Assessing the Impacts of Land Use and Climate Changes on River Discharge towards Lake Victoria

The Lake Victoria basin’s expanding population is heavily reliant on rainfall and river flow to meet their water needs, making them extremely vulnerable changes in climate land use. To develop adaptation mitigation strategies it urgently necessary evaluate the impacts of change quantity rivers that drain into Victoria. In this study, semi-distributed hydrological SWAT model was used impact current use for period 1990–2019 assess probable future near (2030–2060) Simiyu discharge draining Victoria, Northern Tanzania. General Circulation Model under RCPs 4.5, 6.0 8.5 predicted an increase annual average temperature 1.4 °C 2030 2 2060 7.8% reduction catchment. simulated from revealed a decreasing trend by 1.6 m3/s 5.66 2019 4.0 2060. evapotranspiration caused primarily responsible decrease discharge. also forecasts extreme events, range between 32.1 232.8 10.9 451.3 2030–2060 period. present combined showed higher effects peak at different return periods (Q5 Q100) with values 213.7 (Q5), 310.2 (Q25) 400.4 (Q100) compared contributions climate-change-only scenario discharges 212.1 300.2 390.2 (Q100), only 295.5 207.1 Q25) 367.3 (Q100). However, contribution ratio larger than change. proved be useful tool forecasting complex semi-arid catchments towards These findings highlight need catchment-wide management plans Basin.