China’s Sinking Land Problem

always cracks me up that "small" cities in China have the same population as my entire country

It is often overlooked that urbanization covers the land with impermeable roofs and streets. So the rain water is prevented from percolating into the earth. This creates paradoxical floods even in cities that are in drought conditions. Any little rain that falls overwhelms the drainage, because it is no longer absorbed into the ground.

"The Unbearable Weight Burden of Your Butt"

I think the craziest place this is happening is in Mexico City, where the rate of subsidence is massive and the whole city is built over one of the worst chosen locations for a megacity, a lake.

There is a similar issue in industrialized West Germany in the Ruhr area, from which black coal had been extracted for a very long time, and in some places it is still ongoing. As a side effect the entire area had to manage just this sinking of the land by a sophisticated water infrastructure, and there are areas in which houses face damages because of the sinking ground. But this makes no headlines, and beyond the local area, in Germany, this remains rather unknown, and I came to know it only when I moved there for some time for a job. This problem is, like in China, 100 years old, and locals are just used to it. With the explanations from this video, I would assume the same problem exists pretty everywhere where heavy industry and/or water supply overused the land beyond repair.

It could also be ignored or inadequate Chinese building standards. As a professional hydrogeologist, you've completed a well documented report.

Germany has also that Problem. But not because the extraction of water but of coal. Some cities in North Rhine Westphalia would be meters deep on the bottom of lakes without pumps running for 24/7 for the next eternity.

1:12 San Joaquin Valley, California (in this photo) used to be largely covered by a massive lake (largest west of the Mississippi) and surrounding marshlands, but after we diverted the water to LA and other cities, it became a dry, parched environment. That’s why the ground sank so much. Ironically, after the unusually large rains last year, the farmland where the lake used to be flooded and we got Tulare Lake back for a time.

Most ground water extraction is for agriculture and industry rather than for drinking water.

Cats? I wonder what the weight of all the cats in China is.

Subsidence can also cause local apparent sea-level trends to greatly differ from the widely advertised (but actually very slow) global rate. However, subsidence isn't always caused by groundwater pumping. Oil and gas extraction can also cause subsidence. More importantly, natural processes, like post-glacial rebound, can cause uplift in some places and subsidence in others. Ironically, Greta's Thunberg's hometown of Stockholm is one such place. Uplift there is about triple the global sea-level rise rate, so the local "relative" sea-level trend at Stockholm Harbour is downward, rather than upward. (It is a minor contributor to their periodic dredging expenses.)

The most common cause of subsidence is poor government planning, regulation, and enforcement.

lol it's not often to see "References and sources go here" at 10:34

You have very interesting subjects for your videos. Keep them coming.

In the suburban area that I live in Colorado, subsidence is connected with the area's past underground coal mining industry. There are fields on which they won't even build roads even though they would help traffic patterns. There are awkward breaks in the pattern of sub division housing for parks and openspace that don't fit in with the aesthetics of urban planning. Some significant parts of a major mall were torn down a few years after construction as the buildings were condemned.

In Bangalore, India, Rain water harvesting for every home is made compulsory. Without it that building does not get building permit.

Great research. 👏🏼 One question: How huge the sink has to be to be considered a result of excessive groundwater drain? We are seeing a lot of these in India lately. Most of the groundwater is used for farming. The government tried making some laws that would make people use lesser groundwater but it was protested against and now we're seeing a few sinkholes. I think the reason is the same as you explained.

Love that he lets his curiosity lead this channel. Keep it up.

They’re transporting water by train recently too.

Shipping water across vast distances via canals reminds me of a proposed project where Nevada wanted British Columbia to flood most of the Rocky Mountain trench and pipe the water down to the Vegas area. It was of course rejected, not least of all because it would result in a massive waste of water through evaporation, in much the same way that long-distance electricity transmission results in increased bleed-off of energy. These huge mega-projects remind me of a book by Fiona Hill and Clifford Gaddy on the Soviet attempts to "conquer" the Arctic through sheer force of will. There will be costs to this kind of hubris. The lost Aral Sea is a testament to the unintended consequences of playing around with water on this scale.