Impacts of Climate Changes on the Future Groundwater Storage in the High Plains Aquifer

Groundwater contributes approximately 40% of global freshwater use, and it is critical for water supply and associated food production in arid or semi-arid areas during dry seasons. The increasing demand for water and finite water sources have led to long-term groundwater depletion, creating an obstacle to sustainability in several regions of the world under the pressures of population growth and climate change. The High Plains Aquifer System has an area of 450,000 km2, and is the most pumped aquifer and one of the most important agricultural areas in the United States. In this study, we use coupled climate-hydrological model simulations from the NCAR Community Earth System Model Large Ensemble Project to investigate the groundwater storage changes in the High Plains Aquifer under future climate changes and also to explore how such groundwater storage changes might in turn affect the climate through land-atmosphere coupling. Preliminary results indicate that not only the amount of groundwater recharge declines, but the seasonal variations of groundwater recharge also become smaller, resulting in widespread water table decline in a future warmer climate. We will explore how such variations associate to projected changes in precipitation and evapotranspiration, and feedback to the climate.