2.1.- Clasificación de las entidades del sector público empresarial

Analytical approaches developed rapidly by the 1960s and the Cambridge School was one of the pioneers in the UK for analytical planning. In 1973 the ‘Centre for Land Use and Built Form Studies’ was renamed as the ‘Martin Centre for Architectural and Urban Studies’. March, Steadman, Martin, and Kruger were the leaders of this group; working on the geometry of the environment, urban space and structures. Kruger developed ‘multiple graph representations of urban system’ revealing the street network and built form units. This graph helped him to differentiate different regions of a settlement and at the same time specify various characteristics of these different settlements. Therefore the work of the Martin Centre involved the correlation of these measures of the urban structure with residential densities, employment rates, and service availability. These graphs also helped in the development of land use and transport models (O’Sullivan, 2000).

Space Syntax, which also developed in the 1970s, is another analytical representational graph analysis for urban structures. It looks at the mutual relation between spatial configuration and movement, besides socio-economical issues. As Hillier emphasises, ‘It seeks the relation of relations’, searching for the

way cities are structured as well as how they function. In Chapter 4 the space syntax method is discussed in greater depth, so here we will only scratch the surface of the subject. Before the twentieth century cities were recorded just as they are in reality. This was useful for historical research. In particular, Nolli Map (1748) was the ideal figure-ground image and basemap for representing urban fabric. Today, however, there are various image representations of cities. Space Syntax is a theory, which is applied to interpret the relation between the society and the space and built form. In other words, this descriptive theory of the spatial pattern carries information about the social content, processes and structures that shape that urban form (Sima and Zhang, 2009).

As O’Sullivan (2000) emphasises, Space Syntax is a tool being used more than either Q-Analysis (which is another analytical tool, using geometrical ideas) or Kruger’s graph mentioned above (the Martin Centre’s work). Space is represented by convex space or axial lines. This analysis illustrates how people are moving; how they pass through space, plus their stationary activities. Axial lines are used for movement, and axial analysis is used for analysing the street network of cities; on the other hand convex spaces are being used for mutual co- presence, and visibility graph analysis (VGA) is for analysing patterns of visual fields in public spaces (Hillier and Stutz, 2005; O’Sullivan, 2000). The principal measure in Space Syntax is integration, which calculates the centrality; however choice is being used more recently, and it calculates the betweeness centrality (these are explored further in the research methodology chapter). Consequently, space is decomposed into subunits as in Alexander’s work. Space Syntax is different to the metric geographical approaches of space. These subunits or decomposed elements of space are measured independently from their size and shape; they are also treated similarly in the analysis (O’Sullivan, 2000). There are diverse advantages that space syntax brings for the analysis of cities. Hillier and Stutz (2005) enumerated these points; space syntax underlines the similarities and differences of cities, develops a general theory of a city, analyses the city both at the micro- and the macro-scale at the same time, and helps researchers

to see what effects of future planning and urban design decisions might cause on cities (Hillier and Stutz, 2005). On the other hand, however, O’Sullivan (2000) criticises space syntax as lacking in the exploration of the relation between axial lines, convex spaces, and buildings’ entrances. Nevertheless Hanson (2000), Shu (2001) and Nes and Lopez (2007) further explored this issue in their research studies. For instance, Nes and Lopez (2007) examined the topological depth between private and public spaces in Dutch towns. Their results revealed that the type of relation between indoor and outdoor spaces have an influence on both the safety and liveability of streets.

Although Hillier asserts that spatial configuration is an independent casual factor and there is a relation between space configuration, movement and location of attractors such as shops, according to O’Sullivan, this can only be acceptable if the configuration is regarded as a fixed entity over the course of time. It is really difficult to accept space as a fixed, independent phenomenon, since many factors affect the organisation of that space; and also this organisation affects many other things. For instance, regulations and development plans can direct the spatial configuration. As a result of this process, formation of space might shape the relations in that environment. Conversely, this process can operate in the opposite way; such as with the use of that space, there can be various territories. These include the extension of a shop to the exterior and encouraging social interaction on the street, thus defining a kind of in-between space. This issue is explored further in the coming chapters as the main subject of the study. It will be seen in the conceptual framework of the research that ‘the organisation of space’ is located in the middle of variables, as an interface whether affected by some factors or affecting some other factors. Another important point made by O’Sullivan was that space syntax ignored land use and economics (Gatrell, 1985 in O’Sullivan, 2000). Since then there have been efforts to include land use correlations in space syntax (Hillier, 1996; Ozer and Kubat, 2007). On the other hand, it is a useful tool to observe the effects of interventions.

