An Analysis for the role of middle cities in spatial development of Zagross Major Region

The urban pyramid of Zagross region in 1385, in terms of population percent, indicates disequilibium in population distribution. In this year out of 119 cities in the region, 17% of the urban population belongs to the only great city in the Zagros region and 11.5% is related to the village-cities, (87 cities), which means the cities with less than 25000 individuals. In addition, spatial distribution of the population indicated that urbanization has been concentrated in the center and east perceptibly. In a manner that its population is more than 65% of the urban population. In this article the role of the middle cities in spatial development of Zagross has been analyzed using qualitative methods in models regarding population variants, occupation, educational (health), cultural facilities and their effect on the region. The results indicate that regarding entropy coefficient, the middle cities had partial favorable effect in the development and distribution of population in Zagross region in a manner that without considering these cities, the entropy coefficient becomes less and it manifests more imbalance in the urban system of the region. Regarding elasticity coefficient, the cities of Hamedan, Khoramabad, and Ilam have high elasticity potential and the cities of Borujerd and Malayer enjoy low elasticity potential. Studying the operation of cities with location coefficient indicate that the cities of Malayer, Khoramabad and Borujerd regarding (Agriculture), the cities of Hamedan, Malayer, Saghez, Borujerd and Dorud (industry) and the cities of Hamedan, Sanandaj, Khoramabad and Ilam (Services) have basic conditions and they are exporter of services to the areas under their influence. The comparative study of development degree for the region cities and the position of the middle cities compared to the region cities regarding the study indices with TOPSIS method indicate that the middle cities and their suburbs are respectively included in the deprived and semi-enjoyable cities in the region.