatures also lead to increased soil evaporation and increased water use by plants. According to the results of Carroll’s study, these changes will reduce the ability of water from the monsoon to make it to the river as streamflow.
“Our results indicate that as we move toward a climate that is warmer and our snowpack decreases, the ability of monsoon rain to buffer these losses in streamflow is also going to go down,” Carroll said. “So, the monsoon is not some silver bullet that is going to help mitigate those changes.”
The Colorado River is a critically important resource for people living in Southern Nevada, where it accounts for about 90 percent of the water supply. Although runoff from winter snowpack provides a much larger proportion of streamflow each year than the monsoons, the monsoonal moisture is important to both ecosystems and people in part because it arrives at a different time of year. And in a system like the Colorado River, where every drop of water is allocated, if monsoon rains do not arrive, it creates a shortage somewhere downstream.
“In terms of water resources, if monsoon rains are useful and contribute to late-season streamflow, then the loss of that water obviously has implications for the ecology of these systems,” Carroll said. “This water is really important in supporting aquatic habitat there. But it’s also really important for human use. If any amount of water that we rely on isn’t there, then something has to give. The Upper Basin will have to consider how they are going to manage their water to meet those downstream obligations.”
Additional information:
The full text of the study, Efficiency of the Summer Monsoon in Generating Streamflow Within a Snow‐Dominated Headwater Basin of the Colorado River, is available from Geophysical Research Letters: https://doi.org/10.1029/2020GL090856
For more information on Rosemary Carroll, please visit: https://www.dri.edu/directory/rosemary-carroll/
For more information on the Watershed Function Scientific Focus Area (SFA) program, please visit: http://watershed.lbl.gov/
###
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
Dec 14, 2020 | News releases, Research findings
What happens when rain falls on desert soils?
DEC. 14, 2020
LAS VEGAS, NEV.
An updated model from DRI scientists in Las Vegas provides a new understanding of water movement in dry soils
Several years ago, while studying the environmental impacts of large-scale solar farms in the Nevada desert, Desert Research Institute (DRI) scientists Yuan Luo, Ph.D. and Markus Berli, Ph.D. became interested in one particular question: how does the presence of thousands of solar panels impact desert hydrology?
This question led to more questions. “How do solar panels change the way water hits the ground when it rains?” they asked. “Where does the water go? How much of the rain water stays in the soil? How deep does it go into the soil?”
“To understand how solar panels impact desert hydrology, we basically needed a better understanding of how desert soils function hydraulically,” explained Luo, postdoctoral researcher with DRI’s Division of Hydrologic Sciences and lead author of a new study in Vadose Zone Journal.
DRI scientists Yuan Luo (left) and Markus Berli (right) conducting research at DRI’s SEPHAS Lysimeter facility in Boulder City, Nev. November 2020.
Photograph by Ali Swallow/DRI.
In the study, Luo, Berli, and colleagues Teamrat Ghezzehei, Ph.D. of the University of California, Merced, and Zhongbo Yu, Ph.D. of the University of Hohai, China, make important improvements to our understanding of how water moves through and gets stored in dry soils by refining an existing computer model.
The model, called HYDRUS-1D, simulates how water redistributes in a sandy desert soil based on precipitation and evaporation data. A first version of the model was developed by a previous DRI graduate student named Jelle Dijkema, but was not working well under conditions where soil moisture levels near the soil surface were very low.
To refine and expand the usefulness of Dijkema’s model, Luo analyzed data from DRI’s SEPHAS Lysimeter facility, located in Boulder City, Nev. Here, large, underground, soil-filled steel tanks have been installed over truck scales to allow researchers to study natural water gains and losses in a soil column under controlled conditions.
Above: Yuan Luo and Markus Berli of DRI’s Division of Hydrologic Sciences used data from DRI’s SEPHAS Lysimeter facility (shown here) to refine an existing model called HYDRUS-1D, which simulates how water moves through dry soils.
Photographs by Ali Swallow/DRI.
Using data from the lysimeters, Luo explored the use of several hydraulic equations to refine Dijkema’s model. The end result, which is described in the new paper, was an improved understanding and model of how moisture moves through and is stored in the upper layers of dry desert soils.
“The first version of the model had some shortcomings,” Luo explained. “It wasn’t working well for very dry soils with volumetric water content lower than 10 percent. The SEPHAS lysimeters provided us with really good data to help understand the phenomenon of how water moves through dry soils as a result of rainfall and evaporation.”
In desert environments, understanding the movement of water through soils is helpful for a variety of practical uses, including soil restoration, erosion and dust management, and flood risk mitigation. For example, this model will be useful for desert restoration projects, where project managers need to know how much water will be available in the soil for plants after a desert rainstorm, Berli said. It is also a key piece of the puzzle needed to help answer their original question about how solar farms impact desert hydrology.
“The model is very technical, but all of this technical stuff is just a mathematical way to describe how rainwater moves in the soil once the water hits the soil,” Berli said. “In the bigger picture, this study was motivated by the very practical question of what happens to rainwater when falling on solar farms with thousands and thousands of solar panels in the desert – but to answer questions like that, sometimes you have to dig deep and answer more fundamental questions first.”
DRI scientist Yuan Luo standes near a weighing lysimeter at DRI’s SEPHAS Lysimeter facility in Boulder City, Nev. November 2020.
Photograph by Ali Swallow/DRI.
“In the bigger picture, this study was motivated by the very practical question of what happens to rainwater when falling on solar farms with thousands and thousands of solar panels in the desert – but to answer questions like that, sometimes you have to dig deep and answer more fundamental questions first.”
Additional Information:
This study was funded by the DRI Foundation Innovative Research Program, the National Science Foundation, and the U.S. Army Corps of Engineers. Rose Shillito, Ph.D. (DRI/ACOE) and Nicole Damon (DRI) also contributed to the success of this project.
The full text of the paper “Modeling near-surface water redistribution in a desert soil”, is available from Vadose Zone Journal: https://doi.org/10.1002/vzj2.20081
To learn more about DRI’s SEPHAS Lysimeter facility, please visit: https://www.dri.edu/sephas/lysimeters/
###
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.
DRI scientists Markus Berli and Yuan Luo. November 2020.
Photograph by Ali Swallow/DRI.
Sep 28, 2020 | Blog, Featured researchers
Making Sense of Remote Sensing
Remote Sensing
Evapotranspiration
Hydrologic Sciences
A Q&A with Matt Bromley on remote sensing and the OpenET project
Matt Bromley, M.S., is an Assistant Research Scientist with the Division of Hydrologic Sciences at the Desert Research Institute (DRI) in Reno, and specializes in GIS and remote sensing. He holds a B.S. in Environmental Science and a M.S. in Geography from the University of Nevada, Reno. He is a native Nevadan, an Army veteran, and has been a member of the DRI community for ten years.
Matt is currently working alongside a team of scientists and web developers from DRI, NASA, Google and Environmental Defense Fund (EDF) to develop a new web application called OpenET (https://openetdata.org/), which will make satellite-based data on evapotranspiration widely accessible to farmers, landowners, and water managers. We recently sat down with Matt to learn the basics of remote sensing and how it is used in the OpenET project.
Matt Bromley, M.S. is a an Assistant Research Scientist with the Division of Hydrologic Sciences at DRI in Reno.
DRI: You specialize in remote sensing. Can you tell us a little bit about this field of study?
Bromley: Technically, remote sensing means “the acquisition of data from a distance.” In the context of the work that I do, it means studying the earth’s surface with satellites. These satellites are often sensitive to same portions of the light-spectrum that our human eyes can see, as well as portions of the light spectrum that we can’t see, such as infrared (thermal). The images and data that Earth-focused satellites provide are a great way to learn about the Earth from a distance. There are also other types of remote sensing data, such as aerial images from planes, Radar, and LIDAR, where you use laser light to determine distance which can allow you to measure terrain and geographic features.
DRI: What is OpenET, and what is your role in the project?
Bromley: To understand the importance of OpenET you have to first understand evapotranspiration (ET). ET is the process by which water is transferred from land to the atmosphere – through evaporation from soil and transpiration from plant leaves – which is approximately the amount of water used by crops to grow our food and other resources. OpenET is a new web application that will provide ET data to water managers, land owners, and farmers in 17 western states. We started building this tool in 2018 and it’s scheduled to launch in 2021.
My role is pretty varied within the project. I have a foot in the technical side of it, in that I’m working on some of the data used in the ET models as well as contributing to the analysis. I also have an outward facing role in that I engage with people and organizations who are the preliminary users of the data. I provide some analysis, answer questions, and act as the bridge between the teams developing the evapotranspiration data and the people using it.
OpenET is a new web application that will provide evapotranspiration data to water managers, land owners and farmers across 17 western states.
To learn more about OpenET project, visit their website at openetdata.org.
DRI: How do you use remote sensing data in the OpenET project?
Bromley: The team that I work with uses remote sensing to measure water use from irrigation. We use both optical and thermal data to get information from the land surface. Among other things, the optical data shows how green and healthy the vegetation is, and with the thermal data we can actually detect the cooling effect that’s produced when water evaporates.
When I started at DRI, remote sensing data was generally processed on individual computers. You had to download all the data yourself and then process it with specialized software. About ten years ago, Google started hosting climate and remote sensing data in the cloud. So, rather than having to download all the data to do your analysis on a desktop computer, you can instead send your analysis to the cloud (lots of computers), allowing you to get some of your answers much, much faster. OpenET makes use of that platform, processing remote sensing data through five different models. Through OpenET we’re able to produce not only individual model ET estimates, but also an ensemble estimate using all of those models.
