Evaluating the Simulation of a Simple Hydrology Model Using Long-Term Soil Moisture Measurements in the Nebraska Sand Hills

In this paper, we investigate soil moisture, evapotranspiration and other major water balance components over six sites in the Sand Hills of Nebraska during a 6-year period (1998-2003) using a hydrological model. We simulate water budget components including root zone soil moisture and found that model predictions of soil moisture compare reasonably well with observations for these sites. In the precipitation-limited Sand Hills, a moderate change in precipitation pattern from year to year is found to have profound effects on the fast response components of the hydrological cycle. Despite the homogeneity in terms of soil (sandy) and vegetation (grass), both the spatial and temporal variability in the estimated soil moisture, evapotranspiration, runoff and drainage suggests an active interaction among various hydrological processes in response to precipitation over this semi-arid region.