The depletion of groundwater resources is a serious issue occurring globally, affecting billions of people and various economic and social activities.
A study examining approximately 1,700 aquifers in over 40 countries revealed that the groundwater levels of nearly 850 aquifers have decreased since 2000.
The most significant declines have been observed in arid regions with extensive agricultural land, such as California’s Central Valley in the United States and many areas in Iran…
According to the recently published study in the journal Nature, only about 7% of aquifers experienced rising groundwater levels during the same period last year.
Regions with arid climates and extensive agricultural land show significant declines in groundwater. (Illustrative image).
Groundwater, stored in fractures and pores within permeable rock formations known as aquifers, is essential for human survival, particularly in areas with scarce rainfall and surface water, such as Northwest India and the Southwestern United States.
The reduction in groundwater may make it increasingly difficult for people to access freshwater for drinking or irrigating crops, potentially leading to land subsidence.
According to the experts involved in the study, this is the first research to compile what is happening to groundwater levels on a global scale, which will help scientists better understand human impacts on this valuable resource through over-extraction or indirect effects from climate change-related shifts in rainfall.
“This study was driven by curiosity. We wanted to gain a better understanding of global groundwater conditions by conducting millions of groundwater level measurements,” said Debra Perrone, co-author of the study and associate professor in the Environmental Studies Program at the University of California, Santa Barbara.
Co-author Scott Jasechko, an associate professor at the Bren School of Environmental Science and Management at the University of California, further noted that the Ascoy-Soplamo aquifer in Spain is experiencing the fastest decline in the data they compiled, with an average decrease of 2.95 meters per year.
According to The New York Times, there are several causes for the decline in groundwater, including the use of groundwater for urban consumption in major cities and irrigation for agriculture in rural areas.
Researchers also identified a correlation between groundwater levels and precipitation or snowfall in the same regions. In 80% of the aquifers with rapidly declining groundwater levels from 1980 to 2020, rainfall also decreased.
Additionally, the study indicated that in some areas where aquifers are recovering, such as Bangkok, Thailand, and the Coachella Valley in California, local governments have implemented regulations to reduce groundwater use.
Some regions in the Southwestern United States are actively replenishing aquifers using river water, as residents of the Avra Valley in Arizona have shifted to using water from the Colorado River.
In Los Arenales, Spain, groundwater has been improved through river water, treated wastewater, and rainwater.
“I am very impressed by the smart strategies that have been implemented to address groundwater depletion in some areas, although these positive stories are quite rare,” Jasechko shared via email with CNN.
