An image taken in 2006 by the Landsat 5 satellite of Iraq's Qadisiya Reservoir shows the abundance of water in the man-made lake nestled along the Euphrates River.

An image taken three years later reveals the massive depletion of the freshwater reserve—a result of pumping groundwater faster than natural processes can replenish it. Both images were released this week by NASA. (Read: 8 Mighty Rivers Run Dry From Overuse)

Researchers found that between 2003 and 2009, the Tigris and Euprhates river basins lost 117 million acre feet of freshwater, roughly the equivalent to the volume of the Dead Sea. Only one-fifth of the loss was due to natural causes like the shrinking of snowpack and the drying up of soil during the 2007 drought in the Middle East.

"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," lead researcher Jay Famiglietti at the University of California, Irvine told NASA.

Space Pictures This Week: Airglow, Frozen Trees

Comet PanSTARRS debuted in the north, colorful airglow in the south, and a diminishing water reserve in the Middle East.