Climate change projections in the Awash River Basin of Ethiopia using Global and Regional Climate Models

Understanding the long-term variability and change in climate variables is crit-ical for the sustainable management of water resources. This research aimedto project and analyse climate change in the Awash River Basin (ARB) usingbias-corrected Global and Regional Climate Model simulations. The analysisincluded a baseline period from 1986 to 2005 and two future scenarios (2050sand 2070s) under two representative concentration pathways (RCP4.5 andRCP8.5). Following the evaluation of bias correction methods, the distributionmapping and power transformation were used for temperature and precipita-tion projection, respectively. The 2050s and 2070s RCP4 simulations showedan increase in precipitation during half of the months with 32 and 10%, respec-tively. Moreover, the 2050s and 2070s RCP8.5 simulation indicated a decreasein precipitation with 18 and 26%, respectively. The 2050s and 2070s RCP8.5simulation indicated a significant decrease in precipitation in four of themonths (February/March to May) with the highest decreasing rate of 34.7%.The 2050s and 2070s RCP4.5 simulation showed an increase of 0.48–2.6 Cinmaximum temperature. In the case of RCP8.5, the simulated maximum tem-perature increase reached 3.4 and 4.1 C in the 2050s and 2070s, respectively.The future precipitation and temperature change projected in ARB mightworsen the water stress and incidence of dry spells in the basin, and hence mit-igation strategies and management options to reduce this negative impactshould be developed.