Drought Frequency, Severity, and Duration Monitoring Based on Climate Change in Southern and Southeastern Ethiopia

Abstract

Ethiopia is highly vulnerable to the impact of climate change due to its low adaptive capacity and a higher dependence on rain-fed agriculture for livelihood. The aim of this paper was to identify the long-term climatic trends and the magnitude of those trends and to analyse drought duration, frequency, and severity in southern and south-eastern Ethiopia based on climatic data (1980-2017). This research is a quantitative research method. The southern and south-eastern of Ethiopia were purposely selected based on a frequent occurrence of drought in the country. Monthly data were obtained from National Meteorological Agency (NMA) of Ethiopia. Mann-Kendall (MK) Test coupled with Sen’s Slope Estimator was used to analyse the trend of climatic data and its magnitude, and Standardized Precipitation Evapotranspiration Index (SPEI) was used to analysis drought characteristics. SPEI of 1-, 3- and 6-month timescales were calculated to understand drought characteristics. The result of the MK test showed that annual rainfall trend had non-significant decrease at all station except at Gode. The trend of annual maximum and minimum temperature is insignificantly increasing. The calculated SPEI revealed drought is more frequent and severe from time to time in the study area. Results showed that the most frequent, severe and prolonged droughts occurred during1999-2017 compared to 1980-1999. Climate change mitigation and proactive drought management approach is highly recommended in order to minimize the risk of drought.