Timing is Everything - Drought Classification for Risk Assessment

Drought is one of the most severe natural disasters with the highest risk for human livelihoods. Remote sensing based drought indices can identify dry periods using e.g. precipitation or vegetation information. Besides frequency, duration and intensity, the timing of a drought onset is an important variable to measure drought risk. This study classifies drought events based on the timing of drought onsets and duration. Drought and non-drought seasons are analyzed in two study sites in South Africa and Ukraine where drought characteristics are different. South Africa drought highly depends on the starting point and duration of rainfall, whereas in Ukraine soil moisture and temperature play key roles. Weighted linear combination is applied based on vulnerable growing stages in the seasonal phenology to classify droughts. By integration of socio-economic information this hazard information supports the quantification of the actual risk of a drought event.