Hydrological Response to Climate Change in Baro Basin, Ethiopia, Using Representative Concentration Pathway Scenarios

Droughts and floods are common in the Baro basin, and climate change may exacerbate them. This study aimed to investigate the hydrological response to the impact of climate change on the Baro basin. From four climate models, namely the Hadley Centre Global Environmental Model, version 2 (HadGEM2-ES); Myocardial perfusion imaging, low resolution (MPI-ESM-LR); Coupled Model Version 5, Medium Resolution (CM5A-MR); and the European Community Earth System Model (EC-Earth), dynamically downscaled outputs were obtained from an African coordinated regional downscaling experiment programme. Changes in the hydrological response to climate change were compared to the baseline scenario (1971 to 2000) under the Representative Concentration Pathway Scenarios for the medium term (2041 to 2070). The climate data were heavily skewed before being used in the impact analysis and needed correction. In terms of bias, HadGEM2-ES performed the worst, while EC-Earth performed the best. MPI-ESM-LR was the worst performer in terms of RMSE, and CM5A-MR was the best. The GCM predictions for the RCP 4.5 scenarios suggested that, in the medium period (2041 to 2070), the maximum temperature in the Baro River basin will probably rise by 2.1 °C for MPI-ESM-LR and 2.49 °C for CM5A-MR, while the minimum temperature will likely climb by 1.7 °C for EC-Earth and 2.8 °C for HadGEM2-ES. Annual rainfall is expected to fall by 7.02% for CM5A-MR and 17.01% for HadGEM2-ES, while annual evapotranspiration potential is likely to rise. Except for Belg (from March to May), CM5A-MR consistently generated the greatest streamflow change, while MPI-ESM-LR consistently generated the highest magnitude of streamflow change. Generally, climate change is predicted to significantly impact the hydrological response in the Baro River basin under the RCP 4.5 scenario.