UC Irvine

India's lost waterWater resources are at a premium in many parts of the world, and India is one of them. Indirect evidence suggests that groundwater is being consumed faster than it is being naturally replenished in northwest India, but assessments of large-scale rates of depletion are difficult to construct from ground based measurements, which are often scattered and incomplete. Gravity observations from NASA's Gravity Recovery and Climate Experiment (GRACE) satellites, combined with land surface models, have been used to produce monthly time series of groundwater storage variations in India. The analysis reveals a progressively more severe reduction in groundwater in Northwestern India between 2002 and 2008. Groundwater has been depleted at a mean rate of 4.0 cm of water per year averaged over the northern Indian states of Rajasthan, Punjab and Haryana, equivalent to a net loss of 109 km3 of groundwater during that period. The authors consider unsustainable consumption of groundwater for irrigation and other anthropogenic uses as the most likely cause.