Drought Evolution Features and Risk Assessment Across Three Agro‐Ecological Zones of Ethiopia During 1990–2020

ABSTRACT Ethiopia, despite its abundant potential of water resources, is experiencing highly variable drought patterns due to its diverse topography and climate. In this study, we investigated drought dynamic evolution in all three agro‐ecological zones (Dega, Woina Dega, and Kola) of Ethiopia during 1990–2020. By applying statistical techniques, runs theory, and wavelet spectra on drought indices, we found that significant abrupt changes (spectral peaks) in drought patterns occurred in all three agro‐ecological zones during 2008–2010 and 1995–2000, driven by known large‐scale climatic drivers (ENSO and IOD) with spectral peaks in the same periods. Compared with Dega and Woina Dega zones, Kola zone experienced consistent deterioration in drought severity with a peak value of −24.3 during 2011–2020 and was facing an increasing challenge of prolonged droughts, especially 21 months of drought during 2010–2020. In order to assess the conditional probability when the next drought event occurs after the end of the current drought event, we used the Kaplan–Meier estimator in survival analysis to generate the first drought risk map in the whole of Ethiopia at different accumulation periods of droughts. These findings highlight the spatio‐temporal shift of drought patterns in Ethiopia and give valuable insights for local governments to adopt drought‐resilient agricultural practices tailored to unique drought patterns of each agro‐ecological zone.