Map above shows drawdown of California groundwater from GRACE satellite data.
Global ground water supplies, crucial for sustaining agriculture, are being depleted at an alarming rate with dangerous security implications, a leading scientist said.
“It’s a major cause for concern because most of the places where it (ground water depletion) is happening are major food producing regions,” James Famiglietti, a University of California professor who conducts research for the National Aeronautics and Space Administration (NASA), said in an interview with the Thomson Reuters Foundation.
“India is the worst off, followed by the Middle East, and the U.S. is probably number three … the Chinese, particularly on the north China plain, are more water limited than people believe.”
–“In 90 percent of the world where there are violent conflicts, there are water scarcity issues,” he said.
Water scarcity has been one component driving Syria’s civil war, he said. The agricultural sector lacks sufficient water to farm, and a “young generation of unhappy farmers moved to the city and conflict ensued”.
J. S. Famiglietti in Nature Climate Change (paywalled):
Consequently, most of the major aquifers in the world’s arid and semi-arid zones, that is, in the dry parts of the world that rely most heavily on groundwater, are experiencing rapid rates of groundwater depletion. Groundwater is being pumped at far greater rates than it can be naturally replenished, so that many of the largest aquifers on most continents are being mined, their precious contents never to be returned.These include the North China Plain, Australia’s Canning Basin, the Northwest Sahara Aquifer System, the Guarani Aquifer in South America, the High Plains and Central Valley aquifers of the United States, and the aquifers beneath northwestern India and the Middle East. Nearly all of these underlie the word’s great agricultural regions and are primarily responsible for their high productivity. Climate change and associated changes to the water cycle vastly complicate the challenge of sustaining groundwater supplies for the foreseeable future.Changing patterns of precipitation and groundwater recharge, and increasingextremes of flooding and drought are among the most palpable impacts of global change, and underscore the need to rethink stationarity in current water management strategies. As the wet, high- and low- latitude areas of the world become wetter, and the dry areas in between become drier (and already limited groundwater recharge decreases), the ‘haves’ and ‘have nots’ of the future water landscape are emerging.
The confrontations between energy and water are particularly stark in China, where the water footprint of energy development and the energy footprint of water are large and growing.
Water drives the economy and dwindling supplies threaten the country’s energy production and economic growth. China’s reliance on water-intensive coal is well known: 70% of the country’s coal plants are situated in arid north and almost half of these plants are already threatened by water shortages.
Alternatives to coal, such as natural gas, nuclear and hydropower are also constrained by water availability. Nuclear power plants use an enormous amount of water for cooling. In almost all of China’s promising shale gas areas –such as the Tarim basin in the northwest – water supplies are limited. Even solar power – where China is the world’s leading market and producer – uses water for the manufacturing of parts and cleaning panels.
Less well known is the rapidly expanding energy footprint of the water sector. Mega-diversion projects to expand water supply like the South-North Water Transfer Project (SNWTP), or the proposed Bo Hai sea water pipeline, drive up the energy costs of providing water. To pump water along the eastern stretch of the SNWTP will require the conversion of millions of tonnes of coal per year into electricity to move the water and, creating further water stress.
maybe if minds were applied to harvesting flood waters? Lazy politics. Flood relief could become water salvage.
That’s one of the reasons dams are built—-to control and “harvest” floods, but if it just doesn’t rain enough, the stored water is depleted over time (like Lake Mead and Glen Canyon). If the reservoir is already full when heavy rains come, they have to release the water, and can’t “harvest” any of it.
Mexico City has a very bad ground water problem, too. Saw a news report on this just this evening on PBS News Hour. Over the decades, they have caused the land to subside as much as FORTY FEET.
Unless they said four feet – either way, it is a lot. They have leaning buildings to prove it.
Didn’t see that show, but most of Mexico City had subsidence of over 30 feet during the 20th century, so 40 feet sure could be true in small areas. The iconic photo of the pole in the San Joaquin valley shows 28 feet of sinking from 1925 to 1977, the greatest subsidence in the U.S..
I’m no hydrologist, but I do know the reason the land subsides is that the pores in the aquifer layer collapse under the weight of the earth above when the water is withdrawn, and once that happens, it’s pretty much permanent—-you can’t “jack it up” if and when the rainfall increases to the point that recharging occurs, and the capacity of the aquifer never returns to its old level.
This problem is only going to get worse.
An interesting study on the The Assyrian Empire from Adam Schneider of the University of California, San Diego and Selim Adalı of Koç University in Istanbul, Turkey:
I’m not sure that the (fossil fuelled) Californian desalination plants are going to help too much in the long run:
“Schneider also sees an eerie similarity between Nineveh and Southern California. Though people weren’t forcibly relocated to Los Angeles or San Diego to help an emperor grow himself a “great city,” still, the populations of these contemporary metropolitan areas are probably also too large for their environments.
On a more global scale, Schneider and Adalı conclude, modern societies should pay attention to what can happen when immediate gains are prioritized over considerations of the long term.
“The Assyrians can be ‘excused’ to some extent,” they write, “for focusing on short-term economic or political goals which increased their risk of being negatively impacted by climate change, given their technological capacity and their level of scientific understanding about how the natural world works. We, however, have no such excuses, and we also possess the additional benefit of hindsight, which allows us to piece together from the past what can go wrong if we choose not to enact policies that promote longer-term sustainability.”
http://phys.org/news/2014-11-people-years.html
Graphs may have intercepts. When does the water run out?
( I need to budget my ammunition stockpiling.)
The groundwater runs out when the farmers run out of money to drill deeper wells to get to it. And since they can keep jacking their prices to pay for the drilling, the question eventually becomes “When do Americans run out of money to buy food?” Since California doesn’t much regulate water use and hardly studies it, no one really knows how much there is and where the “bottom” lies. Sad but true.
“California doesn’t much regulate water use”?? WTF?
That’s some Category 5 stupidity given the region’s history.
Hard to believe, isn’t it? They have just passed some laws, but until now CA has been the only western state that had NO regulations in place regarding groundwater.
http://thinkprogress.org/climate/2014/08/30/3477615/underground-water-regulation-california-first-ever/
PS
Andrew Fez lives in the middle of the “dry zone” and commented on this in the past. If I remember, some CA towns don’t even meter water to homes—-just charge a rather low flat monthly fee to be hooked up. Use all you want.