DRI: What type of remote sensing data do you use to calculate evapotranspiration (ET)?
Bromley: All of it right now is from the Landsat series of satellites, which gives us the optical and thermal data that we need to calculate ET. Landsat is a series of earth-observations satellites which are operated as a joint program between NASA and the USGS. The modern series of Landsat satellites started in the early 1980s, so with this collection of data we can actually look back in time and see how water use has changed over the decades. The duration and consistency of the Landsat program really sets it apart from other sources of remote sensing data.
OpenET is being built by scientists and web developers from DRI, NASA, Google and Environmental Defense Fund (EDF). The web application is scheduled to launch in 2021.
DRI: How did you become interested in working in this field?
Bromley: Being a native Nevadan, you grow up being aware of how special water is. As a kid my family would go on road trips through the Great Basin and as much as I loved seeing the sagebrush and mountains, it felt like we were discovering an oasis whenever we’d drive past a river or lake. In working to understand water use, I’m providing information to the people who manage that precious resource, as well as to the farmers and ranchers who grow our food. It feels like I’m helping not just my community but the state and the region.
The work that we’re doing at DRI and with OpenET is especially important, because detailed information on water use at a large scale has typically been hard to access and very expensive. OpenET is working to change that and make this data widely accessible to spark improvements an innovation in water management across the West.
“In working to understand water use, I’m providing information to the people who manage that precious resource, as well as to the farmers and ranchers who grow our food.”
Aug 21, 2020 | Blog, EEL, Featured projects
Photo: The sand band used to prepare hydrochar from microplastics. Credit: Erick Bandala/DRI.
By Nicole Damon, Nevada Water Resources Research Institute
Microplastics, plastic fragments that are smaller than 5 mm in any dimension, have been found in ecosystems worldwide. These emerging contaminants are even in environments that are supposed to be free from human contact, such as Antarctica and the deep ocean floor, and their toxic properties make them a significant environmental hazard.
“After the first acknowledgement of microplastics in the early 2000s, their presence in the environment has raised ever-increasing concerns because of their effects on organisms and ecosystems, and because approximately 1.5 million tons of microplastics are estimated to be released into aquatic environments every year,” explains Dr. Erick Bandala, the principal investigator of this project, which also includes Dr. Menake Piyasena from New Mexico Tech, graduate research assistants Adam Clurman and Ahdee Zeidman, and summer intern Yajahira Dircio. “Unfortunately, very little is known about the capability of engineered separation and/or degradation technologies to remove this highly ubiquitous contaminant.”
Commercial products that are manufactured to contain microplastics—such as personal care and pharmaceutical products, industrial abrasives, drilling fluids, and 3D printing products—are the primary sources of microplastics. However, the degradation of plastic debris can also generate microplastics.
“Wastewater treatment plant effluents are the main pathway for microplastics to be released into aquatic environments,” Bandala says. “Although the microplastic removal rate of a conventional wastewater treatment plant is reported to be in the range of 73 to 79 percent, the treated effluent can carry as much as 220,000 to 1.5 million microplastic particles per day.”
Yajahira Dircio, a student at Rancho High School and summer intern on the project, is
preparing hydrochar from MPs using a sand band. Credit: Erick Bandala/DRI
In recent years, the effects microplastics have been found to have on aquatic species and their unknown effects on human health have increased concerns about their presence in water sources.
“Because conventional water treatment processes are unable to effectively eliminate microplastics in water, developing new technologies that can separate them from effluents and prevent their release into the environment is a high priority to protect water quality and water security,” Bandala says.
For this project, the researchers will use acoustic focusing and electrocoagulation to separate microplastics in freshwater effluents and determine the removal process mechanisms.
“Acoustic standing waves are a fast, noncontact, gentle particlemanipulation technique for microfluidic conditions that have emerged as a promising new technology for the purification, separation, and concentration of beads and biological cell samples,” Bandala explains.
The researchers will also assess the efficacy of using electrocoagulation to remove MPs from wastewater.
“Electrocoagulation has several significant advantages to conventional chemical coagulation, such as it increases treatment efficiency, generates less sludge, requires less space, and prevents chemical storage,” Bandala adds. “It has been proven to be highly efficient in removing contaminants. Our research group has used it for water defluoridation and to pretreat effluents that were heavily contaminated with petrochemicals.”
Because microplastics in freshwater are increasingly detected, it is even more important to find effective water treatment process that remove them.
“Although ultrafiltration, or microfiltration, have microplastic removal efficiencies as high as 99.4 percent, they also have high operational and maintenance costs and require skilled operators,” Bandala explains. “Finding efficient, costeffective methods to separate microplastics from freshwater effluents is critical to preventing population exposure.”
Adam Clurman, an undergraduate student at Nevada State College, is conducting the
electrocoagulation experiments for the project. Credit: Erick Bandala
Another challenge that microplastics in freshwater present is how to dispose of them once they are removed from water. For this project, the researchers will use advanced oxidation processes (AOPs) as complementary processes to degrade the plastic waste after it has been separated from the wastewater. Advanced oxidation processes are an eco-friendly way to degrade organic compounds. In previous projects, the research group has tested the capability of these processes to degrade a wide variety of dissolved organic contaminants in water.
“Advanced oxidation processes have been used to degrade organics and have shown high cost-efficiency and short detention time compared with conventional water treatment processes,” Bandala explains. “Using AOPs to degrade microplastics will not only be an interesting challenge because of the complexity of their polymeric chains, but also because these contaminants are suspended in water and treating contaminants in a different phase in water using AOPs has not yet been reported.”
Maintaining the quality of water sources is an increasing issue, particularly in arid and semiarid regions with rapidly growing populations, such as Nevada.
“Desert Research Institute has reported the presence of MPs in places such as the Sierra Nevada and Lake Tahoe, which are the origin of several drinking water supply systems in Nevada,” Bandala explains. “We live in a region with a moderate-high water stress and as Nevadans, we need to protect our water sources from contamination to ensure the sustainable development of our communities.”
This story was originally written for the Nevada Water Resources Research Institute (NWRRI) Summer 2020 Newsletter. Success and the dedication to quality research have established DRI’s Division of Hydrologic Sciences (DHS) as the Nevada Water Resources Research Institute (NWRRI) under the Water Resources Research Act of 1984 (as amended). The work conducted through the NWRRI program is supported by the U.S. Geological Survey under Grant/Cooperative Agreement No. G16AP00069.
For more information on the NWRRI, please visit: https://www.dri.edu/nwrri/
Jun 29, 2020 | Blog, Featured researchers
Sandra Brugger, Ph.D., is a Postdoctoral Researcher with DRI’s Division of Hydrologic Sciences, and a Swiss National Science Foundation (SNSF) Fellow.
DRI: What brought you to DRI?
Brugger: I started at DRI in October 2019 with an Early Postdoc Mobility grant funded by the Swiss National Science Foundation (SNSF). DRI is home of one of the world-leading ice core labs. I am extremely grateful that I could join Professor Joe McConnell’s ice core group in the Division of Hydrologic Sciences (DHS) and be co-supervised by Professor Dave Rhode in the Division of Earth and Ecosystem Sciences (DEES).
DRI: What are your research interests?
Brugger: I am interested in past vegetation dynamics and their relationship with climate change and human activities. Using optical pollen, charcoal, and other microfossil analyses in ice cores, we can infer how the ecosystems and fire regimes have changed over time. We can then try to reconstruct sensitive ecosystems in high latitude regions to gain a better understanding how they will react to rapid global warming.
DRI: What is the SNSF Fellows Virtual Conference?
Brugger: The conference is a multidisciplinary platform where Postdoc fellows are sharing their exciting results and show how diverse the research is that the Swiss National Science Foundation is funding with over 700 projects around the world.
DRI: How did you get involved in helping lead this unique event?
Brugger: Most conferences were cancelled this summer. Young scientists rely very much on presenting their results, networking at scientific meetings, and interacting with other research fellows. Therefore, my SNSF-Mobility fellow Tobias Schneider (University of Massachusetts) and I spontaneously decided on a Friday evening over a virtual glass of wine on Zoom to turn our own pandemic misery into a virtual conference for us and our fellow SNSF-postdoc fellows in the US and around the world. Six weeks and several virtual wine glasses later, we are ready and excited to host the four-day long conference on Zoom.
The multidisciplinary character of the conference is also reflected in the exciting keynotes that will be presenting their research. Among them, we have two from DRI: Professor Monica Arienzo will introduce us to her latest research on microplastics in Alpine environments, and Professor Joe McConnell will be presenting on Roman lead pollution in Arctic ice cores.
Since we have one thing in common among all fellows, the COVID-19 pandemic, we decided to hold a daily panel on COVID-19 with invited frontline workers that will be hosted by Theresa Watts, Professor at ORVIS School of Nursing at UNR. On Thursday, Professor Ajay Sethi from the University of Wisconsin-Madison will give a keynote on conspiracy theories around COVID-19.
Sandra Brugger (Klimaforscherin), Institute of Plant Sciences, PhD student – Palaeoecology. © Manu Friederich
DRI: What are you hoping to accomplish? What would be the best outcome for this event?
Brugger: We hope to provide an inspiring meeting where people can present their work, get new input, and maybe even provide additional research motivation during difficult home-office situations they are experiencing. And above all, we are excited to get to know our fellows and their fascinating research projects.
DRI: How can people get involved or watch the event?
Brugger: The event is free of registration and will be hosted on three platforms: Zoom, Youtube and Remo. The program and the links to join the virtual conference can be found on our Event website: https://www.swissnexboston.org/event/snsf-fellows-conference/ hosted by Swissnex Boston, our partner for the conference.
