Prioritizing management options using a risk assessment for soil erosion based on GIS, remote sensing, and RUSLE. A case study of Midhagdu Watershed, Eastern Ethiopia.

Abstract This study prioritises management options and assesses the risk of soil erosion in the Midhagdu Watershed in eastern Ethiopia. The themed map was developed using satellite data including SRTM-DEM, Landsat OLI, rainfall data, and soil data. The RUSLE model as well as GIS and remote sensing methods were used in the experiment. The experiments revealed that the factors that affect soil erosion risk such as rainfall erosivity (R), soil erodibility (K), slope length and steepness (LS), cover management (C), and anthropogenic soil erosion control practises factor values were distributed spatially and ranged in values from 41.365 to 43.793MJ mm ha-1yr-1, 0.26 to 0.31t ha-1MJ-1mm-1, 0 to 220.512, 0.21 to 0.87, and 0.11 to 1, respectively, and the most powerful factor that influences soil erosion risk was topography(LS) with a value of 0.885. The results of the grid cell-based RUSLE model showed that 52.24 percent of the Midhagdu watershed (28.37 km2 out of 54.3 km2) had low to moderate soil erosion levels and that 47.76 percent (25.94 km2 out of 54.3 km2) had high to extremely high soil erosion risk levels. By taking into account regions and priority classes based on soil erosion risk levels, the conclusions of this article suggest an early intervention to better plan soil erosion risk management.