Since 1984, the relevant departments have approved the "Three Gorges" plan; In 1994, the construction of the "Three Gorges" officially began; By May 20, 2006, the Three Gorges Dam was completed.
The Three Gorges Dam took 22 years and cost 250 billion yuan to complete, and has received numerous international accolades. However, is it really worth it for Chinese, especially for residents who have been uprooted by the Three Gorges Dam?
As the most eye-catching water conservancy project on the Yangtze River, the Three Gorges Dam has six major functions: flood control, power generation, shipping, agricultural irrigation, water resources utilization and environmental protection.
Over the past 18 years, the project has been protecting and improving the ecological environment and the quality of life of residents in the Yangtze River basin, but at the same time, the problem of sediment accumulation has become increasingly serious.
What will happen if the sediment continues to accumulate like this?
The problem of sediment accumulation needs to be solved urgently.
Professor Huang Wanli (1911-2001), who devoted his life to the study of river hydrology and sediment flow in China, objected to the Three Gorges Dam when it was first built.
Because of the topography, the Yangtze River can only flow down through the Three Gorges; If the dam were to be built as planned, it would intercept gravel from the bottom of the water and hinder the removal of sediment. Once a certain magnitude is reached, no one can say for sure whether there will be a blockage event in the next ten years.
The Three Gorges Dam has always been very concerned about how to deal with sediment, and the storage and drainage of turbidity is regarded as the most basic means of dealing with sediment.
In the construction of the Three Gorges Dam, in fact, we have also learned from the successful experience of the Gezhouba Hydropower Station at the end of the Three Gorges of the Yangtze River in the 70s of the last century, not only about the various practical problems that may arise in the construction process.
The research on Gezhouba began in the 50s of the last century, and the theoretical data accumulated by it is rich and sufficient, which is not harmful to the implementation of the entire Three Gorges Dam project.
As an integral part of the Three Gorges Project, almost 90 percent of the sediment in the Gezhouba project is concentrated during the flood season, but it is worth emphasizing that it can be removed by normal means of storage and removal of turbidity.
The water level of the Three Gorges Dam needs to be adjusted according to the sediment situation, and usually during the flood season, when there is a lot of sediment, the dam will lower the water level appropriately to ensure smoother drainage. However, the movement of sediment does not always follow a regular pattern.
At the end of the flood season, sediment is reduced, and water storage can be increased accordingly for a variety of uses such as power generation, shipping or agricultural irrigation.
In fact, no water storage project can avoid the occurrence of sediment accumulation. Despite the scale of the Three Gorges Dam and the worsening of sediment accumulation, all problems are under control.
If one day in the future, the situation of sediment accumulation becomes very urgent, we must also believe that the increasingly sophisticated scientific research and technology will be able to realize the method of manual sediment removal.
If this happens one day, don't worry about the sand that is manually removed, because it is also popular as a construction raw material.
From any point of view, the increasing sediment accumulation at the Three Gorges Dam undoubtedly confirms Professor Huang's prediction.
Small dams with long-term siltation may be filled up after a period of time, turning into swamps or flat land.
For now, and even in the next fifty years, it is unlikely that this will happen with the Three Gorges Dam. As for when this will happen, it is difficult for modern hydraulic experts to give an exact time, in short, such a cycle is very long.
Excessive anxiety. Some water conservancy experts found in follow-up research that when Professor Huang Wanli made this **, because the relevant water resources statistics are not clear, this ** may be biased.
In addition to the well-known functions of flood control, power generation and improved shipping, the most important role of the Three Gorges Dam is to store water, which is of great benefit to local residents.
Manpower cannot reverse the effects of extreme weather, and the water accumulated in the wet year is stored and used in the dry year** to achieve a balance and sufficiency of water resources.
In the 20s of the 20th century, after the completion of the Boulder Canyon project in the United States, the experience of Lake Mead and the Hoover Dam showed that the Three Gorges Dam would definitely be highly valued.
Arguably, the Hoover Dam in the United States supports almost one-third of the country's vegetable production, especially in the Mead region, where 75% of the water is used for agricultural irrigation.
Over the past century, the Hoover Dam and Lake Mead have been in full swing to combat extreme climate change, which has caused them to deplete them.
Today, Lake Mead, where the Colorado River is located, is challenged by massive water demands both upstream and downstream, making Lake Mead, a previously freshwater lake, gradually dry and perhaps even "desertified."
It has only been 22 years since the Three Gorges Dam was started and completed, and now it has benefited the people and the country! It can be seen that the extent to which sediment will accumulate in the future is still a relatively distant question.
There is an old Chinese proverb that says, "If you don't have a long-term plan, you must have a near-term worry", which reminds people to think long-term. At the same time, there is also an allusion about "worrying about the sky".
After 22 years of development, China has become one of the most respected powers in the world, from the frenzied rise of the 90s to the 21st century. However, who can be sure that in the coming decades, the Three Gorges Dam will be backed by more in-depth scientific research to ensure its perpetual survival?