The Survey of Sprawl Trend and Spatial Changes of Babol City

Sprawl as one form of expansion entered the literature of urban management and planning in the last half-century. Some Iranian cities have experienced this kind of expansion at a rapid pace. These cities have faced numerous problems including unplanned development, an increase in informal settlements, a sharp and environmental fluctuation in land prices and housing, high infrastructure costs and urban services, conversion of agricultural lands, consumption of more energy and pollution.Iran urbanization ratio has risen from 28% in 1922 to 68.5% in 2007. Urban development accelerated in the country after rising oil revenues as well as increase in the level of urban migrations following 1960s and 1970s. Taking into consideration an exogeneous nature of Iran’s urban expansion, the motorization of cities , injection of oil revenues in the urban economy, the place of Iranian cities in the global economic system ,and land bourgeoisie all demanded wide range of inland areas expansion into periphery which could well exemplified itself in urban sprawl.Babol is one of the medium-sized cities which is located to the northeast of Iran in Mazandaran Province. The corresponding latitude is 36 degree as opposed to 52 eastern longitude. The distance between this city and Tehran is 210 km. Its population amounted to be 250,217 which is associated with 3,036 hectares. The main question of this research is that what has been the pattern of expansion of Babol from 1957 to 2017? And what has this city changed in terms of spatial? Therefore, The main objective of this study is to find out the pattern of Babol expansion between 1957 and 2017as well as its spatial properties .

The research method has applied nature . It requires the application of Quantitative Technique. This research is conducted via descriptive-analytical method. The statistical society of this research is associated with city of Babol. The study period covers 1957 to 2017. Data gathering were conducted via documentary and field work technique. Data analysis demands application of GIS in order to analyze the rate, direction, and form of Babol sprawl during the study period. This is further followed by application of Holdren model regarding computation of degree of sprawl development in Babol. This study demands the usage of many variables including physical, economic, social and political ones along with 15 corresponding indicators.

This study suggests that the area of Babol has steadily risen from 1957 to 2017. Acccording to Holdren model over the entire study period from 1957 to 2017, approximately 74% of the city's horizontal growth is associated with population growth as apposed to 26% pertaining to sprawl development. This in turn has led to the integration of villages around the city. So far, 16 villages around this city have been merged within the legal range between 1957 and 2017. This dispersion is linearly attributed to both the northern and southern axes. It has led to physical changes in peripheral settlements. It has also changed the structure and functions of Babol.

The construction of public residential housing complexes around the city of Babol , the migration of poor to the periphery and the absence of natural barriers has led to sprawl development of the city. In addition, the connecting interra urban axis played a significant role in this regard. The largest expansion of the city was occurred in the north on the Babol-Babolsar axis and on the Babol-Babolkenar axis and Babol-Bandpe in the south. It is argued that, transit roads located from west to the east of Mazandaran have affected the expansion of the city to the west and east. As such ,most of the villages that have merged in Babol have been located along these connecting axes.