Effect of land use/land cover changes on surface water availability in the Omo-Gibe basin, Ethiopia

Land use/land cover (LULC) changes due to natural and anthropogenic interference have altered the hydrological processes of the Omo-Gibe basin, Ethiopia. In this study, hydrological modelling and remote sensing techniques were used to assess LULC changes in water availability in the basin. The LULCs were classified from satellite imagery from 1987 to 2017 using normalized difference indices, and the changes were observed to be significant for the basin. The calibration and validation performance of the Soil and Water Assessment Tool (SWAT) model using the observed streamflow and sediment yield for the basin was satisfactory. Afterwards, the SWAT was used to simulate the runoffs and sediment yields for different management practices such as introducing filter strips, parallel terracing, and reforestation. The sediment yields in critical sub-basins of Omo-Gibe reduced significantly on reforestation as the best practice. The study outputs are helpful for the various stakeholders and policymakers in managing water resources properly.