PREDICTING FLOOD HAZARDS

The expansive flat surfaces of playas (dry lakebeds) located in desert regions of the southwestern United States historically have been viewed as ideal locations for air-transport facilities. The U.S. Department of Defense (DoD) has utilized these nearly ready-made runways at numerous military installations. Severe flooding on playas, resulting from intense or long precipitation events, has potential for causing extensive construction, operation, and maintenance costs to facilities constructed on these geologic features.

A viable method for assessing flood hazards associated with existing and potential sites was needed to reduce costs, expedite construction, and facilitate the site-selection process for new air-transport facilities. For this reason, the U.S. Air Force and U.S. Army Corps of Engineers jointly sponsored a Desert Research Institute (DRI) research project to investigate flooding characteristics of playas. This project was led by DRI scientists Richard French, Julianne Miller, and Charles Dettling, along with John Carr of the University of Nevada Reno.

These scientists applied DRI’s advanced capabilities in hydrologic engineering, hydrometeorology, and remote sensing to develop a new predictive method. This method comprises a group of models where climatic and hydrologic data are employed to estimate frequency, duration, and depth of flooding on playas at both Edwards Air Force Base (EAFB) in California and at the Nevada Test Site in Nevada. The models were successfully verified at EAFB by comparing remote-sensing images with model results. Flooded runways are unusable! Therefore, it is critical for military, as well as municipal, facilities in arid regions to possess predictive tools to characterize playa flooding to avoid adverse economic, strategic, and operational impacts resulting from inaccurately estimating potential volumes of flood waters. This predictive tool will lead to more efficient construction of airfield infrastructure, address safety issues surrounding bird-airplane collisions, and allow airport facilities to remain operational during flood events.