دانلود رایگان ترجمه مقاله فرم های پایدار شهری – Sage 2006

فرم های ماندگار شهری: تیپولوژی، مدل ها و مفاهیم آن ها

Sustainable Urban Forms Their Typologies, Models, and Concepts

The form of the contemporary city has been perceived as a source of environmental problems (Alberti et al. 2003; Beatley and Manning 1997; U.S. Environmental Protection Agency [EPA] 2001; Haughton 1999, 69; Hildebrand 1999b, 16; Newman and Kenworthy 1989). The EPA (2001) concludes in Our Built and Natural Environments that the urban form directly affects habitat, ecosystems, endangered species, and water quality through land consumption, habitat fragmentation, and replacement of natural cover with impervious surfaces. In addition, urban form affects travel behavior, which, in turn, affects air quality; premature loss of farmland, wetlands, and open space; soil pollution and contamination; global climate; and noise (Cervero 1998, 43-48). Moreover, growing evidence from around the world indicates that, owing to our excessive use of fossil fuels, especially in affluent countries, greenhouse gas concentrations are accumulating at an alarming rate. Prospects for the future are dire indeed, unless we act collectively to alter our energy-dependent lifestyles. Urgent changes are needed not only in our behavior but also in the design of the built form. The emergence of “sustainable development” as a popular concept (see Jabareen 2004) has revived discussion about the form of cities. Undoubtedly, it has motivated and provoked scholars and practitioners in different disciplines to seek forms for human settlements that will meet the requirements of sustainability and enable built environments to function in a more constructive way than at present. The concept of sustainable development has given a major stimulus to the question of the contribution that certain urban forms might make to lower energy consumption and lower pollution levels (U.K. Department of the Environment [DoE] 1996; Breheny 1992a, 138). This challenge has induced scholars, planners, local and international NGOs, civil societies, and governments to propose supposedly new frameworks for the redesigning and restructuring of urban places to achieve sustainability. These approaches have been addressed on different spatial levels: (1) the regional and metropolitan levels, such as the Bio-Region approach (see Forman 1997; Wheeler 2000); (2) the city level (e.g., Girardet 1999; Nijkamp and Perrels 1994; Gibbs, Longhurst, and Braithwaite 1998; Roseland 1997; Engwicht 1992; OECD 1995; Jenks, Burton, and Williams 1996); (3) the community level (e.g., Nozick 1992; Paulson 1997; Corbett and Corbett 2000; Rudin and Falk 1999; Van der Ryn and Calthorpe 1991); and (4) the building level (e.g., Roelofs 1999; Edwards and Turrent 2000; Boonstra 2000; Woolley, Kimmins, and Harrison 1997). A critical review of these approaches demonstrates a lack of agreement about the most desirable urban form in the context of sustainability (see Williams, Burton, and Jenks 2000, 347; Hildebrand 1999a; Tomita et al. 2003, 17). Moreover, there is no common conceptual framework that allows us to compare these approaches, planning propositions, and policies. For example, there is a lack of theory that helps us to evaluate whether a given urban form contributes to sustainability or to compare different forms according to their contribution to the sustainable development objectives and agenda. Therefore, this article seeks to answer the following questions: What are the distinctive urban forms proposed by each of these approaches? And what are the design concepts and principles that these forms share? In addition, the article aims to offer a conceptual framework for assessing the sustainability of urban forms. The remainder of this article consists of five sections. The second section focuses on the methodology of the study and its parts. The study applies thematic analysis, which is an appropriate methodology when analyzing a large body of interdisciplinary texts. In addition, it presents the operational aspects of urban form to examine it more accurately. The third section identifies and describes the design concepts of sustainable urban forms. The fourth section discusses the specific sustainable urban forms that appear in the literature. The fifth section offers a conceptual framework for assessing the sustainability of urban forms. The final section draws some conclusions and suggests several issues for future research.

Method

Form is not easy to define; therefore, it is useful to operationalize the term in order to apply it in this study. Generally, urban form is a composite of characteristics related to land use patterns, transportation system, and urban design (Handy 1996, 152-53). Kevin Lynch (1981, 47) defines urban form as “the spatial pattern of the large, inert, permanent physical objects in a city.” Form is a result of aggregations of more or less repetitive elements. Urban form, then, is a result of the bringing together of many elements-concepts: the urban pattern. Urban patterns are made up largely of a limited number of relatively undifferentiated types of elements that repeat and combine. Hence, these patterns have strong similarities and can be grouped conceptually into what are called concepts (Lozano 1990, 55). Specifically, elements of concepts might be street patterns, block size and form, street design, typical lot configuration, layout of parks and public spaces, and so on. This article assumes that there are concepts that repeat themselves and compose distinct urban sustainable forms. Therefore, the article uses qualitative methods to identify these forms and their design concepts (design concepts) and, eventually, to identify the concepts behind them. In a broad sense, qualitative studies ultimately aim to describe and explain a pattern of relationships, a process that requires a set of conceptually specified categories (Mishler 1990). Miles and Huberman (1994) suggest a set of qualitative “tactics” that might help in generating meanings from different texts. Following them, a thematic analysis has been designed for identifying the forms and their design concepts and for conceptualizing the theoretical base behind these forms and concepts. Thematic analysis is an inductive analytical technique that involves discovering patterns, themes, and concepts in the data that includes planning and multidisciplinary literature. The main steps of this study’s methodology are as follows: 1. Review of planning, design, and other multidisciplinary literature that is related to sustainable development. The aim is to deconstruct (“take apart”) a multidisciplinary text related to urban sustainable form. The outcomes of this process are numerous themes, “design concepts” in this case, that are related to urban form. 2. Pattern recognition—“the ability to see patterns in seemingly random information” (Boyatzis 1998, 7). The aim is to note major patterns and concepts within the results of the first step. This second step looks for similarities or patterns within the sample and codes the results by concepts. 3. Identifying urban forms—to recognize specific and distinctive urban forms. 4. Conceptualization—to find theoretical relationships among the identified concepts and urban forms.