Estimating Sediment Yield and Soil Loss for Conservation Prioritization: Implications for Natural Resource Management in the Boricha Sub-Catchment, Rift Valley River Basin, Ethiopia
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Soil erosion continues to threaten the sustainability of farming activities in Ethiopia’s highland areas, where steep slopes and variable rainfall persistently impact productivity and environmental health. Focusing on Boricha Sub-Catchment in the Rift Valley Basin, the study examined patterns of soil loss and sediment yield using the RUSLE model and 2022 GIS-based spatial inputs. Key input parameters included rainfall, elevation, soil type, and land cover. Estimated annual soil loss ranged from 0 to 359.76 t/ha/yr, with an average of 31.63 t/ha/yr, well above Ethiopia’s tolerable soil loss threshold. Sediment yield across the catchment varied between 0 and 80.7 t/ha/yr, averaging 2.01 t/ha/yr. The sediment delivery ratio was calculated as 0.2234. Northern and central zones were identified as erosion hotspots, particularly in sub-watersheds SW1, SW10, and SW9. In contrast, SW3, SW4, and SW7 showed minimal erosion activity. These findings support a prioritization framework for soil conservation, offering evidence-based recommendations such as reforestation, terracing, and check dam construction. The study confirms the value of GIS-integrated RUSLE modeling as a practical tool for decision-making in watershed protection.