PARTS AND WHOLE IN METROPOLITAN CONURBATION: the case of porto alegre metropolitan area - Brazil 007
Décio Rigatti Keywords: Universidade Federal do Rio Grande do Sul - UFRGS Conurbation Cláudio Mainieri de Ugalde Metropolitan areas Fundação Metropolitana de Planejamento – METROPLAN Brazilian cities Porto Alegre
Décio Rigatti Universidade Federal do Rio Grande do Sul – UFRGS, Rua Carazinho, 146 Ap. 04 - 90460-190, Porto Alegre, RS, Brazil [email protected] Cláudio Mainieri de Ugalde Fundação Metropolitana de Planejamento – METROPLAN, Rua Osvaldo Pereira de Freitas, 175 Ap. 1010, 91530-080, Porto Alegre, RS, Brazil, [email protected] Abstract During the last fifty years, cities located near Porto Alegre City, capital of Rio Grande do Sul State/Brazil, have had a significant urban growth because of an intense industrial activity took place in this territory. Slowly, the urban areas started to connect to each other forming a new space at another scale disregarding the administrative city limits. The Porto Alegre Metropolitan Area comprises 31 municipalities from which 13 concentrate the main conurbation and will be the case study in this paper. About 4 million people live there (37 % of the State population), occupying 3.5% of the State territory, and are responsible for about 40% of the State's gross product. The main goal of this paper is to investigate and evaluate how this conurbation was structured, i.e. how urban areas belonging to different municipalities are linked together producing the new global structure. Besides the analysis of the metropolitan structure, the research also aimed to verify the emergence of local structures to assist in building up this conurbation. This study is part of an ongoing research and starts with examining the structure of the metropolitan area, which then supports a comparison with the results produced by analyzing the cities separately. Hence, it is possible to identify the regularities and the differences among these cities, allowing understanding how their specific features are related to their roles in the region. It was possible to identify a spatial typology among the cities, based on the way they are linked together to build up the conurbation rather than based on their internal features. Furthermore, it was possible to identify new “conurbations” within the conurbation, which seems to be seen only when the cities are analyzed together. Finally, the local structures seem to arise in the conurbation as a result of the way the parts are connected to the whole, following the emergence laws and the construction of the integration process. Conurbation as a Socio-Spatial Phenomenon Conurbations are an interesting problem of investigation, both from a theoretical point of view and as part of actual urban problems. From a theoretical point of view, conurbations can be analyzed regarding how an urban fabric can be structured from the growth and spread of several different and independent urban areas which, from a certain point of their development are able to produce an urban structure of another scale and order. This is not only a matter of size of these
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
spatial systems but also about how spatial relations are established within the logics that run the socio-economical structure where the space acts like a fundamental element to understanding these logics. Conurbation is about how it is possible to keep features, particularities, identities and a certain degree of autonomy in each of the parts that make up the conurbation and, at the same time, taking part of a new socio-spatial logic of organization that disregards the politically determined boundaries of each part of the whole, linking them to some new order and rules that define how this new organism work. From the point of view of actual problems, particularly regarding conurbations in metropolitan areas of regional capital cities like Porto 007-02 Alegre City, from developing countries like Brazil, the construction of a metropolitan structure puts into relation not only the phenomenon of the conurbation itself but creates a new space which, in spite of the relative autonomy of the parts, it is proven as a spatial unit whose functioning is rooted in the interdependent relationships among the parts. Many times it is impossible to understand how some of the parts work and are, apart from the roles they actually play in the regional scale. The space as an instance of the phenomenon is crucial to structure this new socio-economic logic once it makes it Figure 1: possible to understand the relationships between the relative location of the parts and how they work in the agglomeration process. The Location of the Porto Alegre relations among jobs, income, access to goods and services are Metropolitan Area in Rio aspects of the reality that are present in cases like the conurbation of Grande do Sul State and in the Brazil Porto Alegre Metropolitan Area – PAMA.
