Characterizing the aridity indices and potential evapotranspiration using CMIP6-GCMs in two distinct regions of Ethiopia

Abstract

Using an ensemble of three global climate models, the current study aims to estimate climate change and quantify the changes in the aridity and evapotranspiration of two distinct areas in Ethiopia. To adjust for bias in the climate dataset, the Hydrological Modeling Tool (CMhyd) was used. These studies were initially run using station data and employed the shared socioeconomic pathways scenarios for the short-range (2011–2040) years and medium-range (2041–2070) years. Climate-related aridity is measured using the De Martone and United Nations Environment Programme aridity indices. The study's findings for the western and eastern catchments for the reference period (1981–2010) years reveal an average annual temperature rise of 1.5 and 0.06 °C and a drop in annual precipitation of 15.73 and 3.68 mm/year, respectively. These alter the climate in the geographical areas that have historically supported drought. Evapotranspiration in the western and eastern catchments may grow by up to 24.6 and 21.6%, respectively, by the 2070s. The observation implies that the western catchment may experience more pronounced climate change and volatility than the eastern one. The consequences of this observation influence agriculture, water resource management, and the social and economic well-being of those living in drought-prone areas.