Emergency population warning
An emergency population warning or public warning system is a method whereby local, regional, or national authorities can contact or notify members of the public to warn them of an impending emergency. These warnings may be necessary for a number of reasons, including:
- weather emergencies such as cyclones, flooding, tornadoes, avalanches and severe weather;
- geological disasters such as earthquakes, landslides, volcanic eruptions, and tsunamis;
- industrial disasters such as the release of toxic gas or contamination of river water;
- radiological disasters such as a nuclear plant disaster;
- medical emergencies such as an outbreak of a fast-moving infectious disease or pandemic;
- warfare such as air raids or acts of terrorism; and
- other events, such as prison escapes, abducted children or emergency telephone number outages.
Warnings are often disseminated during urgent events such as evacuations or where a severe threat to life is expected. Common alerting methods include sirens, radio, television, local media, telephone, SMS and Cell Broadcast.