My research focuses on the effects of soil–plant–atmosphere interactions on unsaturated flow and transport processes, and on methods for characterizing these processes. The research approach includes laboratory, field, and modeling studies of both natural and disturbed/engineered systems. I am presently involved in studies of the soil-water balance and ground-water recharge, contaminant transport, and hydrologic performance of landfill covers in arid and semiarid environments. I also serve as Project Coordinator for the U.S. Geological Survey’s Amargosa Desert Research Site (ADRS; http://nevada.usgs.gov/adrs/ ). Studies at the ADRS are a multidisciplinary collaboration among scientists from the USGS, universities, National Laboratories, and other research institutions.