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1、 CITY FORM 7 INTRODUCTION This chapter examines the relationship between urban form and sustainable development. In particular, it outlines a typology of city forms. The three main archetypal urban forms discussed are: the linear city; the city set out in the form of a grid; and the highly centraliz
2、ed or inward- looking city. The form of each archetypal plan may be modified by the prevailing metaphor: the city as a replica or model of the cosmos; the city as a machine; or finally the city as an organism. The grid layout, for example, has been used to express physically both the cosmic and the
3、machine city metaphors (Lynch, 1981). More rarely, as in Gracehill, it has also been used to express the community needs of the settlement built according to the organic metaphor. The Chinese model city uses a grid to relate the city to a cosmic structure (Boyd, 1962; Wheatley, 1971). In Chinese cul
4、ture the city is designed as a microcosm of the universe, but complete in itself. In contrast, the grid, when used to give form to the city as a machine, emphasizes the autonomous parts, each having a distinct function. Devices such as size, scale or the imposing axis are used to give emphasis to th
5、e dominance of the motor car or the world of business: they are never used in this context to mirror the universe. This difference can be illustrated graphically by the contrast between a Roman encampment or the project for a contemporary city by Le Corbusier with the Mandala, which sets out the Ind
6、ian ideal pattern for city structure (Figure 7.1; see also Figures 6.25 and 6.32). Ancient Indian city planning theory is based upon texts, Silpasastras, defining the methods of land sub-division which control the evil forces of chaos (Rowland, 1953; Dutt, 1925; Shukla, 1960). The Mandala, adopted t
7、o give form to the city, comprised a set of enclosing rings of development divided into squares, the most powerful point being the centre. Main movements, particularly processions through the enclosures, are clockwise following the apparent direction in which the sun moves in the northern hemisphere
8、. Madurai (Figure 7.2), dating from the sixteenth and seventeenth centuries, follows the idealized pattern of the mandala. There are encircling streets, no radials as 119 such and the use of a deformed but clear grid, while the most holy buildings occupy a central position. The three main archetypal
9、 city forms have been converted into an array of hybrid types of city structures to serve different ends. The particular form of a city may owe its shape to a number of factors such as imperatives of location, land values, or social structure. The choice of a structural concept for a new urban found
10、ation may have been influenced by attitudes to: density; the form and distribution of central area functions; the predominant means of transport; the location of social infrastructure or places of work; and, more generally, ideas about ideal forms of lifestyle. Narrowing the range for use in sustain
11、able development is a daunting task. Fortunately in Britain there were a number of new towns built after the Second World War in the last century, which offer a wide range of urban structures available for close study (Osborn and Whittick, 1977). LINEAR URBAN FORMS Linear urban forms can be found in
12、 many unplanned developments of the Middle Ages (Beresford, 1967) (Figure 7.3). However, they are more usually a product of the industrial revolution. They are most closely associated with the metaphor of the city as a machine. The main feature of the linear urban form is its ability to deal with th
13、e rapid and efficient mass movement of people and goods within and between cities. A further quality of the linear structure is its ability to deal, in theory, with infinite growth. Two early examples of linear urban forms are Ciudad Lineal by Soria y Mata for the suburbs of Madrid and Cite Industri
14、elle by Tony Garnier (see Figures 6.26 and 6.27). The linear suburb for Madrid was discussed in Chapter 6, while the Cite Industrielle has also been mentioned before. However, other features of this project are worthy of discussion in the light of sustainable urban form. The most important locationa
15、l factor for Garniers ideal city was to be an energy source (Wiebenson, undated). Garniers prescient choice of energy source, hydro-electric power, foreshadows much of todays preoccupation with renewable energy. The form and layout of housing in the Cite Industrielle was to be governed by orientatio
16、n. The design aim of the building form was to achieve good ventilation and high levels of sunlight into all homes. Both of these qualities are important considerations Figure 7.2 Madurai, India (Lynch, 1981) Figure 7.1 Indian Mandala U R B A ND E S I G N :G R E E ND I M E N S I O N S 120 for the des
17、ign of sustainable housing where the aim is to maximize solar gain and reduce the need for mechanical ventilation (Figures 7.4 and 7.5). Garniers ideas about land use zoning was also a precursor of one of the important but perhaps less sensitive innovations of modern city planning. 7.3 7.4 7.5 Figur
