Key Takeaways
- 23 crore people at risk: The Ganga-Brahmaputra delta is sinking 1.5-2.5 mm per year.
- Double threat: Land subsidence combined with sea-level rise accelerates flooding risk.
- Major cities vulnerable: Kolkata, Howrah, Khulna, and the Sundarbans face heightened danger.
- Urgent action needed: Study calls for reducing groundwater extraction and revising infrastructure plans.
A major new scientific study reveals the Ganga-Brahmaputra delta, supporting over 23 crore people, is sinking rapidly, compounding the threat of sea-level rise and putting millions at risk of severe flooding.
What the Research Found
Published in the journal Earth’s Future, the research by teams from IISc and IIT Kanpur used satellite and ground data. It found the delta is subsiding at 1.5 to 2.5 millimetres annually. This sinking, driven by sediment compaction and excessive groundwater extraction, dramatically worsens the impact of global sea-level rise.
A “Slow-Moving Disaster”
“This is a slow-moving disaster. The combined effect of subsidence and sea-level rise means the relative sea level is increasing much faster than we thought,” said one of the lead authors.
The consequences are severe: more frequent and intense floods, saltwater poisoning fertile agricultural land, and more destructive storm surges during cyclones.
Regions and Cities at Heightened Risk
The delta spans and Bangladesh. Major urban centres like Kolkata, Howrah, and Khulna, along with the fragile ecosystem of the Sundarbans mangrove forest, are directly in the danger zone. Researchers warn that existing coastal defences will fail if sinking is not accounted for.
The Call for Urgent Policy Intervention
The study’s authors stress the need for immediate action. “We need to urgently reduce groundwater extraction and re-evaluate our infrastructure plans. Managed retreat from the most vulnerable areas may also need to be considered in the long term,” they stated. The findings are a direct call for policy measures to protect the region’s massive population from an escalating environmental crisis.
