Rainfall induced soil erosion assessment, prioritization and conservation treatment using RUSLE and SYI models in highland watershed of Ethiopia
Natnael Agegnehu Ayele, Hasan Raja Naqvi, Daniel Alemayehu
Abstract
Soil erosion and the subsequent sedimentation are the major problem in Ethiopia. We assessed the impact of rainfall-induced soil erosion and prioritize the sub-watersheds using RUSLE and SYI models. We procured mean annual precipitation, Abay Basin soil map, Digital Elevation Model (DEM) and LANDSAT 8 OLI/TIRS, 2017 datasets. Results show that annual estimated soil loss was ≤270 and ≤120 t ha−1 yr−1 whereas, mean rates were 37.72 and 23.92 t ha−1 yr−1 for RUSLE and SYI models respectively. Both the models have identified ∼25% area of sub-watersheds (SW19 to SW23) has similar average soil loss (>20 t ha−1 yr−1) at higher elevations. Interestingly, similar erosion severity, priority level and ranks were observed through RUSLE and SYI. Findings indicate a strong relationship between erosion rate and topography. The severe erosion prone area requires immediate action for conservation treatment proposed in study.