Natural hazards such as floods, droughts and storms are a threat to human security.
Floods are the most frequent of all natural hazards. They cause the greatest economic loss and claim the most lives. Droughts are disasters that occur suddenly because of a prolonged absence of rainfall. If an affected region does not have sufficient food reserves and no relief efforts are forthcoming, a drought can result in catastrophic famines. Storms take many different forms according to region. They may occur as tornadoes, winter storms or tropical cyclones. With wind speeds of up to 400 km/h, storms can develop incredibly destructive force and leave devastation in their wake.