-Explaining the physical expansion of Tehran’s peripheral cities with emphasis on state’s urban land use policies (case study: Damavand city)

Introduction
Metropolises, along with internal transformation and structural changes, produce new spatial forms and processes that, although seemingly different, have essentially the same logic of formation. This spatial logic is based on a chain of "exclusion" and "integration" processes that is the result of the functions of these structural transformations. This dual process is the main mechanism of spatial development of metropolises. In Iran, there are metropolises that have faced with the problem of the growth of cities and settlements. The rapid growth of urban population, the growing trend of land use and unbalanced location of settlements make the need for management and planning for sustainable development. Today, Tehran, as a national metropolis, has faced with a large number of settlements around it.
This study aims to find out what has the role of influential forces in urban land policies and consequently Damavand urban growth been. Therefore, in order to answer this question, it has explained the growth pattern of the city above as a city in the east around the metropolis of Tehran with emphasis on urban land policies.
Methodology
The current research is consistent with the descriptive-analytical method and is considered as an applied research. In this research, the method of receiving information is in the field of library-documentation. The statistical population of this study is the city of Damavand since the way of growth and growth pattern of this city have been considered in this research. First, the government policies in the field of land use in Damavand city are explained, then the trend of changes in the structure of Damavand city in the period 1366-1366 using the automatic cell model is analyzed and finally, the physical growth trends of the city in the period 1396-1410  has been stimulated.
Results and Discussion
Damavand city is generally one of the summer areas around Tehran and is located in the foothills of Damavand mountains. Due to its geographical location and summer, as well as being located on the main road Tehran-Firoozkooh-Mazandaran in recent years, especially in the part of Gilavand ،Damavand city has developed significantly.
The results of the study show that the city of Damavand in the early years of urban growth (1987) had an irregular and scattered pattern. Continuation of urban growth until 2003 has not been able to make much change in its urban growth pattern and urban growth is still scattered and irregular. But urban growth in the years 1382-1382 has experienced a different aspect. Urban growth in these years has not only happened very fast, but also in certain directions and has been more regular. This growth is mostly on the northwest and southeast sides and has been along the Tehran road. The more interesting point in the urban growth of Damavand in the years between 1382-1386 is that the southwest side has had faster urban growth; in this part of the city lie Mehr housing lands, so under the influence of government policies, urban growth towards the capital has occurred.
Conclusion
The study of urban growth patterns in many developing countries according to the specific socio-economic conditions of countries shows that scientific management and planning should be based on a proper understanding of the spatio-temporal processes of urban growth. The city of Tehran, as the most important city in the country since the beginning of the new era, affected the surrounding settlements and these settlements were directly and indirectly affected by the physical-economic and social changes in Tehran; especially since the 1350s, Tehran's continuous development has given way to separate development and access to surrounding settlements.
In general, it can be concluded that urban land policies have been one of the most important factors in the formation of Damavand urban growth patterns, in other words, government forces through the development of rules and regulations, the preparation of urban development plans, assignment of land and housing in the form of preparation plans show their roles in the formation of urban growth patterns in Damavand.