Potential Impacts of Prospective Climate Change on Groundwater Recharge in the Western United States

University Of Arizona, Tucson AZ

Investigators

Abstract

Groundwater withdrawals in the western US are a critical component of the water resources strategy for the region. Recharge estimation methods include water balance accounting, groundwater modeling, remote sensing, observational methods and environmental tracer analysis. This project will assemble a team of investigators to synthesize current understanding of recharge in the West and how it may respond to climate change in the coming decades. The synthesis will build on previous work that quantified major aquifer systems within the United States under the USGS-Regional-Aquifer-System-Analysis program. The synthesis will (1) draw upon geographically targeted process-based studies of recharge controls and their sensitivity to climatic forcing in various parts of the region; (2) take advantage of recently available dynamically downscaled climate-change projections; (3) meld process-exploring results from high-resolution water balance studies and modeling analyses. These approaches will be used to develop enhanced estimates of groundwater recharge (with estimated uncertainties) and a detailed list of research needs will be developed for more robust estimates of groundwater recharge across the region. This project is cooperative with the USGS John Wesley Powell Center Science Board. This project will significantly advance regional knowledge of the controls on groundwater recharge and the impact this has on regional water sustainability for the US southwest. By synthesizing the state of knowledge as well as the best methods of analysis and reanalysis, the project will define new methods (and better estimates) of regional scale groundwater recharge. The project will also significantly impact water resource and water management strategy for the southwest by providing an improved basis for long timescale analysis.