The Tigris and the Euphrates are among the most intensively dammed rivers in the world, according to the ENEP. In the past 40 years, the two rivers have been fragmented by the construction of more than 30 large dams, whose storage capacity is several times greater than the volume of both rivers.
The dams have substantially reduced the water available for downstream ecosystems and eliminated the floodwaters that nourished the marshlands.
Even the last patch of the once vast marshlands is at risk, scientists warn, as its water supply is impounded by new dams and diverted for irrigation.
To save the remaining transboundary marsh, the UNEP is calling for immediate action to reassess the role of the area's water engineering works and modify them as necessary. Over the longer term, it recommends the use of managed flooding.
The agency is also urging Iraq, Syria, Turkey, and Iran to develop a joint program to manage the dwindling water supply and halt further environmental damage.
The newest satellite data used in the Mesopotamian study are from a collection of about 16,000 Landsat images from space, taken from 1992 to 2000, that the U.S. government and its National Aeronautics and Space Administration recently donated to the UNEP to monitor major environmental changes.
"With these new data sets, we hope to learn much more about the true level of environmental damage happening on Earthfrom the real extent of illegal logging in Southeast Asia and urban sprawl in the United States to habitat loss in sub-Saharan Africa," said UNEP chief Toepfer.
The images will also aid the work of the UNEP's program to identify regions particularly vulnerable to devastation from drought, flooding, hurricanes, and other catastrophes.
"More precise information on the extent of environmental degradation, urban sprawl, and the effects of phenomena such as El Niño and global warming should allow us to better predict areas of the world at greatest risk from natural calamities," said Tim Foresman, director of the UNEP's Division of Early Warning and Assessment. "In turn, this should help local, regional, and national governments to act before it is too late."
As countries seek to implement the many international and regional conservation agreements that have been adopted in recent years, satellite imagery will also make it possible to more accurately assess conditions and track progress, said Foresman.
In the past, efforts to assess environmental conditions such as the extent of illegal logging or the drainage of wetlands have depended mainly on individual countries' willingness and ability to gather information in the field.
"Once these images, giving us wall-to-wall coverage of Earth, are studied," said Foresman, "we will be able to say for the first time, with a great deal of precision, if the government figures are sound."
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