عنوان مقاله [English]
Urban sprawl has been one of the most important concerns of urban planners in recent decades, affected by a complex set of factors. Although this phenomenon can be seen in both developed and developing countries, but the causes and levels are different. Many social, economic and political factors have been expressed to explain his phenomenon by scholars. One of the factors caused urban sprawl can be governments and their policy decisions. This factor has had the largest portion in the expansion of this phenomenon in Iran in recent decades. In recent years, the government has decided to establish some new provinces, resulting in the new role for some cities to be new centers for the newly established provinces. Such decision may affect the process of intensive urban sprawl. This paper aims to answer the question of whether such changes can increase urban sprawl and what factors are the causes and effects.
The city of Bojnourd, located in the north-east region of the country, has been selected as a case study. After the formation of Northern Khorasan Province in 2004, this city was selected to be the center of the newly established province. Since then, the population growth and expansion of the city was accelerated. The amount of the city sprawl was measured in two periods, 2004 and 2011. Using the literature review, and based on the comprehensive studies of Ewing, Torrens, Galster and Frenkel and Ashkenazi, 15 variables were selected in accordance with the research objectives, and possible access to related data and information. It should be noted that these variables for measuring sprawl are adjusted according to circumstances of Iran by some native researchers. The needed data of variables in 27 districts of the city in 2004, and 31 districts in 2011 were extracted. Using confirmatory factor analysis, four factors of the density, accessibility, mixed use and centrality were classified and analyzed.
Comparing the results of two periods shows that in total, urban sprawl of Bojnourd increased, and both centrality and mixed-use factors have been the greatest impacts on the area sprawl in recent years. This was due to the distance of new constructions from downtown, as well as the scattered land uses occured. The survey of the effective factors on the spatial and physical structure of the city and changes in the two the period, before and after the centrality of the new province, shows several impacts. Among these impacts are intensive increase in immigration, growth of informal settlements, extension of government organizations, increase in governmental construction, resulting from the necessary provision of employees housing, the need to provide specialized services in the fields of commercial, industrial, healthcare and education. Furthermore, as a result of the change in the regional role of the city, excessive increase in land and housing values has also been the effective cause on physical development of the city after being as the capital of the province.