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.

  • 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