esfandiyar zebardast

Urban sprawl is an issue in many cities throughout the world, which has affected many aspects of urban life negatively. Urban sprawl, which is generally attributed to horizontal and leapfrogged extension of city boundaries caused by citizen’s will to leave central urban areas and live in urban countryside. The first step for tackling this problem is the identification of sprawled places and the influential factors on sprawl in urban land. Therefore, this article analyses urban sprawl phenomenon in Qazvin city districts. Relying on relevant theoretical texts, 13 indicators are chosen among others in literature for measuring urban sprawl in Qazvin districts. These indices are localized according to the conditions of Iran and the data associated with each of them are extracted using census statistics and Geographic Information System (GIS). Then, factor analysis technique is implemented by SPSS software and the indicators are attributed to four factors. By assessing the contributing indicators to each factor, they are named density, configuration, land-use and accessibility respectively. The results of factor analysis are very consistent with literature. These factors explain the variance of urban sprawl by 27.8, 21.6, 11.3 and 9.5 percent respectively. It is shown that "shape index" and "fractal dimension" as new indicators for measuring urban sprawl are significantly effective on this phenomenon. Results show that districts 4, 5, 7, 11 and 12 are the most sprawled and districts 17, 28, 38 and 39 are the least sprawled districts in Qazvin. These two new indexes in Iranian urban literature can be used in other sprawl studies in the country. In addition, the results of this study can guide Qazvin municipality to make important decisions about the direction of city development.

Social sustainability is a subject that has attracted the attentions of researchers since the early years of 21st century. Social, economic, and ecological sustainability are considered as the three components of urban sustainable development. On the other hand, the urban form, as an important component of the city comprises communication networks, public transportation systems, pedestrian and bicycle accesses, spatial structures, spatial distribution of activities, housing and settlement size, natural phenomena and non-spatial aspects which all are important for studying and analyzing a city from different viewpoints. Considering the interdependence of the components of this concept with different dimensions of the city, its role on different aspects of sustainability, including social sustainability, would be indisputable. The emergence of urban sustainable development concept pushed the international NGOs and planners to introduce new frameworks for redesigning and reorganizing of cities in order to achieve the sustainability. A critical review of these approaches suggests a disagreement upon the most desirable form of urban sustainability. Social sustainability, due to its intangible nature as well as its focus of mankind and his interactions is subject for such contradictions. The present study was seeking to explain the relationships between the components of urban form and social sustainability in 22 districts of Tehran using a descriptive-analytic research method. Quantitative models such as factor analysis and linear regression as well as resident’s questionnaire (2200 questionnaires were completed among 22 districts of the city) and SPSS software helped the researchers to navigate this route. The findings of the present research showed that there is a significant relationship between the main factors of urban form and the factor of combined social sustainability indicators in all 22 districts of Tehran. Social sustainability indicators included citizen’s access to local services, social security, participation rates in social and group activities, interaction with other residents or social groups, residence satisfaction, and access to affordable housing for citizens. It was also determined that districts 5 and 6 had the highest scores in terms of social sustainability in Tehran.