Friday 26 June 2020

Three Gorges Dam - disaster awaiting?

The Three Gorges Dam is an engineering and construction marvel. Or at least a technological challenge. And a socially disruptive endeavour. With environmental and ecological impacts that were... ignored?

My personal superficial view of this feat of engineering and construction was that it is what a big country does. It is what a rising power chooses to do to showcase its capacity and ability.

It is what it is.



Then the last few days, my Youtube feed was getting quite a few videos about unceasing storms in China, leading to flooding, and the danger of the Three Gorges Dam giving way.



A lot of the reports... are suspect to me. As in the reports are by critics of China. For example this "news report" by NTD - that's "New Tang Dynasty" - set up by Falun gong members, based in New York.



Of course, as a persecuted organisation in China Falun Gong (and by extension, NTD) would hardly be sympathetic to China.

However, they were also less likely to take the "whitewashed" position of the Chinese state. Like the defence by Global Times:
Three Gorges Dam ‘not at risk of collapse,’ safe for heavy rainfall: experts 
The water level in China's massive Three Gorges Reservoir reached 147 meters on Saturday, two meters above the flood warning line. Meanwhile, the inflow increased to 26,500 cubic meters per second from 20,500 cubic meters per second on the previous day.
The alarming water level gave rise to rumors that the dam is under structural strain and nearby residents should evacuate. Some Western media hyped claims that the dam is at risk of collapse, which was not new in their discredit of the project.
Guo Xun, a research fellow at the Institute of Engineering Mechanics at the China Earthquake Administration in Beijing, refuted the rumors and speculation, saying that the dam is capable of holding far larger inflows than it is seeing now.
The dam is designed to meet "once-in-a-millennium" water level at 175 meters or flow up to 70,000 cubic meters per second. Currently, the 147-meter water level and 26,500 cubic meters per second levels are absolutely safe for the dam to bear, Guo told the Global Times on Monday. 
My opinion of the Global Times is that they are a lying mouthpiece of the CCP. So, I'm not exactly convinced. Still one needs to consider all views, and there is a chance that they are correct. Even a stopped clock is right twice a day.

But the fact is, there have been heavy rains, and more is coming:
Rainstorms and downpours are expected to hit vast stretches of China from Friday through Tuesday, with a high risk of flooding, landslides and urban waterlogging, the flood control agency said in a website statement. 

Anyway, there are two possibly partisan views - pro and anti CCP. So I looked for more "independent" or "impartial" videos. And I found some alternative sources.

This one seems rather "gossipy". He is doing what I am doing here. Compiling news and videos from various sources, and presenting the findings (facts?) in a video. I'm doing it as a blog piece.

The information repeats some of the points in the NTD "China in Focus" video above.




Another video I found was this one.



This video references videos from twitter (or the Chinese version of it) and from Taiwan News so THAT source may have an anti-China agenda. And I believe he is Australian, so he might not be impartial either.

But he does try to present some facts. At about 4:12, he notes that the Three Gorges Dam is so massive, that the water pressure has deformed the plate, which says something about the effects of the dam. Which have been noted elsewhere: impacts or effects such as pollution, reservoir-induced earthquakes, landslides/mudslides, lake effect (increasing rainfall in the surrounding mountains), among others.

But he shows the weather forecast by Windy from 3:00 where the charts shows rain accumulation of over 1000 mm over 10 days. When I checked the website, I did not get the same forecast. I did not even get 200 mm over 10 days. So... they changed the forecast? That's not what the Chinese authorities are preparing for.

At 4:34 he notes that many of the videos are on Chinese Social Media (Weibo), and the Chinese authorities don't seem to be stopping those videos.

Okay, so the indisputable fact is, there have been heavy rains, there have been floods, and there have been incredible and unprecedented damage to homes, businesses, property, and even cultural landmarks.

The question then is, so what?

Well, the most sensational thing that could happen is if the huge surge of rain and flood water hitting the Three Gorges Dam would lead to the dam breaching.

Which is what NTD is reporting. And which the Chinese authorities are refuting through their mouthpiece.

So apparently, the dam's serious warping is a trick of bad satellite imagery.

Rumours of the fragility of the dam may be exaggerated. Or wishful thinking by those who want to see China fail.

But while the dam may not fail, the rains and the floods are real enough. And disastrous enough.


Three Gorges Dam ‘not at risk of collapse,’ safe for heavy rainfall: experts 

By Wan Lin 
Global Times 
2020/6/22 

Photo taken on June 8, 2020 shows the Three Gorges Dam in Yichang, central China's Hubei Province. The water level of the Three Gorges reservoir dropped to 144.99 meters as of Monday afternoon, two days ahead of schedule, in a bid to make room to contain water from potential seasonal flooding. (Photo by Xiang Hongmei/Xinhua) 


Chinese experts have dismissed rumors hyped by some Western media that the Three Gorges Dam, the world's biggest hydropower project, is at risk of collapse, noting the dam is intact and has spare capacity to hold the current inflows of water after southern parts of China experienced heavy rainfall and the Three Gorges reservoir's water level exceeded the flood control line.
Since China entered the flood season in June, southern and eastern regions of the country have experienced heavy and extensive rainfall. Floods have affected more than 2 million people and caused economic losses of billions of yuan.
The water level in China's massive Three Gorges Reservoir reached 147 meters on Saturday, two meters above the flood warning line. Meanwhile, the inflow increased to 26,500 cubic meters per second from 20,500 cubic meters per second on the previous day.
The alarming water level gave rise to rumors that the dam is under structural strain and nearby residents should evacuate. Some Western media hyped claims that the dam is at risk of collapse, which was not new in their discredit of the project.
Guo Xun, a research fellow at the Institute of Engineering Mechanics at the China Earthquake Administration in Beijing, refuted the rumors and speculation, saying that the dam is capable of holding far larger inflows than it is seeing now.
The dam is designed to meet "once-in-a-millennium" water level at 175 meters or flow up to 70,000 cubic meters per second. Currently, the 147-meter water level and 26,500 cubic meters per second levels are absolutely safe for the dam to bear, Guo told the Global Times on Monday.
Guo noted that the two-meter excess indicates that water in the reservoir needs to be discharged to balance outflow and inflow to prevent the water level from continuing to mount, a common practice in rain seasons. But the water is not a challenge to the reservoir, Guo said.
Speculation that the dam is an impending disaster have long circulated online both at home and abroad.
In July 2019, a satellite image of Google Maps appeared to show that the Three Gorges Dam was distorted, sparking concerns that it is at the edge of breaking.
The operator of the dam, the China Three Gorges Corp (CTGC), said in a statement then that monitoring data showed the dam was in normal working condition and the project was safe and reliable. Minor deformation happens all the time and it will not affect the dam's safety as long as it's within an elastic range, analysts explained then.
Guo said that the dam is equipped with a multi-channel "health monitoring system" that will issue an alert when there is an abnormity such as deformation, long before the change is visible.

[Update 17 July: There are more reports of heavy rain and extensive flooding around the Yangtze River with images of bridges, buildings, roads, dykes and polders, destroyed by the flood waters. Images of vehicles and buildings washed away by flood waters, and people evacuating their flooded homes. To save the dams and cities (like Chongqing), the dams are releasing floodwater that will inundate villages and towns, thus reducing the flooding for cities, and the stress on the dams, but threatening and destroying the homes and lives of villages and towns people. Farms and crops are also destroyed, washed over by the flood waters. But their pride - the Three Gorges Dam - will be saved. For now.]

No comments: