Earth’s ground­wa­ter be­ing drained at rapid rate: study

The China Post - - LIFE -

Hu­man ac­tiv­ity is lead­ing to the rapid drain­ing of about one third of the planet’s largest un­der­ground wa­ter re­serves and it is un­clear how much fluid re­mains in them, two new stud­ies have found.

Con­se­quently, huge sec­tions of the pop­u­la­tion are us­ing up ground­wa­ter with­out know­ing when it will run out, re­searchers said in find­ings that will ap­pear in the jour­nal Wa­ter Re­sources Re­search and were posted online Tues­day.

“Avail­able phys­i­cal and chem­i­cal mea­sure­ments are sim­ply in­suf­fi­cient,” Univer­sity of Cal­i­for­nia Irvine pro­fes­sor and prin­ci­pal in­ves­ti­ga­tor Jay Famigli­etti said in a state­ment.

“Given how quickly we are con­sum­ing the world’s ground­wa­ter re­serves, we need a co­or­di­nated global ef­fort to de­ter­mine how much is left,” added Famigli­etti, who is also the se­nior wa­ter sci­en­tist at NASA’s Jet Propul­sion Lab­o­ra­tory.

Sci­en­tists used data from

spe­cial NASA satel­lites to mea­sure ground­wa­ter losses.

In the first pa­per, they looked at 37 of Earth’s big­gest aquifers be­tween 2003 and 2013. Eight of these were clas­si­fied as “over­stressed,” mean­ing they were be­ing sucked dry with al­most no nat­u­ral re­plen­ish­ment to off­set the us­age.

Five other aquifers were de­ter­mined to be “ex­tremely or highly stressed.”

Sci­en­tists warned the sit­u­a­tion would only worsen with cli­mate change and pop­u­la­tion growth. The most over­bur­dened aquifers are in the world’s dri­est places, where there is lit­tle nat­u­ral re­plen­ish­ment.

“What hap­pens when a highly stressed aquifer is lo­cated in a re­gion with so­cioe­co­nomic or po­lit­i­cal ten­sions that can’t sup­ple­ment de­clin­ing wa­ter sup­plies fast enough?” said Alexan­dra Richey, the lead au­thor on both stud­ies.

“We’re try­ing to raise red flags now to pin­point where ac­tive man­age­ment to­day could pro­tect fu­ture lives and liveli­hoods.”

Re­searchers found that the Ara­bian Aquifer Sys­tem, pro­vid­ing wa­ter for more than 60 mil­lion peo­ple, is the world’s most over­stressed source.

The In­dus Basin aquifer of north­west­ern In­dia and Pak­istan is the sec­ond- most over­stressed, and the Murzuk-Djado Basin in north­ern Africa is third, sci­en­tists said.

In drought- striken Cal­i­for­nia, the Cen­tral Val­ley aquifer was la­beled as “highly stressed.”

The sec­ond pa­per con­cludes that the to­tal re­main­ing vol­ume of the world’s us­able ground­wa­ter is poorly known and huge dis­crep­an­cies ex­ist in es­ti­mated “time to de­ple­tion.”

“We don’t ac­tu­ally know how much is stored in each of these aquifers. Es­ti­mates of re­main­ing stor­age might vary from decades to mil­len­nia,” Richey said.

“In a wa­ter-scarce so­ci­ety, we can no longer tol­er­ate this level of un­cer­tainty, es­pe­cially since ground­wa­ter is dis­ap­pear­ing so rapidly.”

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