Assessment of climate change impact on groundwater reservoirs and water resources management in the Upper Santa Cruz River, Arizona

Planning to meet water demands in semi-arid regions is particularly challenging for groundwater dependent communities where aquifers are being replenished by intermittent streamflow events. We employed a modeling framework that addresses climate uncertainties in the Upper Santa Cruz River near the US-Mexico border crossing. At the heart of this modeling framework is a weather generation model that simulates likely-to-occur rainfall scenarios. The weather generation model was further modified to reflect future climate projection that are based on analyses of selected dynamically downscaled global climate models that well represent tele-connection features between the Southwest climate and eastern Pacific. Rainfall realizations from the weather generation model were used as forcing for a series of hydrologic models that simulate likely scenarios of streamflow, recharge to the groundwater reservoirs, and various groundwater states. This modeling framework enables for a reliability assessment of various water resources management scenarios. Funded by: NOAA, Sectoral Applications Research Program (SARP)