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| Some
facts about the Gezhouban Dam |
After
rushing out of Nanjin Pass, the Yangtze River slows down and widens
from 300 meters to about 2,000 meters. Three kilometers east, in the
suburbs of Yichang City, a huge dam lies across the river. This is
the Gezhouba Dam, a major part of the multi-purpose water control
project to bend the Yangtze to human purposes.
The main channel here was closed off on January 4, 1981,and navigation
and power generation began in June the same year, marking the completion
of the first phase of the key project. Beyond Nanjin Pass, two islets-Gezhouba
(from which the dam project gets its name) and Xiba-divide the river
into three waterways, the main, second and third channels. The main
channel is filled with water all year round while the other two are
dry during the low-water season. The possibility of diverting the
water of one into the others so that construction work can be carried
out makes the site ideal for the water conservancy scheme. |
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Overview |
With
the closure of the main channel, the Yangtze has changed its age-old
course to roll forward through the second channel. Building a dam
across the main section of a river which is wide, deep and has an
enormous flow is something unheard-of before.
Now the 2,561-meter-long dam has created a reservoir upstream with
a holding capacity of 1.58 billion cubic meters. The project involved
the removal of 55 million cubic meters of earth and rock, the installation
of 65,000 tons of metal structures, and the pouring of 10 million
cubic meters of concrete. This last figure equaled the combined total
for the five other key water conservancy projects in the country -
the Liujiaxia, the Sanmenxia, the Danjiangkou, the Gongzui, and the
Xin'anjiang -and is enough to build a 10-meter-wide and 50-centimeter-thick
road extending from Guangzhou to Beijing.
The designing and construction of the dam and the installation of
the equipment were all undertaken by Chinese personnel. As far as
the amount of work and the technical standard are concerned, this
cross-river structure ranks first among China's hydropower projects.
A major component of the future Three Gorges multipurpose water conservancy
scheme, Gezhouba project consists mainly of power stations, ship locks,
spillways silt-scouring sluices, silt-prevention dykes and auxiliary
dams. |
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Waiting
for gate to open and come out of the shiplock. |
There
are two Power stations at the dam site one in the main channel the
other in the second channel. They have sets of turbo-generators, with
a total installed capacity of 2.715 million KW to generate about 14.1
billion KWH of electricity a year. The biggest in China today, they
supply power to the central China grid, greatly promoting industrial
and agricultural Production in Hubei, east Sichuan, north Hunan and
southwest Henan.
There are three shiplocks at Gezhouba. Lock No. 1 in the main channel
and Lock No. 2 in the third channel each have a chamber 280 meters
long and 34 meters wide, with a depth of five meters, allowing the
passage of 10,000-ton passenger or cargo ships. They both rank among
the world's largest before Three Gorges Dam. Lock No. 3 in the third
channel is 120 meters long and 18 meters wide, with a depth of 3.5
meters. It can handle vessels below 3,000 tons and local boats.
Two silt-scouring sluices and two silt-prevention dykes have been
built to facilitate navigation. When the reservoir is filled with
water, the water level at the dam can be raised by 20 meters. In the
dry season, the water can retreat 180 kilometers, to the west end
of Wu Gorge, while at flood time, the water can move back as far as
Badong, a distance of 100 kilometers. With the conclusion of the first
phase of the project, the water level along the Three Gorges has been
elevated by 10 meters and many shoals have been submerged, greatly
improving navigation. |
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Fully
loaded No. 2 shiplock |
The
simultaneous operation of the 27-bay spillway and the three silt-scouring
sluices can discharge a water volume of 110,000 cubic meters per
second, the maximum figure of the 1870 flood. Moreover, a railway-highway
bridge has been built atop the dam. The bridge surface can be raised
or lowered to allow large ships to pass, the Maximum lift being
18 meters.
Apart from economic benefit, the Gezhouba project is a boon to tourism.
With its overall completion, a number of gardens will appear along
this section of the river together with tree-shaded roads at the
sites of the three channels. Chinese and foreign travelers visiting
the Three Gorges will be tempted to include Gezhouba project in
their itinerary. They will find this man-made wonder a feast to
the eye and the imagination, a monument to human ingenuity in taming
China's longest river. |
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