China has been hit by devastating floods in recent weeks, inundating cities and causing deaths and infrastructural damage, as well as raising questions about the effectiveness of its 2015 "sponge city" initiative aimed at reducing urban flood risks.
The initiative was launched to boost flood resilience in major cities and make better use of rainwater through architectural, engineering and infrastructural tweaks.
But cities remain vulnerable to heavy rain. In July alone, floods and related geological disasters caused 142 deaths and disappearances, destroyed 2,300 homes and caused direct economic losses of 15.78 billion yuan ($2.19 billion), China's emergency ministry said on Monday.
Following is an explainer about the sponge city scheme.
WHY WAS THE INITIATIVE LAUNCHED?
China has long sought to improve the way it handles extreme weather, and make highly populated cities less vulnerable to flooding and drought.
The "sponge city" initiative was designed to make greater use of lower-impact "nature-based solutions" to better distribute water and improve drainage and storage.
Those solutions included the use of permeable asphalt, the construction of new canals and ponds and also the restoration of wetlands, which would not only ease water logging, but also improve the urban environment.
Breakneck urbanization has encased vast stretches of land in impermeable concrete, often along banks of major rivers that traditionally served as flood plains. With wetlands paved over and nowhere for surplus water to settle, water logging and flooding was commonplace.
According to 2018 data, 641 out of 654 large- and medium-sized cities in China were vulnerable to flooding and water logging, with 180 facing flood risks every year.
WHAT HAS BEEN DONE SO FAR?
Studies show that many of the local pilot initiatives launched so far have had a positive effect, with low-impact projects like green roofs and rain gardens reducing run-offs.
But implementation has so far been patchy. A total of 30 pilot sponge cities were selected in 2015 and 2016. By last year, only 64 of China's 654 cities had produced legislation to implement sponge city guidelines, researchers said in January.
The researchers said the government had so far paid "minimum attention" to sponge city construction, and called for national legislation to be drawn up as soon as possible.
WHAT ARE THE LIMITATIONS OF SPONGE CITIES?
Even if sponge city measures had been implemented in full, they would have been unable to prevent this year's disasters.
Zhengzhou in Henan province was one of the most enthusiastic pioneers of sponge city construction, allocating nearly 60 billion yuan to the program from 2016 to 2021. But it was unable to deal with its heaviest rainfall in history in 2021.
Experts believe sponge city infrastructure can only handle no more than 200 millimeters (7.9 inches) of rain per day. At the height of the rainstorms that lashed Beijing at the end of July, rainfall at one station reached 745 millimeters over three and a half days. In July 2021, Zhengzhou saw rainfall in excess of 200 mm in just one hour.
Authorities are also playing catch-up to climate change. This year's heavy rain hit cities in the normally arid north, where sponge city development is less advanced.
© (c) Copyright Thomson Reuters 2023.
18 Comments
Speed
I know a guy named Bob that lives there.
cuddly
This shows the need for human activity to control the effects of natural events.
Ricky Kaminski13
A picture tells ten thousand words. Some of the scenes coming out from China seem almost apocalyptic. Stories of mass confusion and central authorities incompetencey already leaking out. Some examples include community based rescue missions being delayed or told to stand down due to official seals ( the holy hanko ) gone missing or washed away. Can’t do a rescue without the proper documentation ! Govt. officials doing a runner when faced with angry and desperate constituents, damns chosen and deliberately opened; certain areas and villages sacrificed through an opaque bureaucracy in charge of water release systems. Massive sink holes appearing the works! The central govt. will end up spending much of its time covering its own butt and suppressing the worst cases of corruption, shoddy building and planning and will rush in to ‘look like’ they are in charge of the situation. Face is everything of course.
Have nothing but pity for anyone that has to live under what would be incredibly frustrating circumstances. Also makes you feel there’s not that much to worry about on the geopolitical stage. If China can’t build and manage their own cities, then all run about pointing fingers at each other when things go pear shaped, am not quite sure why they believe they have the right to dictate to the rest of the world frankly about anything.
Once again, not reveling in the misery, huge levels of pity for those caught up in the natural and man made disasters of our times, in any country. We should all be focusing on how to make better cities and communities that will be able to weather the coming storms. With the typhoon season upon us it should be a timely reminder of what the real priorities should be.
Japan should send a team of its own disaster experts to help out in Beijing. Friends in need could be a friend in deed. Grass roots soft power and regional bridge building! It may even take disasters like this to cool down the drums of war. Turn disaster into hope.
