Impact Of Land Use Changes On Soil Erosion And Sediment Yield At The Meso-Scale Watershed

Rainfall and streamflow are two most important factors of soil erosion that transports the soil particle from one place to other place, than deposits occur. According to the dynamic of land cover, causes decreasing or increasing streamflow and sediment yield. Therefore, the Du watershed was selected as the study area to understanding how can landuse types affect on dynamics of streamflow and sediment yield. Thus, the SWAT (soil and (?)ater assessment model) model is a hydrologic model interface with GIS spatial analysis was used in this study area.Collecting, pre-processing basic data and database preparation were conducted using SWAT model to simulate in the study area. The Du watershed divided into107subbasins and then subbasins were divided into674HRUs, then loaded land use, soil, and climate data, completed trial run of the model.The Parameter sensitivity analysis, for improving the applicability and accuracy of the model was conducted to get more targeted parameter calibration. According to the result showing five parameters such as CH_COV, CH_EROD have significant effect on sediment and10parameters such as ALPHA_BF, CN2, and ESCO have significant effect on streamflow.The model was run for6year as a warm up period from1965-1970. Streamflow and sediment were calibrated for10years time period during1971-1980also10year time period from1981-1990validation was performed for both streamflow and sediment.Calibration and validation results compared with evaluation criteria, the efficiency coefficient ENS, PBIAS and R2for steramflow during the calibration are0.88,6.4and0.94and during the validation0.87,5.1and0.92respectively. The ENS, PBIAS and R2for sediment during calibration are0.67,19.8, and0.84during the validation were0.64,32.1and0.81respectively. The adequate result of ENS, PBIAS and R2values showed for both calibration and validation period the model has applicability in the study area.