Evolution of Spatial Organization in Iranian- Islamic Urban System, the Case of Qazvin Province

The aim of this article is assessing and analyzing spatial organization of urban systems in Qazvin province and studying the population evolution of cities since 1976 to 2011 by using three different types of indicators: primate city¡ concentration and equilibrium. The results shows Qazvin urban system is characteristics by high primacy¡ concentration and unbalanced which is considerably more than urban pimacy of Iran in the same period especially in the early years of the era; although the descending trend of this indicators for studied province is corresponds with Iran’s. It indicates the decrease in concentration of population in Qazvin _Centre of the province and its primate city_ and the increase in urban system balance. The rate of nearing these indicators to the acceptable numbers for Qazvin urban systems has been more than Iran’s in the same studding era. The main reasons of more concentration in Qazvin’s urban system than Iran’s are the considerable share of population in Qazvin against other cities and the limited number and size of cities in median level especially in the early years of the study era¡ but 2006 is a turning point in the evolution because in this year as a result of changing the statues of rural settlements to the cities which they do not have had more than 5000 population¡ the number of cities has been twofold and increased from 12 in 1996 to 24 in 2006. After this change¡ concentration indicators show unbalanced has increased in it’s urban system since they are sensitive to the defenition of population thresshold for cities; so in spite of what commonly had been conceived¡ unbalancing in an urban systems is not necessarily due to population excess in first city but it can be due to population deficiencies in median and small cities and statues change of less populated rural settlements to the urban points.