Euphrates was the longest river of Western Asia but now a large portion of the Middle East lost freshwater reserves rapidly during the past decade.
New data revealed already an arid region of Tigris-Euphrates Basin, which grows even drier due to human consumption of water for drinking and agriculture.
The research team observed the Tigris and Euphrates river basins - including parts of Turkey, Syria, Iraq and Iran, and found that 144 cubic kilometers (117 million acre feet) of fresh water was lost from 2003 to 2009 - the roughly equivalent to the volume of the Dead Sea.
About 60% of the loss was attributed to the pumping of groundwater from underground reservoirs.
When a drought shrinks the available surface water supply, irrigators and others turn to groundwater.