Drought risk assessment and mapping under changing climate: the East Hararge Zone in Ethiopia

ABSTRACT Drought is a period of abnormally dry weather that causes hydrological imbalances, significantly impacting agricultural production in Ethiopia. This study aims to assess and map drought-risk areas in the East Hararge Zone using satellite data and global climate models. We analyzed the spatial and temporal characteristics of historical droughts through remotely sensed CHIRPS rainfall and MODIS vegetation data, utilizing the CanESM5 dataset from CMIP6 to identify drought risk under changing climate conditions. Drought indices, such as SPI, aSPI, NDVI and NDVI anomaly were employed, with validation against crop yield anomalies showing correlation coefficients of r = 0.72, 0.74, and 0.78 for SPI, NDVI, and NDVI anomaly, respectively. The analysis revealed that 29.8% and 26.7% of the area experienced moderate and slight drought over the past 12 years. Trend analysis indicated a significant increase in drought occurrences with a rate of −0.003 (p = 0.046) based on SPI_6, while aSPI analysis showed a general decrease in drought risk areas at a rate of 0.466. Frequency analysis projected drought occurrence every two years under the SSP2-4.5 scenario. This study provides essential baseline information and future predictions to monitor real-time drought situations and inform adaptation strategies in East Hararge, Ethiopia.