Szilagyi Jozsef, Harvey F Edwin, Ayers Jerry F
University of Nebraska-Lincoln, Conservation and Survey Division, Lincoln, NE 68588-0517, USA.
Ground Water. 2003 Jul-Aug;41(4):504-13. doi: 10.1111/j.1745-6584.2003.tb02384.x.
Naturally occurring long-term mean annual base recharge to ground water in Nebraska was estimated with the help of a water-balance approach and an objective automated technique for base-flow separation involving minimal parameter-optimization requirements. Base recharge is equal to total recharge minus the amount of evapotranspiration coming directly from ground water. The estimation of evapotranspiration in the water-balance equation avoids the need to specify a contributing drainage area for ground water, which in certain cases may be considerably different from the drainage area for surface runoff. Evapotranspiration was calculated by the WREVAP model at the Solar and Meteorological Surface Observation Network (SAMSON) sites. Long-term mean annual base recharge was derived by determining the product of estimated long-term mean annual runoff (the difference between precipitation and evapotranspiration) and the base-flow index (BFI). The BFI was calculated from discharge data obtained from the U.S. Geological Survey's gauging stations in Nebraska. Mapping was achieved by using geographic information systems (GIS) and geostatistics. This approach is best suited for regional-scale applications. It does not require complex hydrogeologic modeling nor detailed knowledge of soil characteristics, vegetation cover, or land-use practices. Long-term mean annual base recharge rates in excess of 110 mm/year resulted in the extreme eastern part of Nebraska. The western portion of the state expressed rates of only 15 to 20 mm annually, while the Sandhills region of north-central Nebraska was estimated to receive twice as much base recharge (40 to 50 mm/year) as areas south of it.
在内布拉斯加州，借助水平衡方法和一种客观的自动基流分离技术（该技术涉及最少的参数优化要求），估算了天然存在的长期平均年基岩对地下水的补给量。基岩补给量等于总补给量减去直接来自地下水的蒸发散量。水平衡方程中蒸发散量的估算避免了指定地下水贡献排水区域的必要性，在某些情况下，该区域可能与地表径流的排水区域有很大差异。蒸发散量由太阳能和气象地表观测网络（SAMSON）站点的WREVAP模型计算得出。长期平均年基岩补给量是通过确定估算的长期平均年径流量（降水量与蒸发散量之差）与基流指数（BFI）的乘积得出的。BFI是根据从美国地质调查局在内布拉斯加州的测量站获得的流量数据计算得出的。通过使用地理信息系统（GIS）和地质统计学实现了制图。这种方法最适合区域尺度的应用。它不需要复杂的水文地质建模，也不需要详细了解土壤特性、植被覆盖或土地利用实践。在内布拉斯加州最东部，长期平均年基岩补给率超过110毫米/年。该州西部的年补给率仅为15至20毫米，而内布拉斯加州中北部的沙丘地区估计获得的基岩补给量是其南部地区的两倍（40至50毫米/年）。
