Satellites unlock secret of India's vanishing water

Groundwater levels have fallen 20 per cent more than expected in northern India, Nasa satellite images have revealed.

A team of experts has found the underwater supply in the region is being pumped and consumed by the burgeoning population, and could spark a major food and water crisis.

The study, led by Matthew Rodell from Nasa said groundwater across three states, including the New Delhi region, dropped at a rate of 1.6 inches per year between 2002 and 2008.

The map shows groundwater changes in India during 2002-08, with losses in red and gains in blue, based on GRACE satellite observations.