Certain regions may run out of groundwater in decades: research

Groundwater in parts of India, southern Europe and the United States is at risk of quick depletion in the coming decades because of human consumption, a new research has found.

By 2050, as many as 1.8 billion people could live in areas where groundwater levels are fully or nearly depleted because of excessive pumping of groundwater for drinking and agriculture, according to a research presented at an American Geophysical Union meeting on Thursday.

"Groundwater is the largest available freshwater resource around the world. When freshwater is not freely available, groundwater is often extracted," said Inge de Graaf, a hydrologist at the Colorado School of Mines.

Some areas in India, southern Europe and the United States "are at greatest risk of running out of groundwater," de Graaf told Xinhua. "It's definitely related to climate change," the researcher added.

According to the study, aquifers -- the soil or porous rocks that hold groundwater -- in the Upper Ganges Basin area of India, southern Spain and Italy could be depleted between 2040 and 2060.

In the United States, aquifers in California's Central Valley, Tulare Basin and southern San Joaquin Valley could be depleted within the 2030s. Aquifers in the southern High Plains, which supply groundwater to parts of Texas, Oklahoma and New Mexico, could reach their limits between the 2050s and 2070s.

Groundwater limits refer to the scenario where groundwater levels have dropped below the pumping threshold for two consecutive years.

Aquifers become stressed when too much water is taken out for household, agricultural and industrial use, and not enough surface water seeps in to replenish the underground rock formations.

Previous studies used satellite data to show that several of the world's largest aquifers were nearing depletion. But satellite data cannot be used to measure aquifer depletion on a smaller, regional scale, according to de Graaf.

De Graaf and colleagues from Utrecht University of the Netherlands used their new model to forecast when and where aquifers around the world may reach their limits.

In the study, researchers used new data on aquifer structure, water withdrawals, and interactions between groundwater and surrounding water to simulate groundwater depletion and recovery on a regional scale.

But scientists still lack complete data about aquifer structure and storage capacity to say exactly how much groundwater remains in individual aquifers. Endi