Development of Monthly Water Budget Estimates for the CONUS and Application to the Mississippi Alluvial Plain
Tuesday, December 5, 2017: 11:20 a.m.
As water resources become increasingly strained in the US and globally, the development of reliable methods of water availability estimation becomes ever more critical for making informed water use management decisions. Here we present new monthly 1km-resolution estimates of the set of water budget components of evapotranspiration (ET), surface runoff, snow storage, and recharge for the modern time period of 2000-2013. We use a combination of remote sensing products and empirical estimates from ground-based data, to leverage both the spatial/temporal resolution of remote sensing and the overall magnitude checks from field data. For ET we use a combination of the MODIS-based USGS SSEBop data set and long-term ET magnitude estimates based on water balance data. We estimate runoff with an empirical regression against soil and surficial geology data, and use the SNODAS snow water equivalent product of the National Snow and Ice Data Center to incorporate snow storage. Recharge and groundwater storage change are then estimated as the balance of the precipitation for the month. After presenting the methods and CONUS-scale maps, we show an application of this work to understanding water availability in the Mississippi Alluvial Plain region, which has seen significant impacts on water resources due to irrigation and groundwater pumping. Our monthly timescale estimates are compared with results from other methods, and synthesized into a summary of water budget trends in the region.