Analysis of changes in the urban hierarchy Zanjan province period 1355 - 90

Special conditions of economic, social and political systems, network specific disparate and disjointed urban created, in fact indicates that one or more of parasite growth retardation and other cities in the development process. First there is a lack of consistency reflects the city's economic, social and political cities in a single system. Zanjan province despite having historical development, are lagging behind in terms of development disparities that exist between cities reasonable distribution of services and facilities necessary to explain that. The study of inequality and uneven urban network for any plan to achieve the desired balance. Using multiple models and indicators of urban system in the Zanjan province has been paid. Cities were ranked using four models (rank - size, nearest neighbor analysis, stratified and entropy difference) in the Courses of study, The results indicate that there is inconsistency In Province system urban. The main cause of the First City (Zanjan), which is concentrated in the center of the province's population. Favorable balance during 1355 was established in system cities than in other periods, The greatest inconsistency occurred during 1375, but in subsequent years the balance has gone ago, Finally, in the 1390 period compared to the period before the imbalance has increased slightly. The first topic is the city with three indices, shows that urban primacy of the period 1365 to 1390 has decreased from year to year. Ranked based on urban centrality and accessibility and performance indicators, results are of centrality of cities rank low correlation available.