Analyzing land use dynamics and soil degradation for prioritizing watershed conservation in the Gebre Korke watershed, central Ethiopia

Soil degradation resulting from land use and land cover change (LULCC) poses significant environmental concerns, impacting hydrological balance and ecological well-being. This study focuses on the Gebre Korke watershed of the Blue Nile basin in central Ethiopia, a highland region prone to soil erosion and hydrological disruptions. Human and natural factors contribute to widespread soil erosion, affecting smallholder farmers and hydraulic systems. The study utilized the Revised Universal Soil Loss Equation (RUSLE) to assess soil erosion vulnerability, considering rainfall erosivity (R), soil erodibility (K), topographic (LS) factor, land use/land cover (C-factor), and support practice factor (P). Validation through local engagement and numerical data affirmed the model's accuracy. The study estimated a total soil loss of 297,828.72 tonnes per year (t yr⁻¹), with an average annual soil loss rate of 64.01 tonnes per hectare per year (t ha⁻¹yr⁻¹). Cultivated land showed a higher rate of 106.36 t ha⁻¹yr⁻¹, indicating the need for soil conservation efforts in these areas. Seven sub-watersheds denoted as A, B, C, D, E, F, G were prioritized based on soil erosion severity, with sub-watershed C identified as high-risk, demanding targeted soil conservation measures. Sub-watersheds F, A, and G also needed attention and tailored strategies to reduce soil erosion. The results were validated through field observations and focus group discussions with local communities and experts. Community perceptions aligned with the model outputs, indicating an increase in soil erosion indicators and adverse effects on crop yield and performance. In conclusion, the study provides valuable insights into the estimation of soil loss in the Gebre Korke watershed and highlights the importance of implementing targeted soil conservation measures, integrating local knowledge, soil erosion risk assessments into land use planning, and fostering collaborative efforts to combat soil erosion and promote sustainable land management practices. Continuous monitoring and tailored approaches are also vital for effective soil conservation in Ethiopia's diverse landscapes.