Hazard and Disaster Magnitude Units

Additional Information About the Hazard Extent

Some disaster types may have a reported magnitude in the Magnitude and Magnitude Scale columns of the EM-DAT Public Table. EM-DAT disaster magnitude scales vary depending on the disaster type. The table below specifies magnitude property and units for related disaster types.

Disaster Type Magnitude property Magnitude Unit or Scale
Earthquake Amplitude of seismic waves Richter scale1
Flood Flood extent (area) km² (square kilometers)
Drought Drought extent (area) km² (square kilometers)
Extreme temperature The recorded extreme temperature (maximum or minimum depending on whether it is a heat or a cold wave) °C
Epidemic Number of vaccinated people Vaccinated people2
Wildfire Wildfire extent (area) km² (square kilometers)
Storm Recorded wind speed kph (kilometer per hour)
Industrial accident (Chemical spills) Chemical discharged volume m³ (cubic meter)

  1. See warning above. ↩︎

  2. As the magnitude column provides additional hazard-specific information, it is used to report the number of vaccinated people for epidemics. However, it may not be a good indicator of the magnitude of the epidemic, which is also captured by the health impact. ↩︎