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 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
Jerry Ayers Jerry Ayers
101 Hardin Hall
3310 Holdrege Street
Lincoln NE
68583-0961  
Phone: 402-472-3471  
Fax: 402-472-2946  
E-mail: jayers1@unl.edu
Mean Annual Total Recharge (mm)
Mean Annual Total Recharge (mm)

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Precipitation and gaging stations

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Mean annual base recharge to ground water [mm]

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Ratio of mean annual base recharge to precipitation [mm]

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Mean annual total minus base recharge [mm]

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Mean annual total recharge [mm]

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Ratio of mean annual total recharge to precipitation [%]