ABSTRACT
Aridity is generally defined as a lack of moisture on the basis of average climatic conditions over a region and is manifest through the soils, vegetation and topography. The latter are often used as non-climatic criteria for identifying arid lands. Nevertheless, there is great diversity of physical environments and patterns of human occupation in these areas. Agricultural activities include: endurers (pastoralists who inhabit the most arid parts), avoiders (dry-land farmers who are only active in wet seasons) and escapers (irrigation farmers who create an artificial environment).
