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

Abstract Drought characterization can be used to devise an effective early warning system as a key component in the development of drought preparedness plans that manage drought impacts. The aim of this study was to characterize the drought events, particularly those involving long-term of meteorological and agricultural events, which are the predominant types affecting communities. Conventionally, regional drought analysis is performed on the basis of drought indices for the identification of drought intensity, frequency, duration and areal extent across southeast Ethiopia. The indices used for the study were the Precipitation Deciles (PD), Standardized Precipitation Index (SPI) and Reconnaissance Drought Index (RDI) for the period of 1987–2018. The spatial extent of drought in the study area was interpolated via the inverse distance weighted method via the spatial analyst tool of ArcGIS. Most of the studied stations experienced drought events in 1991/1992, 1998/1999, 2001/2002, 2010/2011 and 2011/2012. The results indicate that 2010/2011 was a year of exceptionally widespread drought. To this end, having information on 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 in drought-affected areas.