عنوان مقاله [English]
One of the basic challenges of governments, especially in developing countries, is to organize the desired national spatial structure in the changing urbanization. Such a structure allows us to divide economic and social functions in the urban and regional hierarchy in a balanced manner. In most provinces and territories of Iran, the urban hierarchy has formed completely cluttered and irregular, and the tasks of cities are unknown. This has led to several problems. This study examines and analyzes the urban hierarchy of Lorestan province from 1986 to 2011. The main research method is descriptive-analytical, and the research type is applied-developmental. The required data were collected with the documentary-desk method. The study aims to evaluate urban hierarchy changes in Lorestan province from 1986 to 2011. The entropy model, the rank-size rule, class difference limit model, and nearest neighbor are used for data analysis. The results indicate that the urban network of Lorestan province from 1986 to 1996 has had an almost balanced state in terms of special distribution of cities but from 2006 to 2011, this balance has disturbed and the spatial distribution of cities has become unbalanced. One of its major reasons is the emergence of very small towns (village-towns). In addition, in terms of distribution of urban population based on the class difference limit model, there is a statistically significant disharmony and disruption during the studied periods in the cities of the province.
In this article, the main goal is the analysis and assessment of the hierarchical system of the cities of Lorestan province between the years 1986 to 2011. Lorestan province had ten cities in the year 1986 but in the year 2011 this value increased to 24 that means 14 cities have added to the cities of Lorestan during these years (between the years 1986 to 2011). The main changes have been done after the year 1986. Thus, in this article we’re going to explain that weather the increasing of these cities has had any effects on balance and distribution of population of these cities or not. In the hierarchical system, this point must be cleared that the unbalanced spatial distribution pattern of population has clear influence on different aspects of economic, political, social and official aspects. The pattern forms a popular and functional vacuum in intermediate and underneath levels of civil clubs. This is also one of the important effects in forming unbalance in the civil hierarchical system. This is a descriptive-analytic research of the applied-developmental type. The required information was obtained from library sources and from collected documents. Statistics concerning the study and related to the period from 1986 to 2011, were collected from the Office of the Governor General of Lorestan Province and from the Statistical Yearbook of the Statistics Center of Iran. The “Rank and Rate,” “Limit of Class Differences,” “Entropy Coefficients,” and “Nearest Neighbors” models were used to analyze the statistics.
Results and Discussion
The results obtained from the nearest neighbors’ model are in agreement with those found by Taleshi et al. In the study, they carried out in Ardabil Province, in which it was shown that there was a balance among the cities in Ardabil Province, but do not conform with the results of Sadr Moosavi and Talebzadeh in their research in 2009. The results obtained from the model of rank-size rule somewhat agree with those of a study Gharakhanloo et al., conducted in 2008 on the urban network of Ardabil.
The results obtained from the model of the limit of class differences are in agreement with those by Tavakkolinia and Shali in their study on urban systems in West Azarbaijan Province in 2011. They found that there were great statistical discords in population distributions in the cities of the province and that a clear disharmony and disequilibrium existed in urban population distribution in the province.
Urban hierarchy in Lorestan Province has experienced great fluctuations with respect to spatial distributions in the cities during the periods. The population distribution shows great variations in these periods, one of the main reasons of which is the appearance of newly founded cities during the period from 2006 to 2011. During the period from 1986 to 2006, there were 10 cities in the province, but in 2006, this number suddenly increased to 23 and reached 25 in 2011. In other words, during the span of a single decade, more than 13 cities were added to those already existing in the province. In 2006, there were 12 cities with populations less than 5000, and their number also increased to 13 in the year 2011, i.e., more than 50 percent of the cities of the province had populations less than 5000. This, in itself, confirms the sudden increase in the populations of major cities: a city like Khorramabad with a population of more than 300000 indicates that there are great differences among the cities of the province with respect to their populations. In general, given the issues raised, and taking the obtained results from the models into consideration, it is quite clear that the urban network system of Lorestan Province to some extent preserved an equilibrium state with respect to spatial distribution of cities in the period from 1986 to 1996. However, after the period from 2006 to 2011 and following the creation of new cities, this equilibrium was replaced by a state of disharmony and disequilibrium.