Streamflow Forecasts and Assessment of Reservoir Performance

Currently the impact of climate change affects many water resources projects that result in pattern change of annual runoff, reservoirs pool level change, increasing of irrigation demand due to increasing temperature and evaporation and etc., and thus it is important to assess its impact on streamflow and reservoir performance. This study mainly forecast streamflow and assesses the performance of Upper and Lower Dabus reservoirs under the impact of climate change using Reliability, Resilience and Vulnerability indices (RRV). The future climate variables which were downscaled by Climate Limited area Model (CLM) at the basin level for A1B emission scenario was used for future flow simulation. For streamflow generation and reservoirs inflow estimation HEC-HMS model was used using the bias corrected precipitation and Evapotranspiration which was estimated by FAO Penman-Monteith. After the flow was forecasted, the performance of the model was assessed via calibration at Dabus near Asosa, Sechi near Mendi and Aleltu at Nedjo using Relative Volume Error (D), coefficient of determination (R2) and Nash-Sutcliffe Efficiency (NSE) performance coefficients.