Frontier conurbations:rather than twin cities, a symbiotic outcome

of two national cultures and identities

Andrea DA COSTA BRAGA Décio RIGATTI

Claudio MAINIERI DE UGALDEFábio ZAMPIERI

PROPUR - Programa de Pós-Graduação em Planejamento Urbano e RegionalFaculty of Architecture / UFRGS- Universidade Federal do Rio Grande do Sul / Brazil

Santiago do Chile – January, 2012

TARGETS

To explore the role played by cultural differences in shaping the spatial structure of emergent international conurbations;

To describe the spatial configuration regarding urban spread, potential movement and land use allocation ;

To identify configurational distinctions due to national social and cultural codes;

To discuss the typical features of Latin American and Brazilian urban configurations found on the conurbations emergence;

To focus broadly at the Conurbation Index (CI, as in RIGATTI, 2009) strength in order to verify continuity and connectivity efficiency in fusion processes between the cities beyond contiguity.

METHODOLOGY AND TOOLSSpace Syntax theory / methodological tools provided evidence on the conurbations structural and morphological peculiarities, highlighting typological differences and dominances emerging from a single urban grid produced by two national societies.Axial maps (HILLIER & HANSON,1984): processed using MindWalk® (FIGUEIREDO, 2002) tools;Accessibility hierarchy / grid deformation spatial description : co presence patterns (locals /strangers, HILLIER and HANSON, 1984) and movement potential (HILLIER et al, 1993);

Syntactic measures applied: Global (Rn) and Radius Radius (RR) Integration;

Correlations: Integibility / Synergy / Fast Choice Map (HILLIER et al,1987) used to identify distinctions in national social codes and consolidation of centralities;

Brazil and Latin America urban typology (MEDEIROS & HOLANDA, 2007): comparison between urban spread peculiarities to Brazilian & Uruguayan societies ;

Conurbation Index (IC= R / Σ (Rn/n), RIGATTI, 2008): contiguous urban grids structures interpenetration formed a new kind of spatial system by comparison of Syntactic compactness indicators Rn, Mean Depth, Integibility and Synergy.

IC > 1 = strong conurbations. Meaning that syntactic measures tend to be more robust for the whole conurbation system than for its parts. Their spatial patterns and urban dynamics are better explained if taken as a whole system . The spatial structure logic laying in the core of the conurbation process (RIGATTI, 2009, 2011).

CONTEXT & HISTORICAL BACKGROUND• The region has been in disputation since the

18th century, therefore the founding of mirror-like surveillance settlements along the borderline: a village built in Brazilian territory caused the rise of an Uruguayan one opposite to it, and vice-versa;

• The efforts to restrain permeability and vulnerability on both territories caused the recurrence of twin-cities phenomena along the borderline (there are 6 of them);

• Social and economical practices followed advantages perceived by locals, disregarding political struggles between Nations. That configured a frontier territory and a transnational “way of life” through commerce, seasonal work and social networks;

• Insulation from Brazilian most important towns and easier communication with Montevideo caused regional economical and cultural linkage to Uruguay and Argentina;

• The frontier social pattern of interaction and coexistence is marked by a pretense invisibility or unawareness of the stranger (here as in HILLIER & HANSON, 1984).

Brazil / Uruguay borderline is 1006Km long, settled in 1848, after the recognition of Uruguay as an Independent Nation.

Map of the landmarks limiting Brazil and Uruguaysource: www2.mre.gov.br/daa/uesc/html

BRAZIL / URUGUAY FRONTIER CONURBATIONS

LOCATION

CHARACTERISTICS

• Continuous and porous urban grids without geographical barriers;

• High permeability through / around both settlements;

• Non ostensive checkpoints nor built barriers;

• Intense / fuzzy movement of Brazilian and Uruguayan nationals across the border;

• Complementarities in commerce and services / shared centralities;

• Exchange rates fluctuation between currencies mediate transnational interchanges;

• Fluidity between strangers / inhabitants marks co-presence & movement;

• Configurational differences due to national social codes / cultural identities.

• A stretch of non aedificandi land runs along the borderline, separating the doubled street system on each side.

