Land degradation-the wearing down of the land by the erosive action of water, wind, or ice.
Perennial irrigation -artificial application of water to land to assist in the production of crops
Wadi-the channel of a watercourse that is dry except during periods of rainfal
Coup-unexpected stroke, act, or move; a clever action or accomplishment
Ancestor Worship-ancestors whose spirits are frequently held to possess the power to influence the affairs of the living
Ethnocracy-a branch of anthropology dealing with the scientific description of individual cultures