Erosion and sedimentation pose major challenges to water and soil resource management, exerting detrimental impacts on ecosystems.Human societal development and increased anthropogenic activities have caused land degradation and altered land use patterns, consequently intensifying erosion and sedimentation.Assessing the impact of watershed rehabilitation operations on reducing soil erosion and sediment yield is essential to evaluate their effectiveness and inform optimal implementation strategies.This study evaluated implemented watershed conservation operations and their effects on erosion and sedimentation rates in the Alanza watershed from 2016 to 2023, comparing post-implementation conditions with preproject baselines using the empirical MPSIAC model.Results indicate that conservation and rehabilitation operations reduced the sediment delivery ratio from 114 to 101 (11.4% decrease) and lowered the specific sediment yield per unit area across the watershed from 3009 m/year to 1587 m/year (47% reduction) before and after implementation, respectively.Overall, findings demonstrate that integrated biological and mechanical measures in the Alanza watershed can serve as an optimal strategy for sedimentation mitigation.However, sustaining these outcomes requires full and precise execution of the regional management plan, including: optimal budget allocation for unimplemented mechanical operations in designated areas, expansion of biological interventions (e.g., reseeding and rangeland exclosure), stakeholder education and local community engagement, reduced livestock grazing pressure, and continuous monitoring of erosion-sedimentation dynamics.
Ravanbakhsh et al. (Fri,) studied this question.