Identification of erosion hotspot areas in the data-scarce Birr watershed for prioritization of conservation measures using the InVEST model

ABSTRACT Ethiopia is extremely vulnerable to water-induced soil erosion due to its physical and climatic features, which poses a major risk to its water and soil resources. To support the prioritization of conservation measures, this study identifies areas in the productive Birr River watershed that are susceptible to erosion. Soil loss and sediment yield were estimated using the InVEST (Integrated Valuation of Environmental Services and Trade-Offs) Sediment Delivery Ratio (SDR) model, which included pertinent thematic layers and criteria. Based on the primary outlet, the watershed was separated into eleven sub-watersheds. According to the results, 49% of the basin loses more than 5.5 tons of soil per hectare annually, and the risk of erosion rises with gradient, slope, and agricultural land use. Sub-watershed 3 has the greatest soil loss (118.9 tons per hectare annually), according to a prioritization based on erosion risk. To ensure effective resource allocation, these findings offer crucial guidance for planning soil and water conservation initiatives that target high-risk sub-watersheds.