Sustainability in the Desert

According to the definition of sustainability, the achievements of past civilizations, e.g. the floodwater farming near the site of Umm el-Jimal, were sustainable since they did not rely on non-renewable resources. But they did not allow continuous settlement from antiquity until today. It is often assumed that breaks in settlement history were due to over-exploitation of the environment, e.g. overgrazing and soil erosion [1].