Evaluating Changes of Primate City and Urban System in Zagros Region (1976- 2006)

The urban system and urbanization in Iran have influenced and changed deeply due to industrialization and the dominance of exogenous development policy which accompanied by the decline of agriculture. The obvious character of such transition was the urban oriented development and the increased hierarchical migration from small towns and villages towards large cities which provided a gradual change of traditional pattern of settlement hierarchical and urban spatial distribution. The region of Zagros with five provinces has a rich and old history of urbanization and high population density in the western part of the country; this area has experienced considerable changes in its human settlement distribution. The purpose of this research is to evaluate the urban system of the region. The methodology of the research is based on descriptive-analytical methods and the data were collected via secondary sources such as national censuses. The results showed that despite the growth of city size and the number of urban places، the region has no sign of primate city and there has been balance in the most of the censuses so that the primate city index only changed from 0. 171 to 0. 178. Also the de-concentration index of the region has decreased from 0. 765 in 1335 to 0. 750 in 1385 which illustrates that in general concentration increased in the area; however from 1375 the region has experienced urban concentration annually.