Application of Soil and Water Assessment Tool (SWAT) Model to Predict Streamflow and Sediment Yield in Wahig-Inabanga Watershed, Bohol, Philippines

抄録

The study applied the Soil and Water Assessment Tool (SWAT) model -- to predict streamflow and sedimentation in Wahig-Inabanga Watershed, Bohol, Philippines. The applicability of the SWAT model was evaluated and its output was integrated to GIS to generate sedimentation hazard map. The result of the SWAT model performance evaluation on stream flows was satisfactory given prediction efficiency values: NSE = 0.6578; R² = 0.7038; PBIAS = 14.94%; and RSR = 0.5850. Satisfactory result was also achieved in model validation with model accuracy values on NSE, R², PBIAS and RSR of 0.41, 0.57, 25.09%, and 0.71, respectively. However, the model did not provide precise estimates of sediment yield in sub-basins and hydrological response units (HRU) especially with corn as single land use or one of the landuses even on flat to gently rolling terrain. Inaccuracy issue on sediment yield prediction deferred further analysis including thesedimentation risk valuation which supposed to provide baseline information for watershed management and land use planning.