Affecting Demographic Factors and Physical Changes in Settlements around Metropolises and Related Consequences, Case Study: Gharachak City

Immigration and the growth of metropolitan areas are always associated with major changes in the areas around them. National Tehran metropolis with its rapid growth in recent decades has caused population increase and physical development of the surrounding towns and villages. The aim of this study is to investigate the factors affecting demographic and physical changes in Garachak city as a settlement around Tehran metropolis. The research method is descriptive-analytic and data collection was based on library documents, observation, in-depth interviews and 300 household questionnaires completed randomly. The data were analyzed by using single T- test, multi-variable regression, interpretation of satellite images (in years 1987 and 2011), and Holdern model. The results showed that due to reasons such as locating on Tehran-Varamin road, short distance and the rapid access to metropolis ​​Tehran and its facilities, and also due to the low costs of land and housing in that area, Garachak city has had high population growth so that the city as a complementary area for Tehran has an additional role in residency and settlement. According to Holdern model analysis, approximately %68 of physical growth and nearly %32 of growth in Garachak city is respectively associated with population growth and horizontal-sprawl growth which have caused huge changes in economic, social, and ecological aspects of the city.