Here are five facts about the phenomenon of encroaching desert lands.

He was Cardenis, prince of engineers, fighting to save his people from the encroaching deserts.

Countries that lacked the means to defend themselves watched as the encroaching desert devoured their land.

Can an expansive row of trees and some strategically placed grass really stave off an encroaching desert?

The U.N. is running a food-for-work programme for villagers who remain, paying them for clearing the main road threatened by the encroaching desert.

"Was Armaghast like this?" asked Sol, making a gesture with his arm that included the valley, the Tombs, and the encroaching desert.