Meteorological drought dynamics and vegetation sensitivity in Ethiopia, Genale Dawa Basin

Introduction: Drought is one of the most critical climate-related hazards in Ethiopia, significantly affecting agriculture, water resources, and ecosystem stability, particularly in the highly vulnerable Genale Dawa Basin in southeastern Ethiopia. Materials and methods: This study analyzed the spatial and temporal characteristics of drought and its relationship with vegetation dynamics using historical rainfall and temperature data. Drought conditions were quantified using the Standardized Precipitation Index (SPI-3) and Standardized Precipitation Evapotranspiration Index (SPEI-3). Vegetation responses were assessed using MODIS-derived Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). Seasonal correlation analyses were conducted to evaluate vegetation sensitivity to drought. Results: The findings reveal frequent and recurrent droughts, with severe events occurring in 1984, 1992, 2002–2004, 2011, and 2022. SPEI captured stronger drought signals than SPI, indicating the increasing role of temperature and evapotranspiration. Significant positive correlations were observed between SPI-3 and NDVI during March–May (r = 0.72, p < 0.01) and September–November (r = 0.68, p < 0.01), highlighting the importance of bimodal rainy seasons. In contrast, SPEI–vegetation relationships were weaker and seasonally variable. Conclusions: The Genale Dawa Basin is highly drought-prone, with strong vegetation–climate linkages during key rainy seasons. These findings emphasize the need for season-specific, climate-informed adaptation strategies to enhance drought resilience and sustainable resource management.