Impact of land management scenarios on sediment yield in the Gateno sub watershed Ethiopia using the InVEST model

Abstract Sediment yield poses significant challenges to agricultural productivity, water availability, and watershed sustainability in the Ethiopian highlands. However, spatially explicit assessments of how alternative land management trajectories influence sediment dynamics at the sub watershed scale remain limited. This study provides the integrated evaluation of sediment yield responses to four contrasting land management scenarios including baseline, agricultural expansion, urbanization and reforestation in the Gateno watershed Tekeze River Basin Ethiopia using the InVEST sediment delivery ratio model coupled with RUSLE and GIS techniques. Spatial analysis revealed significant variability in sediment yield across scenarios. Under the baseline scenarios 91.6% of the watershed exhibited very low sediment yield while high and very high classes covered 3.5%. In Agricultural expansion and urbanization increased high and very high sediment yield areas to 7.2% and 4.7% respectively due to vegetation removal and soil exposure. In contrast reforestation scenarios reduced sediment export lowering the mean annual sediment yield to 17.2 t ha−1 yr−1 compared with 39.3 t ha−1 yr−1 under agricultural expansion. By quantitatively comparing future land management pathways this study advances understanding of scenario based sediment modeling in data limited highland catchments and provides spatially explicit evidence to support reforestation and sustainable land use planning for watershed resilience. Hence, policymakers’ should strive on promoting reforestation and implementing sustainable land-use practices to safeguard watershed practices and ecosystem health.