Szilagyi Jozsef, Zlotnik Vitaly A, Jozsa Janos
School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583.Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, NE 68588.Department of Hydraulic and Water Resources Engineering, Budapest University of Technology and Economics, Muegyetem Rakpart 1-3, Budapest H-1111, Hungary.
Ground Water. 2013 Nov-Dec;51(6):945-51. doi: 10.1111/gwat.12007. Epub 2012 Dec 14.
One-km resolution MODIS-based mean annual evapotranspiration (ET) estimates in combination with PRISM precipitation rates were correlated with depth to groundwater (d) values in the wide alluvial valley of the Platte River in Nebraska for obtaining a net recharge (Rn) vs. d relationship. MODIS cells with irrigation were excluded, yielding a mixture of predominantly range, pasture, grass, and riparian forest covers on sandy soils with a shallow groundwater table. The transition depth (dt ) between negative and positive values of the net groundwater recharge was found to be at about 2 (±1) m. Within 1 (±1) m of the surface and at a depth larger than about 7 to 8 (±1) m, the mean annual net recharge became independent of d at a level of about -4 (±12)% and 13 (±10)%, respectively, of the mean annual precipitation rate. The obtained Rn(d) relationship is based on a calibration-free ET estimation method and may help in obtaining the net recharge in shallow groundwater areas of negligible surface runoff where sufficient groundwater-depth data exist.
基于1公里分辨率的中分辨率成像光谱仪（MODIS）估算的年平均蒸散量（ET），结合PRISM降水率，与内布拉斯加州普拉特河宽广冲积河谷的地下水位深度（d）值相关，以获得净补给量（Rn）与d的关系。排除了有灌溉的MODIS单元格，得到的区域主要是沙地，覆盖着草原、牧场、草地和河岸森林，地下水位较浅。发现净地下水补给量正负值之间的过渡深度（dt）约为2（±1）米。在地表1（±1）米范围内以及深度大于约7至8（±1）米处，年平均净补给量分别在年平均降水率的约-4（±12）%和13（±10）%的水平上与d无关。所获得的Rn（d）关系基于一种无需校准的ET估算方法，可能有助于在地表径流可忽略不计且有足够地下水位深度数据的浅层地下水区域获得净补给量。
