Sustainable and Cost-Effective Management of Degraded Sub-Watersheds using Ecological Management Practices (EMPs) for Genale Basin, Ethiopia

Abstract

Land, water, and air are the most essential resources blessed by nature to humankind, conserved and maintained with steadfast efforts. This study applies the Modified Universal Soil Loss Equation (MUSLE) to identify erosion prone sub-basins and a non-linear optimization algorithm to determine the optimal area combination of Ecological Management Practices (EMPs) control sediment yield within permissible limits at a minimum cost. The model is practiced for critical sub-basins in the Genale watershed to assess the effectiveness of five EMPs individually and as a combination in controlling sediment yields and peak flow. A relative assessment revealed that terracing as an individual (61.8%) and EMPs combinations (78.5%) are better in reducing sediment yield at the sub-basin scale. Considering the environmental and economic viewpoint, the total cost of EMPs (for five critical sub-basins), applied to reduce sediment yield, is 46.101 million USD (United States Dollar) or (1.844 billion Ethiopian birr). EMPs are environment friendly and cost-effective to reduce sediment yield.