18、e 7.3 Medieval linear settlement, Olney, Bucks (Beresford, 1967) Figure 7.4 Cite Industrielle, residential quarter (Wiebenson, undated) Figure 7.5 Cite lndustrielle, housing (Wiebenson, undated) C I T YF O R M 121 Other manifestations of the modern movements in architecture and planning were develop
19、ing in Russia early in the twentieth century. Early in post-revolution Russia the discipline of architecture was examined to see if it could serve the needs of the proletariat rather than the expensive taste of the aristocracy or wealthy bourgeoisie. Two main groups with conflicting ideas emerged: t
20、hey were, the urbanists and de-urbanists. The urbanists were advocating high-rise, high-density development: .a network of enormous communal houses with integrated collective services (Houghton-Evans, 1975). The de-urbanists, in contrast, suggested communities of houses dispersed throughout the coun
21、tryside. The aim of the de-urbanist was to end the distinction between town and country: The agricultural areas must become centres not only for producing but also for processing raw materials. .Rural housing.is a prerequisite of production. . The transfer of manufacturing industry to the sources of
22、 raw materials, the integration of industry and agriculture, is likewise a new condition of residential planning and population distribution. But the new planning raises the problem of cheap housing built of local materials. The view of the de- urbanist is holistic, the city is seen in its total env
23、ironment: We must stop designing piecemeal and start to plan whole complexes, to organise the distribution of production and the territorial distribution of industry and housing over entire economic regions of the Soviet Union (Kopp, 1970). Many fine thoughts are contained in the manifesto of the de
24、-urbanists; some no doubt are in tune with the ideas being put forward in the name of sustainability. The developments in what was the Soviet Union did not, however, live up to the high sounding ideals of the de-urbanists. The agenda of the urbanist was politically more acceptable, with state contro
25、l and planning resulting in a dehumanized urban development. The planned exploitation of the environment to sustain the process of urbanization has also led to environmental degradation on a grand scale: a degradation which equals anything the free market of the West has achieved. A significant cont
26、ribution made by the de-urbanist was the development of the idea of the linear city. Miliutin, in his writings and in his inter-war plan for Stalingrad, used the linear concept as a flexible extensible form for the city and its region. According to de-urbanist theory, which Miliutin followed, popula
27、ted areas were to be associated with a major road; dwellings were to be located in the countryside within easy reach of urban facilities dispersed in a ribbon about 300metres wide and arranged on either side of the road. Each facility was planned to occur at different frequencies depending on the po
28、pulation required to support the service (Figures 7.6 and 7.7). MARS PLAN FOR LONDON The linear city concept has occupied the minds of many urbanists since Miliutin. The Modern Architectural Research Group, who became known as MARS, were interested in applying the ideas of CIAM (Congres Internatione
29、aux dArchitecture Moderne) to conditions in Britain. They produced a master plan for the rebuilding of London after the destruction caused by the Second World War. It became known as the MARS Plan for London. The MARS group saw London as a deteriorating factory which was technically inefficient. MAR
30、S proposed a more efficient structure based upon the U R B A ND E S I G N :G R E E ND I M E N S I O N S 122 analysis of the problems of movement in a great but congested metropolis. They also saw the problem as including the provision of homes, work and the maximum possible number of amenities, incl
31、uding adequate open space for the population. The approach was one of problem-solving, that is, discerning the salient characteristics of the problem, London, then devising: .a master plan, a grid on which the town can be developed (Korn and Samuelly, 1942). The plan was not based on a grid in the c
32、onventional sense in which the word will be used later in the chapter. The MARS Plan for London was based on a series of linear forms arranged around the transport network. Each structural unit, though in practice constrained by existing development, was nevertheless, as a theoretical form, capable
33、of expansion (Figure 7.8). The MARS concept for the transport grid is deceptively simple. The reality, however, based on the rational movements of people and goods, led to the development of complex systems of interchange between great transport highways. An aim of the plan was to increase the impor