The morphology of urban agglomerations has been recently discussed by a number of researches that add important contributions to the issue, like Chau (2005) with his comparative study of city regions in Malaysia and, particularly, the identification of centralities that are differentiated according to morphological types. The roles and differences between what he calls historically evolved centrality and planned centrality besides the identification of different hierarchies and sizes at various scales within regional spatial system are highlighted. Also interesting is the work by Benguigui et al (2006)
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil about the evolution of Tel Aviv metropolitan area through the concept of urban cluster defined as a continuous built-up area. The representation of urban evolution is quite different from that usually made by space syntax techniques once only the built-up areas are mapped and “roads, railroads, and other non-buildings in the maps were suppressed” (p.272). Even not dealing with the metropolitan dimension of urban spaces, Read (2001) introduces an important contribution to the debate through the concept of the super-grid and the identification of overlaps between spaces that are important to articulate and to be used for global and large-scale movement and others whose major role is to be used more locally. This study is useful to our purposes, especially regarding the connection between local structures – which we could think of like every part of the 007-03 conurbation – and the global structure, related to the entire conurbation. At last and basic to understand the conurbation phenomenon is the work by Hillier (1996) and particularly the chapter “The Fundamental City” where the construction of the spatial integration is discussed. Following these ideas, the main goal of this paper is to evaluate how was structured the conurbation of the Porto Alegre Metropolitan Area - PAMA. Is intended to verify how urban areas belonging to different municipalities are linked together producing a new global structure and how this process is linked to the different roles of the parts of the PAMA conurbation. Firstly, a brief profile of the conurbation of PAMA is presented in terms of urban evolution, demography, economy, and the main roles of the parts regarding the conurbation and what are the main connections within the region. The metropolitan structure will be described through space syntax method, which allows analyzing both the results concerning the parts and the entire conurbation as well. A Brief Account of the Conurbation of the Porto Alegre Metropolitan Area - PAMA Despite spatial continuities found in a larger territory, it was considered here the group of municipalities where the conurbation can be better identified and where spatial continuities do not easily allow identifying each of the politically determined boundaries among them. From the 35 municipalities officially belonging to the PAMA, only the 13i that are part of the main metropolitan conurbation were considered. These 13 municipalities were born in different times and from different purposes. Porto Alegre, Viamão and Gravataí are the oldest cities and start their evolution from the second half of the 18th century on, in a time when Portuguese and Spanish crowns were fighting for a territory whose limits used to change according to several non-lasting treaties. These are the cases of cities that evolve slowly from small foundation cores. In the beginning of the 19th century the northern part of the region begins to be occupied by Germans and São Leopoldo is the first colony and the main center to the immigrants. Later on Novo Hamburgo, Estância Velha, Campo Bom and Sapiranga start their development as expansions of São Leopoldo. Porto Alegre was linked with the colonies (firstly with the German ones and, by the end of the 19th century, with the Italian ones) through a railroad built in 1874. Along this railroad new urban settlements were built around some of the rail-stations like Canoas, Esteio and Sapucaia do Sul. The entire region experiences a remarkable growth during and just after the Second World War as a result of an industrialization process. The growth of the population that follows this process produces cities like Alvorada and Cachoeirinha whose origins are based on consecutive land division developments to low-income dwelling and
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
not in the evolution of a pre-existing urban core. The PAMA’s demographic profile can be observed in the table 1, below.
