The recent Assam flooding and its magnitude have highlighted North East India’s vulnerability to flood.
Reasons for flood vulnerability of North East India
- River instability: The Brahmaputra and the Barak rivers are braided and unstable in their reaches due to high sediment charges, steep slopes and transverse gradients.
- Geology: The entire area is part of a seismic zone and periodic severe earthquakes are also a factor of river instability.
- Hydrometeorology: The drainage area of Brahmaputra, and Barak in India is subjected to cyclonic storms originating in the Bay of Bengal, particularly in the latter part of the monsoon season.
- Climate change: Although overall rainfall is decreasing in North East, in some areas intensity of rainfall has increased (CSE).
- For example, in Assam, districts north of the Brahmaputra show an increasing trend in rainfall in the last 30 years (CSE).
- Drainage congestion: Due to heavy rainfall of short duration coupled with high flow levels in the main river rainwater is prevented from draining quickly into the riverbed.
- Anthropogenic: Construction, encroachment of river bodies, embankments obstructing natural flows, etc. also induce drainage congestion.
Recommendations for enhancing flood resilience of North East India
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