Showing posts with label Nile. Show all posts
Showing posts with label Nile. Show all posts

Wednesday, October 10, 2007

Egyptian Desert Irrigation

A delightful item yesterday. They are starting to grow trees out in the Egyptian desert beside the Nile. They are relying on some form of direct irrigation from the river. As someone who grew up in a world were the Middle East seemed to resist any simple application of common sense that might imply spending money on the potential welfare of the people, this is refreshing.

We do not know the scale anticipated, but we only have to think of the Great Valley of California to grasp the potential. This will also open up living space for the population among the orange groves.

This particular corner of the Sahara will be totally dependent on river water for as long as the remainder of the Sahara remains untouched. It is as far down wind as one can be without been in Saudi Arabia. I do not think that there is enough atmospheric water available in this part of the desert to ever hope to harvest water that way. We have to wait for the forests to be expanded up to these regions.

For those who like massive engineering schemes that can impact local climate there is the Qattara depression. It is below sea level covering 80 by 120 kilometers and runs sub parallel to the Nile at a distance of less than 100 kilometers. Filling it with sea water is a rather attractive option and using the intake flow as a power source is an option. More interesting, it has been proposed that the Nile flood waters could be diverted into desert channels that would end up in this same depression. The barrage would be built far to the south in the Sudan, I think, and would create a separate riverine system.

This hydraulic system would be a natural replacement for the Aswan High Dam which will eventually silt up and become useless as a storage reservoirs.

In the meantime, really good water management can provide a green cover for thousands of square miles of desert around these riverine systems. And eventually all the Sahara can have a green cover thanks to atmospheric water harvesting, and this will also induce a natural hydraulic cycle that will include ample rainfall now so sorely missing.

It ia all possible and it is good to see the Egyptians taking the first steps.