Abstract

Long-term mean annual base recharge to ground water in Nebraska was estimated with the help of a water balance and an automated base flow separation technique. Base recharge is less than or equal to actual recharge. The difference is the part of evapotranspiration that originates directly from ground water. Evapotranspiration was calculated by the WREVAP model at the Solar and Meteorological Surface Observation Network (SAMSON) sites. Base recharge to ground water was derived by the product of estimated long-term mean annual runoff (the difference between precipitation and evapotranspiration) and the base flow index (BFI) obtained at the United States Geological Survey's gaging stations in Nebraska. Utilizing base recharge estimates, mean annual actual recharge to ground water was estimated by the repeated application of a water-balance method. This approach uses Geographic Information Systems (GIS) layers of land cover, elevation of land and ground-water surfaces, base recharge and the recharge potential in combination with monthly climatic data. Mapping was achieved by GIS and geostatistics. The estimates do not include the potential effect of crop irrigation on recharge.

Authors

Contact Information
	Jozsef (Joe) Szilagyi
625 Hardin Hall 3310 Holdrege Street Lincoln NE 68583-0996
Phone: 402-472-9667 & 402-472-3471
Fax: 402-472-2946
E-mail: jszilagyi1@unl.edu

Contact Information
	Ed Harvey
603 Hardin Hall 3310 Holdrege Street Lincoln NE 68583-0996
Phone: 402-472-8237
Fax: 402-472-2946
E-mail: feharvey1@unl.edu

Contact Information
	Jerry Ayers
229c Hardin Hall 3310 Holdrege Street Lincoln NE 68583-0996
Phone: 402-472-7545
Fax: 402-472-2946
E-mail: jayers1@unl.edu