DRI: How has your work been impacted by the pandemic?
Brugger: My own research has been severely impacted. I started the project only 8 months ago and since March we have only very limited access to lab facilities. This is critical for sample preparation and analyzing data in this early stage of the project.
Also, our group had to cancel fieldwork and as mentioned above, most conferences got cancelled this summer and for the upcoming months hopefully can be replaced by virtual meetings. It was a tough time to arrive new to the USA from Switzerland and to face the pandemic in a foreign country.
May 12, 2020 | Blog, Featured projects
The DRI Foundation has just awarded the next round of seed grants to six teams of researchers through the Innovation Research Program (IRP). The IRP provides the start-up funding DRI scientists need to test new ideas and produce initial data, which will help them build the scientific case for future research projects.
The 2020 Innovation Research Project winners were chosen through a competitive selection process and reviewed by a committee comprised of previous IRP recipients and DRI’s Vice President for Research. The selected projects demonstrate creative, innovative research or technological development that advances DRI’s mission.
Dr. Mary Cablk’s cadaver dog Inca sniffing in the field.
Advancing the science behind canine odor detection evidence in criminal trials
Mary Cablk, Yeongkwon Son, Andrey Khlystov
Cadaver dogs are often called on to detect the odors of human remains at a crime scene, and the evidence they find—the odor left behind from a body on a killer’s clothing, for example—is treated as hard scientific fact in criminal trials. However, there are currently no physical or chemical forensic methods to verify this kind of evidence. In a first-of-its-kind study, Dr. Mary Cablk and her team are employing a scientific approach to compare the detection of residual odors by dogs and laboratory instrumentation. This research will bolster the scientific foundation for canine evidence used in homicide cases and position DRI to secure future funding for projects investigating a wider span of canine evidence, such as contraband.
Workers in Pajaro Valley, Watsonville, CA. Credit: Lance Cheung/USDA.
Supporting climate adaptation for specialty crop farmers
Kristin VanderMolen
Climate change impacts like flooding and drought threaten the production of specialty crops like fruits, nuts, and vegetables in California, a state that grows more than half of these crops nationwide. DRI’s Kristin VanderMolen, PhD, and partners at the Climate Science Alliance at Scripps Institution of Oceanography are investigating how farmers are adapting to these challenges in order to identify how climate research can best support them. This research lays the groundwork for field studies to test and verify the effectiveness of farmers’ adaptation strategies and the development of climate information products to support farmers into the future. Additionally, this project builds relationships between DRI and critical partners, like the Climate Science Alliance and University of California Cooperative Extension.
A section of Smoke Creek Road in rural Northwestern Nevada. Credit: Bob Wick/BLM.
Enhancing soil moisture data to improve hydrologic modeling
Ming Liu
Soil moisture is a critical variable when it comes to understanding processes like evapotranspiration, the transfer of water from land surfaces and plants into the atmosphere. Most hydrologic models rely on soil moisture data from satellite remote sensing, but this data lacks ground truthing, especially in remote arid places. In collaboration with Myriota, an Internet of Things (IoT) nanosatellite startup, DRI’s Ming Liu, PhD, is developing sensor stations by integrating Myriota’s nanosatellite transceiver with custom-made universal dataloggers. The sensor stations will be deployed across Nevada to collect soil moisture readings from the field. This project aims to improve the data used in hydrologic models and build the foundation for broader sensor deployment for environmental research in arid lands.
Researchers sample snow for a previous research project. Credit: Nathan Chellman/DRI.
Tracing the history of atmospheric river events to improve water resource management in the Western U.S.
Joe McConnell, Nathan Chellman, Christine Albano
Atmospheric rivers carry significant amounts of water vapor from the tropics to the Western United States, providing 30-40% of the total precipitation during a typical winter season. However, these rivers in the sky can also result in extreme weather like flooding and wind storms, which pose risks to infrastructure and human safety. Despite the significant impacts of atmospheric rivers, little is known about how their frequency and intensity has changed over the past several centuries. Using chemical analysis in DRI’s state-of-the-art Ice Core Laboratory, Joe McConnell, PhD, and his team are working to identify isotopic signatures that differentiate snow produced by atmospheric rivers from that produced by other storms. If successful, researchers will be able to leverage this work in future projects to develop a history of atmospheric rivers over the last several hundred years. Such a record will be valuable for informing water resource management and hazard mitigation, especially as the climate continues to warm and change.
A cannabis growing facility, part of a previous DRI air quality study. Credit: Vera Samburova/DRI.
Evaluating health risks from cannabis smoking and vaping
David Campbell
The legalization of cannabis products for both medical and recreational use in many states, including Nevada, has resulted in widespread commercial production of non-tobacco smoking and vaping products. However, this growth hasn’t been accompanied by research into the health effects from use of those products—in fact, there has been virtually no analysis of the many chemical compounds that are inhaled by users when smoking or vaping cannabis, due in part to federal research restrictions. Dr. David Campbell is developing a portable sampling system to collect the smoke or vapor for laboratory analysis, and it will be tested with cigarettes made from legal hemp, which is identical to marijuana except for the lower THC content. This research will bolster what we know about the health risks associated with cannabis use and develop intellectual property DRI researchers can leverage in future projects.
The Oceano Dunes State Vehicular Recreation Area (SVRA) on the Central California Coast, where Gillies and colleagues have previously conducted research on dust and wind erosion.
Modeling and Analysis of Fluid Flow Interactions with Porous/Permeable 3-Dimensional Forms
Jack Gillies, Eden Furtak-Cole
Dust emissions, particularly from arid regions, directly impact air quality, human health, agricultural production, and the planet’s climate. Windy conditions drive the formation of dust through erosion, and while vegetation and structures like fencing are known to mitigate wind erosion and dust emissions, researchers have been unable to quantify their actual impact in large scale models. Dr. Jack Gillies and his team are working to incorporate the erosion mitigation impact of vegetation and engineered control structures into wind erosion models. These models will provide a cost-effective, efficient way to develop dust control strategies and improve air quality. This work will also position DRI as a leader in the ability to evaluate dust emissions and lay the foundation for future projects, particularly as problems like drought and desertification become more pronounced under a warming climate.
Mar 5, 2020 | Announcements, News releases
Reno, Nev. (March 5, 2020) – Today, the Nevada System of Higher Education (NSHE) Board of Regents awarded the 2020 Rising Researcher Award to Mark Hausner, Ph.D., of the Desert Research Institute (DRI) in Reno. This honor is given annually to researchers from DRI, the University of Nevada, Reno (UNR) and the University of Nevada, Las Vegas (UNLV) based on early-career accomplishments and potential for future advancement and recognition in research.
Hausner is an assistant research professor with DRI’s Division of Hydrologic Sciences, and specializes in ecohydrology, the study of interactions between water and ecological systems. His research has increased our understanding of how heat and water move through the environment, how climate change and disturbance affect those processes, and how to assess the resultant impacts to various aspects of the hydrologic setting and the ecosystem.
“I am honored to be recognized by the Board of Regents for my work in the field of hydrology,” Hausner said. “I look forward to continuing to explore new questions about how water and ecosystems affect one another throughout my career.”
Mark Hausner (right) installs temperature sensors in Devils Hole with researchers from the US National Park Service and US Fish and Wildlife Service. 2010.
Much of Hausner’s recent work focuses on the use of satellite imagery to fill in information gaps about the impacts of human activity on riparian landscapes in the Western US. He has worked extensively on Devils Hole in southern Nevada, a unique geologic formation that provides the only naturally occurring habitat for the endangered Devils Hole Pupfish. Hausner’s other notable projects include studies of groundwater-surface water interactions, as well as applied science support for the US military, US Department of Energy, and resource managers such as the South Tahoe Public Utility District and Tahoe Regional Planning Agency.
Since beginning his career at DRI in 2014, Hausner has given over 60 presentations at national scientific conferences and workshops and published 18 peer reviewed publications to high quality journals such as Groundwater and Water Resources Research. He has successfully developed and funded more than 15 grants and contracts from diverse sources such as the Department of Energy, Oregon Department of Fish and Wildlife, NASA, and the Death Valley Conservancy, a total of more than $938,000 in funded projects.
Hausner holds a B.S. in civil and environmental engineering from Cornell University, and M.S. and Ph.D. degrees in hydrologic sciences and hydrogeology form the University of Nevada, Reno. He joined DRI in 2014 as a postdoctoral fellow, and transitioned to an assistant research professor in 2016.
For more information about Hausner and his work, please visit his directory page.
###
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI is one of eight institutions in the Nevada System of Higher Education.
Jan 28, 2020 | Blog, Featured projects, Science Alive Blog
Take a moment to picture a scientist who has made a groundbreaking discovery. What does that person look like?
Perhaps it’s a person in a white coat standing in a lab with microscopes and test tubes, or a distinguished professor accepting an award on stage.
What if we told you that you could have pictured yourself?
In citizen science projects, community members like you utilize their curiosity, enthusiasm, and talents alongside professional scientists in real-world research projects. They act as the eyes, ears, or an extra set of hands for scientists, helping to extend the spatial reach of a study or adding important perspectives that scientists cannot provide themselves.
That’s precisely what Lake Tahoe locals did this summer to help DRI scientists identify microplastic pollution in the Lake for the first time ever.
DRI microplastics researchers sample water from the shore of Lake Tahoe in spring 2019.
Why citizen science?
