AHQ: Could Amda Seyon have made good on his threat to redirect the Nile?

Behold, a geological POD that isn't ASB!
In 1321, in response to Mamluk Sultan an-Nasir Muhammed persecuting the Coptic Christians in Egypt, Emperor Amda Seyon I of Ethiopia threatened to permanently destroy Egypt by redirecting the Nile.
Redirecting rivers to cause floods is a tactic that has been used throughout history, from the Qin flooding Wei's capital with water from the Yellow River in 225BC to Ukraine creating mud to force the Russians to use vulnerable roads in 2022. It also happened by accident when California created the Salton Sea in 1905. However, doing the opposite and redirecting a river to create drought and famine is not such a common tactic.

Let's imagine a scenario where Amda Seyon and an-Nasir Muhammed come to blows and the Ethiopian Emperor chooses to redirect the Nile.
Firstly, did Ethiopia have the technology to pull this off? While digging irrigation canals wasn't exactly new technology, redirecting a river is quite a bit larger in scope!
Secondly, where would be the easiest place to redirect the Nile to? North-West to the Sahara Desert (possibly flowing into the Qattara Depression)? East to the Red Sea? Or even draining Lake Tana South into the Awash River, leaving the White Nile (which only carries 10% of the Nile's water) untouched?
Finally, what would be the consequences of this abhorrent act of un-terraforming? Obviously, it would cause a severe humanitarian crisis in Egypt, and probably also all the states near Egypt as they get flooded with refugees (ironically including Ethiopia itself) but this still leaves the issue of long term effects such as ecological damage and the loss of the Mediterranean's biggest breadbasket and link to Sub-Saharan Africa.
 
Probably not.

What I said a while back in another thread applies.
Looking at Google maps, the most likely possibility SEEMS to be have the Nile be blocked at or near modern Atbara, a bit north of Khartoum. Then have the water flow backwards up the Atbarah river towards the Red Sea. Then, instead of continuing on south, have it head east past modern Oleb, and then flow down what seems to be a break in the mountains, coming out at a place called Tokar (rather south of Port Sudan).

It would still flow through a chunk of the Sudan - but not at all into Egypt.
To do all that by human action (instead of having a volcano suddenly erupt and block the valley)
Would take a HUGE amount of effort. I'm not sure how high that dam would have to be, but it would be high.

Edit:
Elevation of Atbara is 356m
Of Khartoum: 381
I'm having some problems finding elevations up river.

Following the river upstream, AL Butana Bridge/ kubry al butane is at 424m

And I don't think we've come near the diversion east yet...
 
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Amda Seyon control only Ethiopia, not Sudan or Nubia. He can only control Blue Nile in Ethiopia. Build massive Dam during dry season and create lakes probably best he could do.
 
Probably not.

What I said a while back in another thread applies.

To do all that by human action (instead of having a volcano suddenly erupt and block the valley)
Would take a HUGE amount of effort. I'm not sure how high that dam would have to be, but it would be high.

Edit:
Elevation of Atbara is 356m
Of Khartoum: 381
I'm having some problems finding elevations up river.

Following the river upstream, AL Butana Bridge/ kubry al butane is at 424m

And I don't think we've come near the diversion east yet...
Following the 400m and 600m contours on google maps, I don't see anywhere where there's a pass as low as even 800m to the Red Sea. You might have to dig a 100km or more of canal ranging from 200m deep to 600m for a few km.

So.... surely not plausible even with today's tech, let alone in the14th c.

At
 
If it isn't possible how much could actually be done before they give up, and would failing have an historical impact?

Build massive Dam during dry season and create lakes probably best he could do.
This option could at least benefit his own people, even if the project ends without a full blockage.
 
It would inevitably kill a lot of people to try digging as much as Dathi suggested so that would have a definite impact. Idk much more about the historical situation to add my opinion though, sorry.
 
Looking at a topographical map of Africa, it looks like the answer to my question is a decisive "no". The Nile runs through the lowest part of the Sahara, so redirecting it West would require pulling the water up. Redirecting it East or South also doesn't work because there are mountains in the way and strip mining and entire mountain is beyond the capabilities of a pre-industrial state.
The closest the Nile gets to the edge of its own basin is around 22°N, 32°E, which is well within Egyptian territory.
 
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