Characterize of Drought Events Using Decile, SPI and RDI in Southeast of Ethiopia

Drought characterization can be used to devise an effective early warning system as a key component to building drought preparedness plan that manage drought impacts. The aim of this study was to characterize the drought events, particularly those of meteorological and agricultural events happened for long period that has been the predominant types to affect the communities. Conventionally, regional drought analysis is done based on drought indices for the identification of drought intensity, frequency, duration and areal extent across southeast Ethiopia. The indices used for the study were Precipitation Deciles (PD), Standardized Precipitation Index (SPI) and Reconnaissance Drought Indexes (RDI) for the period of 1987 to 2018. The spatial extent of drought in the study area has been interpolated by inverse distance weighted method using the spatial analyst tool of ArcGIS. Most of the studied stations experienced drought event in 1991/1992, 1998/1999, 2001/2002, 2010/2011 and 2011/2012. The results point to 2010/2011 as a year of exceptionally widespread drought among the other. To this end, having information in the intensity, frequency, duration and areal extent of drought needed in water conservation policies can help bridge the gap between water availability, supply, and demand of drought affected areas.