Geographical Variability of Drought in Northern South Africa

This study focuses on the geographical variation of drought in northern South Africa (hereafter NSA). It assesses seasonal rainfall characteristics to determine drought occurrence and persistence in NSA. Seasonal rainfall data for the period 1960-2009 is used and was obtained from the South Africa Weather Service (SAWS). Rainfall stations in NSA are well distributed, forming a dense network of point-source data samples. Standardised Precipitation Indices (SPIs) are employed to detect drought occurrence and intensity at different locations. Analysis of SPIs with respect to time suggests that the severity of drought results from the accumulation of consecutive dry spells within a rainfall season and sometimes even consecutive dry rainfall seasons. It also shows the intensity and frequency of drought has increased in recent years. The trend towards worsening drought conditions has significant socioeconomic implications for the region and other areas with similar geographical settings.