A 10-day silt clearance campaign for the middle and lower reaches of the Yellow River is set to begin at 8:30 this morning at Xiaolangdi Reservoir in Central China's Henan Province. The campaign aims to clear long-deposited silt in Henan, Shanxi and Shandong provinces, with powerful water flow sent out from the Xiaolangdi Reservoir.
The water flow will blast along the river at a controlled speed of 2,600 cubic meters per second, and the whole process is expected to last 10 days, said Li Guoying, director of the Yellow River Water Conservancy Committee.
Li said the planned trial is the world's largest silt-clearing campaign to date, and the committee is optimistic about the results.
The middle and lower reaches of the Yellow River have long been plagued by expanding silt deposits. The high river banks established to resist silt in many places have surpassed the altitude of urban regions, which is a great danger to local populations.
Li said the committee expects the powerful water flow to flush away much of riverbed silt and reduce the pressure caused by silt expansion.
Though well prepared, Li said they were still not sure if the 2,600-cubic-meters-per-second volume of water is enough to rush the long-deposited silt away. The committee will send water in various intensities over the 10 days, and monitor the clearance conditions closely throughout the three provinces involved.
Li believes this trial will collect useful data for the committee's future silt-clearing efforts.
On the down side, the artificial powerful water flow will cause some small-scale flooding in the provinces through which it passes, especially along some narrow riverways.
The water conservancy departments in the three provinces have been alerted about a possible deluge. They were all ordered to monitor the water flow around the clock, and have prepared enough rescue materials for the worst case scenario.
The Xiaolangdi Reservoir is one of the most important water management tools along the Yellow River, China's second largest river. Besides providing industrial and agricultural water for nearby cities, the reservoir also helps adjust water volume flowing to the lower reaches in different seasons.
Construction on the reservoir began on August 20, 1998, and it was put into operation in October. The total expenditure was 126 million yuan (US$15 million).
The water conservancy committee sources said the successful operation of the water reservoir so far has proved it can be used effectively for the silt-clearing test.
With data gathered in this trial, the sources said, they will launch more water-clearing campaigns along the lower reaches. The precondition is that such efforts do not endanger the cities along the river.
(China Daily July 4, 2002)
