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Groundwater depletion, food, and fossil fuels
"Out of sight, out of mind"


Agriculture also depends on groundwater, aquifers.

Saudi Arabia had an agriculture that depended completely on fossil water, an aquifers. Dairy cows had to be cooled by sprinklers, they say.

The project has now been abandoned, it seems. In how far did the depletion of the local aquifer contribute to this decision?
    From the Egyptian oasis Baharaya we received this report:

    Helmut,

    right, my idea was not to comment on oasis Baharaya ground water situation, but it is true and tragic, as you can see on my attached pictures. The oasis is green and lush and one of the most important Egyptian producer of dates, some of the best you can taste.
    In ancient times, before industrialisation, Baharaya's hot springs burst out of the ground just by themselves and the oasis bloomed. This is also the reason why many high-ranking pharaonic officials lived there, the most important ones even had small temples, and about 10'000 it is estimated are mummified there.

    Today the hot water still flows, at about 45 C, you can put hand or feet in for just a few seconds. What a pleasure the day before yesterday when the air was so cold and we could warm up our feet.

    But, look at the diesel engine of which there are now many around the oasis, they pump the water from deep below because the ground water level has sunk so much.

    I do not know how long this can go on and when the sources will be definitively dry and the oasis will be dead.

    It seems the locals are not so much worried, as long as diesel fuel for the pumps are available, insh'allah.
 
    Regards now from Sharm-el-Sheikh

    Reinhard Christeller [20 January 2010]
Diesel fuel and technology: instrumental in environmental depletion.


http://pubs.usgs.gov/pp/1766/
www.byebyenet.com/Egypt/Oasis/bahariya oasis.htm
http://www.aucegypt.edu/research/ddc/research/WDM/Pages/WaterUse.aspx#nubian
http://www.wrsc.org/story/groundwater-depletion-rate-accelerating-worldwide
http://blogs.nationalgeographic.com/blogs/news/chiefeditor/groundwater.html
http://geology.com/news/2009/groundwater-in-the-central-valley-aquifer.shtml
http://www.peaktoprairie.com/?D=192
http://www.jpl.nasa.gov/news/news.cfm?release=2009-194
http://pubs.usgs.gov/pp/1766/
http://www.globserver.com/en/press/wheat-production-gradually-phasing-out22102010
http://www1.american.edu/TED/SAUDI.HTM - E. ENVIRONMENT CLUSTERS 20. Environmental problem type: WATER A number of problems have been associated with subsidy programs. Meaningful statisticsinclude: a loaf of bread weighing only 200 grams uses 400 liters of water and Saudi Arabia uses 80 percent of its fresh water for agriculture. Dr. Mohammed Al-Qunaibet, head of the Agricultural Department, King Saud University, says the agriculture-promotion policy was environmentally not feasible. The undertaking initiated in 1978 by the Ministry of Agriculture and Water in 1978 was based on the slogan "food security and self-sufficiency at any cost". Saudi Arabia uses irreplaceable fossil ground water to grow wheat. Many Arab environmentalists consider this to be the most outstanding, negative example for water planners. However, about 10,000 water pivots were withdrawn in 1993, along with supporting machinery such as water pumps.

'Groundwater Depletion Raises Likelihood of Global Food Crises'

By original: 17 Jan 2011 12:12 PM PST (Copyright notice)

Water budgets are badly out of balance, throwing many regions into water debt. The water depleted annually could feed 940 million people for a year.

By Sandra L. Postel, National Geographic Freshwater Fellow

This post is part of National Geographic's Freshwater Initiative.

Out of sight, out of mind means deep trouble when it comes to the reserves of freshwater stored underground. New numbers are out on the rate of groundwater depletion around the globe, and if they hold up to further scrutiny, the world is almost certainly facing a future of food shortages.

In an upcoming issue of Geophysical Research Letters, a journal of the American Geophysical Union, Professor Marc Bierkens of Utrecht University in the Netherlands and his colleagues estimate that the rate at which humanity is pumping dry the underground reservoirs that hundreds of millions of people depend upon for food and drinking water more than doubled between 1960 and 2000.

Global map of groundwater depletion, measured in millimeters of water per year, courtesy of American Geophysical Union.

