تحلیل ویژگی‌های پراکنش فضایی در منطقه زاگرس

Extended abstract
1- Introduction
Among various factors resulted in rapid and deep changes in the civil system of our country during some past decades, we could mention population growth, and parallel with it, growing urbanization. Such evolutions may reduce the consolidation and effectiveness of functions of urban system element and their communications and caused spatial disharmony. Therefore, one of main problems of spatial and regional development in Iran is disarrangement of spatial organization and lack of hierarchy based on the interaction between habitants. It seems that spatial organization of urban system in Zagros region level is a reflection of national levels in smaller scales. Increasing urban habitants and deprivation of necessary urban substructures and facilities couldn't help to absorb the population in small cities, practically and prevent migration to big cities. Continuing the current trend in the future, in addition to increasing the problems of urban society, would face the development trend of this region with serious challenges.

2-Theoretical Bases
Inequality during different eras and various views has been considered by philosophers, social scientist, economists, geographers, various fields' theorists and other and resulted in formation of various theories in this context. To day in regional economic literature, there is increasing tendency toward considering causes and consequences of regional inequalities. Attention to spatial inequality and injustice as been appeared in geographical studies during 1970 s, as three contemporary known geographers- Johnston, Nax and Coutess- ac knowledged the study of spatial inequality as the center or focus of new geography.
In the context of spatial inequality, we could mention a number of approaches. Some believe that inequality originates from capitalism performance, while others confirm the establishment of grow poles as main factor and finally there is radical approach that interprets the inequality of countries based on dependency theory: main basis of spatial inequalities is colonialism and in equal exchange rule in the way that the spatial work division caused to collect the investment in some optimal region, there for inequalities will originate and increase due to it.

3- Discussion
With respect to the results of general survey of capita and buildings, urban population of considered region in 1956 was equal to 537635 subjects that increased to 4442577 subjects in 2006 the average rate of urban population growth of this region in the late 50 years is 4/3% annually. The number of urban regions increased from 23 to 119 and urbanization coefficient 24/9% in 1956 increased to 60/99% in 2006.
Considering primary urban changes, except Herfindal concentration index, showed that highest rate during 5 periods of survey from 1956 to 2006 relates to 1986. Also, all indices showed that this phenomenon is increasing from 1996 to present.
To consider the changes of population distribution in urban localities, it was used Antropy coefficient, Ginni coefficient and Lorenz curve. Autropy coefficient showed that in 1976 there was most harmony in the urban system and after this period this harmony is decreasing jinni coefficient showed that during last five decades, this distribution reached toward lack of harmony as in every period, the population is distributed in a less harmonical way in urban regions in relation to the previous period.
Also, by using centrality index, the extent of spatial concentration of services in cities in various cultural, social, educational, health- pharmaceutical, substructural and physical context, it was determined that the obtained results suggested intensive spatial inequality.

4- Conclusion
In Iran, population changes and evolutions, have a rapid and non- prog ramble growth in recent decades. Disharmony of regional development and existing local inequalities because of the effect of current mechanisms on the national socio- economic and political structures resulted to rapid urbanization and disharmony of development of small and big cities. Urban system in Zagros region is a reflection of national levels in the smaller scale. Research results showed that the urban concentration coefficient in this region has been decreasing from 1996 to present. But in respect to antropy coefficient, Ginni coefficient, Lorene curve and centrality index, it has tendency toward spatial disharmony.

5 - Suggestion
In order to prevent and control present situation and decrease disharmony and modify the spatial arrangement in this region, the planners must consider the following procedures:
- Harmonizing urban system with the aims of territory's survey and spatial planning.
- Financing and giving credits and urban facilities, in forcing necessary urban substructures in this region in the direction of establishing regional harmony and balance and prevention of centrality.