Annual estimates of recharge, quick-flow runoff, and ET for the contiguous US using empirical regression equations, 2000-2013

This dataset includes 800m resolution long-term average estimates of evapotranspiration (ET), quick-flow runoff, and recharge within a closed water budget over the 2000-2013 time period and annual estimates for the individual years. It also includes other supporting data associated with the publication of these estimation methods in a concurrent journal article. These estimates were developed with new empirical regressions for (1) quick-flow runoff data generated using data points from a USGS-developed hydrograph separation program (PART) run on streamflow data from 1434 gaged watersheds, as a function of surficial geology type (USGS), precipitation (PRISM), and soil hydraulic conductivity (STATSGO); and (2) long-term evapotranspiration using data points from water balance estimates at 679 gages as a function of land cover (NLCD), precipitation (PRISM), and maximum, minimum, and mean daily temperature (PRISM), and a separate estimate for ET over open water. The recharge quantites close the water budget to sum to the total influx from precipitation. Irrigated water quantities reported in the 2000, 2005, and 2010 USGS Water Use datasets are also incorporated as effective additional precipitation, and a map of these irrigation addition quantities is included as well, in the ET dataset. Estimates are included for both effective recharge, which is approximately equal to base flow and reflects the quantity of water available to replenish the groundwater table, and total recharge, which also includes the estimated recharge quantity that was subsequently intercepted by riparian vegetation and converted to evapotranspiration. The quantities for quick-flow runoff do not include inter-pixel transfers, so do not capture within-watershed variations due to such transfers such as downstream runoff accumulation, but rather represent the portion of the precipitation entering each cell that ultimately contributes to the quick-flow runoff component. Shapefiles for the gaged watersheds used for the ET and quick-flow runoff estimates are also included in this data set, along with supporting input datasets. Methods are fully described in a forthcoming publication accepted for publication as of April 2017; this dataset will be updated with its full citation when available.