Impacts of climate change and variability on drought characteristics and challenges on sorghum productivity in Babile District, Eastern Ethiopia

Abstract

ABSTRACT Examining the characteristics of drought indices in the context of climate variability and change, particularly in semi-arid water-stressed regions, requires adaptation. Observed climate data of the Babile station from 1980 to 2009 were used as a baseline for climate projection. Future climate projection was established under two Representative Concentration Pathway (RCP4.5 and RCP8.5) climate scenarios for the 21st century. Two drought indices, namely standard precipitation index and standard evapotranspiration index (SPI and SPEI) were employed based on temperature and rainfall to characterize droughts. Our study revealed that drought severity and intensity are more likely to increase under RCP4.5 climate forcing in the middle of the 21st century. The average drought severity (S) was 1.1, 1.53, 1.55, and 1.8 in SPEI 3-month time scale; 1.51, 2.1, 2.38, and 2.29 in SPEI 4-month time scale; and 2.15, 2.77, 3.44, and 2.91 in SPEI 6-month time scale, whereas, the drought severity (S) was 1.33, 1.37, and 1.79 in SPEI 3-month time scale; 1.79, 2.05, and 2.19 in SPEI 4-month time scale; and 2.47, 3.19, and 2.69 in SPEI 6-month time scale in observed, near, mid and end of the 21st century under RCP4.5 and 8.5 scenarios, respectively. Increase in drought frequency and severity occurrences under RCP4.5 scenario would have a negative impact on sorghum crop productivity. We recommended further study on practical soil water conservation to drought management in the study area.