An analysis of urban sprawl and land use alterations (a comparative study of Isfahan and Urmia)

Rapid expansion of cities and their uneven physical growth, which calls “urban sprawl”, has some consequences such as; vanishing the villages and their surrounding farm lands, converting agricultural lands into other land uses, and destructing the ecological resources. Such a situation is more serious in regional metropolises. Isfahan and Urmia are two important regional metropolises with different environmental and economic structures. Both cities have experienced a rapid expansion during the recent years. The present paper has adopted a descriptive-analytical approach to study the physical expansion of the mentioned cities and their impacts on the surrounding areas. Required data were collected using documentary method, and required remote sensing data were obtained from Landsat7 images in 2001 and Landsat8 images in 2013. Comparing different periodic images of two cities and analyzing obtained data from Statistical Center of Iran showed that both Isfahan and Urmia are vastly facing with rapid population growth and alteration of their surrounding’s land uses. Application of the Holdren method for a duration of 1956-2011 showed that physical expansion is more than the real needs of the population in both cities, especially in Urmia. The result of such process is alteration of more and more agricultural lands into other applications. The rate of population growth in Isfahan, during the study span time, was nearly consistent, but in Urmia the trend was different with a high population growth especially at the beginning of 1980s due to Iraq-Iran war. It can be concluded that main reasons for alteration of farm lands around Urmia include: inefficiencies associated with urban detailed plans, low levels of farm land prices against the urban ones, vulnerability of horticultural activities next to the city, and lower rates of financial interests of agricultural activities. But, the main reasons for converting the farm lands into urban construction in Isfahan are: industrialization of the area, constructing residential estates around the city, and expansion of academic and government activities at the surrounding area. The mentioned factors have accelerated migration of different groups of people from nearby villages and towns towards Isfahan. Therefore, population growth and need for urban constructions have been leading to change the agricultural land uses and finally more vulnerability and inconsistence of environmental resources.