CLOUDBURSTS (Syllabus: GS Paper 3 – Disaster Mangement)

Context: A recent cloudburst in Himachal Pradesh triggered flash floods, resulting in multiple fatalities and leaving several people missing. The floods caused significant destruction, washing away buildings, bridges, and roads, officials reported.

Cloudbursts

• Definition: The IMD classifies a cloudburst as 10 cm or more of rainfall in an hour over a 10 km x 10 km area; 5 cm in half an hour over the same area can also be a cloudburst.

oNot all instances of heavy rainfall are cloudbursts. These events are highly localized and often occur in areas without rainfall measuring instruments.

• Example: The Kedarnath flash floods, triggered by a cloud burst, represent one of the most catastrophic natural disasters in recent Indian history.
• Mechanism: A cloudburst happens when warm air currents lift raindrops, causing them to become heavier and denser before falling rapidly over a small area.
• Common in Hilly Regions: Cloudbursts are more common in mountainous regions due to orography, though they can occur in plains as well.
• Destruction: The heavy rainfall from cloudbursts can trigger landslides and flash floods, causing significant damage downstream.

Impact of Climate Change

• Increasing Cloudbursts: Climate change is expected to raise the frequency and intensity of cloudbursts.
• Temperature Correlation: The rise in global surface temperatures by 1°C is linked to increased monsoon extremes and cloudbursts.
• Future Projections: Expected temperature rises of 1.5°C by 2040 and 2°C by 2060 may worsen cloudburst events.