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Soil-Water-Balance (SWB) Model used to Simulate Potential Recharge for the Glacial Aquifer System East of the Rocky Mountains, 1980-2011

September 24, 2018

This model archive makes available the calibrated Soil-Water-Balance (SWB) model used to simulate potential recharge for the glacial aquifer system east of the Rocky Mountains in the conterminous United States at a 1-kilometer (km) resolution for the period 1980-2011. The calibrated SWB model in this model archive and associated U.S. Geological Survey Scientific Investigations Report is referred to as the glacial SWB model. Potential groundwater recharge was determined on a daily basis as precipitation in excess of interception, runoff, evapotranspiration, and soil water storage capacity. Daily groundwater recharge amounts were aggregated to an annual basis for grids available in this model archive. Potential recharge as described in this report is water that infiltrates vertically below the plant rooting zone and is assumed to reach the water table. The glacial SWB model was calibrated to base-flow estimates calculated from daily streamflow data by the HYSEP local minimum method for 39 basins across the glacial aquifer system. The glacial SWB model provides insight into the spatial and temporal variability in potential recharge across the glacial aquifer system. The glacial SWB model was prepared as part of the U.S. Geological Survey's Glacial Aquifer System Groundwater Availability Study which assesses groundwater availability for the glacial aquifer system of the United States. Although potential recharge estimates and most model inputs are in units of inches per pound, spatial data such as model grid spacing and some model inputs use the International System of Units.