In fall of 2018, Desert Research Institute scientists Monica Arienzo, Zoe Harrold, and Meghan Collins were formulating a project to search for microplastic pollution in the surface waters of Lake Tahoe and in stormwater runoff into the lake. But the team was not satisfied in seeking to identify the presence of microplastic alone—they also wanted to make connections with community members in Tahoe.
“By involving citizen scientists in understanding the problem of microplastics,” explained Arienzo, “we can naturally connect the community to evidence-based solutions to reduce the microplastic problem.”
To recruit citizen scientists, DRI partnered with the League to Save Lake Tahoe, which runs the Pipe Keepers program. Pipe Keepers volunteers throughout the Tahoe Basin collect water samples from stormwater outfalls into Lake Tahoe and monitor for stormwater pollution.
These outfalls, which drain water from roadways, parking lots and neighborhoods into the lake, are a significant source of fine sediment pollution in Lake Tahoe, which threatens the clarity of Tahoe’s famous blue waters. They’re also a potential culprit of microplastic pollution since plastic litter, tires, and other sources can break down into smaller pieces and be swept away with the stormwater.
“Our citizen science programs are a great way to get locals and visitors directly engaged in protecting the Lake,” said Emily Frey, the League’s Citizen Science Program Coordinator. “We’re really excited to contribute to this groundbreaking research.”
Over the course of the 2019 field season, volunteer Pipe Keepers collected 24 liters of water from six sampling sites. Arienzo, Harrold, and Collins also pumped water samples from several places along the Lake’s shoreline surface waters for the study.
In both the stormwater samples and the surface water samples, a large portion of the microplastics found were small fibers, which can come from the breakdown of synthetic clothing. The stormwater represents a point-source of this microplastic pollution, which, in theory, could be mitigated in the future.
Meghan Collins in the Microplastics Lab at DRI’s Reno campus, holding a sample collected by a Pipe Keeper. Credit: Cat Allison/Nevada Momentum.
Broad benefits
Beyond providing important data for research projects, citizen science also has the power to engage communities in scientific inquiry and inspire care for the places where we live and play.
Laura Schlim has been a volunteer with the Pipe Keepers program for three years, and she worked with the DRI team to collect samples for the microplastics project. The best thing about citizen science for her? It’s fun!
“I’m naturally interested in why things work a certain way,” explained Schlim, a certified California naturalist. “It’s fun to be part of something where I can contribute to the greater body of knowledge while also enjoying the natural world.”
Vesper Rodriguez, a Pipe Keeper since 2018, echoed this sentiment.
“I volunteer because I like to be outside and I have a lot of fun with the projects. Volunteering for the League’s Stewardship Days and their Pipe Keepers program in particular, which allows volunteers to monitor stormwater infrastructure, is really fulfilling,” Rodriguez said. “It’s a rewarding feeling to contribute to the community and the land that I live on.”
Since community members have been vested in the research from the start, the DRI team is optimistic that the findings of their work will be able to go far beyond the lab and begin to solve the microplastic pollution problem in Lake Tahoe.
“A core mission of the DRI team is to generate evidence-based solutions to microplastics in our water, by identifying sources that could be mitigated or finding techniques to better prevent microplastic generation in the first place,” said Collins. “Building a community of citizen scientists creates a strong network of engaged individuals who care and can implement these solutions as they are developed.”
DRI microplastics researchers (beginning top row, from center) Zoe Harrold, Meghan Collins, and Monica Arienzo pose with the Pipe Keeper volunteers on the project. Credit: League to Save Lake Tahoe.
The study on microplastics is one of many active citizen science projects led by DRI and the League to Save Lake Tahoe. DRI also leads Stories in the Snow and Tahoe: Rain or Snow?, projects related to weather and climate in the Sierra Nevada. In addition to the Pipe Keepers program, the League also runs Eyes on the Lake, which helps monitor and prevent the spread of aquatic invasive plants.
Interested in joining the team of citizen scientists in the Sierra Nevada and around Lake Tahoe? Download the Citizen Science Tahoe app to get started.
In addition to volunteering your time to this project, you can also financially support this research effort at the team’s crowdfunding page.
Jan 9, 2020 | Blog, Featured projects
As populations in the southwestern United States continue to grow, the demand on water resources also increases. One region experiencing this stress on its groundwater resources is Pahrump Valley in southern Nye County, Nevada. Pahrump Valley is one of the fastest growing counties in Nevada, which has led to groundwater-related issues such as land subsidence. “Land subsidence has been reported in Pahrump Valley since the 1960s,” says Dr. Hai Pham the principal investigator (PI) of this project, which also includes co-PIs Karl Pohlmann, Susan Rybarski, and Kevin Heintz and research assistant Larry Piatt. “It has caused damage to building foundations and slabs, fissuring, shearing of well casings, and extensive damage to roadbeds.”
In their 2017 Water Resources Plan Update, the Nye County Water District determined that land subsidence is one of the key issues related to population growth in Nye County. However, the causes of land subsidence still haven’t been clearly identified. “Previous studies failed to precisely map spatiotemporal evolutions of subsidence, or adequately clarify the causes of subsidence,” Pham says. “These studies were limited by data quantity and quality. The goal of this project is to identify and prioritize predominant factors that cause subsidence and make predictions using machine learning algorithms and big data.”
A concrete well pad exposed by land subsidence around the well casing (right) observed during a field survey in May 2019 (photo by Karl Pohlmann).
Land subsidence is a complicated process that is driven by multivariate intercorrelated factors, such as groundwater decline, soil and sediment types, and tectonic and geologic settings. For example, excessive groundwater pumping results in soil compaction, which has been identified as a primary cause of land subsidence in Pahrump Valley. However, the magnitude of soil compaction depends on aquifer materials, and therefore understanding the geologic structure of Pahrump Valley is vital to evaluating future subsidence. The advantage of using machine learning to assess potential areas of land subsidence is that it can help illuminate complicated data relationships that may not be as obvious using traditional data analysis techniques.
In this project, the researchers will use machine learning algorithms and high-resolution data sets to identify the predominant factors causing land subsidence in Pahrump Valley. “In this study, we will derive spatiotemporal subsidence maps using recent high-quality satellite images and the Interferometric Synthetic Aperture Radar [InSAR] technique,” Pham says. “InSAR is a powerful technique that allows us to measure and map vertical changes on the earth’s surface as small as a few millimeters.”
The researchers will then build three-dimensional (3-D) computer models of the subsurface geological structures in Pahrump Valley at a very fine (one-foot) vertical resolution using data from 13,000 boreholes. “Compaction of aquifer materials can accompany excessive groundwater pumping and it is by far the single largest cause of subsidence, but the magnitude of soil compaction differs by soil type,” Pham explains. “Therefore, it is important that we account for these well log data to construct high resolution 3-D models of geologic structures.” The researchers will also develop groundwater drawdown maps by processing data from records of 130 groundwater observation wells that range from the 1940s to the present. “Incorporating these high-resolution datasets will help us identify and prioritize the causes of subsidence and make better predictions,” Pham adds.
The groundwater level has declined approximately 25 feet from December 1999 to December 2017 (photo taken in May 2019 by Karl Pohlmann).
Because of the limitations of existing field data, the researchers will generate high-resolution datasets to train and validate the machine learning algorithms. Advanced machine learning algorithms will then be run on supercomputers to analyze the data. By analyzing this data, the researchers hope to identify the factors that cause subsidence and ultimately predict possible subsidence in the future. “Once we have identified these factors, we can roughly predict areas that are prone to subsidence,” Pham explains. “This information can also be used to predict subsidence in other arid and semiarid regions.”
This story was originally written for the Nevada Water Resources Research Institute (NWRRI) October 2019 Newsletter. Success and the dedication to quality research have established DRI’s Division of Hydrologic Sciences (DHS) as the Nevada Water Resources Research Institute (NWRRI) under the Water Resources Research Act of 1984 (as amended). The work conducted through the NWRRI program is supported by the U.S. Geological Survey under Grant/Cooperative Agreement No. G16AP00069.
Sep 30, 2019 | Announcements, News releases
Scientists will investigate water quality and flow in critical desert wetland habitat
LAS VEGAS, NEV. (Sept. 30, 2019) —The Desert Research Institute (DRI) is pleased to announce the launch of two new research projects to study hydrology at The Nature Conservancy in Nevada’s 7J Ranch property near Beatty, Nevada. Work will begin in September on two complementary projects, funded by the Sulo and Aileen Maki Endowment, which will install meteorological stations and develop a watershed model to monitor how future restoration activities at the 7J Ranch will affect its water resources.
The 900-acre working ranch in Southern Nevada’s Oasis Valley is a unique place to study water, as it contains the headwaters of the Amargosa River, one of the world’s longest spring-fed river systems that runs mostly below the surface. The ranch’s unique geography and location where the Great Basin and Mojave deserts meet, and its habitat for many endemic and protected species, make it a globally important site for conserving biodiversity and give it strategic value for facilitating climate change adaptation for wildlife. The highly arid environment of southern Nevada and the Amargosa River’s status as an important source of groundwater discharge in the region also make its headwaters an important place to study hydrology.
The first project, led by Kevin Heintz, will install a hydrometeorological station to monitor the habitat at the 7J Ranch and study how surface water is affected by restoration activities and extreme weather conditions. This study is significant to southern Nevada water issues because it will contribute to estimating the flow of water in a critical wetland habitat and it will continuously monitor for environmental stressors, both of which have implications for southern Nevada’s biodiversity and wetland health.
DRI’s second project, led by Gabrielle Boisramé, Ph.D., will study how the potential removal of ponds will impact downstream hydrology and habitat. This project will use a variety of environmental data to develop a water budget model that can describe the movement of water in and out of the restoration area under various scenarios.
