Context
The Meteorological Drought Magnitude index is relevant to a wide range of water-related sectors, especially agriculture, forestry, hydrology and water management. This Index is based on total precipitation and is part of the Drought Hazard type of the Wet and Dry category of the classification.
The index gives the cumulative severity of drought events in a year that experience drought conditions as determined by anomalously low precipitation values based on the 3-month Standardised Precipitation Index (SPI-3). The magnitude of the event is defined as the sum of SPI-3 absolute values in the months of the drought episodes. SPI-3 accounts for the deficit (or surplus) of precipitation accumulated over 3 months with respect to the corresponding reference value from a 30-year baseline historical period, here 1981-2010. A higher/lower value indicates shorter/longer droughts Magnitudes.
Definition
The cumulative severity of drought events in a year based on the 3-month Standardised Precipitation Index (SPI-3) relative to a reference period, here 1981-2010 (dimensionless). A drought event starts when SPI-3 values fall below -1 for at least two consecutive months and ends when the index returns positive. The magnitude of the event is defined as the sum of SPI-3 absolute values in the months of the drought episode.
Data Sources
The data was assembled on behalf of the Copernicus Climate Change Service (C3S) based on climate projections hosted on the C3S Climate Data Store (CDS). The Index is calculated from the ERA5 reanalysis and a set of nine bias-corrected multi-model simulations from the EURO-CORDEX experiment. These simulations have a spatial resolution of 0.25° x 0.25°, a 3-hourly output, and cover scenarios RCP4.5 and RCP8.5. More information about the dataset can be found in the corresponding CDS documentation resources.
Supporting Information
Further information about this application can be found in the ECDE application User Guide and the Data and datasets underpining the ECDE. Related information can also be found in other sections of the EEA site: