Advantages and disadvantages of Sanmenxia dam

? Why is Sanmenxia called Sanmenxia? This question may have stumped most students. Then I'll tell you. This is because there are three big stones on the Yellow River near Sanmenxia. They are the gate of man, the gate of hell and the gate of God. These three stones stand side by side in the middle of the Yellow River. Formed the Mishima Gorge, from which came the name of Sanmenxia.

Sanmenxia dam is just above these three big stones. However, in order to build the dam, all three stones were removed.

? We can clearly see on the map that the Yellow River has obviously changed from a wide channel to a narrow channel at the Sanmenxia Dam. Sanmenxia Dam, a section of waterway in front of it, is Sanmenxia Reservoir. It can be seen that during the impoundment period, the riverbed there has obviously widened. During the drainage period, the former river channel became narrower obviously.

This time, we are going to discuss whether the Sanmenxia Dam has great advantages or disadvantages.

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? Since ancient times, the flood of the Yellow River has never stopped. Until 196 1, the completion of the Three Gorges Dam brought good news to the people in the lower reaches of the Yellow River. This is because the Three Gorges Dam can control the amount of water in the lower reaches of the Yellow River, so that people in the lower reaches of the Yellow River will no longer suffer from floods.

Moreover, the sediment in the upper reaches of the Yellow River was stopped by the dam. Build the lower reaches of the Yellow River and realize Huang Heqing. The suspended river in the lower reaches of the Yellow River will no longer increase.

The irrigation capacity of the Yellow River is increased, and the water quantity of the Yellow River is effectively and reasonably distributed. Thereby increasing the total amount of irrigated farmland.

However, the completion of the Three Gorges Dam also brought disaster to the Weihe River, with 2.07 million mu of farmland near the Weihe River flooded and 600,000 people resettled. Moreover, the sediment brought by the Yellow River is here, which is a high-quality farmland and has become a salt marsh. From then on, crops can no longer be planted in places flooded by the Yellow River.

Not only these losses, but also the upstream sediment is the life of the dam, which is shortened to 25-30 years.

Moreover, the sediment concentration of the Weihe River in Guanzhong is increased, but the water quantity is not increased. The crops were not adequately irrigated, which led to a reduction in production. Later, sediment deposition extended upstream. It's almost the industrial zone centered on Xi 'an.

In this process, from the construction of the Three Gorges Dam to the closure of the Three Gorges Dam. People in the lower reaches of the Yellow River will always benefit. However, the people in the Weihe River Basin in Shaanxi Province, as well as farmers who have been relying on the Weihe River to irrigate farmland for generations, make a living. They never benefited from this battle.

So far, it seems that the advantages outweigh the disadvantages. Because the lower reaches of the Yellow River can be larger than the river basin. The affected reach is also smaller than the more favorable reach.

Let's think it over. The Yellow River flood will happen sooner or later. After the flood, the downstream farmland can still continue to grow food crops. This land has not been abandoned.

So why the river basin? Their farmland will never grow crops again. Farmland has become a quagmire, and no matter how to remedy it, it can't be remedied. Those farmland will never grow food again.

? But who would have thought? If the Three Gorges Dam is not demolished within 25 to 30 years, it will continue to be used. Sediments are deposited to the same height as the dam. Then the downstream will become as high as the upstream. The flood will come again. Until then. The Weihe River will also be silted up, and the historical ancient capital Xi 'an will also be submerged.

Fortunately, Sanmenxia dam has stopped. Xiaolangdi Reservoir was built. It completely played the role of Sanmenxia Reservoir. And it didn't flood the Weihe River. In this series of processes.