What is a lysimeter?

Lysimeters are buried containers of soil equipped with a weighing device and drainage system to measure evaporatranspiration and percolation. Lysimeters aim to represent existing soil, vegetation, and climatic conditions to improve the accuracy of measurements of physical processes (Hillel, 1998).

The inability to upscale or downscale arid environmental processes influences research areas of hydrology, biogeosciences, mathematical modeling, and global environmental change. Research facilities that span small (column) to larger (basin) scales are either rare or nonexistent. To address this issue, researchers from Nevada’s universities constructed a weighing lysimeter facility in Boulder City, NV.

Our Underground Weighing Lysimeter Facility, in Boulder City, houses 3 round stainless steel lysimeters and 1 square lysimeter in separate rooms and accessed through a central tunnel. Each lysimeter weighs 45,000 Kg and are weighed on a separate balance with a resolution of +/- 200 g. Each lysimeter is equipped with dataloggers that can be accessed remotely so investigators can monitor individual sensors and weather systems as needed. Real-time data will be posted online for research investigators.

Each contains either repacked or intact desert soil and is instrumented with 152 sensors that include 17 different technologies measuring water content, matric potential, temperature, thermal properties, electrical conductivity, soil settlement, and erosion; sampling pore water; and obtaining soil and root imagery. A relatively new technology called distributed temperature sensing system was installed to obtain horizontal temperature profiles at six depths and a continuous vertical temperature profile. Four conservative tracers were applied uniformly at four depths and solution samplers were installed at seven depths to collect soil solution during irrigation experiments.

The lysimeters were designed to investigate:

• landscape dynamics, restoration, and water balance
• carbon sequestration
• characteristics of soil properties at different scales.