The challenge is to develop sustainable water resource programs with increasing stresses from population growth, climate variability/change, and land use change. Water and food production are also closely linked because irrigated agriculture is the primary consumer of global fresh water resources and there are impacts and feedbacks between water fluxes and salt and nutrient cycles.
At SWR, our research focuses on groundwater resources in semiarid regions. Remote sensing is used to monitor changes in groundwater storage using the GRACE satellite and to monitor evapotranspiration using MODIS and Landsat. Groundwater recharge rates are quantified using environmental tracers in soil profiles and provide baseline information on how much groundwater can be pumped sustainably. We also examine impacts of agriculture on water, salt, and nutrient cycles using subsurface environmental tracers. Unsaturated zone chloride and nitrate profiles provide information over decadal to millennial timescales. Our initial work in various countries includes field research programs combined with numerical modeling to determine controls on water, salt and nutrient inventories and transport and evaluate sustainability issues.