What harm does Sanmenxia Dam have now? Why did you tear it down?

Downstream of Sanmenxia Dam, due to the slow flow rate and siltation, the riverbed is rising year by year, forming a "suspended river" spectacle, which directly threatens the safety of people's lives and property in the lower reaches of the Yellow River and should be demolished.

Danger:

1. Sediment deposition at the tail of the reservoir caused the Weihe River to flow into the Yellow River (even sediment flow backward). The lower reaches of the Weihe River were seriously flooded, and the land was salinized, so the water level had to be lowered and used according to storage.

Second, the design water level of the reservoir has been reduced repeatedly due to the control of flooding loss, and the storage capacity has been seriously lost after serious sediment deposition, which can not meet the planning requirements of flood control in the Yellow River (the reason for continuing to build Xiaolangdi). Water conservancy projects waste a lot of investment due to the use of reduced water level and repeated reconstruction, and the power generation benefits are greatly reduced due to the reduction of water head and sediment erosion.

Extended data:

The Sanmenxia project was resolutely opposed by Shaanxi from the beginning. At that time, many government officials in Shaanxi tried to demonstrate the impact of this project on Shaanxi through various channels. In fact, as early as 1955, at the second meeting of the First National People's Congress, the Sanmenxia water conservancy project with "high dam and large reservoir" put forward by experts from the former Soviet Union was unanimously adopted, but it was also opposed by Huang Wanli, a water conservancy expert from Tsinghua University, and Wen, an intern from the General Administration of Hydropower.

1958, one year after the Sanmenxia project started, Shaanxi still strongly opposes the Sanmenxia project. The reason is that good soil and water conservation along the Yellow River basin can solve the flood problem of the Yellow River, and there is no need to build Sanmenxia Project. However, the Sanmenxia project has not stopped. 1960, the dam was basically completed and began to store water.

196 1 In the second half of the year, Shaanxi's worries came true:/kloc-0.5 billion tons of sediment were all laid on the Tongguan-Sanmenxia River, and the Tongguan River was raised, making the Weihe River a suspended river. The groundwater in Guanzhong plain can't be drained, the fields are salinized or even swamped, and the grain production is reduced every year.

1962, Shaanxi people can't hold it any longer. At the Third Session of the Second National People's Congress held in April, representatives of Shaanxi Province submitted a motion requesting the State Council to formulate the operation principle and management plan of Sanmenxia Reservoir of the Yellow River as soon as possible, so as to reduce the siltation in the reservoir area and ensure the production, life and life safety of residents above the 335-meter migration line.

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