Migration on a permanent or temporary basis has always been one of the most important survival strategies adopted by people in the human history. However, the literature devoted to the complex relationship involving environmental change as both a cause and a consequence of migration is rather limited (Hugo, 1996). The knowledge of how economic and environmental factors interact and impinge upon economic development, social change, conflict as well as migration decision is also inadequate. With the acceleration of environmental degradation and the aggravation of environmental stress during the past decades, unprecedented numbers of the population have seen migration as an option. Against this backdrop, attention directed at the relationship between environmental change and migration has arisen among both researchers and policymakers (Richmond, 1993; Doos, 1994; Kibreab, 1994; Black, 1994; Hugo, 1996; Swain, 1996; Xu, et al, 1996; Ma, 1997; O'Lear, 1997 and Hempel, 1997). The migration literature is replete with typologies which differentiate migrants and migrations according to the relative permanency of the move, the distance traversed, the nature of the boundaries crossed, the causes of the move, the characteristics of the movers, etc. (Hugo, 1996). Government policies and direct administrative intervention in the origin and destination of migration can have strong, sometimes even decisive, impacts on the scale of all types of migration.