Chuí / BR 33ºº 41’32.35”S53º 27’22.10”WAltitude: 16m

Santana do Livramento /BR30º 53’31.49”S55º 31’57.05”WAltitude: 211m

sources: Ministério do Interior –BR IPEA / Google Earth

BASIC DATA

CHUÍ / BR – CHUY / UY CONURBATION

Settlement Foundation

Municipality Department

Geographical area Distance to Montevideo

Distance to Porto Alegre

Acessibility Urban population

Urban area

CHUÍ BR

1927 Chuí (2000)

Brazil Southernmost point

340Km 515Km BR 471 5697 inhab

9,370 sqKm

CHUYUY

1888 Rocha NE Uruguay 340Km 515Km Ruta 9 9804 inhab

8 sqKm

images: CBERS / INPE-BR, Google Earth top down: © Ailton Avila / © Margi Moss / © Prefeiruta do Chuí - BR

GENERAL DATA ON CHUY (UY) / CHUÍ (BR)

• Both cities were founded as commercial entrepots. Commerce remains the main economical asset, anchored by Chuy Duty Free Zone / Chuí wholesalers suppliers;

• The region, once Neutral Fields (until 1814) was insulated from the rest of Brazil territory until 1970, when BR 471 road was opened. From 1930 until then, both cities were linked to Montevideo through Rutas 9 / 19;

• Chuy / UY was built earlier, to populate the area with Uruguayans and minimize Brazilian appropriation of rural land in Uruguay territory;

• The conurbation is small and urban spread is constituted almost of low income dwellings meant to absorb migrant rural population on both sides of the border;

• Infrastructure problems are remarkable.Chuy / Chuí peripheral position is undeniable

Top – down: Chuy /UY main square / the end of Brasil – Uruguai avenues (SO) along the borderline / Numancia st in connecting to Brasil avenue (CHUY) / Brasil-Uruguai avenues where it crosses the cities centers / rua Argentina - CHUI-BR links both cities cores / a new Duty Free Shop next to 669 road (leading to the shore) SE – CHUY images: by the author

AXIAL GRAPHS PROCESSED USING MindWalk © Figueiredo, 2002 software

CHUÍ/ BR SYNTATIC MEASURES (186 axial lines)

RN graph shows the avenue parallel to the borderline as the most integrated axis forming the base of a triangle along with BR 471, which encloses the centrality core. Urban spread is linear, formed by low income housing estates stretching away from the borderline (N). Urban voids configure barriers (E-W) to pedestrian / vehicular movement, causing poor permeability parallel to the borderline.Urbanized perimeter is large, densities are low, urban grid is fragmentary and discontinuous, following Brazilian urban spread logic of spatial segregation: high depth land parcels connecting directly to the most integrated axis, fishbone style.

RR graph reproduces Rn logic, except for the incorporation of the longest perpendicular axis which leads to most of low income housing estates built along it.

CHUÍ / BR CONFIGURATION ANALYZIS

CHOICE MAP highlights RN & RR: the only route connecting the whole urban system, vital to vehicular / foreigners circulation is parallel to the borderline. System’s logic lay on the interface with Uruguay. Therefore, the city first expansion dealt with the improvement of interface between towns, enhancing linear centrality.

SYNERGY is high, therefore, equivalence between local / global integration: the system gives no orientation clues on the micro level or is so small that scales are indistinct.

INTEGIBILITY is low, coherent with Brazilian patterns: a stranger has to relay on only one axis access all the other parts of the system.

CENTRALITY is linear, strong along the border line, coherent to the fact that Chuí / BR commerce targets Uruguayan public (wholesalers that supply Montevideo and regional shops). The streets perpendicular to the borderline and connecting directly to BR 471 and to Chuy / UY centre also capture centrality close to the borderline.Mixed uses are ordinary in the centre (shops / dwellings share one single land plot). The Eastern periphery, enclosed by the roads linking Brazilian customs office to the Uruguayan one (BR 471-Ruta 09) and leading to the shore (RS696) where hotels, petrol stations and warehouses are located, has an insipient centrality.

AXIAL GRAPHS PROCESSED USING MindWalk © Figueiredo, 2002 software

CHUY / UY SYNTATIC MEASURES (220 axial lines)

The system is slightly bigger than that of Chuí / BR, but more compact.

RN graph is quite uniform and the average integration found for the orthogonal grid is lower than that of Chuí / BR. The diagonal cutting the whole urban grid and connecting Rutas 19 AND 9 to BR 471 captures integration. This street canalizes heavy load traffic from inner Uruguay to international roads and functions as peripheral limit to the city centre. Commerce doesn’t profit from its locational advantages.SW periphery shows lower integration values due to “slum like” land parceling.The axis parallel to the borderline has different integration status than its Brazilian counterpart, but houses most of duty free shops. The more integrated axis perpendicular to the borderline connects both cities cores and customs offices. RR GRAPH depicts a more local integrated axis on the SW periphery denouncing the local importance of the “slum informal grid” connection to the urban fabric.

 

CHUY/ UY CONFIGURATION ANALYZISFAST CHOICE depicts the diagonal running E-W and cutting the urban grid in two halves as the town’s most important street. It limits distinct morphological zones, where the orthogonal grid changes proportions for newest urban expansions rectangular blocks. Mean Depth is kept low thanks to the diagonal axis.

