GS Paper 1/3
Syllabus: Important Geophysical Phenomena/ Disaster Management
Source: IE
Context: The Chandigarh-Manali highway was blocked following flash floods and landslides in parts of Haryana and Himachal Pradesh.
What are flash floods?
- Excessive or continuous rainfall over a period of days or during particular seasons, can lead to stagnation of water and cause flooding.
- Flash floods occur in a much shorter span of time (say, when rainfall creates flooding in less than 6 hours) and are highly localised.
- Flash floods can also be caused by factors apart from rainfall, like when a dam overflows.
Causes of flash floods in India:
- Nearly 75% of the total rainfall is concentrated over just four months (June to September) → rivers witness a heavy discharge during these months.
- Cloudbursts or thunderstorms and overflowing glacial lakes (in Himalayan states formed due to the melting of glaciers).
- Depression and cyclonic storms in the coastal areas of Orissa, West Bengal, and Andhra Pradesh.
- Flash floods may begin to take place after wildfires. Wildfires destroy forests and other vegetation, which in turn weakens the soil and makes it less permeable for water to seep through.
- Climate change/global warming has increased the frequency/numbers of the above events.
What makes flash floods very dangerous?
- These are accompanied by landslides, which are sudden movements of rock, boulders, earth or debris down a slope.
- Landslides are common in mountainous terrains, where there are conditions created for them in terms of the soil, rock, geology and slope.
Vulnerability of India:
- According to government data, India is the worst flood-affected country in the world, after Bangladesh.
- ~40 million hectares of land in the country are liable to floods annually. (National Flood Commission)
- India accounts for one-fifth of the global death count due to floods.
- Flash floods have been commonly witnessed in cities like Chennai and Mumbai.
Steps taken: India has launched first-of-its-kind Flash Flood Guidance services for India and other South Asian countries – Bangladesh, Bhutan, Nepal, and Sri Lanka.
Way ahead: A comprehensive strategy of monitoring, planning development works in a way that is sensitive to the region’s ecology, and mitigation to reduce the extent of damages.
Insta Links:
India launches flash flood guidance services for South Asia
Mains Links:
What is a flash flood? Analyse the causes and consequences of flash floods and suggest measures to mitigate their impact.
