Intensity and spatial extension of drought in South Africa at different time scales

The standardised precipitation index (SPI) is an index that allows monitoring the intensity and spatial extension of droughts at different time scale. The SPI is used here to do retrospective analysis of the spatial extension and intensity of droughts in South Africa since 1921.There is considerable decadal variability and an 18 to 20 year cycle is only found in the number of dry districts. Combining the retrospective analysis with real time monitoring could be extremely beneficial in the development of response, mitigation strategies and awareness plans.