October 15, 2008
Posted: 11:35 AM ET
The latest satellite image of the Aral Sea shows a disappearing body of water. What was the world’s fourth-largest freshwater lake is almost gone due to an engineering project gone wrong, despite a last-ditch effort to save it.
The Aral Sea straddles the border between Kazakhstan and Uzbekistan in the former Soviet Union. Its water was mainly supplied by two rivers, the Syr Darya (the Persian word for sea) and the Amu Darya. In 1960, the sea covered 25,600 square miles, about 10 percent larger than Lake Michigan.
Under a Stalin-era plan, the Aral started to shrink as the former Soviet Union drastically diverted the two feeding rivers for irrigation of cotton and other crops. Today, the lake’s water is about 10 percent of its original volume and its surface area has shrunk by 74 percent, according to a report published in the Annual Review of Earth and Planetary Sciences in 2007. And the lake’s salinity has increased tenfold.
In 2001, the Kazakh government initiated a rehabilitation plan for the lake, improving the flood levees and building a dam to divide the smaller northern Aral Sea from its larger and more polluted southern portion. By the time the 6 mile-long Kok-Aral Dam was completed in 2005, the surface areas of the northern Aral grew by 30 percent and the water depth increased by about 20 percent.
Deane McKinney, a professor at the University of Texas who led a water research program in the Aral Sea area five years ago, said: “I suspect that it (the northern Aral) may slightly increase in size over the coming years, but that will depend on the climatic conditions of those years.”
But the latest satellite image still found that the main body of the Aral Sea, the much larger southern portion that mostly sits in Uzbekistan, has been shrinking non-stop.
The Uzbeks have announced no plans to reverse this. According to Professor McKinney, the volume of water necessary to refill the Southern Aral Sea is simply so large that “it would require these countries to relinquish their use of the water for other purposes for decades.”
“This is just not economically viable at the present time,” he added.
The Uzbek government, instead, has announced plans to explore the drained Aral seabed for oil. Whether that will change the welfare of local people is unknown, but the consequences of leaving the Aral Sea to die are obvious.
The interruption of the Aral ecosystem has led to many serious problems. The local fishery collapsed. Respiratory and other diseases began to spread. And increased salt and dust storms have taken their toll on both people and property.
Another potential threat may come from Vozrozhdenie (rebirth), which was once a large island in the center of the Aral Sea. Vozrozhdenie was a Soviet germ-warfare facility during the Cold War. The island is now physically connected to the land, increasing security risks and enabling easier transmission of any possible biological hazards on this island to a larger environment.
–Chong Wu, CNN Science & Technology
Filed under: environment
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