Runoff and Sediment Yield Modeling in Meso-scale Watershed Based on SWAT Model

The upper watershed of Luo River which is located in the Xiaohua District (XiaolangdiHuayuankou) was selected as the study area to validate distributed SWAT (Soil and Water Assessment Tool) model with the support of GIS technology. Monthly runoff and sediment yield data from 1992 to 1997 were used to calibrate SWAT. In the process of calibration automated digital filter technique was used to partition direct runoff and base flow. The direct runoff was firstly calibrated, then the base flow, and the total runoff were matched. At last the sediment yield was calibrated to match well. After calibration, monthly runoff volume and sediment yield data from 1998 to 1999 were used to validate SWAT model. Relative Error (RE), Determination Coefficient (R2) and NashSuttcliffe Efficiency (Ens) were used to evaluate the applicability of SWAT model, the results show that SWAT model could be successfully used to model longterm continuous runoff and sediment yield in the mesoscale watershed in the Yellow River Basin.