Figure 2: Municipalities of the PAMA and their boundaries
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Following this socio-economic process, important national and regional roads were built like the BR-116 (in 1938), which runs from south to north crossing Canoas, Esteio, Sapucaia do Sul, São Leopoldo, Novo Hamburgo and Estância Velha; the RS-030 and the RS-020 (during the 40’s) cross Cachoeirinha and Gravataí; the RS- 118, which connects the BR-116 to the BR-290 passing through the territories of Gravataí, Cachoeirinha, Esteio, Sapucaia do Sul and also of Alvorada and Viamão, though far from their urbanized areas. From the 70’s on, the new national and regional roads that cross the region and the increase of regional and interregional connections took an important part in the configuration of the metropolitan space. Important roads built at that time are: BR-290, connecting Porto Alegre to the coast, running east/west from the Porto Alegre northern
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil city limits and passing through the municipalities of Cachoeirinha and Gravataí; RS-239, connecting Estância Velha, Novo Hamburgo, Campo Bom and Sapiranga, almost in the northern limit of the study Table 1: area; BR-386, connecting the metropolitan area to the northwestern Population of PAMA from part of the State. 1991-2000
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Figure 3:
Main Roads, Railroad and Rivers in the PAMA
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
One of the outcomes of this process is that the evolving urban areas begin to carry on roles that are not explained only by a logic internal to them but can only be understood by the way they are inserted in an interdependent and expanding metropolitan system where the conurbation is one of its faces. Another outcome may be understood observing table 2 with some social data of the municipalities of the Table 2: PAMA. Among the 350 State’s municipalities, few of the ones Local Social Extended Index belonging to the PAMA present a good rank. Porto Alegre, Esteio and (LSEI) of the municipalities Campo Bom present the best results while Alvorada presents one of of the PAMA conurbation – the worse results of the entire State. It seems that the conurbation is 1991 to 1996 also an agglomeration of socio-economic problems. 007-06
Morphology of the Conurbation The Measures Firstly, the syntactic properties of PAMA will be analyzed, followed by the analysis of the data of the municipalities, allowing to observe how the structures of the parts are grasped in the metropolitan structure. The data was obtained by processing the axial maps with Mindwalk (Figueiredo, 2002), working with the aggregation of lines with low intersection angles through the concept of continuity lines (Amorim & Figueiredo, 2005) in order to capture aspects of the reality that seem to be lost using the traditional axial maps. The following syntactic measures will be used: global integration, radius-radius local integration, intelligibility, synergy, strength of the integration core (Peponis, 1989) and difference factor (Hiller, Hanson, and Graham, 1987). The Spatial Distribution of the Integration and the Metropolitan Structure The distribution of the global integration values is highly biased by the regional and national roads. The two main roads that articulate the entire PAMA, the north/south axis (BR-116) and the east/west one (BR-290), concentrate great part of the global integration although with some differences. BR-290 groups the more integrated lines of the system, is weakly connected in its surroundings with practically no attractors exploring the locations along it and, as a highway, is linked to its surroundings only by a few numbers of traffic intersections. BR-116 presents two different features: the central tracks are separated by a wall, do not connect each other and categorically separate what happens in the east side of the road from the west side that can be reached only through some traffic intersections. The lateral tracks in a few places connect the central tracks and, at the same time, the blocks along
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil them are intensely used, especially by regional attractors such as car Figure 4: and truck shops, car repair and parts shops, large industries, shopping malls and other facilities that depend on good locations Global integration core of the regarding large scale movement within the region. PAMA
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Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
Because both BR-116 and BR-290 are the spaces responsible for connecting a significant part of the entire PAMA it becomes strongly integrated in a very similar way as described for regional cities in Malaysia by Chau (2005), for the metropolitan area of Brasilia, Brazil, described in Holanda (2001) and for the metropolitan area of Florence, Italy, by Rigatti (2002). Also important in the PAMA’s global structure is the RS-118, which articulates the BR-116 and the BR-290 through a ring at the east of the PAMA. The PAMA’s large-scale movement is very dependent of these main roads and, even if they act as national roads, most of the measured movement - 90% in BR-116 - is internal to the PAMA 007-08 (Lastran, 2001). This means that these roads are very important to the structure of the metropolitan area and their syntactic central positions can explain their roles. Particularly in the case of BR-116, the large scale and interregional movement made possible by the central tracks can be associated to the regional and local movement in the lateral tracks, where the attractors are located. The large-scale movement that can be found in the most integrated lines of the system makes possible to connect the entire region and makes it easier the mobility found in terms of jobs, housing, and consumption within the metropolitan area that, despite the differences among the municipal boundaries, works as a single structure in different levels of