Characterizing Spatiotemporal Patterns of Drought among the Pastoralists of Southern Ethiopia, Eastern Africa

Abstract This paper is an inquiry of investigating trends and spatiotemporal patterns of meteorological drought in semi-arid pastoral areas in southern Ethiopia. Monthly gridded rainfall and temperature data for thirty years between 1986 to 2016 were obtained d from Ethiopian Meteorological Agency. Nonparametric Mann Kendall’s test (MK) along with Sen’s slope estimator was employed to see trends of drought. In addition, Reconnaissance Drought Index (RDI) was used to characterize the drought patterns. The result indicates that under all time scale, drought events tend to show an increasing trend with varying magnitude and intensity. The highest drought severity category for major and small rainy months was identified during May 2000 with RDI= -2.28 and September 2000 with RDI= -2.55 . The drought magnitudes of the small rainy months range from -11.15 in November to -11.76 in September, while it ranges from -10.08 in April to -11.38 in March for the major rainy months. There are some variations of drought magnitude among the seasons while rainfall tend to show gradual decline as a manifestation of spatially varying drought severity, frequency and intensity in the watershed.