| Normal and Extreme Rainfall • India receives about 116 cm of rainfall (Normal year). • During a cloudburst, a place receives about 10% of annual rainfall within an hour. • The extreme rainfall event in Mumbai on July 26, 2005, saw 94 cm of rain in 24 hours, resulting in over 400 deaths and more than USD 1 billion in economic losses. |
- The death toll due to flash floods triggered by cloudbursts in three districts of Himachal Pradesh has increased to 11.
- A cloudburst is a localised, intense rainfall event. It is defined as rainfall of 10 cm or more in an hour over a roughly 10 km x 10 km area.
- By this definition, 5 cm of rainfall in a half-hour over the same area would also be categorised as a cloudburst. This phenomenon is most common in hilly regions and can cause widespread destruction.
- Cloudbursts are not uncommon, particularly during the monsoon months, and are frequent in the Himalayan states.
- These events often trigger landslides and flash floods, causing extensive downstream destruction.
- The India Meteorological Department (IMD) forecasts rainfall events but does not predict the exact quantum of rainfall.
- Specific cloudburst events cannot be forecasted, but warnings for heavy to very heavy rainfall are routinely issued.
- There is no long-term trend indicating an increase in cloudbursts as defined by the IMD. However, incidents of extreme rainfall and other extreme weather events are increasing globally, attributed to climate change.
Dig Deeper: Why hilly areas are more vulnerable to Cloudburst?