complementary functionality. Urban areas like Alvorada and Viamão, which are mainly low-income residential areas to the PAMA, are relatively segregated in the region and are quite dependent on other areas – especially Porto Alegre – for jobs, goods and services beyond a basic level. Due to the features of the BR-116, the growth of the urban fabric along the road is made overcoming a very difficult relationship between its eastern and the western parts. Most of the urban areas along this road are developed to the east, avoiding the western side also because there are some natural restrictions on urban occupation defined by the Sinos River and its flooding area. Canoas is an exception and is crossed almost in the middle by the BR-116 and, because of its connections with other important roads almost all the movement destined to Porto Alegre must pass through its territory. This strategic position produces effects in the use of the BR-116 that constantly present traffic-jams. In Porto Alegre City, this problem is reduced once the main roads for long distance movement are located in its periphery. Local integration, because of the relatively high mean depth, was calculated as radius-radius. It is possible to perceive some overlapping between spaces globally and locally integrated. The BR- 116 is highly integrated in all its extension and local centralities in the PAMA tend to correspond to the integration cores of the municipalities when examined separately mainly those located along and to the east side of the road. Municipalities where clear centralities can not be grasped are Estância Velha in the northern limit of the PAMA, Gravataí and Cachoeirinha, in the center of the PAMA and Alvorada and Viamão that are both globally and locally poorly integrated in the PAMA. For the purposes of this paper, it seems important to analyze how local structures are visible and in which degree in the metropolitan structure. Global and local integration was produced for all the13 municipalities separately from the PAMA and the results were compared to local integration of the PAMA, once this measure could better picture the local centralities. Local integration of the PAMA was processed from step-depth 6 (the first one to present some spatial differentiation) to step-depth 14, one step less than the mean step-
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil depth of the system. It was possible to analyze how the spatial Figure 5: structures of each municipality “behaved” as the step-depth of the PAMA grew and in what step-depth local structures could more clearly Radius-Radius integration be seen in the metropolitan structure. core of the PAMA
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Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
Figure 6: The results are expressed in figure 6, with the global integration core of the parts, and in figure 7, with the local integration core of all Global integration cores of ii the Municipalities of the municipalities . It will be presented only a summary of the results, PAMA based on individual analysis of the 13 municipalities.
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Figure 7: Some Questions Radius-Radius integration cores of the Municipalities of The analysis of the global (figure 6) and local (figure 7) integration of the PAMA the municipalities when examined separated from the PAMA indicates that the integration cores tend to capture the main centralities, corresponding to the central districts of the municipalities and to the places where are found shops, services and urban facilities to the population. Even taking part of a more complex structure as the metropolitan conurbation, every municipality seems to keep some degree of autonomy from the point of view of the locally significance of its central spaces and this is also captured by the way people behaves and perceives their own cities. The main syntactic features of the municipalities and of the PAMA can be observed in table 3 below.
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
Table 3: Syntactic measures of the municipalities belonging to the Porto Alegre Metropolitan Area, of the conurbation and of two groups of municipalities
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Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
The mean connectivity of all municipalities is very similar, almost the same of the PAMA. Mean depth is quite differentiated among the municipalities, with a strong correlation with the size of the systems meaning that, in PAMA, depth increases as they grow in size. Global integration, in spite of their variations among the municipalities, is statistically similar. Viamão is the only municipality with mean global integration lower than the mean integration of the PAMA. It is interesting to observe that examining the municipalities separately from the PAMA and the breaking up of some important lines that are responsible for the structure of the entire conurbation and for the large-scale movement like BR-116, apart from Canoas, which is 007-12 crossed by the road, in the other municipalities it is less important, fitting with the location of the city centers in the integration cores, always aside regarding the main road. The spread of global integration is also very similar among the municipalities. The proportion of spaces responsible for 10% of total integration varies from 6.98% in Canoas – the presence of the BR-116 in the middle of the system plays an important role in this property – to approximately 10% in Alvorada – where the global integration is less concentrated compared to the rest of the spatial systems, which present a value around 7%, very similar to the PAMA. Synergy varies from around 0.66 in two contiguous municipalities, Campo Bom and Sapiranga, in the north of the PAMA to less than 0.2 in two cases: Alvorada and Viamão that evolved in a fragmented way. Their roles as residential areas for Porto Alegre seem to indicate that their urban structures are subordinated to some goals