Newly-obtained results show that 144 cubic kilometres of freshwater – a volume nearly equivalent to that of the Dead Sea or Lake Tahoe – had been removed from the ground in the area that encompasses Turkey, Iran, Iraq and Syria between 2003 and 2009.
“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,” said Jay Famiglietti, the UC Irvine professor who led the team who made the findings, which are due to be published on Friday in Water Resources Reasearch magazine.
While 40 percent of the decline is in the soil and surface water, the decrease in groundwater, caused by human actions, is responsible for 90 cubic kilometers of the shortfall.
“Satellite data shows 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,” said Famiglietti.
The study was made possible by the US space agency’s Gravity Recovery and Climate Experiment (GRACE) satellites. The two identical vessels measure miniscule changes in the planet’s gravity through the variations in distance between them as they circle the Earth, their positions influenced by the varying mass of the water reserves.
The research team said the depletion was caused by poor water management, combined with unfavorable climate conditions.
A devastating 2007 drought in the area not only caused depletions of surface water, which have still not been compensated, but also forced Iraqi authorities to order the drilling of more than 1,000 water wells. The actual number of wells drilled is likely to be much higher, as official statistics in the region are often patchy.
“That decline in stream flow put a lot of pressure on northern Iraq,” said Kate Voss, another study author. “Both the UN and anecdotal reports from area residents note that once stream flow declined, this northern region of Iraq had to switch to groundwater.”
At the time, the country was at the height of a deadly sectarian conflict.
“In an already fragile social, economic and political environment, this did not help the situation,” said Voss.
Last year’s authoritative Global Water Security report, produced by US intelligence agencies, marked the Middle East, naturally the driest region in the world alongside North Africa, as the area most vulnerable to water shortages, saying the situation was exacerbated by a lack of legal agreements and political instability.
“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,” Famiglietti said. “Those dry areas are getting dryer. Demand for freshwater continues to rise, and the region does not coordinate its water management because of different interpretations of international laws.”
Turkey, whose territory houses the headwaters of the region’s two major rivers, Tigris and Euphrates, enjoys a strained relationship with Syria and Iraq, the countries further downstream, and has systematically diverted water for its irrigation, which is frequently inefficient (throughout the Middle East).
Meanwhile, the World Bank predicts that water demand in the region will rise by 60 percent by 2045.
Groundwater has made up the shortage so far but it is being extracted at much faster rates than it is replaced.
“Groundwater is like your savings account,” said Matt Rodell, another study author. “It’s okay to draw it down when you need it, but if it’s not replenished, eventually it will be gone.”