A cloudburst over the Kheer Ganga River (a tributary of Alaknanda River) led to flash floods in Uttarkashi district.
- Such events are becoming more frequent in Uttarakhand, with the 2013 Kedarnath disaster being a significant example.
What is a Cloudburst?
- If 10 cm rainfall is received at a station in one hour, the rain event is termed as cloud burst.
- They are difficult to predict due to their small scale and short duration.
- Monitoring requires dense radar networks or high-resolution weather models.
- Though possible in plains, they are more common in hilly areas due to the terrain.
- National Disaster Management Plan, 2019, provides for Cloudburst Disaster Risk Reduction (DRR) strategy.
Reasons for vulnerability of Himalayan states
- Geographical:
- The steep slopes force warm, moisture-laden air from the Arabian Sea to rise rapidly, a process called orographic lift.
- These forms towering cumulonimbus clouds that can sustain large rain droplets.
- As this moist airflow is being lifted, and the cloud gets bigger and bigger, and with no chance of having rainfall, it becomes so heavy that at a point, it starts bursting,
- Anthropogenic: Overall, extreme rainfall events have increased in India as global temperatures rise.
- A study on the Kedarnath floods found that over half the rain was likely due to greenhouse gases and aerosols.
