Rainfall induced soil erosion assessment, prioritization and conservation treatment using RUSLE and SYI models in highland watershed of Ethiopia

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.

Keywords:

• Soil erosion
• erosion models
• prioritization
• conservation
• highland watershed

Acknowledgements

We are highly thankful to Addis Ababa Meteorological agency for providing long-term climate data. We are thankful to the Koga Dam Reservoir Office that whenever we needed any information regarding soil erosion and study area, they gave us time. We are thankful to the editor and the reviewers for their critical comments and suggestions for making this manuscript more informative.

Disclosure statement

No potential conflict of interest was reported by the authors.