Abstract:
Climate change is a clear fact today, and its impact is seriously disrupting regional hydrometeorology. In this study, four
dynamical downscaled regional climate model output variables with 0.44° spatial resolution were used to assess climate
change's impact on hydrometeorology of the Gidabo river basin. Based on the climate model performance evaluation result
RACMO2.2T model performed best in the basin and the outputs from this model were used as input data for the successfully
validated HBV model to assess climate change impacts. The Mann Kendell trend test result shows an increasing trend in
maximum temperature, minimum temperature, and potential evapotranspiration but the test result does not show any trend
in precipitation. The climate projection result shows streamflow will decrease in the mid-future due to a significant decrease
in precipitation and an increase of potential evapotranspiration in the basin. The drop-in stream flow can be up to 19.6% and
6.7%, under RCP 4.5 and RCP 8.5, respectively. This drop-in streamflow will have an impact on the river basin's prospective
water resource availability. Therefore, it is recommended that adequate water-related adaptation strategies and choices must
be planned and implemented throughout the river basin in the future.