that are more dependent on their relationships with Porto Alegre than to a relatively independent process. The results indicate an almost independence between the globally important spaces – responsible for the articulation of the entire system, for large-scale movement and for the extra-municipal connections - and the locally important ones. In these cases, it seems that the space reinforces a particular role of the cities as commuter suburbs and it seems also that this role is configurationally confirmed. In order to identify other aspects relevant to indicate particularities among the municipalities, strength and difference factor were analyzed but in both cases the values of the municipalities and of the PAMA presented no differences. Even requiring a deeper investigation, at this point, it seems that the results indicate that, despite differences in origin, time of existence and morphologies, there is a tendency to similar syntactic features among the municipalities and the metropolitan area. It seems that, over time, different spaces adjust themselves to a common spatial logic introduced by the conurbation. The Structure of the Parts in the Metropolitan Area A closer analysis in the way local and global integration of the municipalities can be more or less captured while the step-depth of local integration of the PAMA grew, as expressed in 3.2 above, revealed some changes during this process. Based on this analysis it was possible to identify a typology of municipalities and suggested some issues to be discussed especially regarding the heterogeneities and similarities found as well as the reasons why they emerge. Also it is possible to compare the results with other case studies allowing understanding the peculiarities of the processes responsible for structuring metropolitan areas around the world. The results regarding the typology of the municipalities are summarized in table n° 4, according to the following observations:
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
Type 1 – From a clear RN visible in small step-depths, it becomes weaker as the step-depth rises and eventually the RR is stronger (RN → RR). This is the case of Campo Bom, Canoas, Novo Hamburgo and Porto Alegre. Type 2 - From a clear RR visible in small step-depths, it becomes weaker as the step-depth rises and eventually the RN is stronger (RR → RN), exactly the opposite of type 1. This is the case of Alvorada and São Leopoldo. Type 3 – From a week RN and RR in small step-depth, the RR become more and more visible as the step-depth rises (─ → RR). This is the case of Estância Velha. 007-13 Type 4 - From a clear RR visible in small step-depths, it becomes weaker and weaker as the step-depth rises and eventually looses both RR and RN structures (RR → ─). This is the case of Sapucaia do Sul and Viamão. Type 5 – In this case, the change of step-depth is unable to capture both RN and RR of the municipality (─ → ─). This is the case of Table 4: Cachoeirinha, Esteio and Gravataí. Types of transformations of Type 6 – Both RN and RR are visible in low step-depths and RN e RR of the eventually the RN becomes more visible as the step-depth rises municipalities with the increase of step-depth of the (RN/RR → RN). This is the case of Sapiranga. local integration of the PAMA
It is important to remark that these “typologies” of tendency have different emphasis among the municipalities. For instance, Alvorada and São Leopoldo are in the same type, but they are not similar in the way the properties of Alvorada’s configuration arises in this analysis, which is always very week and becoming a little more evident only in 14 step-depth, while in São Leopoldo the tendency is always strong and steady as the step-depth rises. To the study of conurbations the results suggested some questions, especially regarding the cases that are difficult in capturing any kind of structure in any of the step-depths. This is the case of types 4 and 5. Due to the spatial distribution of these cases it should be possible to infer – though in a preliminary analysis – that, even within conurbations there are cases when the way the parts are connected to the whole can keep a great deal of the individualities of the parts, while in other cases the urban fabric is so dense and continuous that is almost impossible to analyze the parts independently and, therefore, there could be “conurbations within the conurbation”. This seems to be the case of two sub-systems: Cachoeirinha and Gravataí (C+G), close to the BR-290 and Esteio and Sapucaia do Sul (E+S), along the BR-116. A close analysis of the metropolitan conurbation shows that some municipalities are still apart from each other by physical obstructions and this might be affecting the results. Along the BR-116 Porto Alegre is separated from Canoas by the Gravataí River, which runs east/west
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
close to the BR-290; Canoas is separated from Esteio by the Sapucaia River and by some urban voids; Esteio and Sapucaia do Sul are separated from São Leopoldo by a group of large urban voids; São Leopoldo, even with a territory that occupies the northern bank of the Sinos River where it connects with Novo Hamburgo, has the river as a restriction to a more compact occupation; Novo Hamburgo is separated from Campo Bom in the east border by a sequence of small urban voids and Campo Bom is linked to Sapiranga only through a single line; to the west side, Estância Velha also has a group of small urban voids that interrupts its own urban fabric, which is extended until the BR-116 (an area that till now people do not know whether it belongs to Estância Velha or to Novo Hamburgo) and can explain the 007-14 “weird” result; in the south of the PAMA, the Feijó River separates Alvorada from Porto Alegre and in the north border the Rio Gravataí separates it from the rest of the PAMA; Viamão, besides its internal spatial fragmentation, is separated from Porto Alegre by a chain of hills and is linked to Alvorada only by a few connections.
