2024-09-02 02:42:34
Groundwater is a natural resource found underground, in the cracks and gaps of soil, sand and rocks. It is held in aquifers and, even if it is buried, when it bubbles up, it can help replenish surface levels of rivers, lakes and streams.
Beyond this, in recent years, aquifers have also been seen as one of the last resources to alleviate the drought that threatens us. However, the world may be losing until this last ace.
According to a study that has just been published Naturethe world’s aquifers are drying up. 71% have lost water volume since 1980, 30% of them at an accelerated paceThe rate of decline is estimated to be more than 0.5 metres per year.
The figure may also be higher over the years. As the researchers point out, the volume of decline between the 1980s and 1990s was much smaller than that experienced from 2000 to the present, which highlights that the problem It’s getting worse and worse.
“Our study is driven by curiosity. We wanted to better understand the state of global groundwater by analyzing millions of groundwater level measurements,” he says. Debra Perronelead author of the study and associate professor in the Environmental Studies Program at the University of California, Santa Barbara (United States).
More than 40 countries
The findings of the professor and her team are the more complete analysis of global groundwater levels to date. In total, they have compiled data from 170,000 wells in more than 40 countries.
The task has been arduous, but it has served to highlight the incident problem of the exhaustion of this resource. packed with advantages: It is easy to find, it is drought resistant and it serves to satisfy the water needs of the population. In fact, around 50% of the population of the United States uses it as drinking water, although its main use is for crop irrigation and agricultural productionIt is its exploitation for this purpose that is the beginning of the problem.
Based on the research, the decline is not the same in all parts of the world. The most accelerated decline is in arid and semi-arid landssomething that, according to Professor of Environmental Sciences Scott Jasechko and co-author of the research, was to be expected. “It’s one thing to expect it and quite another to prove that it’s happening with real data,” he clarifies.
A clear example of the problem of aquifers is here, in Spain. According to the Report on the status of aquifers in the Doñana area (2020-2021), the Doñana aquifer shows a negative trend and most of its areas are in “alert status”.
The same report details that “if the current level and method of exploitation of the underground resources of the aquifer is maintained, its good condition would be compromised.” and that of the terrestrial ecosystems that depend on it«.
In the case of the study of Naturethe Cingla-Cuchillo aquifer (Murcia) and Aquifer 23, in the Alto Guadiana, have been included. Just recently, it was reported that the latter had dropped by 1,750 hm3 in 43 years.
Viable solutions
However, it’s not all bad news. The researchers also found that 6% of aquifers rose at a rate of 0.1 meters per year, while 1% grew at a rate of 0.5 meters/year.
“This study shows that humans can change things “with deliberate and concentrated efforts,” says Jasechko.
Researchers believe that the growth figures are due to several factors, including: measures that advocate reducing groundwater consumption, the implementation of policies on the issue, surface water transfers, changes in land cover and recharge projects.
Jasechko gives the example of Tucson, Arizona, USA. There, water from the Colorado River is used to replenish the aquifer in the nearby Avra Valley in order to store water for the future. “Groundwater They are usually considered a kind of bank account“, explains the professor. “Deliberately filling the aquifers allows us to store that water until a time of need.”
Governments can spend millions of euros to build infrastructure to retain water on the surface, but what the study of Nature proposes is that, if you have the right geology, you can store large quantities of water undergroundwhich is much cheaper and less dangerous and would also kill two birds with one stone.
Beyond this method of reserve, the importance of maintaining aquifers is based on multiple variables. As the authors recall, the depletion of groundwater can damage infrastructure due to land subsidence, harm river ecosystems, endanger agricultural productivity and compromise water supply.
Fuente: www.elespanol.com