Agroecology-based analysis of meteorological drought and mapping its hotspot areas in Awash Basin, Ethiopia

Abstract

Drought-related risk is among the major global challenges of our time. It negatively impacts food security and ecosystem health. It is becoming a persistent problem in many parts of sub-Saharan Africa and specifically in Ethiopia. Information on its intensity and spatiotemporal distribution is critical to contextualize interventions and build agroecosystem and community resilience. This study aims at analyzing spatiotemporal characteristics of meteorological drought over eight Agroecological Zones (AEZs) of the Awash Basin, Ethiopia. Annual gridded temperature and precipitation dataset obtained from the National Meteorological Agency of Ethiopia for the period 1983–2016, covering 1655 grid points, were used. The study applied the Standard Precipitation and Evapotranspiration Index (SPEI) and Standard Precipitation Index (SPI) methods to characterize the meteorological droughts. The study applied Arc GIS 10.5 to map the drought hotspots. From the result, the value of SPEI and SPI methods was divergent in characterizing the magnitude and spatial occurrence of drought episodes. SPEI has more advantages in detecting dry months and a small advantage in detecting dry seasons compared to the SPI. Temporally, wet and dry years dominated the 1990s and 2010s, respectively. Drought dominated 1980s and normal years dominated the 2000s. The spatial context of drought hotspot showed that AEZs in the upper and lower parts of the Awash Basin were hit by severe to extreme drought while the escarpments and middle parts of the basin experienced mild to moderate drought. This contrasts with the common perception that the hot to warm arid lowlands AEZs are the only hotspot areas to drought. Moreover, previously none frequent drought AEZs, such as tepid to cool humid mid-highlands were identified as drought hotspots in the basin. This information could help policymakers to target AEZs and implement context-specific and informed drought risk management decisions and adaptation measures.