The report said that an amount of freshwater "almost the size of the Dead Sea" has been lost in parts of the Middle East over the past seven years.
According to a NASA press release, scientists at the University of California, the Goddard Space Flight Center in Maryland and the National Center for Atmospheric Research in Colorado, found that "During a seven-year period beginning in 2003 that parts of Turkey, Syria, Iraq and Iran along the Tigris and Euphrates river basins lost 144 cubic kilometers of total stored freshwater."
The researchers attribute about 60% of the loss to pumping of groundwater from underground reservoirs, the NASA release said.
The findings, which will be featured in the coming issue of Water Resources Research, are the result of one of the first comprehensive hydrological assessments of the entire Tigris-Euphrates-Western Iran region.
According to the researchers, since obtaining ground-based data in the area is difficult, satellite data, such as those from NASA's twin Gravity Recovery and Climate Experiment (GRACE) satellites, were essential.
GRACE is providing a global picture of water storage trends and is invaluable when hydrologic observations are not routinely collected or shared beyond political boundaries, NASA said.
GRACE satellite data (Screenshot: NASA website)
"GRACE data show an alarming rate of decrease in total water storage in the Tigris and Euphrates river basins, which currently have the second fastest rate of groundwater storage loss on Earth, after India," Jay Famiglietti, principal investigator of the study and a hydrologist and professor at UC Irvine, said.
"The rate was especially striking after the 2007 drought. Meanwhile, demand for freshwater continues to rise, and the region does not coordinate its water management because of different interpretations of international laws."
GRACE," he added, "Is the only way we can estimate groundwater storage changes from space right now."
The data led the team to conclude that about one-fifth of the water loss noted was the result of soil drying up and snowpack shrinking, partly in response to the 2007 drought.
According to the study, loss of surface water from lakes and reservoirs accounted for about another 20% of the losses. The majority of the water lost – roughly 90 cubic kilometers – was due to reductions in groundwater.
"That's enough water to meet the needs of tens of millions to more than a hundred million people in the region each year, depending on regional water use standards and availability," Famiglietti said.
"Water management is a complex issue in the Middle East," fellow researcher Kate Voss noted. "It's an area that is already dealing with limited water resources and competing stakeholders."
Famiglietti added: "The Middle East just does not have that much water to begin with, and it's a part of the world that will be experiencing less rainfall with climate change.
"Those dry areas are getting dryer. The Middle East and the world's other arid regions need to manage available water resources as best they can."
NASA's GRACE is a joint mission with the German Aerospace Center and the German Research Center for Geosciences, in partnership with the University of Texas at Austin.