Analyzing the Rank-Size Model in Spatial Order of Urban System in Ardebil Province During 1986-2006

Accelerated urbanization process، mainly in developing countries، has been distributed as spatial system of urban settlements in many cases whose main consequences are the occurrence of instability conditions in urban networks. This research has been done by a descriptive-analytical method to study the hierarchy and transformation of urban system and their population distribution. In this regards، cities in Ardebil have been analyzed based on general population and housing censuses period of 1986 to 2006 by using the rank-size and regulation rank-size models. The results indicate that spatial patterns of urban settlement follows a random pattern whereby 18 English Abstracts in recent decades the tendency of urban population centers and classes are rising toward chaos. The spatial and functional dominance of Ardebil، the first city of province، has caused the urban hierarchy not to follow the rank-size model. Hence this discrepancy and spatial inequality in hierarchical system is clearly recognizable. On the other hand، in the recent decade (2000s)، the population imbalance distribution has been more enhanced comparing to the past. The optimal spatial pattern in the Province would be obtained by the policy of non-centralization on one hand and accessing suitable services and appropriate balance between economical and physical opportunities for medium and small cities on the other hand which have been the objectives of this research.