Effects of climate and irrigation on GRACE-based estimates of water storage changes in major US aquifers

Abstract Understanding climate and human impacts on water storage is critical for sustainable water-resources management. Here we assessed drivers of total (TWS) variability from Gravity Recovery Climate Experiment (GRACE) satellites compared with drought severity irrigation use in 14 major aquifers the United States. Results show that long-term TWS tracked by GRACE dominated interannual most US aquifers. Low trends humid eastern U.S. are linked to low intensity. Although pumpage Mississippi Embayment aquifer exceeded semi-arid California Central Valley, a surprising lack depletion attributed extensive streamflow capture. Marked southwestern Valley south-central High Plains totaled ?90 km 3 , about three times greater than capacity Lake Mead, largest reservoir. Depletion was driven droughts (?5 yr) amplified switching mostly surface groundwater irrigation. or slightly rising northwestern (Columbia Snake Basins) dampening satellite data highlight synergies between irrigation, resulting little impact east, southwest southcentral US, dampened deletion northwest north central Sustainable management benefits conjunctive groundwater, inefficient promoting recharge, efficient minimizing depletion, increasing managed recharge. This study has important implications development many regions globally.