The Verde river is one of the last fluid rivers in Arizona, wrapping what is called the Verde valley before feeding on the Salt river. Agriculturally, the valley is relatively fertile, supporting crops such as sweet corn, luzerne, peaches and pacan, as well as a small wine industry. Recently, however, residents found that water under their feet dries up.
Faith Kearns grew up in the region and her mother still lives in her childhood home. This summer, when they tried to turn on the garden hose, which is linked to their underground water well – a common source for household water in the region – nothing is out.
“We have had challenges here and there, but that has certainly worsened in recent years,” the research director of the research of Arizona Water Innovation at the Arizona State University told Grist.
Arizona is far from the only place where groundwater is in great difficulty. According to a study published last week in the academic journal evaluated by Advances peers, freshwater has decreased at an alarming rate since researchers began to observe the world groundwater in 2002, creating areas of “mega-scagge” which cover a large part of the northern hemisphere.
Although climate change is a contributing factor, with high temperatures undermining soil humidity, the main culprit is an over -eating surposer. Once the water is put in human use, it escapes in the ocean where, revealed that the study contributed more to the elevation of the sea level than the cast iron of the Greenland ice cap. The groundwater is responsible for approximately 44% of the world level of the average sea level, against around 37% of Greenland and around 19% of the merger in Antarctica.
The fact that “human management of water resources has such a significant effect on elevation of sea level, I think it has not been seen before,” said Martin Stute, a hydrologist at Barnard College who has not contributed to the study. He stressed that even the oceanic and atmospheric national administration still characterizes the transfer of groundwater to the ocean as a rather minor addition to the elevation of the sea level.
Unless strict water management policies are implemented on a global scale, the main author of the Science Advances study, Jay Famiglietti, warns that the consequences could trigger extreme political instability, since 75% of the world population lies in countries affected by this extreme drying. “What this study clearly shows is that the world is considering an incredible elevation of sea level,” he said. “I think threats to food security and food production [aren’t] receive enough attention.
These policies may not be published anytime soon. The United States, which supplies in half of its drinking water from groundwater, do not have a unifying water management plan, rather based on a fragmentary local regulations network. California has adopted the law on sustainable groundwater management, which aims to regulate water withdrawals and prevent the exhaustion of aquifers in 2014, but the state should not reach models of sustainable water until the early 2040s. Other states such as Louisiana and Maine grant to land owners of “absolute domination” means that any landowner can constantly draw from their well, even to the detriment of their neighbor, even if the aquifers are exhausted and threatened by the intrusion of salt water.
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In some regions of the country, so much water has already been drained that the aquifers have collapsed on themselves, explained the co-author of the Hrishikesh Chandanpurkar study. This causes land sagging, infrastructure damage and an increase in sea level in coastal areas. Sometimes the collapse is irreversible, which means that a given region has no chance of recovering their lost aquifer by recharging the supply of groundwater. Instead, the dead aquifer becomes a public nuisance, creating large chasms that can sprinkle the area like asteroid craters. A recent study by researchers from the University of California, Riverside, noted that houses built in substitution regions lost 2.4% to 5.8% value compared to houses on more stable land.
The study of last month on the worldwater loss of groundwater was carried out using a pair of satellites of NASA, collectively known as the Gravity recovery and climate experience, or Grace, which Famiglietti called “a scale in the sky”, because the system is designed to respond to tiny variations in the storage of groundwater. The genesis of the new research occurred just after the Pandemic COVID-19, when the Famietti worked with colleagues who asked it to review the levels of the groundwater in Germany.
While examining the data, Famiglietti was alarmed: there seemed to be a tilting point after an El Niño event particularly strong in 2014 caused a general drought. The West of the United States, Europe and Central and South America have all experienced a sharp increase in drying during this period. World dry areas are currently developing in an area about twice the size of California each year, even after the end of the drought.
Other research shows that the exhaustion of groundwater is only part of history: what remains of this water, another recent study in the newspaper evaluated by peers, nature Geoscience, warms up. The author of the Susanne Benz study explained that the effects of global warming began to penetrate underground, 40 or 50 meters deep in certain regions. Warming could degrade the quality of groundwater by increasing microbial production, and warmer water facilitates dangerous chemicals generally locked safely in rock, such as arsenic, to dissolve in drinking water. This could also upset freshwater habitats in lakes, ponds and rivers – allowing more harmful proliferation of algae and killing aquatic life.
The biggest problem, Stute said clearly to people that groundwater – like oil – are a finite resource. “It will disappear. What are we doing then? ” He said. “In principle, we are aware of [these] problems, and we do nothing. »»
