Three Gorges Project is 75 years since Dr.SunYat-sen first proposed to launch the Project. Thanks to several decades of extensive scientific research and international cooperation by numerous scientists, scholars and experts of several generations, the extremely complex engineering poser for the construction of the Three Gorges Project (TGP) was finally resolved. These studies provided the scientific basis whereby the National People's Congress passed “The Resolution for the Construction of the Three Gorges Project on the Yangtze River”.
It was during the fifth session of the Seventh National People's Congress that the examination and debate on the feasibility of the Project which lasted more than half a century came to an end and a new era to harness and develop the Yangtze was ushered in. The project will not only make contributions to the present age but also benefit the nation and people for centuries to come.
From its source to its estuary, the Yangtze River meanders over 6,300 kilometers. Its annual runoff into the sea amounts to nearly 1,000 billion m3 and its total drop is more than 5,800 meters with a hydroelectric power potential of up to 268 million kW. In order to harness the River and develop its resources, extensive efforts in survey, planning and scientific research have been made since the founding of the People's Republic of China. After overall planning, repeated studies and verifications, the conclusion has been reached that the TGP is the key to the comprehensive control of the floods and exploitation of the resources of the River.
From Fengjie County to Yichang City, a 200-kilometer-long stretch of the River, it rushes through the majestic Qutang, Wuxia and Xiling gorges, after which the Yangtze Three Gorges is so called. The TGP, which is attracting worldwide attention now, is located at the town of Sandouping, Yichang, Hubei Province in the middle section of Xiling Gorge, about 38 km upstream of the Gezhouba Project. The dam site boasts excellent natural conditions such as a rather wide valley, sound and intact granite bedrock, an average annual runoff of about 500 billion m3 and a vast drainage basin of more than 1 million km2. Decades of arduous reconnaissance and studies resulted in the final approval of Sandouping to be the site of the TGP.
The TGP will be built in accordance with the scheme of “development in one cascade, construction at one stroke, impoundment at stages and resettlement in succession”. The concrete gravity dam will be 3,035m long on the top, with the crest at EL 185 meters. The designed normal pool level of the reservoir is EL 185 meters, and the total storage capacity 39.3 billion m3, of which 22.15 billion m3 is for flood control. The silt flushing bays are to be arranged in the concrete gravity dam and at the bottom of the power station, with a silt flushing capacity of 2,460m3 per second. The discharging capacity of the spillway which constitutes the middle section if the dam is 110,000m3 per second. The designed two powerhouses to be located on both sides of the spillway have 26 units of generators of 700,000kW each, with a total capacity of 18.2 million kW and an annual output of nearly 84.7 billion kWh. The designed one-way shipping capacity of the navigation facilities (including a twin 5-step shiplocks and a one-step vertical shiplift) is 50 million tons a year. The shiplocks can adequately handle tows up to 10,000 tons and the shiplift can provide immediate service for any vessels under 3,000 tons. The major work amounts of the Project are as the principal indices in Table attached.
It is expected that the preparation work and the main works of the Project will take 2 years and 15 years respectively. By the ninth year the permanent shiplocks and the first group of units will be put into operation. Owing to the construction of the Project, 1.13 million people are expected to be resettled and 28,800 ha. of farmland inundated. |