Using global groundwater data and hydrologic modeling to calculate the volumes of water added to and withdrawn from underground aquifers, the researchers estimate that groundwater depletion rose from 33 trillion gallons (126 billion cubic meters) per year in 1960 to 75 trillion gallons (283 billion cubic meters) per year in 2000. The rate increased more or less linearly from 1960 up to the early 1990's, but then climbed sharply--likely due to escalating groundwater use in China and India.

Although the research team doesn't delve into the implications of their findings, a lot is at stake--especially for the world's food supply. Irrigation, which accounts for 70 percent of world water use, is the principal cause of the groundwater depletion. About 40 percent of the world's food supply comes from the 18 percent of farmland that's irrigated, making irrigated farming a cornerstone of global food security. But in recent decades as more farmers have turned from rivers to groundwater for their water supply, groundwater pumping in many areas has become unsustainable.

Just as a bank account shrinks when withdrawals exceed deposits, so does a groundwater account. Water budgets are badly out of balance, throwing many regions into water debt. In effect, farmers are using some of tomorrow's water to meet today's food demands.

(Related: "How to Stem a Global Food Crisis? Store More Water" and "365 Trillion Gallons of Water Thrown Away With Our Food Every Year.")

It takes approximately 396,300 gallons (1,500 cubic meters) of water to produce one ton of grain. (That's an approximate average based on the water needed to produce rice, wheat and corn.) So the estimated 75 trillion gallons (283 billion cubic meters) of groundwater depleted in 2000 is sufficient to produce 188.6 million tons of grain. That's enough to feed 943 million people a subsistence diet for a year.

The highest rates of water loss are occurring in critical regions of irrigated farming--including the north plain of China, northwestern India, and the central valley of California. In most areas groundwater is not monitored or regulated, so as increasing numbers of wells extract ever more water, the "tragedy of the commons" is playing out on a large scale.

A little over a decade ago, I took a stab at estimating groundwater depletion using national-level data for China, India, the United States, North Africa and Saudi Arabia. For these regions, I came up with a net loss of 43 trillion gallons (164 billion cubic meters) a year. Adding in a ballpark estimate that inclusion of the rest of the world would bump this figure up by 25 percent, I arrived at a global depletion rate of 53 trillion gallons (200 billion cubic meters) per year--not too far off from the 283 billion figure of this current study, which may lend a little confidence to both.

This global assessment comes on the heels of regional studies that also corroborate the severity of the groundwater depletion problem. Using new satellite technology called GRACE - the Gravity Recovery & Climate Experiment - scientists with the University of California at Irvine and the National Atmospheric and Space Administration have estimated that California's Central Valley - the fruit and vegetable bowl for the nation - has lost a volume of groundwater equivalent to about two-thirds the volume of Lake Mead. Scientists with the U.S. Geological Survey have estimated that as of 2005, a volume of water equivalent to two-thirds of Lake Erie had been depleted from the Ogallala Aquifer, which supplies 30 percent of the groundwater used for U.S. irrigation. And in a 2009 study in Nature, again using the GRACE technology, scientists estimated that northern India, which encompasses that nation's breadbasket, is losing groundwater at a rate of 54 billion cubic meters per year, placing the livelihoods of 114 million people in that region at risk.

(Read "NASA Satellites Track Vanishing Groundwater" in National Geographic News.)

With modern satellite capabilities and new modeling and monitoring techniques, it is now possible to know what is happening to our water supplies underground. The picture is not good. The challenge now is to encourage the adoption of more efficient irrigation systems, more appropriate cropping patterns, and other measures to bring the world's groundwater accounts into balance. The future food security of hundreds of millions of people depends on this.

Sandra Postel directs the independent Global Water Policy Project and lectures, writes, and consults on international water issues. She is also Freshwater Fellow of the National Geographic Society, and serves as lead water expert for the Society's freshwater initiative.

Sandra is the author of several acclaimed books, including Pillar of Sand: Can the Irrigation Miracle Last? (W.W. Norton, 1999) and Last Oasis (W.W. Norton, 1997), which appears in eight languages and was the basis for a 1997 PBS documentary. She is also co-author, with Brian Richter, of Rivers for Life. Her essay "Troubled Waters" was selected for Best American Science and Nature Writing. She is a 1995 Pew Scholar in Conservation and the Environment.

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