Morphometric analysis: sub-watershed prioritization in the temcha watershed, upper Blue Nile Basin, Ethiopia

The degradation of the Blue Nile basin threatens its agricultural, ecological, and socioeconomic stability. This study aims to address this challenge by identifying and prioritizing erosion-prone sub-watersheds within the Temcha watershed. Leveraging digital elevation models (DEMs) and ArcGIS, 26 sub-watersheds were delineated to aid spatially informed conservation planning. Morphometric analysis revealed complex drainage networks, while vulnerability assessment categorized sub-watersheds based on conservation priority. Integrating quantitative morphometric parameters and land use/land cover analysis allowed for a comprehensive assessment of watershed conditions. The quantitative morphometric values represent the morphological characteristics of each sub-watershed, while the land use/land cover percentages indicate the distribution of different land cover types within each sub-watershed. By considering both factors, decision-makers can prioritize conservation efforts in areas where the combination of land cover and morphometric characteristics poses the greatest environmental risk. The vulnerability assessment classified sub-watersheds into four categories: very low, low, moderate, and high priority, with lower Compound values (Cp) indicating greater erosion risk, emphasizing targeted interventions. Sub-watershed 04 emerged as a high-priority area due to significant erosion risk, contrasting with sub-watershed 07, which showed lower susceptibility. Based on the findings the top five priorities possibly having high erosion are SBWS4 falls under first or high priority; SBWS2 under the 2nd priority; SBWS3 under 3rd priority, SBWS12 under the 4th priority and SBWS5 under the 5th priority. This prioritization framework offers a systematic approach for resource allocation and tailored conservation measures, crucial for mitigating environmental challenges and ensuring the long-term sustainability of the watershed ecosystem.