Analysis of Historical Climate Change and Variability in the Selected districts of Eastern Ethiopia

Abstract

Climate change and variability pose major challenges to agriculture and food security in Eastern Ethiopia, where rainfed farming dominates. This study assessed long-term rainfall and temperature trends across districts in East and West Hararghe Zones using daily data from 1992–2022 obtained from the National Meteorological Agency. Statistical methods, including Mann-Kendall and Sen’s slope, were applied to detect trends, while precipitation concentration index, anomaly index, and coefficient of variability measured rainfall variability. Results indicated non-significant increasing rainfall trends in Haramaya, Tulo, Chiro, and Gurawa, while Mieso (-4.46 mm/year) and Babile (-3.40 mm/year) showed non-significant decreasing trends (P > 0.05). This study analyzed historical climate variability across districts in East and West Hararghe Zones, Oromia Region, Ethiopia. Kiremt rainfall exhibited increasing trends over past decades, though not statistically significant (P>0.05). Belg rainfall showed non-significant decreases in all districts except Chiro. Rainfall anomaly analysis revealed positive anomalies in Chiro, Tulo, Gurawa, and Haramaya, while negative anomalies were observed in Mieso and Babile districts. Rainfall patterns demonstrated high inter-annual variability, with delayed onset, early cessation, and frequent dry spells, directly impacting crop growth and yield. Spatial differences highlighted localized vulnerabilities, with lowland areas experiencing more frequent droughts compared to highland zones. Results further indicated significant increases in mean annual and seasonal maximum and minimum temperatures, with pronounced warming during the main cropping season. Over the past thirty years, most districts experienced rising temperatures, rainfall fluctuations, increased water stress, and notable El Niño events in 2015, 2016, and 2017. These findings provide critical insights for climate adaptation strategies.