Trends of Climate Change and Variability in Different Agroecological Zones of Sidaama Region, Ethiopia: Application of Innovative Trend Analysis

Abstract

This paper analyzes climate change trends and variability in the Sidaama region, comparing three agroecological zones (AEZs). The dataset, covering 1981 to 2020, was sourced from the National Meteorological Institute of Ethiopia using a 4x4 km grid. The trend in precipitation and temperature was assessed using Innovative Trend Analysis (ITA), the MK test, and Sen’s slope, while the variability was analyzed through the Precipitation Concentration Index (PCI), Coefficient of Variance (CV), and Rainfall Anomaly Index (RAI). Results showed mean annual rainfall of 942.4 mm, 1101.2 mm, and 757.0 mm for the highland, midland, and lowland zones, respectively, with 2020 being the wettest year and 2015 the driest across all zones. Rainfall demonstrated a decreasing trend, while both maximum and minimum temperatures increased. The midland zone experienced the most significant changes, with a rainfall decrease of approximately 12.1 mm/year and a mean annual maximum temperature increase of 0.063°C/year. Most results across tests were consistent, except for a few instances. PCI indicated moderate intra-annual and inter-seasonal rainfall variability, while RAI results highlighted varying drought conditions, particularly affecting the lowland zone. Without timely interventions, these climatic changes could worsen poverty, malnutrition, and migration in the region, necessitating adaptive strategies like enhanced water conservation, climate-resilient agricultural practices, and afforestation to counteract deforestation-induced precipitation declines.