I have a large plateau, and roughly in the center are mile-high cliffs surrounding a valley.

Inside the valley is a green sandy desert. The sand is composed of olivine. Unfortunately for the inhabitants of the green desert, a hostile power has resolved to remove all the sand out of the valley, off of the plateau, and into the lowlands below it via a huge ramp/shaft that they dug and some vague (and very classified) magic trickery.

What does this do to the local climate? Is a desert in a closed-off valley even entirely possible?

Of equal interest: what happens to the lowlands? This particular area of them where the sand is being drained is a region of badlands. Keep in mind that it isn't all of the sand being dumped at once, but rather a steady (albeit massive) flow of the stuff.

And what would happen to the flora and fauna on both ends?


closed as too broad by RonJohn, Aify, ShadoCat, James Aug 2 '18 at 16:44

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    $\begingroup$ FYI: Angle of repose. For dry sand, its 34 degrees. Sand will not flow down if its slope is less than 34 degrees. $\endgroup$ – Alexander Aug 2 '18 at 0:12
  • 2
    $\begingroup$ @RonJohn It is made of olivine. The hostile power's motivations are hardly relevant to the question, but suffice it to say that it's a brute-force and roundabout way of committing genocide for a variety of reasons. As for your last question, I'm not a climate scientist, even by armchair qualifications. That's why I'm asking. $\endgroup$ – Classified Angel Aug 2 '18 at 0:17
  • 3
    $\begingroup$ @RonJohn Again, not relevant to the question, but these aren't humans they're committing genocide against. They're a species entirely dependent upon the existence of their desert without much ability to live in other climates. $\endgroup$ – Classified Angel Aug 2 '18 at 0:25
  • 3
    $\begingroup$ @RonJohn Except I'm not asking about the inhabitants, I'm asking about the natural world around them. I couldn't care less what happens to the inhabitants for the purposes of this question; I'll do some handwavium in my story regarding that. $\endgroup$ – Classified Angel Aug 2 '18 at 0:30
  • 4
    $\begingroup$ @ronjohn This is purely a question about ecological effects. None of that other stuff matters. It's not nearly that complicated, and the presence of predictable environmental effects makes this not opinion based. $\endgroup$ – user49466 Aug 2 '18 at 1:09