River loses 200m tons of sand
( 2004-01-08 21:53) (Xinhua)
The Yellow River, China's second largest, has shed nearly 200 million
tons of sand in the past two years, said Li Guoying, deputy director of
the Yellow River Water Resources Committee, here Thursday.
The loss had increased the river's flow by 100 to 400 cubic meters per
second, Li said at the National Conference of Water Resources Directors.
The committee organized sand washing operations in July of 2002 and
September of 2003 by discharging speeding currents from the massive
Xiaolangdi Reservoir on the lower reaches of the river, successfully
carrying 187.1 million tons into the sea.
The reservoir had prevented some 900 million tons of silt from flowing
to the lower reaches since it started storing water in October, 1999.
However, the build up of silt in the lower reaches of the river was still
severe, with 400 million tons filling the riverbed every year.
The silt had built up a new riverbed, known as the "second hanging
river" by the locals, on top of the original riverbed, on the lower
reaches from Kaifeng to the mouth.
The Yellow River carries some 1.6 billion tons of silt into the sea every
year, raising the level of the riverbed in the lower reaches by 10
centimeters.
|
