In the past I've made posts about draining the Bohai Sea over 50 years to create new land the size of the UK, and diking/damming/draining Sundaland, to reclaim an amount of land equal to the Americas (over 2-4 centuries)

Here, I state that focusing on the Taklamakan desert (the oval depression in Xinjiang) specifically offers some advantages

  1. the population of Xinjiang is already one of the fastest growing in China. So there's already a natural incentive to focus on this area.

  2. The Taklamakan is huge, 180,000 sqmi. For reference, Germany is 140,000 sqmi, and Turkey is 300,000.

Takla is also basically the size of the North Chinese plain, but with one very important advantage. Note the BROWN color on the map, this means higher elevation (green is low). Takla is much higher than sea level.

The REASON for this highly elevated, but uniformly flat land, is the millennia of sediment deposits laid there from the mountain-fed rivers surrounding it. In other words, the Taklamakan desert should have some of the BEST and also MOST soil in the world (just add water)

  1. A secondary to the "mountain fed rivers" from above--the fact that it is surrounded by mountains on all sides guarantees moisture stability.

If you were to put water in the Sahara, it may dry up quickly, because of rain/wind patterns, because the Sahara is a very open space. This is not stable.

But if you were to put a bunch of water in the Taklamakan, any evaporated moisture would simply hit the surrounding mountains and condense (leeward and windward), returning back into the basin. Basically, it should be a "one-time fix".

The only issue is physically desalinating and moving that much water into the basin. But once that's done you'll basically have the most fertile and resilient green space on earth.

  • Coolkidbozzy [he/him]
    ·
    edit-2
    3 years ago

    holy shit china is planning on actually doing this with TUNNELS

    Chinese engineers plan 1,000km tunnel to make Xinjiang desert bloom (2017)

    Chinese engineers are testing techniques that could be used to build a 1,000km tunnel – the world’s longest – to carry water from Tibet to Xinjiang, experts involved in the project say.

    The proposed tunnel, which would drop down from the world’s highest plateau in multiple sections connected by waterfalls, would “turn Xinjiang into California”, one geotechnical engineer said.

    China’s longest tunnel is the eight-year-old 85km Dahuofang water project in Liaoning province, while the world’s longest tunnel is the 137km main water supply pipe beneath the city of New York.

    However, the Chinese government started building a tunnel in the centre of Yunnan province in August that will be more than 600km long, local media reported. Comprising more than 60 sections, each wide enough to accommodate two high-speed trains, it will pass through mountains several thousand metres above sea level in an area plagued by unstable geological conditions.

    Researchers said building the Yunnan tunnel would be a “rehearsal” of the new technology, engineering methods and equipment needed for the Tibet-Xinjiang tunnel, which would divert the Yarlung Tsangpo River in southern Tibet to the Taklimakan Desert in Xinjiang. Downstream, in India, the river becomes the Brahmaputra, which joins the Ganges in Bangladesh.

    The Tibetan Plateau stops the rain-laden Indian Ocean monsoon from reaching Xinjiang, with the Gobi Desert in the north and the Taklimakan Desert in the south leaving more than 90 per cent of the region unsuitable for human settlement.

    However, the Taklimakan sits right at the foot of the Tibetan Plateau, which is known as the water tower of Asia. The more than 400 billion tonnes of water it releases each year – almost enough to fill Lake Erie in the United States – also feeds the source of other major rivers, including the Yellow, Yangtze, Mekong (known in China as the Lancang) and the Ganges.

    The earliest proposals to divert water from Tibet to Xinjiang were made by Qing dynasty officials Lin Zexu and Zuo Zongtang in the 19th century. In recent decades, Chinese government branches, including the Ministry of Water Resources, have come up with engineering blueprints involving huge dams, pumps and tunnels.

    “The water diversion project in central Yunnan is a demonstration project,” said Zhang, who has played a key role in many major Chinese water tunnel projects, including the one in Yunnan. “It is to show we have the brains, muscle and tools to build super-long tunnels in hazardous terrains, and the cost does not break the bank.”

    The Yunnan tunnel and support facilities will take eight years to build at an estimated cost of 78 billion yuan (US$11.7 billion). It will carry more than three billion tonnes of water each year from northwestern Yunnan to the province’s dry centre and directly benefit more than 11 million people, according to the provincial government.

    Zhang said China would definitely go ahead with the project one day. “In five to 10 years from now, the technology will be ready and the cost affordable, and the temptation of the benefits will be difficult to resist,” he said.