34、tance of public transport: With an excellently organized public transport system, the number of people going to and from town in private cars will be few, being confined to certain professions. Other private cars would serve mainly for pleasure (Korn and Samuelly, 1942). The group were also advocati
35、ng the design of highways for use only by public transport. These bus-only highways would be without interruption of crossings, and the service was to be strictly timed by schedule. Here in Britain in 1942 was the origin of the idea for an integrated public transport system of rail and bus. Furtherm
36、ore, the urban form was designed to give equal importance to organized transport, or public vehicles, as was allocated to flexible transport, or the private car. The MARS plan envisaged residential belts 1.5miles wide by 8miles long. The housing density was to be fifty-five persons per acre, which i
37、s similar to densities being discussed at the moment. Green wedges extending from the periphery of London to the city centre were to provide sites for recreation, health and education. All inhabitants would be living within walking distance of both borough centre and landscaped areas. The MARS group
38、 7.6 7.7 Figures 7.6 and 7.7 The linear city of Miliutin (Kopp, 1970) C I T YF O R M 123 suggested the idea of landscape fingers connecting the countryside with the city centre, an idea which reappears in Towards an Urban Renaissance (The Urban Task Force, 1999). The MARS Plan for London is a fine t
39、heoretical exploration of urban form. In practice, however, it was the ideas of Howard as interpreted by Abercrombie which were finally accepted as the basis for planning London and its region in the post-war period (Abercrombie, 1945). BRITISH NEW TOWNS IN THE TWENTIETH CENTURY A number of the seco
40、nd generation of new towns built after the Second World War in the 1960s were clearly based upon the linear city concept. Notable amongst these linear new town plans are: Redditch; the linear city for Central Lancashire comprising Preston, Leyland and Chorley; Runcorn; and the first proposals for bo
41、th Telford and the new city for North Bucks. In his report on a regional study for Northamptonshire, Bedfordshire and Buckinghamshire, Hugh Wilson advocates a linear structure based upon a public transport spine linking all new development (Wilson et al., 1965). Wilson also developed this idea for t
42、he new town of Redditch, for which he was commissioned in 1964. The basic structuring concept for Redditch is shown in Figure 7.9. The fundamental feature of the plan is a road for public transport, unimpeded by other vehicles. Community facilities were to be placed on this public transport spine at
43、 the bus stops which were to act as the foci of the districts. The districts were to be of mixed use and to contain residential, industrial, recreational Figure 7.8 MARS plan (Korn and Samuelly, 1942) Figure 7.9 Redditch (Houghton-Evans, 1975) U R B A ND E S I G N :G R E E ND I M E N S I O N S 124 a
44、nd other related land uses. All parts of the districts were planned to be within half a mile or 10minutes walking distance of the district centre and its bus stop. These proposals in 1964 seem as fresh today as the time they were written: such ideas now appear in many proposals for sustainable devel
45、opment. A regional study for mid-Lancashire included a proposal for a linear city incorporating Preston, Leyland and Chorley (Matthew, 1967). The three existing settlements were to be connected by a triple strand of routes, the central one being a community route for use by public transport only. Bo
46、th outer routes were to be roads for the motor car. The city region was planned for a population of 500000 housed in Radburn-style residential development on both sides of the public transport route (Figure 7.10). Arthur Ling, who had worked on the MARS plan for London, was the first planner since S
47、oria y Mata to implement a plan specifically designed for public transport. Runcorn in Cheshire was the extension of an existing settlement with a population of 30000. It already had an industrial base, and Ling planned to increase the population to 100000, attracting additional employment outlets o
48、nto a strong local economic base. The population was arranged in a dispersed linear form: A linear arrangement of new residential communities, on either side of a spinal public transport route, has been evolved so that the majority of people will be within five minutes walking distance, or 500 yards
49、, of a route which is especially reserved for buses (Ling, 1967). It was not possible to use a pure linear form for the town because of the existing development. Lings solution to the problem was both simple and elegant: he turned the linear structure in on itself to form a figure- of-eight with the town centre in a focal position (see Figure 6.24). The spine of the plan is the bus-only road which links all the neighbourhoods to each other and to the town centre. The expressways for private cars bound the urban area and have spur roads that enter e