A flash flood is a sudden, rapid flooding event that occurs within minutes to a few hours.
Cause
- Cloudburst or intense localised rainfall.
- Glacial Lake Outburst Floods (GLOFs) in the Himalayan regions.
- Dam or embankment failure.
- Urbanisation leading to impervious surfaces and blocked drainage.
- Deforestation and slope destabilisation in hill areas.
Areas Generally Affecting
- Hilly Terrain: Flash floods in the Himalayas (Uttarakhand) and Afghanistan.
- Urbanised Region: Flash flood in an urban region like Chennai.
- Arid and Semi-Arid: Rajasthan dry river beds
Source: The Hindu