Scientists uncovered the water depletion by conducting one of the first comprehensive and publicly available sets of hydrological measurements of the area. Over a seven-year period beginning in 2003, sections of Turkey, Syria, Iraq and Iran lost 144 cubic kilometers (117 million acre feet) of water – about the equivalent of all the water in the Dead Sea. The scientists attribute the bulk of the loss—some 60 percent—to pumping of water from underground reservoirs.
Using measurements from the Gravity Recovery and Climate Experiment (GRACE) satellites, researchers at the University of California, Irvine, NASA and the National Center for Atmospheric Research have identified the Tigris and Euphrates River Basin as having the second fastest rate of groundwater storage loss, after India. In the Middle Eastern region, “GRACE data show an alarming rate of decrease in total water storage,” the scientists report in a paper accepted for publication in Water Resources Research, a journal of the American Geophysical Union. The study will publish on 15 February.
The GRACE mission, which NASA launched in 2002 to measure the earth’s local gravitational pull from space, is providing a global picture of trends in water storage, said Jay Famiglietti, principal investigator of the new study and a hydrologist and UC Irvine professor of Earth System Science.
GRACE is “like having a giant scale in the sky,” he said. Within a region, rising or falling water reserves alter the Earth’s mass in a particular region, influencing how strong the local gravitational attraction is. By periodically measuring the gravity regionally, the satellites provide information about how much each region’s water storage changes over time.
“GRACE is really the only way we can estimate groundwater storage changes from space right now,” Famiglietti said. “Whenever you do international work, it’s exceedingly difficult to obtain data from different countries. For political, economic, or security reasons, neighbors don’t want each other to know how much water they’re using. In regions like the Middle East, where data are relatively inaccessible, satellite observations are one of the few options.”
The 754,000-square-kilometer (291,000-square-mile) Tigris and Euphrates basin jumped out as a hotspot when UC Irvine researchers looked at the global water ups and down, Famiglietti said. Within the seven-year period of GRACE data they analyzed, he and his colleagues calculated that water storage in the region shrunk by an average of 20 cubic km (16 million acre feet) a year. “This rate of water loss is among the largest liquid freshwater losses on the continents,” the authors wrote in the study, noting it was especially striking after a drought afflicted the region in 2007. Meanwhile, the region’s demand for fresh water is rising, Famiglietti noted.
From the satellite measurements of decreasing water storage, he and his colleagues calculated that about one-fifth of the observed water losses resulted from soil drying up and snowpack shrinking, partly in response to the 2007 drought. Loss of surface water from lakes and reservoirs reservoirs accounted for about another fifth of the decline. Looking at those results and the GRACE data, they determined that the majority of water loss - approximately 90 cubic km (73 million acre feet) over the seven-year period – was due to reduced groundwater.
When a drought shrinks the available surface water supply, irrigators and others turn to groundwater, Famiglietti said. The Iraqi government drilled about 1,000 wells in response to the 2007 drought, but that doesn’t include the numerous private wells that landowners very likely drilled as well.
Water management is a complex issue in the Middle East, “an area that already is dealing with limited water resources and competing stakeholders,” said Kate Voss, lead author of the study and a water policy fellow with the University of California’s Center for Hydrological Modeling in Irvine, which Famiglietti directs.
Turkey controls the Tigris and Euphrates headwaters, as well as the reservoirs and infrastructure of Turkey’s Greater Anatolia Project, which dictates how much water flows downstream into Syria and Iraq, the researchers note. And due to different interpretations of international laws, the Tigris and Euphrates basin does not have coordinated water management. Turkey’s control of how much water flows into neighboring countries has already caused tension, such as during the 2007 drought, when Turkey continued to divert water to irrigate agricultural land, the scientists state.
“That decline in streamflow put a lot of pressure on northern Iraq,” said Voss. “Both the UN and anecdotal reports from area residents note that once streamflow declined, this northern region of Iraq had to switch to groundwater. In an already fragile social, economic and political environment, this did not help the situation.”
Famiglietti, Voss and two colleagues from UC Irvine are visiting another Middle Eastern region beginning on 18 February, on a “science diplomacy” trip to Israel, Palestine and Jordan. One goal of the trip is to simply raise awareness and share their data about groundwater depletion, which is also a serious issue in the three countries they will visit. While the researchers hope to establish collaborations with local groups to measure aquifers on site, the trip is also a chance for the American scientists to learn about some of the water-efficiency practices in arid regions, Famiglietti said.
