New Delhi: With several parts of the country already reeling under drought, there is more bad news. Scientists in United States have found that groundwater levels in north Indian cities, including Delhi, are declining as much as one foot per year over the past decade.

Concerned over this trend, the scientists said this was due to “human activity” and warned that if measures were not taken, the region could witness collapse of agriculture output and severe shortage of potable water.

The scientists, with the help of Nasa satellite data, have found that ground levels in northern India have been declining by as much as 33 centimeters (one foot) per year over the past decade, according to an article in NASA website.

And the “researchers concluded that loss is almost entirely due to human activity”.

More than 108 cubic kilometers of groundwater disappeared from aquifers in areas of Haryana, Punjab, Rajasthan and the nation’s capital, between 2002 and 2008, the article said.

The findings is based on data from Nasa’s Gravity Recovery and Climate Experiment (GRACE).

“The region has become dependent on irrigation to maximize agricultural productivity. If measures are not taken to ensure sustainable groundwater usage, the consequences for the 114 million residents of the region may include a collapse of agricultural output and severe shortages of potable water,” said the article, which was reprinted on US embassy website.

A team of hydrologists, led by Matt Rodell of Nasa’s Goddard Space Flight Center, found that underground water supply is being “pumped and consumed by human activities, such as irrigation cropland, and is draining aquifers faster that natural resources process can replenish them”, it said.

“We don’t know the absolute volume of water in the northern Indian aquifers, but GRACE provides strong evidence that current rates of water extraction are not sustainable,” Rodell said.