China Great Three Gorges Reservoir project, if open all the gates, the Three Gorges Reservoir will drain the water, probably how long?

in #technology6 months ago

image.png
How long will it take for the 39.3 billion cubic meters of the three gorges reservoir to be filled if someone opens all the gates of the dam to release water? If again be like mathematics problem similar, discharge water at the same time still have water to pour in ceaselessly, that can need how long again? We all know that the Three Gorges Dam project is huge, but even if we can visit it, the public's understanding of it is still only the tip of the iceberg. The discharge time of such a large“Reservoir” is also affected by the volume of water, the number of sluice gates and the flow rate.

At that time, Sichuan was blessed with good conditions for growing crops, but there was a drawback: floods often occurred.

image.png
At that time, Li Bing of Qin was working there, and he wanted to make a change. So in the harsh conditions of the time, they did everything they could to cut through the mountains and rocks to create a world miracle, that is, the hydraulic engineering of Dujiangyan Irrigation System. It's a miracle that this hydraulic engineering is still working, and that's why we have a special feeling about this. The Three Gorges Dam is no exception, as early as the 20th century, Mr. Sun put forward this idea, that it can greatly promote the economic development of the Three Gorges basin.

image.png
But it was shelved for a variety of reasons until the end of the 20th century, when hundreds of experts and executives made substantial progress and the project was finalized. As one of the largest hydraulic engineering in China and even the world, the Three Gorges Dam is an important response to previous floods. However, in addition to the high investment required for this project, there is also the problem of resettlement of residents. According to the plan at the time, if the Three Gorges Dam were to be built, hundreds of cities would be flooded and more than a million people would be displaced. The project was absolutely unprecedented.

image.png
Although this cost as much as zero per cent, it was the people's feelings for their hometown that were the most important thing, and the departments in charge were doing their best to do everyone's ideological work. In fact, the dam construction process is not only these problems, but we have overcome one by one, took more than a decade to finally complete.

Have you ever wondered when the Three Gorges Dam will release water? Some speculate that the Three Gorges Dam released water during the drought, but is this actually the case?

image.png
Typically, large reservoirs like the Three Gorges play a crucial role in flood control and drought relief, storing water during the rainy season and releasing it when crops need irrigation. However, the Three Gorges Dam operates in a different way. From April to May, the discharge of water from the Three Gorges Dam is actually relatively low, mainly to reserve reservoir capacity, to deal with the flood peak in July and August. The central task of the Three Gorges Reservoir is flood control and water resources regulation. The system monitors two crucial water levels: the 175-metre maximum designed to keep the dam safe, and the 145-metre limit for flood control, lower than this line is conducive to power production and navigation.

image.png
In terms of environmental coordination, the Three Gorges Reservoir stores water during the dry season in an effort to maintain water levels between 145 and 175 metres, which not only helps improve shipping efficiency but also optimizes electricity generation. The main function of the Three Gorges Dam is to block, slow down the flow, weaken the flood peak and adjust the flood peak. The core function of the Three Gorges Reservoir is not to stop all floods, but to spread them over multiple batches, relieving the Yangtze Plain of flood control and thus reducing the threat of flooding.

The reservoir's water level has climbed to 176 meters, the equivalent of more than 50 stories in the height of a typical residential floor, and the Three Gorges project's astonishing storage capacity of 39.3 billion cubic meters.

image.png
Although it has not yet reached the limit of its design, the Three Gorges Dam has reached 173.35 metres in previous water diversion experiments, accumulating a total of 6.8 bn cubic metres of water. If we fill the spectacular three gorges reservoir with water, will you wonder how long it will take to drain? The Magnificent Three Gorges Dam, not only has the main building and diversion building, the total extension reaches 3,335 meters, of which the main body of the dam across the river 2,335 meters, the highest point up to 181 meters.

image.png
There are 54 gates in the Three Gorges' magnificent reservoir, which are located along the dam's reach and discharge facilities. The 483-metre length of the spillway section has 228-metre wide surface holes and 239-metre wide deep water holes, while nine additional auxiliary spillways have been installed in the barrage section. In an ideal world, with no upstream water and all 54 gates at full capacity, the Three Gorges Reservoir could reach its bottom in about five and a half days at a maximum discharge of 79,000 cubic metres per second. But in practice, as the reservoir level drops, so does the efficiency of the discharge, which can take up to nine days if the water level continues to fall.

image.png
But don't forget, there's still water coming in from the upper reaches of the river, and it may take 20 to 25 days to gradually adjust the water level after the flood peak due to the influx of flood waters and the increasing flow of water during the flood season, to discharge all the water from the Three Gorges Reservoir. If the upstream floods continue during the flood season, coupled with days of rainfall and abnormal weather, the time for flood discharge can only be further extended.

Thinking about how long it will take to drain the dam is Scheherazade, since the chances of that happening are close to zero.
First and foremost, it is not practical.

image.png
If the Three Gorges Reservoir were to discharge all the accumulated water at once, it would be catastrophic. All the water will surge down, and even the Gezhouba Dam River below will not be able to stop it. Downstream flood control will be under great pressure? If the Three Gorges Reservoir really let all the water out, how to guarantee the power generation function of the Three Gorges hydropower station? So those data-based estimates of drainage time only hold up in theory, not in practice, but in our private imagination.

image.png
Such doubts raise the question of whether a foreign attack on the Three Gorges Dam could have catastrophic consequences if it were to collapse? You can rest assured that the Three Gorges Dam is located deep in the interior of China. It is in a special geographical location. A foreign military attack would have to travel over thousands of mountains and rivers. It would have to fly more than 1,000 kilometers to reach it, that is highly unlikely. From a legal point of view, international law expressly prohibits any deliberate destruction of the dam, as it is always the civilian population that is the ultimate victim of such acts, this inhumane act has been universally condemned.

image.png
And the most important thing is that our country has thought about this problem for a long time, so there are 24-hour guards guarding the Three Gorges Dam, you do not need to worry. Although the Three Gorges Dam will not be fully opened to release water, but this has proved its importance and role, is a miracle.