Figure 8: Main physical restrictions for conurbation and the groups of more compact urban fabrics in the PAMA
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
Conurbations within Conurbation In order to examine the hypothesis that, in some cases is not possible to identify configurational properties able to keep the individuality of the parts within conurbations, the same analysis made to the municipalities alone was made to the groups of Cachoeirinha plus Gravataí (C + G) and Esteio plus Sapucaia do Sul (E + S) iii. The visual analysis of the results comparing the RN and the RR of C + G and of E + S as the local integration of the PAMA rises from step- depth 6 to step-depth 14 has revealed some interesting features. Both groups start with a strong global structure visible in the step-depth 6 of the PAMA and, from step-depth 12 on there is a shift in the results, with a stronger RR in the step-depth 14 of the PAMA. What the 007-15 analysis shows up is that the group E + S presents a more consistent and strong result while in C + G the results are not so strongly observed. With these results, both groups would be classified as type 1 in table 4. Therefore, type 5 (cases with no structure visible as the step-depth of the PAMA grew) would disappear and only Viamão would represent type 4. Analyzing the syntactic measures of C + G and E + S, added in table 3, we can see that the mean connectivity remains the same while the mean depth of C + G is higher in the group than the mean depth of the sum of the parts. In E + S the mean depth is smaller than the sum of the parts. This property affects the results of global and local integration that is reduced in C + G and rises in E + S. In both groups Table 5: global integration is slightly more distributed when compared to the Summary of the comparison mean value of the sum of the parts. Synergy is reduced in G + C while between the syntactic rises significantly in E + S. Also the intelligibility of the system C + G measures of the groups present a reduction compared to the mean of the parts and, in E + S Cachoeirinha and Gravataí the intelligibility is higher in the group than the mean of the parts. The (C + G) and Esteio and syntactic strength of the integration core is smaller in C + G and a little Sapucaia do Sul (E + S) and higher in E + S. These results are summarized in the table 5, below. the mean values of the sum of the parts
From the visual as well from the syntactic measures it is possible to say that the two groups present different results. Cachoeirinha when aggregated to Gravataí tend to present measures that are worse compared to the mean values they present separately while Esteio aggregated to Sapucaia do Sul presented a significant improvement. This observation reinforces the idea that there are differences in the structure of groups of parts as the step-depth of local integration of the PAMA increases. The hypothesis that the difficulties in observing internal structures of some of the municipalities were due to how these “conurbations within conurbation” were aggregated is clearly demonstrated in the case of Esteio and Sapucaia do Sul where the continuity and the compactness of the urban fabric makes it impossible to understand the parts when isolated. In addition and reinforcing the analysis, even considering that both Esteio and Sapucaia do Sul present their own urban centers clearly recognizable, they are located very close to each other and, more importantly, along the same avenue, which is one of the most globally integrated of the entire system. The results of Cachoeirinha and Gravataí can be related to the presence of some large urban voids, especially in their boundary. It is important to remark that the visual analysis shows that the internal structures of G
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
+ C are more visible compared to the lack of spatial differentiation of both global and local integration. From the analysis made so far of the PAMA, it is possible to say that the metropolitan conurbation is not a homogeneous phenomenon both from the point of view of the structuring of the space as well as of the degree in which the parts of the whole are complementary in terms of their socio-economic activities. This is specially the case of the specialization in the roles of some municipalities like Alvorada, Viamão and Cachoeirinha, which work as dormitory suburbs. The strong global structure of the metropolitan space is built up in order to guarantee the large-scale movement and connections and is very 007-16 concentrated in the main roads that cross the area, allowing high levels of general mobility. Local structures, visible through local integration of the PAMA, seem more dependent on the way every municipality is connected to each other than only of individual and internal properties. The results for the PAMA suggest that the phenomenon of spatial conurbation is essentially understood through the laws of