Integrating RUSLE model with remote sensing and GIS for evaluation soil erosion in Telkwonz Watershed, Northwestern Ethiopia

Soil erosion is the main environmental problems that mainly challenging farmers particularly in the highland part of Ethiopia where the topography is high and rugged, and the rainfall is immense. Hence, the aim of this study was to evaluate annual soil loss using RUSLE Model in Telkwonz Watershed for prioritization and conservation measures in South Gondar Zone, Amhara Region, Ethiopia. After processing various input datasets in Arc GIS and ERDAS imagine software, the required input parameters such as soil erosivity (R), soil erodibility (K), slope length and steepness (LS), land cover (C) and land practice and management (P) were prepared for the Model. The final images for the model were resampled using nearest resample method to keep the images' resolution uniformity, and then the annual rate of soil erosion was computed using the RUSLE model in Map Algebra, Arc GIS. Therefore, the yearly soil loss in the area found to be between 1 and 576 t/ha/year. Soil loss with high, very high and sever erosion rate together embrace 3509.17 ha of land and constitute 18.85% of the total study area. Mainly, 146.86 ha (2.21%), 841.31 ha (4.16%) and 2521.00 ha (12.48%) of the total study area were labelled as first class, second class and third-class priority, and geographically distributed in the northwest, central and southeast part of the watershed where steep slope and undulating topography is prevalent and crop cultivation is intense and huge. High population pressure, over grazing, over cultivation, poor farming and conservation practices coupled with the steepness of the land scape were the main causes that provoked soil erosion in the catchment. Therefore, this study demands instant attention for soil and water conservation efforts on highly eroded areas in basin.