Assessment of Trends and Magnitude of Climate Variability and Change in the Kembata Tembaro Zone in Southern Ethiopia

Incorporating large-scale climate indices like the El Niño/Southern Oscillation (ENSO) is essential for understanding climate variability and change on a finer scale. Therefore, this study aimed to investigate the trends and magnitude of climate variability and change in the Kembata Tembaro zone in Southern Ethiopia. Climate data from the Kadida Gamella (KG), Kacha Birra (KB), and Hadaro Tunto (HT) stations were collected. The coefficient of variation (CV), standardized anomaly index (SAI), and standard precipitation index (SPI) were used to assess the climate variability. The Pearson product moment correlation was used to determine the association between rainfall variability and ENSO. In addition, the Mann–Kendall (MK) trend test was used to assess climate trends. The results revealed that rainfall variability was observed between seasons, with CVs ranging from 14.1% to 25.0%. Higher percentages of dry (negative) rainfall anomaly values over time were estimated during the Kiremt (June–September) (51.6%) and Belg (February–May) (53.8%) seasons, indicating an increase in the number of dry years. These findings show that droughts have become more frequent and severe in the study area. Additionally, ENSO strongly influences both Kiremt and Belg rainfall amounts. However, some of the stations had significant (p<0.05) positive trends in Kiremt for KB and HT as well as in annual rainfall for KB. Furthermore, annual and seasonal temperature trends showed significant (p<0.05) increasing trends at all stations. The average rates of change for the maximum and minimum annual temperatures were 0.029 and 0.030°C, respectively. Overall, the findings showed that over the past 31 years, the study area has experienced significant fine-scale climatic variability and change. This suggests that microscale analysis of trends and magnitude of climate variability and change could be useful for developing context-specific adaptation strategies.