    Zhang said the water shortage in Xinjiang was in many ways similar to that in California early in the 20th century. The Central Valley Project, devised in 1933, diverted water from northern California to the San Joaquin Valley, turning it into the world’s most productive agricultural region.

    • EmmaGoldman [she/her, comrade/them]
      ·
      3 years ago

      If you're diverting this much water from Tibet, would this not result in other ecosystems elsewhere lacking for water, potentially those other major rivers mentioned?

      • Coolkidbozzy [he/him]
        ·
        3 years ago

        I can't find anything else about it so its possible they aren't actually planning on doing this, but yeah idk that sounds like it could be an enormous issue

      • Serendipity [none/use name]
        ·
        3 years ago

        I would be extremely pissed if I was India and was already facing looming water shortages due to thawing mountains.

        • sooper_dooper_roofer [none/use name]
          hexagon
          ·
          edit-2
          3 years ago

          that's why my post focused on water desal. It's going to take a lot longer, but it's the safest and most consequence-free method. The water just comes from the ocean, it's essentially a free lunch. I really don't like the idea of diverting rivers, even from wet places, because it will necessarily disturb something, that's just how it is.

          However, this is the Brahmaputra, not the Ganges. It flows through Arunachal/Assam straight into Bangladesh, these are the wettest parts of continental India, wetter than the US northeast. It has the highest rainfall in the world, after the Amazon, Papua, and Borneo (excluding ocean rainfall obviously)

          I still don't like it that much but it's not as bad as it sounds. I'd still rather they get desal to work somehow though

          Another possibility is to dam the Bay of Bengal. It would save Bangladesh from flooding, and it would also create a huge freshwater reservoir with one of the highest rainfall rates in the world. It's also the shortest route water source to the Tarim Basin. Cons: the water pipeline would have to go through India, so geopolitics would have to change radically. Although maybe the benefits of the project could convince the parties to agree, idk.

          • ToastGhost [he/him]
            ·
            3 years ago

            you cant just build a dam 1000 km long across a kilometers deep ocean to turn literally the largest bay in the world into a freshwater lake

            this is your brain on elon musk shit

            • sooper_dooper_roofer [none/use name]
              hexagon
              ·
              edit-2
              3 years ago

              you cant just build a dam 1000 km long

              you mean 600 km

              SKorea already built one that's 30 km, it's already been largely drained with recovered land being used for agriculture
              The dike (not dam) would be 20x longer, and 10x deeper, true
              China's economy is 20x bigger than Korea's, its population is 26x bigger, and cooperation from Indian countries would make this even more feasible

              don't confuse actual geoengineering with "lul let's go to mars in underground tunnels because reasons"

              • ToastGhost [he/him]
                ·
                3 years ago

                the difficulty of such a project most definitely doesnt scale linearly, geoengineering is largely crank musk shit to pretend we dont have to stop using fossil fuels entirely

                musk's tunnel shit is so many times more realistic than this proposal

                • sooper_dooper_roofer [none/use name]
                  hexagon
                  ·
                  3 years ago

                  musk’s tunnel shit is so many times more realistic than this proposal

                  how so?

                  the difficulty of such a project most definitely doesnt scale linearly,

                  of course it doesn't, when did I say otherwise? The manpower and combined capabilities of China + India + Bangladesh is also a little bit bigger than those of South Korea

                  • ToastGhost [he/him]
                    ·
                    3 years ago

                    musks shit is more realistic because it can actually be built, itll just be impractical and exclusively for the bourgeoisie. I really dont think you understand the scale of the things youre proposing.

                    • sooper_dooper_roofer [none/use name]
                      hexagon
                      ·
                      edit-2
                      3 years ago

                      https://en.wikipedia.org/wiki/Northern_European_Enclosure_Dam
                      This thing (necessary to prevent mayoland from flooding) would cost 1/2 a trillion and take 75 years to complete

                      A Bengal dam would be the same length but 4x shallower, maybe 300 billion and 20 years to complete, even if we err on the conservative side

                      It would dam Bangladesh, preventing flooding
                      It would create a freshwater reservoir the same volume as lake Erie, but with 2.5x as much rainfall.

