Zhengzhou hit by massive floods due to heavy rainfall

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Leo Liu
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https://en.wikipedia.org/wiki/2021_Henan_floods
The situation in Zhengzhou is still grim as the utilities are out and many people have been displaced. At around 5PM on July 20, the level of rainfall reached 2.01 m/h. The flood created by the rain rushed into a subway station from a ventilation chimney, causing a metro to get trapped in the tunnel, in which the water raised above the necks of many passengers. 12 people died in this accident.

A netizen also posted a picture featuring a flooded public hospital, with which they claimed that electrical power was unavailable, the backup batteries were drained, doctors were using manual ventilators to save lives, and the patients were dying.
1626894772709.png


BBC news report:
https://www.bbc.com/news/world-asia-china-57861067
Collection of videos/pics depicting the situation in Zhengzhou:
https://twitter.com/search?q=zhengzhou+china&ref_src=twsrc^google|twcamp^serp|twgr^search
Compilation of videos showing the the impacts of the floods (NSFW)




I wish that people in Zhengzhou stay safe.
 
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Answers and Replies

  • #2
rsk
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The planet has had enough of us and I can't say I blame it.
 
  • #3
BWV
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Saw some of the subway pics. Any implications for those downstream on the Yellow River?
 
  • #4
Leo Liu
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Saw some of the subway pics. Any implications for those downstream on the Yellow River?
No so many to my knowledge. I guess it's because the Yellow River could handle far more volume per unit time than the amount of water caused by the strong precipitation in the city of Zhengzhou. I will inform you if I have more information on this matter.
 
  • #5
BWV
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No so many to my knowledge. I guess it's because the Yellow River could handle far more volume per unit time than the amount of water caused by the strong precipitation in the city of Zhengzhou. I will inform you if I have more information on this matter.
Hope so, we have seen high levels of upstream rainfall lead to floods hundreds of miles downstream in the Mississippi river
 
  • #6
Astronuc
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2.01 m/h.
The rainfall in one hour was as high as 201.9 mm (7.95 in), or 0.202 m/h, which is still a heavy rainfall. Even 0.05 m/h is considered heavy. On hilly ground, the rain on the ground will flow to the lowest area, so low lying areas will fill with water, or valleys become streams or rivers.

Nevertheless, the rainfall rates are extraordinary, and of course, the flooding is catastrophic.
 
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  • #7
Leo Liu
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The rainfall in one hour was as high as 201.9 mm (7.95 in), or 0.202 m/h, which is still a heavy rainfall. Even 0.05 m/h is considered heavy. On hilly ground, the rain on the ground will flow to the lowest area, so low lying areas will fill with water, or valleys become streams or rivers.

Nevertheless, the rainfall rates are extraordinary, and of course, the flooding is catastrophic.
Zhengzhou received the same amount rainfall in two hours as Belgium did over two days. I can't find any data about the precipitation in Germany so I couldn't compare.
 
  • #8
Leo Liu
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Hope so, we have seen high levels of upstream rainfall lead to floods hundreds of miles downstream in the Mississippi river
Meh, even if there were floods down stream due to the unanticipated increase in the amount of rainwater, I doubt the government would disclose their existence, as it now busies itself with casting as much positive mood onto the public as they can to ensure that people won't question about the misconduct of the provincial government. But I am pretty sure someone is going to get fired to shift the blame from the system to a particular person, just as the central government removed the former mayor of Wuhan after the outbreak of COVID even though he was just executing commands from the top.
 
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  • #9
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Floods on China’s two rivers created some of the worst natural disasters in history, with death tolls in the hundreds of thousands or millions - largely due to subsequent outbreaks of cholera and other diseases and/or malnutrition from disruption of food supplies. Found this video on some of the unique features of the Yellow River

 
  • #10
Astronuc
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Zhengzhou received the same amount rainfall in two hours as Belgium did over two days. I can't find any data about the precipitation in Germany so I couldn't compare.

More than 7 inches (178 mm) of rain fell on parts of the western German states Rhineland-Palatinate and North Rhine-Westphalia between Tuesday and Thursday— roughly double the normal expected rainfall for the whole of July, . . .
https://time.com/6081472/germany-flooding-climate-change/

More than 182mm (7.2ins) fell in 72 hours in some areas between 12 and 15 July, according to Deutscher Wetterdienst - the German meteorological service.

Among the worst-hit parts of Germany, the area of the city of Cologne known as Köln-Stammheim saw more than 153mm of rain on 14 July. To put that in context, it is six times higher than the average heaviest rainfall days for the area in July.
https://www.bbc.com/news/world-europe-57862894


CNN, July 22 - A week after severe flooding hit western Europe, devastating Germany, Belgium and the Netherlands, German officials said Thursday they fear the 158 people still missing there may not be found.
The death toll from the floods has risen to at least 205 across the continent, while a total of at least 176 people remain accounted for. Belgium accounts for 32 deaths and 18 missing, according to its national crisis center.
https://www.cnn.com/2021/07/22/europe/germany-belgium-europe-floods-death-climate-intl/index.html


About 11 years ago, at my house, we had two successive weekends where on Friday it rained about 10-12 cm of rain, then ~35 cm during all of Saturday, then 5-10 cm on Sunday. The first time, the water trickled into the basement. The second weekend, the hydraulic pressure was so great in the ground that I jets of water shooting into the basement, so I had to set up a pump in the basement to run more or less continuously because of the flooding. We have a hill behind our house and the basement is the lowest point on the property. The street is slightly above our basement elevation, but the utility easement is fortunately lower, so that's where we pumped the water from the basement. Since, we have installed a trench system, sump and pump to remove any water entering the basement.
 
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  • #11
Leo Liu
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Update: To my dismay, more tragedies in Zhengzhou were revealed. Among one of them is the 2-km long tunnel on Jing Guang Road, which was fully filled with rainwater.



Rescue mission is now underway: https://www.thepaper.cn/newsDetail_forward_13692786

It was said that there were at least several dozens of vehicles in the flooded tunnel. It only took the rain a short period of time to fill it, so it is unlikely that people deep in the tunnel had exited the tunnel before it was too late.

This is the most devastating news about the flooding in Zhengzhou so far. My heart goes out to the victims of this incident. 😢 RIP.
 
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hilbert2
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