DRI researcher Gabrielle Boisrame, Ph.D., inspects a floating evaporation pan at The Nature Conservancy’s 7J Ranch on September 18, 2019. Credit: Ali Swallow/DRI.
“Stream restoration in arid environments like the Mojave Desert has not been studied extensively,” explained Boisramé. “Our hope is that this new research will help guide other restoration work in similar spring-fed streams systems of southern Nevada.”
The Conservancy plans to encourage long-term research at the 7J Ranch, and this project will provide an important base of knowledge for future researchers to build upon.
“This research will provide critical information for needed restoration projects at 7J Ranch, and we are so grateful to the Desert Research Institute for their support,” said John Zablocki, Southern Nevada Conservation Director for The Nature Conservancy. “The insights gained from these projects, and the instruments installed, will help inform better water management decisions for southern Nevada, help predict hydrologic responses to climate change, and help improve modeling on how groundwater flows in the region.”
The Sulo and Aileen Maki Endowment was established by the Sulo and Aileen Maki Trust to be used by the DRI’s Division of Hydrologic Sciences for research, instruction, and scholarships relevant to southern Nevada water issues. The endowment supports innovative, creative, and multidisciplinary research, as well as scholarly endeavors such as journal publications and presentations at scientific conferences, water resources course instruction and student scholarships, and community outreach and service. The overall goal of these efforts is to make the DRI’s Division of Hydrologic Sciences and the name Maki stand for excellence in water resources research, education, and outreach.
Desert Research Institute scientist Gabrielle Boisrame, Ph.D., (left) and graduate research assistant Rose Shillito from the University of Nevada, Las Vegas (right) prepare a pressure sensor for measuring water depth at The Nature Conservancy’s 7J Ranch on September 18, 2019. Credit: Ali Swallow/DRI.
For more information, please contact Sara Cobble, Marketing and Communications Manager for The Nature Conservancy in Nevada, at sara.cobble@tnc.org or Kelsey Fitzgerald, Science Writer for the Desert Research Institute Communications Office at kelsey.fitzgerald@dri.edu.
To view a photo gallery of images from 7J Ranch, please visit: https://flic.kr/s/aHsmHaHULv
###
About The Nature Conservancy
The mission of The Nature Conservancy is to conserve the lands and waters on which all life depends. Guided by science, we create innovative, on-the-ground solutions to our world’s toughest challenges so that nature and people can thrive together. Working in 72 countries, we use a collaborative approach that engages local communities, governments, the private sector, and other partners. We’ve been working in Nevada for nearly 35 years. To learn more, please visit www.nature.org/nevada.
About the Desert Research Institute
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI is one of eight institutions in the Nevada System of Higher Education.
About the Nevada System of Higher Education The Nevada System of Higher Education (NSHE), comprised of two doctoral-granting universities, a state college, four comprehensive community colleges and one environmental research institute, serves the educational and job training needs of Nevada. NSHE provides educational opportunities to more than 100,000 students and is governed by the Board of Regents.
Aug 28, 2019 | Blog, Featured researchers
Rosemary Carroll, Ph.D., is an associate research professor in DRI’s Division of Hydrologic Sciences. She has been a member of the DRI community since 2000 when she was hired as a research hydrologist. Rosemary works remotely from Crested Butte, Colorado, where she studies mountain hydrology. She recently published a paper in Geophysical Research Letters titled, “The Importance of Interflow to Groundwater Recharge in a Snowmelt-Dominated Headwater Basin,” so we sat down to talk to her about the project and her other work at DRI.
What is your background, and what do you do at DRI?
I pursued both my Master’s and Ph.D. in hydrology at the University of Nevada, Reno. I joined DRI upon the completion of my Master’s degree in 2000 working primarily on groundwater modeling projects. In 2006, my family and I moved to Colorado while I was finishing my Ph.D. on mercury transport in the Carson River. I’ve been able to maintain projects at DRI and build new science programs because of the wonderful support of my division director as well as from DRI faculty and staff who still look out for me despite not being on site.
My current research is focused on groundwater and surface water interactions. Specifically, I create numeric models, or computer simulations, of watersheds that begin high in the mountains and are fed primarily by snowmelt, like those in the East River where I live. I am trying to understand how snow dynamics influence the amount of groundwater that feeds into mountain streams. In 2014, I began working with Lawrence Berkeley National Laboratory using the East River as their experimental watershed to quantify how mountain systems store and release water and solutes and the relationship of that process to climate. Through these efforts, I am interacting with a wide range of scientists from universities, national labs, and federal agencies as well as with water managers in the state of Colorado.
What are the challenges in studying hydrology in mountainous landscapes like the East River?
The challenges are largely associated with either lack of data or the difficulty in collecting data. Mountainous watersheds contain steep terrain and extreme weather to make access, safety and maintaining deployed sensor networks difficult. I am in charge of the East River stream network. Avalanches are a very real problem here, and some of our stream field sites require skiing 20 miles round-trip to sample in the winter. In the spring, streams are fast and cold and not safe to wade. Spring runoff can also wash away equipment, erode banks and make rivers very turbulent. All of this puts traditional techniques of observation to the test and can mean lost data. We also spend quite a bit of effort protecting equipment from animals. Beavers, moose, elk and cattle are an inevitable part of planning a sensor network in the Colorado Rocky Mountains.
It sounds like mountain hydrology involves a lot of time outdoors. How often do you go out in the field?
I am part of a larger team of field scientists and technicians, so I go out about once a week but I now largely oversee several others. The fieldwork is rigorous, and the conditions are not easy. There’s a lot of hiking and backcountry time, including skiing and snowmobiling, and there’s intense spring runoff to contend with. My next big field push will be in September and October to make sure all our equipment is winterized before snow begins to accumulate.
Carroll checking weather station monitoring equipment in the East River, CO.
So taking measurements directly from streams is one thing, but modeling a watershed seems an entirely different challenge. How exactly do you build a model, and what goes into it?
Essentially what you’re doing with a hydrologic model is combining data on climate—precipitation, temperature—and watershed characteristics—elevation, vegetation, soils, geology—into a single framework to solve mathematical equations that describe how water moves through the system. The model is tested against data we can collect in the field, like streamflow, solar radiation and snow accumulation.
As part of our modeling approach, we integrate LiDAR (light detection and ranging) radar imaging of snow through the NASA Jet Propulsion Laboratory Airborne Snow Observatory (ASO). ASO essentially produces a 3-D map of snow depth. We use these detailed snow maps to show how snow redistributes through forces like avalanches or wind. We see that the majority of East River snow resides in the upper subalpine, or the zone between the tree-less alpine environment and the forested subalpine. The upper subalpine is a mix of barren and low-density conifer forests.
Carroll measuring water content in snow of the East River, CO.
What does your hydrologic model help us understand?
What our model shows is that the upper subalpine is a very important location in the watershed for replenishing groundwater supplies, which is called recharge. Snow is redistributed to the upper subalpine, where it lasts late into the spring and summer—it then melts quickly and this generates recharge. In addition, snowmelt from steep, alpine regions in the watershed is transported via shallow soil or weathered rock to the upper subalpine where it recharges into the deeper groundwater system.
Over the last several decades, the model suggests that groundwater replenished by snowmelt in this zone has remained stable, even in low snowpack years. This could mean that the water supply coming from a watershed with a large upper subalpine area may be more resilient to climate variability than watershed with little of this zone.
At least that is what our model is suggesting. The next steps are to observe this recharge process in the field, and to see if something similar is happening in other mountain watersheds with different geology. Ultimately, we want to explore how this kind of information can be used by water managers in long-term watershed management planning in the Colorado River and other snow-dominated systems around the world.
Carroll’s model suggests that the upper subalpine zone—where forest gives way to the alpine zone—could be a particularly important place for replenishing groundwater supplies in mountain watersheds like East River, Colorado.
Aug 14, 2019 | Blog, Featured projects
Photo: Duane Moser (left) and Xuelian Bai (right) collect filters from the sampling pump to take back to the lab for analysis.
Research on antibiotic resistance genes at DRI
Antibiotic resistance—the ability of bacteria to survive in the presence of antibiotics—is an increasing environmental and public health concern as more antibiotics enter urban waterways and treated wastewater is increasingly used to supplement limited water resources. Current wastewater treatment processes have difficulty removing antibiotics, which also encourages the growth of antibiotic resistance in urban watersheds, such as the Las Vegas Wash.
“Contaminants that are persistent in treated wastewaters that are discarded or reused may lead to health risks for humans,” explains Dr. Xuelian Bai, the principal investigator (PI) of this project that also includes co-PI Dr. Duane Moser and student researcher Rania Eddik-Zein. “The U.S. Centers for Disease Control and Prevention, the World Health Organization, and numerous other global and national agencies recognize antibiotic resistance as a critical challenge.”
The Las Vegas Wash is a unique watershed that is highly affected by anthropogenic activities and flooding during wet seasons.
“A lot of research has been done to monitor chemical contaminants such as nutrients, heavy metals, and organic contaminants, as well as antibiotics in the Las Vegas Wash and Lake Mead,” Bai says. “However, there is still a lack of information on the presence of microbial contaminants and antibiotic resistance genes [ARGs] in the watershed.”
Understanding the presence and abundance of ARGs in this watershed will provide insight into possible antibiotic resistance developing in the wash.
For this project, the researchers will evaluate the occurrence and prevalence of ARGs in the Las Vegas Wash.
