تقسیمات سیاسی فضا و تعادل در نظام شهری منطقه (مورد مطالعه: تقسیم استان خراسان بزرگ)

Extended Abstract
 
Introduction
Cities, as dynamic and at the same time complex systems which control most of the economic-social affairs of every region, play a decisive role in the economic, social, and cultural development process and optimal spatial structure of a territory. Different patterns adopted by urban systems are the consequence of interaction and interplay of effective social institutions and forces. Among the most important of these factors in the current conditions government, market, social movements, developments in communication technology, exterior incentives, the present structure of the spatial organization and etc. can be mentioned. Nowadays, governments and governmental decisions are among the most influential factors in forming the hierarchical model and residential relations. 
In this regard, among the powerful governmental tools, political organization of space and state divisions can be mentioned. Political divisions of space are changed by various methods, such as abstraction, interpolation, integration and improvement in different levels of the political zoning of a country’s space. When promoting the political level, the lower political-administrative unit is transferred to the higher level. Naturally, simultaneous with promotion of the political level in a state, the whole internal affairs of the country would be accompanied with some transformations. Political organization of space is closely related to growth patterns and economic development on one hand, and physical-spatial patterns on the other hand. This organization is performed based on two objectives including the optimization of places, and optimization of functions and activities. The state divisional system can entail some methods for revision in rules and procedures through which the conditions for actualization of the economic and social development and particularly sustainable development can be provided.
During the recent decades in Iran, the issue of enhancing the administrative-political levels of geographic spaces through formation of new provinces has been considered. After the Islamic revolution in Iran, number of the existing provinces in the country from 24 has reached to 31 provinces. Obviously, in the meantime, several cities have adopted new roles as provincial centers, many cities have promoted to the centers of newly established towns and many villages have become urban areas, while at the same time, direction and intensity of many administrative, political, economic, and cultural processes among the urban areas have been changed. Naturally, by making such decisions and enhancing the position of these cities, the residential network system at the regional and national levels would be affected and changed. The vast Khorasan province is among the provinces where these spatial divisions have occurred and the functions of many of its settlements have been promoted. This province was divided into three provinces including the northern, Razavi, and Southern Khorasan provinces in 2004; and since the main function of the state divisions is decentralization in governing the territory and facilitation in exerting the national will, the main question in the present research is whether with the administrative- political decentralization performed in the great province of Khorasan, the regional urban system has been affected by it and whether its spatial manifestation has been crystallized in decreasing the urban primacy index of Mashhad metropolis, fortifying the medium size cities and small towns, and also providing a more balanced population distribution.
Methods
The present study is a practical one and its study method is descriptive and analytical and the subject entails a comparative and procedural study. The investigated geographical area is the vast province of Khorasan and the research period has been the time before and after the divisions. To achieve the intended goal, the required information and data were collected through study of library sources and documents which included research reviews and the studies performed on the related issue and application of the needed statistics and data during various periods. Also, in order to analyze and process the data, regional techniques and indexes were used including the urban primacy indexes, elastic ability index, entropy index and Gini coefficient.
Results and Discussion
The urban network in Khorasan province like most of the country’s regions that are affected by center-oriented political. Administrative structure is experiencing an unbalanced situation that the population gap and spatial dissociation of its hierarchy is obvious. Following the governmental decisions in political divisions of the provinces during the last decade in the country, the vast Khorasan province was also divided into three separate provinces in 2004. According to the performed decentralization and enhance of the status and administrative-political function of many of the residential areas, it is expected that these evolutions would lead to population decentralization. Also, it is expected that while decreasing the urban primacy index of Mashhad, medium size cities and small towns would be fortified and population distribution become more balanced. Findings of the present study indicated that division of Khorasan province and formation of newly-established provinces have led into the formation of new urban areas. This means the transformation of many villages to towns and promotion of their roles and functions. Also, changes in contribution of demographic classes demonstrate that division of this province has resulted in decentralization of urban population and especially those urban areas which have adopted new centrality roles attracted more population.
Among the other evolutions which are expected from the provincial division is the decrease of the province’s urban primacy index. The performed study indicates that despite the division of the province, the difference between the first populated city with other subsequent cities of the province has not reduced but rather it had been intensified (which is due to the powerful role of Mashhad in the region and also because the new provincial centers are not considered among the first three cities). However, the models in which the population of Mashhad is calculated compared to the total urban population of the province suggest that the urban primacy index has been a little reduced. Additionally, investigating the situation of balance in spatial distribution of Khorasan’s population demonstrates a lack of balance, though this situation has become a little more balanced after the provincial division based on the entropy coefficient, however, according to Gini coefficient, imbalance has been increased and this can be observed in small towns and medium size cities. An increase in the transformation of villages into small towns has played a crucial role in this regard.
Conclusion
In sum, it must be stated that imbalance in the residential system of the region is the consequence of a variety of natural and human factors which are formed in the context of a series of historical evolutions in a region and efforts for decreasing its heterogeneity cannot be achieved simply and merely by one or several factors. Decentralization in decision-making, assigning new roles to cities, and political promotion of small towns and medium size cities are among the measures which can in turn change the economic, service and population processes in a region. As a result, they can affect the residential system of the region. Nevertheless, it is noteworthy that decentralization through political promotion of space is merely a single factor with limited affecting level and in order to balance the residential system of the region, appropriate planning and solutions should be performed to strengthen the small towns and medium size cities for population control and population stabilization of the region; therefore, by a planning approach and considering the potentials of cities and areas sustainable development can be achieved that would not only decrease the existing population imbalance, but also it would reduce the intra-regional economic and service gaps.