Ganga-Brahmaputra delta sinking faster than rising sea levels, says new study
A new study in Nature reveals that in parts of the Ganga-Brahmaputra delta subsidence rates match or exceed sea-level rise.
Over 90% of this massive delta—home to about 230 million people in India and Bangladesh—is subsiding, putting millions at greater risk from floods.
Groundwater use is making things worse
The main culprit? Too much groundwater being pumped out for farming, industry, and daily life.
Satellite measurements show local subsidence rates of several millimeters per year according to the Nature study, with some areas exceeding 5-8mm/yr.
In the coming decades, this subsidence could substantially increase local relative sea-level rise in parts of the delta.
Double trouble: Sinking land plus rising seas
In nearly half of the deltas studied worldwide, including this one, land is sinking faster than water is rising.
This "double burden" means more flooding and damage to homes and infrastructure.
What can help?
Experts suggest cutting back on groundwater extraction, refilling aquifers with floodwater or treated wastewater, letting some areas flood naturally to rebuild sediment, and avoiding heavy construction in risky zones.
These steps could help protect millions living in the delta's path.