Investigation and analysis of urban growth patterns and its driving forces in the Tehran urban agglomeration

Today, more than half of the world's population lives in urban areas, and many developing countries have experienced rapid urbanization, which in some cases has led to the formation of metropolitan areas. Each metropolitan area can follow a different growth pattern according to its characteristics and environmental conditions. In Iran, metropolitan areas such as Tehran have faced the problem of growth around their settlements, this growth has been associated with the destruction of green lands. Under these circumstances, if this process is ignored, fragmentation in the spatial structure will lead to inefficiency of regional development policies. Tehran metropolitan area, as the largest area of human gathering in the country due to its attractions, has a large population that is added every year. Therefore, the analysis of growth patterns in different stages of urban development and the driving forces affecting its formation can have an impact on understanding how to planning in this area. Therefore, the present study intends to analyze the growth patterns and the driving forces influencing the formation of Tehran and Alborz urban agglomeration by using quantitative research approach and using satellite images and secondary data. The spatial pattern of growth of Tehran urban agglomeration during the years 2000 to 2020 has been analyzed through the SLEUTH model and its driving forces by logistic regression. first the land use changes of Tehran urban agglomeration during the last two decades are examined and then, according to the coefficients obtained in the implementation of the calibration of the SLEUTH model, the urban growth pattern is determined and logistic regression has been used to evaluate the effects of driving forces. During the last two decades, the share of urban areas and bare lands in the study area has increased and the area of agricultural lands, grasslands and gardens has decreased. Thus, the biggest change was in the increase in the share of barren land use, where most of the agricultural land and orchards have been converted to other uses. The results of calibration of historical data in the region have shown that the past growth pattern of Tehran urban complex is more influenced by the two growth patterns through the tendency to road and growth following the slope. The main pattern of urban growth in the suburban areas of the region has a linear nature and edge expansion due to slope resistance. However, the coefficients of expansion, diffusion and beer show less probability for a new diffusion center and spontaneous growth in this study. Therefore, it can be concluded that the main factor of urban growth in this region is road-based infrastructure. Also, in areas with high topography such as eastern areas and Alborz area, slope has an important role in urban configuration. In the changes of the built areas, the distance from the bare lands, in the changes of the agricultural lands, the distance from the main roads and in the changes of the bare lands, the distance from the agricultural lands have had the most impact.

Keywords: Urban growth patterns, urban growth driving forces, SLEUTH model, Tehran urban agglomeration.