emergence and the construction of the spatial integration, as discussed in Hillier (1996). The case of the PAMA represents a process of construction of a new large-scale spatial entity but, at the end, is structured by the same basic rules described for isolated urban areas. The evolution of urban areas of the conurbation follow socio-economic logics but use the space as a strategy to ensure or to promote differences in the roles of the parts in the whole, to ensure a greater or smaller degree of relationships among the parts, reinforcing some spaces and not others. In sum, the construction of the conurbation seems to be a particularity of what Hillier (1996) describes as the laws of emergence, the laws of generic function and the construction of spatial integration. In this way, it is possible to assert that the construction of the conurbation follows the same rules of the fundamental city: “In structuring space by physical objects we suggest possibilities by eliminating others. But the spaces in the interstices of physical forms are still ‘open’. Within these limits, the infinite structurability of space still prevails. In our cells we may dance” (Hillier, 1996:345). References Benguigui, L., Blumenfeld-Lieberthal, E., Czamanski, D., 2006, “The Dynamics of the Tel Aviv Morphology”, Environment and Planning B: Planning and Design, Vol 33, pp. 269-284, Pion, London. Chau, L.W., 2005, “Probing Different Centralities in City Regions: A Space Syntactic Approach”, A. van Nes (Ed.), Proceedings, 5th International Space Syntax Symposium, TUDelft, Techne Press, vol. 1, pp. 309-330. Figueiredo, L., 2002, Mindwalk”, version 1.0, Space Syntax Software, Available at: http://www.mindwalk.com.br Figueiredo, L., Amorim, L., 2005, “Continuity Lines in the Axial System”, A. van Nes (Ed.), Proceedings, 5th International Space Syntax Symposium, TUDelft, Techne Press, vol. 1, pp. 161-174. Hillier, B., Hanson, J., Graham, H., 1987, “Ideas are Things: An Application of the Space Syntax Method to Discovering House Genotypes”, Environment and Planning B: Planning and Design, Vol 14, pp. 363-385, Pion, London. Hillier, B., 1996, Space is the Machine: A Configurational Theory of Architecture, Cambridge University Press, Cambridge Holanda, F., et al., 2001, “Eccentric Brasilia”, J. Peponis, J. Wineman, S. Bafna (Eds.), Proceedings, 3rd International Space Syntax Symposium, Ann Arbor, A. Alfred Taubman College of Architecture and Urban Planning, pp. 53.1-53.9.
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
Lastran, 2001. “Análise de alternativas para os problemas advindos da saturação da BR-116”, Trecho Entre Porto Alegre e Novo Hamburgo, Porto Alegre, LASTRAN. Mello, O., 2001, “Evolução populacional segundo subregiões da RMPA no período 1991-2000”, Porto Alegre: METROPLAN (Documento Interno). Peponis, J., et al., 1989, “The Spatial Core of Urban Culture”, Ekistics, vol. 56, number 334/335, January/February/March/April 1989, pp. 43-55. Read, S., 2001, “‘Thick’ Urban Space: Shape, Scale and the Articulation of ‘The Urban’ in an Inner City Neighborhood of Amsterdam”, Proceedings, 3rd International Space Syntax Symposium, Ann Arbor, A. Alfred Taubman College of Architecture and Urban Planning, pp. 18.1-18.12. Rigatti, D., 2002, “Urban transformations in Florence and the dynamics of the 007-17 centrality”, Research Report, Florence.
i. List of the municipalities according to their socio-economic features, and considering four groups of indices and their variables: a) housing and sanitation (mean population per municipality; proportion of houses with water supply and sewage service); b) education (rate of failure in the fundamental school; rate of abandonment in the fundamental school; rate of enrolment in the high school; rate of illiteracy in persons 15 years old or older); c) health (number of first-care units per 1,000 persons; number of hospital beds per 1,000 persons; number of doctors per 10,000 persons; percentage of new-born children with low weight; rate of mortality in children less than five years old; d) income (income concentration; proportion of social expenses in local budgets; gross internal product per person). ii. It is important to remark that some analyses may become difficult to understand due to the representation of integration maps. Black and white maps showing the integration core of large systems, such as a metropolitan conurbation, do not capture the variations in the levels of the integration as does the color map. The visual analysis in this paper was based on the color maps. iii. This exercise will later be conducted for more groups of municipalities as well as considering other numbers of aggregated parts.
Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007 Rigatti, Ugalde; Parts and Whole in Metropolitan Conurbation: The Case of Porto Alegre Metropolitan Area - Brazil
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Proceedings, 6th International Space Syntax Symposium, İstanbul, 2007