Prediction of Variable Source Areas for Two Coshocton Watersheds

Abstract

The Soil Moisture Routing Model (SMRM) and a modified SMRM that included the effect of clay outcrop were used to model runoff source areas for watersheds W103 and W110 located within the North Appalachian Experimental Facility (NAEW) in Coshocton, OH, USA. The two adjacent watersheds have visually similar landscape and soil types but exhibit very different runoff responses. Daily measured and predicted runoff for nineteen years (1980-1998) and periodic measured and estimated soil moisture at three locations in each watershed for four years (1975-1978) were compared using Nash-Sutcliffe efficiency (R 2 ) to evaluate adequacy of model prediction. Overall, the performance of the model was reasonable. Daily runoff was predicted better at W103 (R 2 = 0.59) than at W110 (R 2 =0.47). Soil moisture at all locations was also reasonably predicted (R 2 > 0.5). Most of the high runoff generating areas in W103 and W110 were located in the middle and lower landscape positions.