• Marked Spatiotemporal Heterogeneity : Extreme rainfall and temperature indices vary significantly across AEZs in the Woleka Sub-basin. • Increasing Temperature Extremes : Upward trends in warm indices (e.g., TX90p, TN90p) and a decline in cold extremes (e.g., TN10p, FD0) indicate a progressive warming trend. • Mixed Patterns in Rainfall Extremes: Indices such as R10mm, R25mm, and Rx1day exhibit inconsistent distributions, with some zones experiencing increased heavy rainfall while others show weak or non-significant changes. • Implications for Agroecological Resilience : These trends suggest increased risks to rainfed agriculture, including greater variability between drought and flood conditions, as well as heightened heat stress. This underscores the need for zone-specific adaptation and climate-resilient land management strategies. Extreme weather and climate events pose significant risks to agricultural systems in Ethiopia, particularly in climatically sensitive regions such as the Woleka Sub-basin. This study examines the spatiotemporal variability and trends of rainfall extreme indices using ETCCDI metrics derived from ENACTS gridded data for 1981–2022. Trend analysis was conducted with the Modified Mann–Kendall test, including autocorrelation correction and Sen's slope estimator, while spatial patterns were assessed at pixel and agroecological zone (AEZ) levels. Results indicate considerable spatial variability in rainfall extremes across the basin, with inconsistent trends in direction and significance. Annual total precipitation (PRCPTOT) shows mixed, locally significant increasing and decreasing trends, reflecting heterogeneous rainfall behavior. Intensity- and frequency-based indices (Rx1day, Rx5day, SDII, R10mm, and R20mm) generally exhibit non-significant trends, suggesting a lack of spatial coherence in changes to rainfall intensity and frequency. Statistically significant trends are more pronounced in extreme percentile indices (R95p and R99p), with several areas experiencing increased contributions from very wet and extremely wet days, indicating a shift toward more intense precipitation events, despite inconsistencies in total rainfall trends. Seasonal analysis reveals contrasting behaviors between the main rainy season (JJAS) and the short rainy season (FMAM). The JJAS season displays stronger and more spatially coherent trends, including localized increases in rainfall totals and other extremes, while the FMAM season exhibits high variability and predominantly non-significant trends. Overall, findings illustrate that rainfall extremes in the Woleka Sub-basin are spatially heterogeneous and seasonally distinct, with significant changes concentrated in high-percentile precipitation events rather than in rainfall frequency or duration. These patterns have important implications for hydrological processes and climate risk management, highlighting the need for location-specific and seasonally targeted adaptation strategies.
Abebe et al. (Fri,) studied this question.