تحلیل و مقایسه‎ی توزیع اندازه‎ی شهرها در سیستم شهری ایران و کشورهای همسایه

Extended Abstract

Introduction
The twenty-year outlook, Iran must first place in 1404 in the region, including Central Asia, Caucasus, Middle East and neighboring countries have developed is in the Indices. One of these indicators and balanced urban system decentralization. Centralists as a pattern development in Iran and neighboring countries, most of opportunity and development is allocated to. After some problems and adverse effects centralists to create an imbalance in many areas, disorganization in the urban network and capture all opportunities and equality and disturbing development in these countries have charts.
According to that the size of the urban hierarchy long time the source is interesting for researchers, including discussions of the distant past, to his mind, geographer's have focused on. Formation and expertise in this kind of urban hierarchy detection rate is one of the main populations.
This research study was aimed at Iran's position in terms of indicators of size distribution of cities among neighbors (including Iraq, Pakistan, Afghanistan, Turkmenistan, Tajikistan, Bahrain, Azerbaijan, Armenia, Saudi Arabia, Turkey and UAE) has been done. Chosen because neighboring countries in this study, according to a text document twenty years in which countries are "in the twenty-year Vision 1404: Iran is a developed country with first place in the Southwest Asia region, including Central Asia, Caucasus Middle East and neighboring countries".
Methodology
A question that this research is to find the answer is whether the size distribution of urban population in the prime focus of crystallization has been investigated in three reduced or increased. To achieve this goal, this research background initially between experts in the world spent, and then the various concepts and theories, and we introduce indices presented. In the next section using indicators measuring the amount of focus and lack of concentration during the three periods we examined.
Overview of methods and criteria for measuring first shows that the city generally through the application of the three prime indicators of urban decentralization and the use of indicators to compare the size distribution of urban rank size countries comments (proposed Zypf), the rate is first examined city. This article first two methods to check the level and changes the way the first city in Urban Primacy (including Urban Primacy Index, two cities Index, Mehta's Four City Index, Ginsberg's four-city index, Moomaw index Herfindahl-Hirschman Index) and Decentralization indicators (including indicators and the Entropy index decentralization Henderson) was use.

Results and Discussion
The results of applying indicators and indices of the first urban decentralization and coordinate with all the indices of the process almost the same amount of Urban Primacy developments in the countries studied shows. Indices studied, the phenomenon shows that the first city in Iran and its neighbors in all this period there was a city system is unbalanced and the unbalanced population distribution. the focus of this kind that Iran is moving toward balance.
Urban Primacy Index shows first results despite the decline in the first city in the third period, in Afghanistan, Tajikistan, Turkey and Pakistan, this index has increased. two City Index, three periods examined in balanced, but in Iraq, Saudi Arabia, Turkmenistan and Armenia have increased in other countries like Iran, has been declining. Ginsberg numerical values of the four cities showed the highest rate in the first period is related to the first city states of Armenia (4.66) then, of Afghanistan (2.48), the second and third time the two countries decreased slightly compared with the first period with the highest rate among the first countries studied urban face. Numerical values of the four city index Mehta and Richardson compared with normal values for measuring the intensity of the first city shows that the first rate cut in the city and state have been superior. Moomaw index was determined by examining the first city in the amount of 3.51 to 3.45 it has decreased. In Iraq, and Armenia increased the first city in line with our other countries is more balanced. Index Herfindahl that GM focus is shows in comparison the focus of numeric value 0.5 to 0.4 decreased during have in Iraq, Saudi Arabia, Azerbaijan, Bahrain and UAE, like Iran than focusing dropped and in other countries focus more on the city dweller is seen first. Entropy rate in this period shows the concentration and statistical imbalance is compared with the countries of Tajikistan, Turkey, Turkmenistan, Pakistan, Saudi Arabia, Iraq, Armenia, Azerbaijan and Afghanistan have better conditions than their lower degree of focus on Iran is. Henderson decentralization index shows that in focus than the previous period, and declined to move toward balance. In Iraq, Saudi Arabia, Iran, Azerbaijan and the UAE as the balance moves in the remaining countries focus more happened. In general, you should say that increasing and decreasing trend in all indicators of the Urban Primacy been consistent and compatible with almost all the results are.

Conclusion
So, using strategies such as decentralization policies, capital investment in infrastructure between urban and transference of authority to regional and local agencies focused too much on the first cities to avoid. Although all these strategies and programs third Iranian economic and social development was considered and proposed adopting However with the implementation and courageous policies can reduce land preparation and focus on areas of population density and activity country - which is now moving its position - a positive effect on the process of decentralization process in Tehran and the city had the first decrease and also the realization of more balanced urban network in the country reached the final step in being able to achieve goals the country twenty-year survey.