Analysis of the structure and spatial organization of the city-region of Mazandaran during the period 1390-1365

In the different cases, population changes are always influenced by centripetal and centrifugal forces. These forces make changes in the spatial structure of urban areas that characterized by the pattern of mono-centric with a strong center, or according to a polycentric structure, in which peripheral centers emerge. The aim of this study is to analyze the spatial structure of the population distribution and its evolution in mazandaran city-region on intervals of 1365 and 1390. The aim of this study analyze the spatial structure of the population distribution in the city-region of Mazandaran and its evolution in the period 1365 -1390. The article in terms of the nature and purpose is functional and Descriptive-analytical. Findings of concentration indicators analysis shows that during of 25 years ago, concentration trend of population is always increasing. Thus, Population spatial pattern has been identified as Decrease in southern districts and increase in the larger and more important population centers. Next, to evaluation the spatial structure of the population and prove of morphological polycentricity are used GIS analysis tools (such as mean nearest neighborhood and hot spots analysis) and rank-size model. The results of morphological Indicators showed that during mentioned period, sari, amol, babol and ghaemshahr cities has retained its position as a major regional centers and a relatively balance between these centers there. In fact, dominant of four cities with settlements of relatively same size around them demonstrates formation of polycentricity structure from the perspective of morphological