By Norberto Ovando
“The human being is in the midst of all nature, as a member of it and not as a dominator and exploiter of natural resources " - Rodolfo Pocop Coroxon - Maya Kaqchiquel
The researchers used NASA's GRACE satellites to take precise measurements of the world's underground aquifers. The satellites detected subtle changes in Earth's gravitational pull, observing where the heavier weight of water exerted the greatest tug on the orbiting spacecraft. Slight changes were recorded in the water levels of the aquifers over a decade, from 2003 to 2013.
"This has really been our first opportunity to see how these large reservoirs change over time," said Gordon Grant, a research hydrologist at Oregon State University, who was not involved in the studies.
Hidden vital water
The health of the world's aquifers varies widely, depending primarily on how they were used and are currently being used.
Underground aquifers supply 35 percent of the water used by humans worldwide. Scientists had long suspected that humans were taxing the world's groundwater supply, but NASA data was the first detailed assessment to show that major aquifers are struggling to keep up with the demands of agriculture. , population growth, poorly developed thermal tourism and industries such as oil and mining.
Aquifers can take thousands of years to fill as they slowly recharge with meltwater and rain.
Twenty-one of the 37 largest aquifers in the world have passed their tipping points in sustainability, meaning that over a decade, the study period, more water was removed than the natural rate of recharge. Thirteen aquifers declined at rates that placed them in the most problematic category. The researchers said this indicated a long-term problem and is likely to worsen as dependence on water from aquifers grows.
The Guaraní Aquifer is an important transboundary underground water body formed in the Mesozoic era. It is a group of sandy rocks that is below the level of the ground that has water in its pores and fissures. These rocks were deposited there between 245 and 144 million years ago.
Its dimensions are fabulous: it exceeds Spain, France and Portugal combined in size.
A 2014 newspaper El Pueblo report highlighted that the danger of collapse was already announced, a fact denounced by an indiscriminate number of thermal water wells that uselessly lose a significant amount of water daily, which goes to the rivers.
In Brazil alone, where the aquifer extends about 840 thousand square kilometers, it supplies more than 300 towns, including some 6 million inhabitants of Sao Paulo.
In Argentina, with its 225 thousand square kilometers and Uruguay, with 45 thousand, in addition to drinking water wells, there are numerous thermal water drilling and others for rice plantations.
On the situation of the aquifer, the report explains that the total volume of water is estimated at about 30,000 km³. However, the exploitable reserves are about 2,000 km³ / year, and the recharge in the places where it emerges is only 5 km³ / year.
The Uruguayan geologist, Jorge Montaño, pointed out that "in a matter of 10 years the salinization of the aquifer had increased significantly, so now the issue could have worsened," he warned.
The head of the Chair of Hydrogeology at the University of Buenos Aires, Dr. Miguel Auge, warned the media that "it is urgent to stop the massive and intensive exploitation of the Aquifer, including for healing baths."
The Guaraní Aquifer, which today the University of California researchers put on a red alert because it loses more water than it receives, has a grim prognosis.
"The situation is quite critical," said Jay Famiglietti, a scientist at NASA's Jet Propulsion Laboratory in California and the principal investigator of the studies led by the University of California at Irvine, adding, IT IS NOT KNOWN HOW MUCH REMAINS "Physical measurements and chemicals available are simply insufficient considering how rapidly we are consuming the world's groundwater reserves, we need a coordinated global effort to determine how much is left. "
The total volume of groundwater is probably much less than the rudimentary estimates made decades ago.
Source: NASA / AAPN
Prof. Norberto Ovando
President / Friends of National Parks Association - AAPN -
Expert World Commission on Protected Areas - WCPA -
International Union for Conservation of Nature - IUCN