Cheng Xiaotao, an expert on flood control and disaster reduction in China Academy of Water Resources and Hydropower Research, pointed out that the primary task of building the Three Gorges Project in that year was to prevent the Jingjiang levee from collapsing. Jingjiang levee is located in the upper reaches of Wuhan and the lower reaches of Zhicheng. Whether it is decided in the south or the north, it may endanger the lives and property of more than 8 million people. Therefore, there used to be a saying that "the Yangtze River is in Jingjiang". No other measures can replace the flood control function of the Three Gorges Dam.
Extended data
The flood control capacity of the Three Gorges Dam can be divided into "emergency rescue" and "self-rescue". "Saving people" refers to the flood control ability of the Three Gorges Dam to ensure the downstream flood control safety, that is, the ability to help the downstream flood control. In the event of a flood that does not exceed "once in a hundred years" (the peak flow exceeds 83,700 cubic meters per second), the Three Gorges Project can control the maximum flow of Zhicheng Station to not exceed 56,700 cubic meters per second, and the water level in Shashi can not exceed 44.5 meters without flood diversion project, so the Jingjiang reach can safely discharge flood.
In case of "once in a thousand years" flood, the corresponding flow through Zhicheng will not exceed 80,000 cubic meters per second after being regulated by the Three Gorges Reservoir. With the application of Jingjiang flood diversion project and other flood diversion and storage measures, the water level in Shashi can be controlled within 45 meters, thus avoiding the possible devastating disasters in Dongting Lake Plain and Jianghan Plain on the north and south sides of Jingjiang River.
"Self-rescue" means that for the Three Gorges Project itself, the flood control standard is 10% based on the design and check of "once in a thousand years", that is, when the "once in a thousand years" flood with a peak value of 98,800 cubic meters per second comes, the dam itself can still operate normally, and all the engineering facilities of the Three Gorges Project can generate electricity as usual.
When the flood peak flow is 1 1.3 million cubic meters per second plus 10%, the main building of the dam will not be damaged, and the Three Gorges Dam is still safe, and the normal use function of individual facilities may be affected.
People's Daily Online-Four Questions on Three Gorges Dam: How big is the flood control capacity of the Three Gorges Project?