Story 2015-06-26 CJ8E Half of the world's biggest aquifers are being depleted

Half of the world's biggest aquifers are being depleted

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in environment on (#CJ8E)
story imageIn two new studies, a team of researchers led by hydrologists from the University of California, Irvine assessed the depletion of groundwater on a global scale using readings from NASA's GRACE satellites. The satellites monitor changes in Earth's gravity and act as a "scale in the sky," measuring shifts in the total amounts of water, both above and below ground. They concluded that likely much less water remains in aquifers than previously estimated. Groundwater is the primary source of water for about 2 billion people.

Over half of the world's biggest aquifers are being depleted. They are past sustainability tipping points, and a third of those big aquifers — 13 of those — are seriously distressed. The most severe situations seen in dry areas where little or no water is seeping into the ground to offset the amounts pumped out. The researchers found the Arabian Aquifer System, which supplies water to more than 60 million people, to be the most overstressed in the world, followed by the Indus Basin aquifer of northwestern India and Pakistan, and the Murzuk-Djado Basin in northern Africa, the Canning Basin in Australia and the aquifer system of the North China Plain. The aquifer beneath California's Central Valley was labeled as highly stressed. The Ogallala Aquifer didn't show up as being in decline, overall, even though portions of it likely have only a few decades of water left.

These problems can be addressed with proper management strategies, including replenishing aquifers when possible, recycling wastewater and adopting water-saving irrigation techniques.
Reply 9 comments

Land size vs water availability (Score: 0)

by Anonymous Coward on 2015-06-28 22:42 (#CQ3D)

Often there are calls from people abroad to increase the migrant intake for Australia. You have lots of land, they say. Size of a european country or three, they say. Farms bigger than cities. Waste of space, they say. Get more people! Wonderful. Where will the water for these people come from?

Re: Land size vs water availability (Score: 1)

by evilviper@pipedot.org on 2015-06-28 22:59 (#CQ40)

Re: Land size vs water availability (Score: 0)

by Anonymous Coward on 2015-06-29 03:21 (#CQH9)

Tell me, where do you think the money to build that would come from? Wouldn't be cheap, and from I hear, the Australian economy is faltering somewhat.

Re: Land size vs water availability (Score: 1)

by evilviper@pipedot.org on 2015-06-29 04:30 (#CQMS)

More people coming in means more tax revenue. And when purifying wastewater, you can save money that would otherwise need to be spent on sewage treatment plant upgrades.

Re: Land size vs water availability (Score: 1)

by bryan@pipedot.org on 2015-06-29 07:11 (#CQZH)

We are getting a water desalination plant in San Antonio, where I live. Even though we are pretty dang far from the coast, the bottom half of our aquifer is brackish and too salty to drink. The desalination plant will clean up the (slightly) too salty water so that we can suck the rest of the aquifer dry that we otherwise had to ignore. :)

Re: Land size vs water availability (Score: 0)

by Anonymous Coward on 2015-06-29 22:34 (#CTDM)

Is there a reason why we couldn't desalinify water to pour into rock/sand filters so the water ends up in the aquifers?

Re: Land size vs water availability (Score: 1)

by evilviper@pipedot.org on 2015-06-30 01:10 (#CTPJ)

You COULD do that, but you're wasting a lot of energy pumping it back up to the surface from the depths of the aquifer, for no good reason.

Re: Land size vs water availability (Score: 1, Informative)

by Anonymous Coward on 2015-06-30 02:23 (#CTTZ)

In other parts of the world, fresh water is pumped down into underground salt formations. Then brought back up and the water evaporates out of the brine in big shallow ponds--it's one way to mine salt.

Re: Land size vs water availability (Score: 0)

by Anonymous Coward on 2015-06-30 08:45 (#CVHV)

I meant Sea Water --> Purify to 95% --> Pour into limestone/sand/similar filtering system to feed into aquifer. Some places boil water through systems to effect this. Very interesting setups can be done with natural heat ala lava