Future drought and aridity monitoring using multi-model approach under climate change in Hintalo Wejerat district, Ethiopia

Abstract

Drought is a complex natural phenomenon and recurring meteorological event that affects environmental factors and agriculture, humans and wildlife, as well as local economies. For countries located in arid and semi-arid regions, drought monitoring has become important tool. This study aims to evaluate the performances of drought indices and monitor future drought, evapotranspiration and aridity in Hinalo Wejerat, Ethiopia. The baseline climate data (1980–2009) were projected to near (2010–2039) and mid-term (2040–2069) using an ensemble of 20 general circulation models in the mitigation scenario. Drought was estimated using an ensemble of seven indices, namely Standardized Precipitation Index, Percent of Normal Index, Effective Drought Index, Z-score, Rainfall Anomaly Index, Modified China Z-index and Reconnaissance Drought Indexes using Meteorological Drought Monitoring and DrinC software. Time series analyses were calculated using AnClim software. All indices show significant correlation with each other and ensemble at p < 0.05. The frequency of moderately dry condition might be increased from 13.3, 13.3 to 16.7%, extremely dry condition from 3.3 to 6.7, 6.7% during the current, near and mid-terms, respectively. The trends of extremely wet, moderately wet and normal might be similar. The change of drought frequency in the current, near and mid-term is significant at p < 0.05. Potential evapotranspiration is projected to increase from 1645.6 to 1902.4 and 1988.9 mm per year in the near and mid-term when compared with current. Accordingly, aridity in the near and end-term might increase by 9.9 and 22.1%, respectively. Therefore, this study notes that sustainable water resource management and drought policy should be applied to ensure household food security.