Presenting a Method for Determining Residential Density based on Smart Growth Approach; a Case Study: District 22 of Tehran

Urbanization, globally, has led to a general perception that cities are becoming more dense and overcrowded places. While the urban form and land-use activities in the centre of cities have increased significantly, globally the population density of cities is falling. Quick expansion of cities’ area compared to the population growth rate during recent half-century has turned the concept of “urban sprawl” to an umbrella term. Because of Urban Sprawl all countries, both developed and developing have faced many problems such as waste on land consumption, degradation of natural resources and environment, economic problems resulting from the development of required facilities and services,… The concerns resulting from the urban sprawl and expanding urban areas have made different countries all over the world take actions for restraining this crisis. Taking new strategies, new expressions are formed, namely urban consolidation, sustainable city, compact city and Smart growth. Smart growth provides a solution to the concerns facing many communities about the impacts of the highly dispersed development patterns characteristic of the past 50 years. The Urban Density is the most widely recognized indicator of sprawl and low density development is a hallmark of sprawl. The current research is endeavours to detect and analyses the effective elements on determination of residential density by applying principles of Smart growth and introducing appropriate strategies for a practical guidance on expansion of urban fabrics. Tehran is one of the cities which have experienced quick expansion of area in proportion to its population growth; as it can be said that Sprawl and spread-out development is the city’s growth pattern. District 22 of Tehran is the vastest and largest urban development connected to this city which is developed with the aim of addressing the deficiencies in urban services and resettling part of the population of Tehran. This district with dispersed towns and vast land lots free of urban constructions has been selected as the case study for this research. The research first refers to investigation of theories and experiences related to the issue of urban density and the applied theoretical framework is introduced. Thereafter, the residential density is defined for district 22 by cognition of specifications of studied area, selection of variables effective for residential density, performance of factor analysis, returning to principles and strategies of Smart growth regarding urban density. Along this, six factors of population density, Floor Area Ratio, rate of compactness of residential lands (distribution of residential land plots), locations and state of public services, state of passage network, and the existence of green and open spaces were introduced as explaining factors of residential density pattern in district 22. At the end, fourfold regions of this district were evaluated based on the defined pattern. For this, investigation of fourfold regions of this district indicates that region four has the maximum and region three has the minimum conformity with the principles of Smart growth.