Dongting Lake, the second biggest freshwater lake in China, will completely disappear from the earth because of accumulated silt after a century, experts have warned.
"One hundred years later, Dongting Lake with sprawling water surface will become a memory in books," says Liu Guangyue, director of Dongting Lake Section of the Hunan Provincial Water Resources Bureau.
However, Liu hopes that the construction of the Three Gorges Project on the middle reaches of the Yangtze River, China's longest, might slow the pace of the disappearance of Dongting Lake, second only after Poyang Lake in east China's Jiangxi Province.
"The dam will hold back large quantity of silt that might bury lakes in the lower reaches of the Yangtze," he said.
Dongting Lake, currently with a water area of 2,625 sq km, is situated alongside the lower reaches of the Yangtze in northeastern Hunan Province. It is named after the hill on its northeast.
The waters of Xiangjiang, Zishui, Yuanjiang, Lishui rivers flow into Dongting Lake from the south and west, while the Yangtze River enters from the north and goes out at the town of Chenglingji on the northeast. The lake thus serves to regulate the waters of the five rivers.
Dongting Lake used to have a water area of 6,000 sq km at peak time but shrank to 4,350 sq km in the early 1950s because of factors such as silting and land reclamation by mankind, according to Liu.
About 2.7 billion cu m of silt landed in Dongting Lake between 1951 and 1978, according to statistics given by the Yangtze River Water Resources Committee.
The climate in the Dongting Lake basin is temperate and rainfall is plentiful. The alluvial plain around the lake is good for rice and cotton. This lake abounds in aquatic products and is good for shipping service.
"On completion, the Three Gorges Project will not only play a role in combating summer floods on the Yangtze, but also help stop 60 percent of the silt washed down into the mainstream of the Yangtze," says Liu.
Liu's opinion is echoed by Chen Weili, deputy head of the office with the Flood Control and Drought Relief Headquarters of Yueyang City Water Resources Bureau, Hunan Province.
"When the Three Gorges Reservoir is keeping more water, there will be less silt carried into Dongting Lake and silting will be on decline accordingly," says Chen, "The Three Gorges Reservoir is beneficial in terms of alleviating pressure of silting on Dongting Lake and prolongating life of the lake."
Dongting Lake is at its lowest level of water in 30 years because of extensive drought in the Yangtze River valley.
Statistics provided by the Yangtze River Hydrological Bureau suggest that only 14 million tons of silt landed in Dongting Lake last year, down by 110 million tons from the past annual average of 114 million tons.
Even though, experts have said that the shrinking of the lake is doomed for the future.
(Xinhua News Agency October 28, 2006)
