The proposal he's linking to, does indeed read like satire, but he seems to think it's serious and feasible. Which is deranged with even a moments thought, as soon as you look at a map.Seems to be satire.
It's proposing starting in the UAE between Dubai and Abu Dhabi so at least 100km, probably closer to 200km.
How large a crater does he want per explosion? Even he must think that such craters are roughly circular, so with no knowledge of the power of nuclear explosions, if you wanted a 1km wide canal (insanely large) you would need 100 bombs. If there were no mountains. And that's far too wide. The Sedan crater is 400m wide and 100m deep and used a 104kT bomb, so that's 300 bombs.



