Climate extremes: trends and magnitudes for different recurrence intervals in the South Ethiopia region

Impacts of extreme climate hazards including storm rainfalls, temperatures, droughts and floods remains a significant challenge in South Ethiopia Region, with far-reaching impacts on agriculture, human health, livelihoods, and the economy. This study aimed to understand climate extremes in terms of trends and magnitudes for different recurrence intervals in the study area. The research was designed to analyze the trends and magnitudes for different recurrence intervals of temperature and precipitation extremes using long-term observational data. It employed daily temperature and precipitation data with a time span of approximately 38 years from 1981 to 2018. Daily temperature and precipitation data from 36 stations across the study area was collected from Ethiopian Meteorological Institute. The study focused on ten extreme climate indices recommended by the Expert Team for Climate Change Detection Indices to assess temperature and precipitation extremes trends. The trends analysis for each station was conducted using the RClimDex package in R software while CumFreq was used to estimate magnitudes for six recurrence intervals (2, 5, 10, 25, 50 and 100 years) of the extreme cases. The findings revealed significant warming trends throughout South Ethiopia. Specifically, 75% of the stations reported increase in the number of warm nights, and 83% observed more warm days, with some of these being statistically significant. The duration of warm spells increased, while cold spells became shorter, indicating a persistent rise in temperature extremes. Regarding precipitation, 77% of stations recorded longer consecutive dry days, and over half showed increases in the number of very wet or extremely wet days, as well as heavy rainfall events. Importantly, the recurrence intervals for both high-temperature and heavy precipitation events shortened, suggesting that these extremes are becoming more frequent. Observed shifts in climate extremes, characterized by more frequent and intense temperature and precipitation events will threaten agriculture, water access, and the overall resilience of local communities. The findings highlighted the urgent need for adaptive strategies and interventions to reduce the escalating vulnerability of climate extremes in the South Ethiopia Region.