OnTheTrail
Very well said Ricky
virusrex
More than that, it shows the need for control of the effects of the climate change, which is the one fueling the extreme weather events and will do it even more in the future. That is part of the current problem, measures that are enough for natural events, but not for the much more serious and frequent human derived ones.
gcFd1
Yes, these natural events (rain, earthquake, typhoons etc.) that have been occurring for eons are part of the cycle.
Constructing buildings that can withstand high winds and earthquake effects, and building dams and so forth to control flooding are basic examples of human activities that attempt to make it easier to live with nature.
virusrex
No, they are not the experts in the field have clearly concluded the sudden increase of extreme weather events is a consequence of climate change and they are predicted to increase. Obviously they are a much better reference about weather than nameless people on the internet saying they are wrong.
This article and many others have clearly pointed out how the current human activity derived events surpass what have been enough previously, precisely because of the increased intensity.
gcFd1
Wrong, as the experts in the field have clearly tracked historical meteorological events.
It didn't just start to rain yesterday.
Obviously they are a much better reference about weather than nameless people on the internet saying they are wrong.
In other words, I will listen to the experts, not the trolls trying to deny science.
kaimycahl
@cuddly ARE YOU SERIOUS? This shows the inability of the CCP to plan for such climatic events. They are to busy being greedy, war mongering and bullying no amount of human activity could change the CCP mind set they do as they please and we see the results. Heads in the Sand!!! Thats their motto!
This shows the need for human activity to control the effects of natural events.
isabelle
It, however, spends the money needed for this on oppressing its people, and harassing all its neighbors instead, so it never actually does so.
Desert Tortoise
I was thinking it shows the futility of man trying to control nature. The more intelligent course of action is to not build or re-build in a flood plain.
Desert Tortoise
Before throwing too many stones Ricky read up on the May 2022 central Michigan dam failures. If I didn't kill too many brain cells on liberty in Hong Kong the dams permits to operate had expired years earlier and their operator was having a pissing contest with the state about safety upgrades the utilities that owned the dams claimed were unnecessary.
This sort of thing happens in every country. I'm not convinced it is possible to prepare any city to absorb over 200 mm of rain per day for three days straight.
Btw, even in the US dam operators will open spillway gates and other outlet works flooding everything downstream to prevent the water from going over the top of the dam, which generally leads to a complete failure of the dam. Sometimes dam operators are presented with situations where there are no really good choices, only a least worst one. No conspiracy there. It comes with the territory.
virusrex
Not wrong, you have not brought yet any expert that say this explanation is wrong, that claim comes only from you, which of course can't make any appeal to authority.
Which has no relevance, the argument is that climate change is what is making the extreme weather events stronger and more frequent, not that they make rain appear for the first time ever, that again is just a claim you yourself are making.
In this case no expert support what you claim, which is denying science.
Insulting other commenters is not working anymore to get comments you feel ashamed of writing deleted, you will have to do much more and break the rules of the site more openly to get that.
gcFd1
Clearly wrong, as the experts contradict your personal opinion.
The expert consensus is that events such as hurricanes are not more frequent, and in fact, are less prone to reach the mainland in places such as the USA.
virusrex
Still not wrong, no expert have said anything that could be interpreted as opposite to the comment.
Still not, you have brought no expert saying this, that is still your own personal claim.
gcFd1
You are wrong again.
Strange obsession of yours, this trolling.
The initiative was launched to boost flood resilience in major cities and make better use of rainwater through architectural, engineering and infrastructural tweaks.
Just looking at the second paragraph of the article shows that your personal claim that human activity is not related to the failure of the flood control measures is false.
theFu
If you've never been though a flood that lasted weeks, you have no idea. The water needs to go somewhere. Waiting for it to evaporate isn't a viable option. Controlling flood waters needs to be engineered years in advance and validated to ensure it actually works the way you believe or the models show. Modeling only does so much.
Massive storms ARE more frequent and more intense. https://www.undrr.org/publication/human-cost-disasters-overview-last-20-years-2000-2019 That's the United Nations.
Basically more than double the events, double the costs, and double the number of people impacted between the most recent 20 yrs and the 20 yrs prior to that period.
Why do people insist on making false claims that just show ignorance?
virusrex
Obsession would be to insist on insulting and attacking others when they demonstrate something you believed is not correct. You keep doing that even when it is against the rules.
Since I have never made that claim, then this is irrelevant. Just an excuse you are using to avoid addressing the actual arguments of the experts that say that not only the events have become more frequent, they have also impacted more people by factors easily attributable to climate change.