The global Drought Risk Projection products capture projected risk of drought across the
globe using well-established drought monitoring metrics such as Standardized Precipitation
and Evaporation Index (SPEI). This risk indicator was computed using the monthly time series of
SPEI at six time scale (6-month, 12-month, 18-month, 24-month, 30-month, and 36-month) and applying
the relative frequency approach – the ratio of the number of months when the index is below or
equal to a threshold indicating drought of moderate magnitude (SPEI < -1) to the total number
of possible outcomes, looking at a series of decadal time steps into the future as analysis periods.
These products are categorised into short-term and long-term drought blends for different applications.
Short-term products are more suited towards vegetative and agricultural drought monitoring, while the long-term products are more suited towards hydrological drought monitoring. These risk maps reflect the future risk from drought across North America at decadal time steps for Shared Socioeconomic Pathway scenario SSP2-4.5.