Assessment of soil erosion risks and prioritizing nature-based conservation practices using RUSLE, geospatial techniques and household surveys in central Ethiopia

Land use and land cover changes (LULCC) have aggravated catchment degradation, threatening socio-ecohydrological services (SEHSs). This study integrates RUSLE with geospatial technologies, household surveys (HHSs), and field observations (FO) to assess soil erosion risks, LULCC drivers, and prioritize nature-based solutions (NBS) in Berga catchment. Landsat Images (1990, 2001, 2012, 20203) were analyzed using maximum likelihood classification method. Results show agricultural (60.1%) and built-up areas (9.8%) replaced by natural ecosystems and accelerating degradation. The mean soil loss rate (SLR) increased from 31.52 t/ha/yr (1990) to 57.89 t/ha/yr (2023), surpassing tolerable limits (0−20 t/ha/yr). The mean sediment yield (SY) increased from 8.82 t/ha/yr (1990) to 27.19 t/ha/yr (2023), exceeding the limits (0−10 t/ha/yr). Mann‒Kendall tests (τ = 1.0, p < 0.0001) and Sen's slope confirm significant upward trends in SLR and SY. Sub-catchments 5, 7, and 8 experienced severe erosion; sub-catchments 9, 10, and 12 experienced very high erosion. SSP5-8.5 projects >10% extreme rainfall increases by 2050, heightening erosion risks. The HHS and FO results align with the model findings, confirming that the SEHS decreases. These findings can inform policymakers, strengthen NBS, and guide targeted interventions. Future studies should use Monte Carlo and perturbation to improve sensitivity for better erosion prediction and NBS optimization.