“Resistance to antibiotics is encoded in ARGs, which are segments of DNA that enable bacteria to fight antibiotics,” Bai explains. “The major concerns about antibiotic resistance are the tendency of bacteria to share ARGs through horizontal gene transfer and that efforts to kill resistant bacteria, such as UV or chlorine disinfection in wastewater treatment and drinking water facilities, may not remove ARGs.”
The researchers anticipate that the data from this study will provide insight into the prevalence of ARGs in the wash and provide valuable information that can be used to determine water quality and potential human health concerns in southern Nevada.
First, the researchers will take field samples of water and sediment from the Las Vegas Wash to assess the presence of ARGs in an urban wetland ecosystem.
“Municipal wastewater appears to be a significant reservoir of ARGs,” Bai says. “Many studies have detected ARGs at all stages of the municipal wastewater treatment processes.”
Urban water supplies are particularly susceptible to developing antibiotic resistance because of the concentrated quantities of antibiotics that are released when treated municipal wastewater is discharged into the environment.
“Microorganisms in wastewater discharge can transport ARGs to downstream surface waters used for recreation or sources of drinking water, which can lead to human exposure over local, or even global, scales,” Bai explains. “This is a concern in southern Nevada because five major wastewater treatment plants discharge into the Las Vegas Wash. The Las Vegas Wash then discharges into Lake Mead, which is the primary drinking water supply for the Las Vegas Metropolitan Area.”
The DRI research team including (from left) Duane Moser, David Basulto, Hai Pham, and Xuelian Bai carry equipment down to the bank of the Lake Mead, one of several sampling sites along the Las Vegas Wash.
Lake Mead supplies water to millions of residents in the southwestern United States, so identifying potential antibiotic resistance is increasingly important, especially with the drastic population growth in the region. Effluent discharged from wastewater treatment plants, urban runoff, and floodwaters during wet seasons carry sediment, nutrients, and other contaminants to Lake Mead. This generates several water-quality concerns, particularly about the effects of contaminants on aquatic habitats.
“The Las Vegas Wash provides the full continuum of major freshwater aquatic habitats, includingwetlands, flowing water, lake water, and sediment,” Bai explains. “Wetlands, flowing water, and lake water are defined by aerobic conditions and exposure to photosphere influence. However, sediments almost always go anoxic very quickly below the surface, usually within millimeters in eutrophic systems. The fate of antibiotics and the microbial genes that mediate changes in anaerobes have been relatively understudied.”
The researchers anticipate that the field sampling and the lab studies conducted for this project—which include microcosm and microbial community experiments, and DNA analysis—will allow them to specifically identify southern Nevada water issues.
“We will detect and quantify target ARGs in water samples collected upstream and downstream along the Las Vegas Wash, as well as target ARGs in sediment samples collected from the Las Vegas Wash wetlands,” Bai says. “We will also determine the fate and spread of ARGs in the aquatic ecosystems, and assess the effects of elevated antibiotic concentrations on the ecosystem.”
Because evaluating ARGs in surface water and sediment has not been fully studied locally or globally, this project will address local water issues in Nevada and provide useful antibiotic resistance data about urban watersheds that can be used worldwide.
This story was originally written for the Nevada Water Resources Research Institute (NWRRI) July 2019 Newsletter. Success and the dedication to quality research have established DRI’s Division of Hydrologic Sciences (DHS) as the Nevada Water Resources Research Institute (NWRRI) under the Water Resources Research Act of 1984 (as amended). The work conducted through the NWRRI program is supported by the U.S. Geological Survey under Grant/Cooperative Agreement No. G16AP00069.
Jul 8, 2019 | News releases, Research findings
Photo: Dr. Joe McConnell and graduate student Nathan Chellman work in the ice lab at the Desert Research Institute, in Reno, Nev., on Wednesday, May 15, 2019. Photo by Cathleen Allison/Nevada Momentum.
RENO, Nev. (July 8, 2019) – How did events like the Black Death plague impact the economy of Medieval Europe? Particles of lead trapped deep in Arctic ice can tell us.
Commercial and industrial processes have emitted lead into the atmosphere for thousands of years, from the mining and smelting of silver ores to make currency for ancient Rome to the burning of fossil fuels today. This lead pollution travels on wind currents through the atmosphere, eventually settling on places like the ice sheet in Greenland and other parts of the Arctic.
Because of lead’s connection to precious metals like silver and the fact that natural lead levels in the environment are very low, scientists have found that lead deposits in layers of Arctic ice are a sensitive indicator of overall economic activity throughout history.
In a new study published in the Proceedings of the National Academy of Sciences, researchers from the Desert Research Institute (DRI), the University of Oxford, NILU – Norwegian Institute for Air Research, the University of Copenhagen, the University of Rochester, the Alfred Wegener Institute for Polar and Marine Research used thirteen Arctic ice cores from Greenland and the Russian Arctic to measure, date, and analyze lead emissions captured in the ice from 500 to 2010 CE, a period of time that extended from the Middle Ages through the Modern Period to the present.
This work builds on a study published by some of the same researchers in 2018, which showed how lead pollution in a single ice core from Greenland tracked the ups and downs of the European economy between 1100 BCE and 800 CE, a period which included the Greek and Roman empires.
“We have extended our earlier record through the Middle Ages and Modern Period to the present,” explained Joe McConnell, Ph.D., lead author on the study and Director of DRI’s Ultra-Trace Ice Core Chemistry Laboratory in Reno, Nevada. “Using an array of thirteen ice cores instead of just one, this new study shows that prior to the Industrial Revolution, lead pollution was pervasive and surprisingly similar across a large swath of the Arctic and undoubtedly the result of European emissions. The ice-core array provides with amazing detail a continuous record of European – and later North American – industrial emissions during the past 1500 years.”
“Developing and interpreting such an extensive array of Arctic ice-core records would have been impossible without international collaboration,” McConnell added.
The research team found that increases in lead concentration in the ice cores track closely with periods of expansion in Europe, the advent of new technologies, and economic prosperity. Decreases in lead, on the other hand, paralleled climate disruptions, wars, plagues, and famines.
“Sustained increases in lead pollution during the Early and High Middle Ages (about 800 to 1300 CE), for example, indicate widespread economic growth, particularly in central Europe as new mining areas were discovered in places like the German Harz and Erzgebirge Mountains, “McConnell noted. “Lead pollution in the ice core records declined during the Late Middle Ages and Early Modern Period (about 1300 to 1680 Ce) when plague devastated those regions, however, indicating that economic activity stalled.”
Even with ups and downs over time due to events such as plagues, the study shows that increases in lead pollution in the Arctic during the past 1500 years have been exponential.
“We found an overall 250 to 300-fold increase in Arctic lead pollution from the start of the Middle Ages in 500 CE to 1970s,” explained Nathan Chellman, a doctoral student at DRI and coauthor on the study. “Since the passage of pollution abatement policies, including the 1970 Clean Air Act in the United States, lead pollution in Arctic ice has declined more than 80 percent.”
“Still, lead levels are about 60 times higher today than they were at the beginning of the Middle Ages,” Chellman added.
This study included an array of ice cores and the research team used state-of-the-art atmospheric modeling to determine the relative sensitivity of different ice-core sites in the Arctic to lead emissions.
“Modeling shows that the core from the Russian Arctic is more sensitive to European emissions, particularly from eastern parts of Europe, than cores from Greenland,” explained Andreas Stohl, Ph.D., an atmospheric scientist at NILU and coauthor on the study. “This is why we found consistently higher levels of lead pollution in the Russian Arctic core and more rapid increases during the Early and High Middle Ages as mining operations shifted north and east from the Iberian Peninsula to Great Britain and Germany.”
Lead pollution found in 13 ice cores from three different regions of the Arctic (North Greenland, South Greenland, and the Russian Arctic) from 200 BCE to 2010 CE. Increases in lead deposition coincided with times of economic prosperity, such as the Industrial Revolution in the mid-19th century. Dramatic declines in lead pollution followed crises such as the Black Death Plague Pandemic starting about 1347 CE, as well as pollution abatement policies such as the 1970 U.S. Clean Air Act.
The combination of expertise on this study is unique, continuing collaboration between researchers in fields as different as ice-core chemistry and economic history. These results, the team argues, are a testament to the benefits of interdisciplinary collaboration.
“What we’re finding is interesting not just to environmental scientists who want to understand how human activity has altered the environment,” said Andrew Wilson, Ph.D., Professor of the Archaeology of the Roman Empire at Oxford and co-author on the study. “These ice-core records also are helping historians to understand and quantify the ways that societies and their economies have responded to external forces such as climate disruptions, plagues, or political unrest.”
Collection, analysis, and interpretation of the ice cores used in this study were supported by the U.S. National Science Foundation, NASA, the John Fell Oxford University Press Research Fund and All Souls College, Oxford, the German Ministry of Education and Research, the German Research Foundation, and the Desert Research Institute.
Locations of the 13 Arctic ice-core drilling sites, as well as ancient and medieval lead/silver mines throughout Europe. Atmospheric modeling shows the impact of emissions from different regions on pollution recorded in the Arctic ice cores. The Russian Arctic, for example, is relatively more sensitive to emissions from mines in eastern Europe, while North Greenland is relatively more sensitive to emissions from western Europe.
###
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policymakers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI is one of eight institutions in the Nevada System of Higher Education. Learn more at www.dri.edu, and connect with us on social media on Facebook, Instagram, and Twitter.
