Application of GeoWEPP for Determining Sediment Yield and Runoff in the Orcan Creek Watershed in Kahramanmaras, Turkey

The geo-spatial interface of the WEPP model called GeoWEPP uses digital geo-referenced information integrated with the most common GIS tools to predict sediment yield and runoff. The model determines where and when the sediment yield and runoff occurs and locates possible deposition places. In this study, the sediment yield and runoff from Orcan Creek watershed in Kahramanmaras region was estimated by using GeoWEPP model. To investigate the performance of the model, the sediment yield and runoff results from the GeoWEPP model were compared with the observed monthly data collected from the sample watershed. The average Root Mean Square Errors (RMSE) between observed and predicted average annual sediment yield and runoff were 2.96 and 8.43, respectively. The index of agreement was 0.98 and 0.99 for sediment yield and runoff, respectively, which indicated that the model predictions provided good results.