Recently various dynamic models of urban spatial process have been developed. O’Sullivan (2000) gives cellular automata (CA) (Ulam and Von Neumann, 1940s) and fractal geometry (father of fractal, Mandelbrot 1975, Batty and Longley 1980s) as mathematical tools, which reveal cellular or grid-based simulations of urban growth process. Cities are dynamic and not in equilibrium, hence CA is the most efficient approach for understanding spatial processes. However they are also criticised for placing too much emphasis on the ‘geometry of emergent forms’ and not giving enough consideration to the ‘validity of transition rules’. In conclusion O’Sullivan criticises the fact that urban spatial structure and spatial processes are being studied separately; as well as the lack of exchange between the different disciplines researching urban morphology. In addition there is not enough study that correlates urban spatial structure with its social and economical processes. The Martin Centre models, Kruger’s work, Q-analysis, and space syntax put the emphasis on understanding a static urban structure, whereas, processes and spatial form are interrelated elements and snapshots at different times of the urban space, which will be more useful not just to grasp the underlying processes but also in connecting with pedestrian movement and socio-economical activities (O’Sullivan, 2000). Recently space syntax analysis is more widely being correlated with the other qualitative and quantitative tools.

2.4

C

Change is important for adaptation. We cannot build exactly the same styles of buildings derived from past times in our era, as this would be nothing more than a nostalgic experience. However, we have to learn from the past through examining the formation process of settlements. As Lefebvre states, production process and product are two inseparable aspects. Moreover he criticises morphological research for misunderstanding physical space by operating in the materialist space rather than the social and mental space (Lefebvre, 1991 in Mugavin, 1999). In order to understand the urban form as a product, the processes and shaping forces - whether social, physical, cultural or political - should be properly comprehended. As Kropf (2005) underlines, understanding

internal structure is crucial for the successful management of urbanism and urban design. Since then all recent theories about urban form are related to functional theory which asks how and why cities take the shape they have as well as how cities function (Lynch, 1981). For example, space syntax emerged as a new method for analysing spatial configurations of settlements developed by Hillier and Hanson in the late 1970s. This method focuses on the social and economical processes that shape space and is also interested in the evolution of cities, which are self-organising mechanisms. It looks for the relationship between the structure and function of cities. It has the advantage of analysing the city at the micro- and macro-scale concurrently. It does not only establish a more general theory of city and reveal the similarities or differences between cities, but it is also concerned with future planning and urban design (Hillier and Stutz, 2005).

The modern city is facing various radical changes. Not only does transformation occur in the patterns of cities but also in the building types from unique to ordinary and universal; from dense compact and continuous cities; to diffuse, loose, and discontinuous cities. As Levy (1999) emphasises, zoning projects result in open, heterogeneous, fragmented, and disrupted fabrics. In addition to this, closed urban fabric is transformed into an open fragmented peri-urban fabric. Elements of the urban fabric have changed; plots to building areas, streets to transportation infrastructure, blocks to point blocks, and open space to lawn. Traditional urban fabric has changed with the superimposition of a major fabric on the existing one. Consequently mega structures have emerged and scale has changed. From now on buildings just have functional relationships between them. Within this vast territorial expansion cities came up against the problem of urban sprawl. Hence the problem is how to engage the new urban forms with the existing ones. As Larkham (2005) mentions “new urban and architectural forms have been developed at speed and to a large scale, but with little or no reference to existing urban form and context”. In order to understand the processes that caused the change in the urban fabric, morphological analysis is

very important and these new elements should be refined and developed (Larkham, 2005, p. 24).

Car-oriented settlements changed the physical and social aspects of cities. For inhabitants, where to park their car comfortably became one of the crucial subjects in terms of choosing their neighbourhoods. Public spaces and the role of the street lost meaning through wide transportation links, and streets have become spaces just for movement. Buildings have become autonomous with no respect and relation to the street and its dimension. Additionally the city turned into an entity with multiple centres, mega structures, and shopping malls out of the centre. Therefore many researchers highlight the problem of urban morphology as dealing with the contemporary urban fabric and its components through understanding the underlying factors that create these urban elements. Consequently, it is important to understand the urban morphology for future designs and plans, and to have an insight of how cities are functioning. I would like to conclude this chapter with Lynch’s statement that “It is impossible to explain how a city should be without understanding how it is” (Lynch, 1981, pg. 39).

Figure 2.1 Circular Relation between Part and Whole

Therefore this study tries to understand how the street pattern of Izmir works through morphological analysis. As a morphological approach it combines the space syntax analytical approach with the urban design approach. Alexander

Analysing and understanding Sub-units Analysing and understanding Whole System

firstly decomposed the urban fabric into small pieces and analysed the parts in order to understand the whole language of the pattern. Hillier pursued a similar approach to Alexander through developing mathematical software in the analysis of street networks. This study firstly starts with a holistic approach using space syntax for exploring the complexity of the city. In addition, in order to understand the evolution of the form, a brief historical analysis was given for each case study explaining concisely under which planning approaches, regulations and circumstances the city transformed. Then case areas are further analysed through urban design parameters. Therefore, as a morphological approach, this research benefits from space syntax and urban design. The process works both as a deductive and inductive system; it starts to analyse the whole and moves into parts, and then from parts again back into the knowledge of global pattern. It is a circular process: on one hand, understanding how the whole urban system works helps to understand the parts, while on the other, to have a better idea about the sub-units is conducive to perceiving the urban system as a whole (see figure 2.1 above).