Media Contact:
Justin Broglio
Communications Manager, Desert Research Institute
This email address is being protected from spambots. You need JavaScript enabled to view it.”>Justin.Broglio@dri.edu
775-673-7610
@DRIscience
Jun 26, 2019 | Blog, Featured projects
Photo: A collection of marine debris including microplastics. Credit: NOAA Marine Debris Program/Flickr.
Microplastics research at DRI
Even the tiniest pieces of plastic are a big pollution problem.
Microplastics are plastic pieces ranging in size from 5mm to microscopic particles, in other words, the size of a pencil’s eraser or smaller. They come from a variety of sources, including the breakdown of larger products like single-use plastic bottles and from the microbeads in products like facewash and toothpaste.
The extent of microplastic pollution is only just beginning to be understood, with researchers discovering the tiny plastic pieces everywhere from the air we breathe to the deep ocean. Because microplastics are durable, insoluble, and potentially toxic, they could pose threat to natural ecosystems and human health. But to determine the impact of microplastic pollution, researchers must first understand just how much tiny plastic is out there and where it’s coming from.
DRI’s Monica Arienzo, Zoe Harrold, Meghan Collins, Xuelian Bai, and University of Nevada, Reno undergraduate Julia Davidson are exploring these questions in two bodies of freshwater in Nevada: Lake Tahoe and the Las Vegas Wash.
“There has been a lot of work done to understand how much microplastic is in marine environments, but there have been far fewer studies in freshwater, and far fewer even in alpine lakes,” explained Collins, Education Program Manager at DRI. “This study is really well placed to identify what microplastics may be in the water, their sources, and their characteristics.”
The research team is collecting samples from four different sites in Las Vegas—one in Lake Mead and three in the Las Vegas Wash—and six sites in Lake Tahoe. Sites were selected to include areas both high and low human activity, like the Tahoe Keys with significant boat traffic and Emerald Bay State Park where human impact is low. Additional sampling was also conducted at three stormwater outfalls into Lake Tahoe in collaboration with the League to Save Lake Tahoe’s Pipe Keepers citizen science program.
The research team sets up the pump and filter system at Lake Tahoe’s Emerald Bay State Park in May 2019.
“The sampling methods we’re using are unique,” said Arienzo, assistant research professor and project lead. “Past studies collected samples by trailing a large net from a boat or standing with it in a moving stream. Our approach is to sample and filter water in the field for microplastics using a pump, which allows us to filter upwards of 15 gallons of water in locations with still water and in places where boat access is limited.”
“Plus, we don’t have to haul netting around or carry the samples back to the lab—everything we need fits into a backpack, which makes sampling in remote and hard to access locations more feasible,” Arienzo added.
To make this novel method work, researchers place a stake with a funnel clipped to it about 20 feet from the water’s edge. The funnel, positioned on the surface of the water, is connected to tubing that runs back to the pump on shore, which draws water through the tubing and over a series of filters which can capture particles of different sizes.
Tubing runs into the column of filters, which capture particles at three different sizes as water flows through.
Tubing runs into the column of filters, which capture particles at three different sizes as water flows through.
Sampling in all locations took place throughout the spring, and now the team is set to process and analyze the samples over the summer.
“To isolate the plastic pieces, we first have to get rid of all the organics, and we’re going to do that by oxidizing them,” explained Harrold, assistant research scientist in DRI’s Division of Earth and Ecosystem Sciences. “It’s a delicate balance between getting rid of the bugs and twigs and whatever else has ended up in there and not dissolving your plastics.”
Once the team oxidizes the organic particles left behind on the filters, they’ll separate the plastics from any remaining sediment using a high-density liquid separation method which will cause the sediments will settle to the bottom while plastics will float to the top.
From there, the team will begin identifying the different kinds of plastic pieces they find. The type of plastic, its size and shape, and the location where it was collected all provide clues about where it may have come from—for example, a nylon fiber may have come from the breakdown of synthetic clothing, and a piece of Styrofoam could have come from a single-use cup.
Harrold removes a filter from the sampling instrument to bring it back to the lab for analysis.
However, making determinations about where individual pieces of microplastic originate is far from straightforward.
“We’re only discovering more sources of microplastics,” explained Harrold. “Recent studies have shown that microplastics can be transported through the atmosphere, so though some of what we find might be coming from local sources, the pollution could also be coming from a factory manufacturing plastic on the other side of the world. We just don’t know.”
While it’s daunting that there’s so much still unknown about this increasingly problematic pollutant, the research team also finds it exciting.
“This is the second study ever to be done on microplastics in Lake Tahoe,” said Arienzo. “It’s amazing to be a part of advancing the science in this new area of study.”
The team hopes that this work will contribute to a foundation of scientific information about the extent of microplastics pollution in Nevada freshwater so that scientists will be able to better identify the sources of microplastic, potential harmful effects to plant and animal life, and ways to remove it from the environment.
From left: Harrold, Arienzo, Collins, Davidson, and Bai after sampling at Emerald Bay in May 2019.
Funding for this project came from the DRI Foundation’s Innovation Research Program (IRP), which is designed to support DRI faculty and staff as they pursue their very best ideas. The IRP is funded by individual contributions from science enthusiasts like you—if you’d like to donate to the IRP and help make projects like this one possible, please visit: https://www.dri.edu/foundation/innovation-research-program.
Jun 4, 2019 | EEL, News releases, Research findings
Photo: Hotter temperatures and longer, more frequent heat waves are linked to a rising number of deaths in the Las Vegas Valley over the last 10 years.
Las Vegas, Nev. (June 4, 2019) – Over the last several decades, extreme heat events around the world—particularly in the North American Southwest—have gotten hotter, occurred more frequently, and lasted longer. These trends pose significant health risks to the growing number of people making cities like Las Vegas home.
A new study by faculty and undergraduate students at the Desert Research Institute (DRI), Nevada State College, and Universidad de Las Americas Puebla traces the relationship between extreme heat and mortality rates, identifying a clear correlation between heat wave episodes and heat-related deaths in Las Vegas over the last ten years.
“Current climate change projections show an increased likelihood of extreme temperature events in the Las Vegas area over the next several years,” explained Erick Bandala, Ph.D., assistant research professor at DRI and lead author on the study. “Understanding recent extreme heat trends and their relationship to health hazards is essential to protecting vulnerable populations from risk in the future.”
Erick Bandala, PhD (left), shows a graduate student the data he and his team analyzed for this study.
Urban areas of the Southwest are of particular concern because several factors compound the health-related risks of extreme heat events. The heat-absorbing properties of common materials like asphalt exacerbate already high temperatures in cities (called the urban heat island effect), particularly at night. What’s more, populations in cities like Las Vegas are growing rapidly, especially among those 55 and older, which means that more and more people are exposed to risk.
In this study, the research team analyzed two measures of extreme heat—heat index and excess heat factor—for the Las Vegas metropolitan area in the June, July, and August months from 2007 to 2016. Heat index (HI) accounts for how the human body reacts to surface temperature and relative humidity. Excess heat factor measures (EHF) heat wave intensity in relation to historic temperature trends to account for how acclimated the public is to a given temperature threshold. Because both HI and EHF incorporate the human body’s response to extreme heat, they are ideal metrics for assessing public health impacts, and both were shown to rise over the study period.
The annual average of severe heat events per year in Las Vegas also showed significant increases in this study, from an average of 3.3 events per year from 2007-2009 to 4.7 per year in the 2010-2016 period. These findings match historic trends, which show a steady increase in severity and frequency of excess heat in Las Vegas since 1980.
Strikingly, the number of heat-related deaths in Las Vegas map onto these trends: as heat wave intensity increases, the number of heat-related deaths does, too.
Heat Index (HI) and Excess Heat Factor (EHF) are metrics that go beyond just temperature to also account for the human body’s response to heat. This study found that rising trends in these measures tracked closely with the number of heat-related deaths in Las Vegas.
“From 2007 to 2016, there have been 437 heat-related deaths in Las Vegas, with the greatest number of those deaths occurring in 2016,” explained Bandala. “Interestingly, 2016 also shows one of the highest heat index measures over the last 35 years. This shows a clear relationship between increasingly intense heat events in our area and public health effects.”
Bandala’s team found that the subpopulation particularly at risk of heat-related deaths is adults over 50 years old—76% of the heat-related deaths in the study period were individuals in this subpopulation. Of the deaths in this group, almost all individuals also showed evidence of pre-existing heart disease. Researchers note that these findings are highly significant given that the population of adults over 50 in Las Vegas is increasing, with more retirees choosing Clark County as a retirement destination.
Only 23% of heat related deaths occurred in the subpopulation of adults aged 20 to 50 years; interestingly, the most common pre-existing condition for this group was drug and alcohol use. More research is needed to understand how heat is impacting this segment of the population, Bandala noted, because though the number of deaths in this group is comparatively smaller, it is still nearly one quarter of heat-related deaths in the Las Vegas Valley. Additionally, this subpopulation includes economically active adults.
With more intense, more frequent, and longer lasting heat events projected in the coming years, the research team hopes that the trends identified in this study can assist local decision-makers in taking steps to protect the most vulnerable groups in Las Vegas.
“This research helps us better understand the connection between the climate changes we’ve experienced in Las Vegas and their impact to public health over the last 35 years,” Bandala said. “Ideally, this data analysis will help our community adapt to the changes yet to come.”
The full study, titled “Extreme heat and mortality rates in Las Vegas, Nevada: inter-annual variations and thresholds”, is published in the International Journal of Environmental Science and Technology. The study abstract and references are available here: https://link.springer.com/article/10.1007%2Fs13762-019-02357-9
This study is based on work supported in part by the National Science Foundation, NASA, and the Desert Research Institute. Other members of the project team include Kebret Kebede, Nikole Jonsson, Rebecca Murray, and Destiny Green, all of Nevada State College; John Mejia of DRI; and Polioptro Martinez Austria of the Universidad de Las Americas Puebla.
