Early ice jams threaten floods
( 2003-12-08 08:07) (China Daily)
Flood-control authorities along the Yellow River are making preparations to deal with ice flows, sources from the Yellow River Water Conservation Committee said yesterday.
With temperatures dropping drastically along the river, China's second largest, ice jams have begun to form on the river's upper reaches, an official from the committee said on condition of anonymity.
This could pose a flood threat to lower reaches, the official said, adding it it is not usual for ice buildup to follow so closely on autumn floods, which ended only in late November this year.
The section of the river in North China's Inner Mongolia Autonomous Region is expected to be completely frozen over from today, according to Jing Lishan, deputy director of the Flood Control and Drought Relief Department in the Inner Mongolia Autonomous Region.
The recent dramatic fall of temperatures contributed to the accumulation of ice jams, which constitute up to 70 to 80 per cent of the water in the river in some sections, Jing told China Daily in a telephone interview yesterday.
In past years, by December, the volume of water flowing in the middle reaches was normally down to 200 to 300 cubic metres per second.
However, statistics from the Tongguan hydrological station in the northwestern part of Shaanxi Province this year reveal that the flow volume has held at around 1,300 cubic metres per second.
Jing said that his department has formulated contingency plans to deal with possible flooding and has instituted round-the-clock inspection of the dams along the river.
"Dams have been strengthened to withstand a possible rise in water level as a result of the freezing,'' Jing said.
Flood-control authorities in East China's Shandong Province, in which the lower reaches of the Yellow River are located, are also gearing up to deal with possible flooding.
The volume of water flowing in the Shandong section has reached 800 cubic metres per second, according to statistics from the local Yellow River Affairs Bureau.
Xiaolangdi Reservoir, a major water conservation and irrigation installation on the Yellow River, has 8.2 billion cubic metres of water in storage, according to Xinhua News Agency.
It has a further capacity of 1 billion cubic metres to handle flooding caused by ice jams, but this is only half of the anticipated required capacity, according to the Xinhua report.
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