Ancient Fertile Crescent Almost Gone, Satellite Images Show
National Geographic News
|May 18, 2001|
The rich Mesopotamian marshlands known for centuries as the Fertile
Crescent have almost completely disappeared, with only 10 percent of the
important ecosystem still remaining, according to a study based on
satellite images of the region.
The Fertile Crescent lies at the
confluence of the Tigris and Euphrates in southern Iraq and extends into
Iran. Analyzing historical data and new images from NASA's Landsat
satellites, scientists at the U.N. Environment Program (UNEP) found that
the marshy area has almost completely dried up over the past three
decades and is now mainly desert with large salt-encrusted patches. A
small northern fringe of marsh that straddles the Iraq-Iran border is
all that remains.
The researchers say the damage is a result of
extensive damming of the two rivers and heavy draining of the river
basin in recent decades.
There have been warnings in recent years that the Mesopotamian marshlands were disappearing. But the UNEP report offers the first hard evidence of how dramatically the marshlands have shrunk.
According to the UNEP study, due to be published later this year, the marshlands previously totaled an area of 15,000 to 20,000 square kilometers (5,800 to 7,700 square miles) but now cover less than 1,500 to 2,000 square kilometers (580 to 770 square miles).
Klaus Toepfer, the executive director of UNEP, said scientists did not have a full understanding of the situation until recently because conditions in Iraq over the past decade limited access to the area and hindered monitoring of the environmental changes.
"These findings on Mesopotamia have only been made possible by 'eyes in the sky,'" said Toepfer.
The UNEP is urging Iraq, Iran, Syria, and Turkey, which are dependent on the marshlands and the rivers that feed them, to undertake a recovery plan. The UNEP and regional organizations are doing a scientific assessment of the Tigris-Euphrates river basin to determine what improvements are needed.
Dams and Drainage Projects
The UNEP report highlights the mounting pressure being put on freshwater areas around the world, which is radically altering the way of life for people in the affected regions and threatening native wildlife.
According to the UNEP, an indigenous group of people known as Marsh Arabswho trace their culture to ancient Sumerians and Babylonianshas been displaced by the loss of the marshlands. About a fifth of the group's estimated population of half a million reportedly have settled in refugee camps in Iran, while the rest live in Iraq.
Scientists say the major ecological changes have put an estimated 40 species of waterfowl at risk, while mammals unique to the region, such as the smooth-coated otter, are now considered extinct. Coastal fisheries in the northern Gulf, which depend on the marshlands for spawning grounds, have experienced a sharp decline. Migratory birds from Siberia to southern Africa may also be seriously affected.
The UNEP attributes the relatively rapid loss of the Mesopotamia marshlands to extensive damming upstream and drainage schemes implemented since the 1970s. More recently, a major factor contributing to the problem is a massive drainage works program installed in southern Iraq in the early 1990s.
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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