Nearly the entire Mekong Delta in Vietnam — an area that helps feed about 200 million people — will sink underwater by the year 2100 at current rates, a new study predicts.
The delta, which is home to almost 18 million people and produces half of Vietnam’s food, faces this potential humanitarian crisis largely because the heavy extraction of groundwater is causing land to sink as sea levels simultaneously rise, the study found.
Researchers at Utrecht University created a delta-wide numerical model to track the impacts of groundwater exploitation over the past 25 years and use that as the basis of future predictions.
When combined with rates of sea-level increase because of climate change, they found that no matter what action was taken the vast low-lying delta plain will be lost — though changes to land use could salvage other areas.
“The results revealed that when groundwater extraction is allowed to increase continuously, as it did in the past decades, extraction-induced subsidence could potentially drown almost the entire Mekong delta,” they concluded.
Philip Minderhoud, a subsurface and groundwater systems researcher at Utrecht University who led the study, said groundwater extraction was one of the most important in a raft of factors causing the delta to sink on average by about 1 centimeter per year.