May 9, 2019 | News releases, Research findings
Researchers drill ice cores from a field camp on Mont Blanc in the French Alps. Credit: B. Jourdain, L’Institut des Géosciences de l’Environnement.
RENO, Nev. (May 8, 2019) – Last spring, an international team of researchers led by Joe McConnell, PhD, Director of the Ultra Trace Ice Core Chemistry Laboratory at DRI’s campus in Reno, Nevada, traced significant atmospheric lead pollution from Roman-era mining and smelting of lead-silver ores in an ice core record from Greenland, providing new insights about the Roman economy.
Now working with colleagues at the Institute of Geosciences and the Environment in Grenoble, France, some members of the same research team have published findings that show a related record of pollution in an ice core from the Col du Dôme area of Mont Blanc in the French Alps.
Published in Geophysical Research Letters, the new study reveals significant atmospheric pollution from lead and antimony, another toxic heavy metal. This study is the first to document an ice core record of antimony, showing that Roman-era mining and smelting activities had implications beyond lead contamination.
Lead (black) and antimony (red) concentrations in ice from the Col du Dôme (CDD). On the bottom scale, age is indicated in years. Phases of increasing lead emissions were accompanied by a simultaneous rise in the presence of antimony – another toxic metal – in the alpine ice. The increases and decreases in heavy metal concentration in the ice correspond with boom times and crises in Roman-era economic history.
“This is the first study of antiquity-era pollution using Alpine ice,” explained lead author Susanne Preunkert, PhD, of the CNRS Institute of Geosciences and the Environment. “Our record from the Alps provides insight into the impact of ancient emissions on the present-day environment in Europe, as well as a comparison with more recent pollution linked to the use of leaded gasoline in the twentieth century.”
Compared to the lead pollution record obtained from a Greenland ice core in the previous study, which reflects heavy metal emissions from across Europe, the Mont Blanc ice core reflects influences from more local pollution sources.
“This study continues an international collaboration between ice core experts, historians, and atmospheric scientists,” said McConnell. “Cross-disciplinary research like this allows us to interpret the ice record in more detail, leading to a better understanding of the impacts of past human activities on the natural environment while also providing new, more quantitative information on those human activities.”
This research received support from the CNRS, ADEME, and the European Alpclim and Carbosol projects, as well as the Desert Research Institute.
The full study, titled “Lead and Antimony in Basal Ice From Col du Dome (French Alps) Dated With Radiocarbon: A Record of Pollution During Antiquity,” is available here.
François Maginiot of CNRS contributed to this release.
May 7, 2019 | News releases, Research findings
Researchers use a drill to extract one of the Greenland ice core samples that became the basis for this research. Credit: Joe McConnell/DRI.
RENO, Nev. (May 7, 2019) – This week, new research outlining the steady decline of phytoplankton productivity in the North Atlantic since the Industrial Revolution was published in the journal Nature. The study, titled “Industrial-era decline in subarctic Atlantic productivity,” is underpinned by data provided by Joe McConnell, Ph.D., director of DRI’s Ultra-Trace Chemistry Laboratory in Reno, Nev.
The recently published study uses measurements from twelve Greenland ice cores to trace the amount of methanesulfonic acid (MSA)—a byproduct of the emissions from large phytoplankton blooms—in the atmosphere. Since the mid-19th century, the concentration of MSA in ice core records has declined by about 10 percent, which translates to a 10 percent loss of phytoplankton. This loss coincides with steadily rising ocean surface temperatures over the same time period, which suggests that populations may decline further as temperatures continue to rise.
A full press release about these findings, originally published by MIT News, is available below.
North Atlantic Ocean productivity has dropped 10 percent during Industrial era
Phytoplankton decline coincides with warming temperatures over the last 150 years.
Jennifer Chu | MIT News Office
May 6, 2019
Virtually all marine life depends on the productivity of phytoplankton — microscopic organisms that work tirelessly at the ocean’s surface to absorb the carbon dioxide that gets dissolved into the upper ocean from the atmosphere.
Through photosynthesis, these microbes break down carbon dioxide into oxygen, some of which ultimately gets released back to the atmosphere, and organic carbon, which they store until they themselves are consumed. This plankton-derived carbon fuels the rest of the marine food web, from the tiniest shrimp to giant sea turtles and humpback whales.
Now, scientists at MIT, Woods Hole Oceanographic Institution (WHOI), and elsewhere have found evidence that phytoplankton’s productivity is declining steadily in the North Atlantic, one of the world’s most productive marine basins.
In a paper appearing today in Nature, the researchers report that phytoplankton’s productivity in this important region has gone down around 10 percent since the mid-19th century and the start of the Industrial era. This decline coincides with steadily rising surface temperatures over the same period of time.
Matthew Osman, the paper’s lead author and a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences and the MIT/WHOI Joint Program in Oceanography, says there are indications that phytoplankton’s productivity may decline further as temperatures continue to rise as a result of human-induced climate change.
“It’s a significant enough decline that we should be concerned,” Osman says. “The amount of productivity in the oceans roughly scales with how much phytoplankton you have. So this translates to 10 percent of the marine food base in this region that’s been lost over the industrial era. If we have a growing population but a decreasing food base, at some point we’re likely going to feel the effects of that decline.”
Drilling through “pancakes” of ice
Osman and his colleagues looked for trends in phytoplankton’s productivity using the molecular compound methanesulfonic acid, or MSA. When phytoplankton expand into large blooms, certain microbes emit dimethylsulfide, or DMS, an aerosol that is lofted into the atmosphere and eventually breaks down as either sulfate aerosol, or MSA, which is then deposited on sea or land surfaces by winds.
“Unlike sulfate, which can have many sources in the atmosphere, it was recognized about 30 years ago that MSA had a very unique aspect to it, which is that it’s only derived from DMS, which in turn is only derived from these phytoplankton blooms,” Osman says. “So any MSA you measure, you can be confident has only one unique source — phytoplankton.”
In the North Atlantic, phytoplankton likely produced MSA that was deposited to the north, including across Greenland. The researchers measured MSA in Greenland ice cores — in this case using 100- to 200-meter-long columns of snow and ice that represent layers of past snowfall events preserved over hundreds of years.
“They’re basically sedimentary layers of ice that have been stacked on top of each other over centuries, like pancakes,” Osman says.
The team analyzed 12 ice cores in all, each collected from a different location on the Greenland ice sheet by various groups from the 1980s to the present. Osman and his advisor Sarah Das, an associate scientist at WHOI and co-author on the paper, collected one of the cores during an expedition in April 2015.
“The conditions can be really harsh,” Osman says. “It’s minus 30 degrees Celsius, windy, and there are often whiteout conditions in a snowstorm, where it’s difficult to differentiate the sky from the ice sheet itself.”
The team was nevertheless able to extract, meter by meter, a 100-meter-long core, using a giant drill that was delivered to the team’s location via a small ski-equipped airplane. They immediately archived each ice core segment in a heavily insulated cold storage box, then flew the boxes on “cold deck flights” — aircraft with ambient conditions of around minus 20 degrees Celsius. Once the planes touched down, freezer trucks transported the ice cores to the scientists’ ice core laboratories.
“The whole process of how one safely transports a 100-meter section of ice from Greenland, kept at minus-20-degree conditions, back to the United States is a massive undertaking,” Osman says.
Cascading effects
The team incorporated the expertise of researchers at various labs around the world in analyzing each of the 12 ice cores for MSA. Across all 12 records, they observed a conspicuous decline in MSA concentrations, beginning in the mid-19th century, around the start of the Industrial era when the widescale production of greenhouse gases began. This decline in MSA is directly related to a decline in phytoplankton productivity in the North Atlantic.
“This is the first time we’ve collectively used these ice core MSA records from all across Greenland, and they show this coherent signal. We see a long-term decline that originates around the same time as when we started perturbing the climate system with industrial-scale greenhouse-gas emissions,” Osman says. “The North Atlantic is such a productive area, and there’s a huge multinational fisheries economy related to this productivity. Any changes at the base of this food chain will have cascading effects that we’ll ultimately feel at our dinner tables.”
The multicentury decline in phytoplankton productivity appears to coincide not only with concurrent long-term warming temperatures; it also shows synchronous variations on decadal time-scales with the large-scale ocean circulation pattern known as the Atlantic Meridional Overturning Circulation, or AMOC. This circulation pattern typically acts to mix layers of the deep ocean with the surface, allowing the exchange of much-needed nutrients on which phytoplankton feed.
In recent years, scientists have found evidence that AMOC is weakening, a process that is still not well-understood but may be due in part to warming temperatures increasing the melting of Greenland’s ice. This ice melt has added an influx of less-dense freshwater to the North Atlantic, which acts to stratify, or separate its layers, much like oil and water, preventing nutrients in the deep from upwelling to the surface. This warming-induced weakening of the ocean circulation could be what is driving phytoplankton’s decline. As the atmosphere warms the upper ocean in general, this could also further the ocean’s stratification, worsening phytoplankton’s productivity.
“It’s a one-two punch,” Osman says. “It’s not good news, but the upshot to this is that we can no longer claim ignorance. We have evidence that this is happening, and that’s the first step you inherently have to take toward fixing the problem, however we do that.”
This research was supported in part by the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), as well as graduate fellowship support from the US Department of Defense Office of Naval Research.
Reprinted with permission of MIT News.
