Urban sustainability : compact versus dispersed form in terms of social interaction and patterns of movement
The relationship between urban form and sustainability in general, and the impact of urban form on the energy consumption for transportation, and also on the quality of life in particular, have become established amongst academics and governments particularly after the United Nation Rio Conference in 1992. This has resulted in the increasing demand for sustainable urban form. However the existence of contradictory theories such as the compact city and urban dispersal, and a lack of empirical research in the field was found to be a major obstacle in identifying alternative models. This study therefore begins to remedy this situation and aims to contribute to the body of knowledge in overcoming existing contradictions. Two approaches are used in this study; theoretical and empirical, and the analyses of both secondary, and primary data are employed. The principal focus of this thesis is `an empirical investigation of the impact of density and land use on efficiency of urban form in terms of the defined `quality of life' and the `use of energy for transportation'. The basic proposition of this study thus is that: `there is a relationship between urban form and sustainability'; then that `the compact city form with a mix use of land is more efficient, and can provide a greater accessibility compared to the low density urban development. It can reduce the use of energy for motorised transportation through less use of private car based journeys and it is a safer place to live. It can reduce air pollution and hence promotes both a healthier environment for living in and a better quality of life for residents. ' To examine the research hypotheses through a systematic approach, four different urban forms were selected as the case study areas. These are located in the context of West of Scotland and each representing a particular development in terms of land use and density. Both primary and secondary data enabled a systematic analysis of the four areas, using a questionnaire survey for the former. Through a variety of descriptive and inferential and statistical analyses and tests, a series of hypotheses are examined within a conceptual model. The results are supportive of the basic proposition in most of the cases. Even after controlling for a range of factors, density and land use are seen to exert a strong independent effect on accessibility, energy efficiency and quality of life for the users. The evidence from this study strongly supports the proposition that there is a relationship between density and land-use on the one hand, and the patterns of movement and social interaction and quality of life on the other. It supports the efficiency of the compact city, where walking was found as the dominant mode of transport. The compact city offered a greater accessibility and it was a safer environment to walk in during the day and the late hours; and it was a place in which by reducing the use of the private car, car related problems reduced significantly compared to its rival low density form. This in turn will reduce much of the pressure on the environment. Nevertheless, deficiencies were observed in the compact city in a few areas which needs clarification through further investigations.