ABSTRACT
Desertification is the degradation of lands in dry areas. This chapter opens with a review of some key definitions of desertification, briefly describes the general distribution of drylands and the reasons for their occurrence, distinguishes between desertification and natural desert, and then introduces the two main physical characteristics of desertification - the degradation of soil and vegetation. Desertification is not the desert expansion of popular imagination. Instead it is essentially a subtle, dispersed and continuous process which mainly occurs far away from desert fringes, with the outright conversion of fertile land into desert only taking place in extreme cases.