“They just do not have that much water to begin with, and they’re in a part of the world that will be experiencing less rainfall with climate change. Those dry areas are getting dryer,” Famiglietti said. “They and everyone else in the world’s arid regions need to manage their available water resources as best they can.”
“Groundwater depletion in the middle east from GRACE with implications for transboundary water management in the Tigris-Euphrates-Western Iran region”
Katalyn A. Voss Science, Technology and International Affairs Program, School of Foreign Service, Georgetown University, Washington, DC, and UC Center for Hydrological Modeling, University of California, Irvine, Calif., USA;James S. Famiglietti UC Center for Hydrological Modeling, and Department of Earth System Science, University of California, Irvine, Calif., USA;MinHui Lo UC Center for Hydrological Modeling, University of California, Irvine, Calif., USA, and Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan;Caroline de Linage Department of Earth System Science, University of California, Irvine, Calif., USA;Matthew Rodell Hydrologic Sciences Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA;Sean C. Swenson Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, Colo., USA.
+1 (202) 777-7507
UC Irvine Contact:
+1 (949) 824-3969
+1 (818) 354-0474
Peter Weiss | Source: American Geophysical Union
Further information: www.agu.org
Further Reports about: American Geophysical Union > Atmospheric > Atmospheric Research > Climate change > Earth's magnetic field > Groundwater > Hydrological > NASA > surface water > water management > water resource
More articles from Earth Sciences:
Climate change puts forty percent more people at risk of absolute water scarcity
17.12.2013 | Potsdam-Institut für Klimafolgenforschung
Recognizing the Elephant in the Room: Future Climate Impacts across Sectors
17.12.2013 | Potsdam-Institut für Klimafolgenforschung
A 12-year study of massive stars has reaffirmed that our Galaxy has four spiral arms, following years of debate sparked by images taken by NASA's Spitzer Space Telescope that only showed two arms.
The new research, which is published online today [17 December] in the Monthly Notices of the Royal Astronomical Society, is part of the RMS Survey, which was launched by academics at the University of Leeds.
Astronomers cannot see what our Galaxy, which is called the Milky Way, looks like because we ...
In collaboration with the University of Basel, an international team of researchers has observed a strong energy loss caused by frictional effects in the vicinity of charge density waves.
This may have practical significance in the control of nanoscale friction. The results have been published in the scientific journal Nature Materials.
Friction is often seen as an adverse phenomenon that leads to wear and causes energy loss. Conversely, however, too little friction can be a disadvantage as well – ...
A new type of transistor that could make possible fast and low-power computing devices for energy-constrained applications such as smart sensor networks, implantable medical electronics and ultra-mobile computing is feasible, according to Penn State researchers.
Called a near broken-gap tunnel field effect transistor (TFET), the new device uses the quantum mechanical tunneling of electrons through an ultrathin energy barrier to provide high current at low voltage.
Penn State, the National Institute of Standards and Technology and IQE, a specialty wafer manufacturer, jointly presented their findings at ...
The team of Johannes Zuber at the IMP in Vienna, Austria, managed to overcome remaining key limitations of RNA interference (RNAi) - a unique method to specifically shut off genes.
By using an optimized design, the scientists were able to inhibit genes with greatly enhanced efficiency and accuracy. The new method facilitates the search for drug targets and improves the interpretation of experimental results.
The IMP will make this „RNAi toolkit“ available to researchers. Results of the study are published in ...
Research The dangerous parasite Schistosoma mansoni that causes snail fever in humans could become significantly less common in the future a new international study led by researchers from the University of Copenhagen predicts.
The results are surprising because they contradict the general assumption that climate change leads to greater geographical spread of diseases. The explanation is that the parasite’s host snails stand to lose suitable habitat due to climate change.
“Our research shows that the expected effects of climate change will lead ...
18.12.2013 | Life Sciences
18.12.2013 | Medical Engineering
18.12.2013 | Studies and Analyses
11.12.2013 | Event News
10.12.2013 | Event News
05.12.2013 | Event News