                      Bengal ---> Xinjiang is also the shortest possible route water can take, without disrupting other rivers/lakes

                      Alternatively, they could divert the Brahmaputra and replace the lost water with the newly acquired Bay of Bengal water (this is probably cheaper but also more complicated and risky)

                      Both Bangladesh and India would benefit massively from it, and the only country that wouldn't (Myanmar) happens to be strongly aligned with China already

                      • ToastGhost [he/him]
                        ·
                        3 years ago

                        The scheme's authors describe it as "more of a warning than a solution"

                        also the north sea is much shallower than the bay of bengal, and the places they would have to dam all sit on the continental shelf, which the bay of bengal does not. this plan is so unfeasible that even its authors say it is impossible and just a thought experiment, but is still more realistic than your proposal.

                        i really dont get how youre arriving at your numbers to claim damming the bay of bengal would be the same length but shorter, what i would assume you mean by damming up the bay of bengal is to dam all the way across from Sri Lanka to West Sumatra, even if you mean to dam to Myanmar instead, it becomes even longer and still crosses open ocean kilometers deep.

                        One final note, the scale of desalination required to transform an entire saltwater ocean into a freshwater resrvoir completely negates the need for a freshwater resevoir in the first place. if you have coastline and enough desalination to do this insane project, you would just cut out the middleman and desalinate your drinking water from the ocean.

                        • sooper_dooper_roofer [none/use name]
                          hexagon
                          ·
                          edit-2
                          3 years ago

                          also the north sea is much shallower than the bay of bengal
                          is still more realistic than your proposal.

                          No it is not. The north sea has a 50 mile stretch that is 1000 ft deep.
                          The Bay of Bengal has only a 10 mile stretch that is 1000 feet deep.

                          Their proposed north sea dam averages 500 ft deep.
                          The greedy version of the Bay of Bengal dam I'm spitballing averages 284 ft deep, and could be made even shallower (at the expense of reducing the size of the freshwater reservoir).

                          I can send you the interpolation excel file I did, or you can check out google earth for yourself.

                          what i would assume you mean by damming up the bay of bengal is to dam all the way across from Sri Lanka to West Sumatra

                          lmao come on, of course I don't mean that. that's ridiculous.

                          The pic I just posted in this comment is the "greedy" version (This one is 1.7x as long but 1.9x more shallow, meaning still slightly more feasible than the proposed North Sea dam). As I said, this can be scaled down to be just as long as the north sea dam, but far shallower. The one I was talking about in my previous comment is the "less greedy" version which would be much much easier than the north sea dam.

                          One final note, the scale of desalination required to transform an entire saltwater ocean into a freshwater resrvoir completely negates the need for a freshwater resevoir in the first place

                          I'm talking about passive desalination. You capture the Brahmaputra freshwater, as well as the rain water (Bengal Bay is literally the rainiest non-island area on earth). Try to desalinate even 1/10 that amount using desalination stations/membranes, I dare you lol

                          The "greedy" version of the reservoir has a volume of 712 cubic miles. The Brahmaputra outputs 146 cubic miles annually, and the reservoir gets 44 cubic miles annually from rain.
                          This is 190 cubic miles of pure freshwater replacement per year, meaning the total replacement of the saltwater should theoretically take only 4 years.

                          Admittedly there is some fuckery you'd have to do with pumping out the saltwater (which sinks to the bottom), and I haven't accounted for this. But hopefully it could be done passively as well, by opening underwater gates when the outside ocean tide is low, and closing them when it's high.

                          the point is that aside from saving millions of lives from flooding, and also preventing a continental refugee crisis spilling into your borders, you would get 6 Lake Eries' worth of free freshwater, and the distance from Bangladesh to the Taklamakan desert is also the geographically shortest way to get massive amounts of water there.

                          Actually GETTING the water there would be a huge project as well. But in the meantime the dam/dike system would just exist, preventing flooding.

                          • ToastGhost [he/him]
                            ·
                            3 years ago

                            thats much less drastic than what i thought you meant, you never specified it would only dam a small part of the bay.

                            • sooper_dooper_roofer [none/use name]
                              hexagon
                              ·
                              3 years ago

                              I thought it was obvious so I didn't mention it. damming the open ocean where it's 18,000 ft deep is obviously economic suicide

        • EmmaGoldman [she/her, comrade/them]
          ·
          3 years ago

          Yeah, that's definitely something that might make someone with ongoing border tensions with their neighbour go to war with that neighbour

      • FidelCashflow [he/him]
        ·
        3 years ago

        The goal, it seems, is to use the mountians to hold the water in after it's diverted. So in theory it would even out after a period of time.

        I say in thwory because this is a super ambitious geoengineering peoject so while the science is sound who knows what will happen.