SYNERGY is high and main distinctions on Rn RR are constituted by few lines perpendicular to the borderline that form the city core. A more integrated axis on the SW periphery denounces the connection to the “slum informal grid” were a big land parcel was subdivided by dwellers according to their own needs.

INTEGIBILITY is higher than that of CHUÍ/BR, but lower than the average found for other Latin American samples (MEDEIROS & HOLANDA, 2007) due to the patchwork of mismatching orthogonal grids that form its urban fabric. The diagonal axis is important to identify the city parts and its shallowness allow orientation at global and local scales.

CENTRALITY is, however, not linear, spreading on the Northern part of the orthogonal grid, especially along avenida Brazil between Artigas and Numancia and on the blocks surrounding its main square where hotels, restaurants and duty free shops are located. It contradicts tendencies depicted from Rn graph and indicates that to understand the city centrality is necessary to weight the effects of CHUÍ – BR Integration patterns.

CONURBATION CHUÍ / BR CHUY / UY

RN & RR graphs make clear that centrality spreads along the borderline, a shared linear centre for both towns, its immediate adjacencies contained by road accesses on both sides, crowned by customs outposts.

The conurbation displays similar global and local integration measures on most axes what reinforce centralities on both local and global levels.

Phenomena seems to be a consequence of the system small size coupled with the symbiotic effects of the conurbation itself. The diagonal highest integration (Rn, / RR) implies that the connection between Uruguayan and Brazilian countryside is extremely important for regional economy.

THE CHUÍ / BR - CHUY / UY CONURBATION

Instead of a conurbation, the system resembles a single city, its configuration laying beyond complementarity, closer to symbiosis.

Separately, each spatial configuration seems illogical and difficult to grasp: both cities share centrality and spatial segregation patterns are less distinctive.

The idea of twin-cities / conurbation does not apply here. Instead, that of one single city spreading over two national territories is more suitable.

SINERGY high level confirms the coherence between global and local integration and basically reproduces the parameters for both cities. INTEGIBILITY improved to Latin American patterns through systems conurbation. MEAN DEPTH is lower than Brazilian sample average (MEDEIROS & HOLANDA, 2007). CENTRALITY relay on the inteface between cities, along the borderline

No Axial Lines

Rn max Rn min RR max RR min Integibility Synergy Mean Depth

CHUÍ / BR 182 3,04 0,56 3,4 0,33 0,29 0,91 3,44

CHUY / UY 220 3,21 0,33 4,47 0,33 0,58 0,95 3,59

CONURBATION 398 2,38 0,64 4,20 0,33 0,58 0,94 4,28

Comparative Space Syntax measures / correlations(data: by the author,)

SANTANA DO LIVRAMENTO / BR – RIVERA / UY CONURBATION

Settlement Foudation

Municipality Department

Geographical area

Distance to Montevideo

Distance to Porto Alegre

Acessibility Urban population

Urban area

SANTANA DO LIVRAMENTO BR

1857 Santana do Livramento

SO 502Km 501Km BR 290BR158

74910 inhab

9,370 sqKm

RIVERAUY

1865 Rivera NO 502Km 501Km Ruta 5 101504 inhab

6,350sqKm

images: Google Earth top down: © Ailton Fabian Ribeiro / © Amilcar Mello (1950) / © Fabian Ribeiro

GENERAL DATA ON RIVERA (UY) / STA LIVRAMENTO (BR)

• Rivera is the 4th Uruguayan city in size and income and situation improves since the creation of duty free zones in all Uruguayan borderline towns (1986);

• Santana do Livramento, an important benefice industry center until 1960, is recently overcoming the decay it has been suffering since then;

• Until 2000, commercial activity was stronger on the Brazilian side of the border, with several shops and wholesalers supplying Uruguayan market. Nowadays, its commercial activity and services are complementary to Rivera free shop zone, linked to Tourism Industry;

• Regional development remains uneven and tied to economical shifts, characteristic to frontier zone dynamics.

AXIAL GRAPHS PROCESSED USING MindWalk © Figueiredo, 2002 software

SANTANA DO LIVRAMENTO / BR SYNTATIC MEASURES (1128 axial lines)

RN graph displays a quilt of grid patterns separated by large voids and connected by a deformed wheel macro system of more integrated lines (BR 290, BR158 roads), which encloses the old core orthogonal grid and links insulated residential enclaves.

The city core most integrated axis is perpendicular to the borderline, linking both Livramento and Rivera symbolic city centers and is one of the busiest commercial street.

RR graph depicts the grid uneven integration distribution. The “X” shape axes

enclosing the borderline surroundings are more integrated locally. The area housed slaughter plants that provided most job offers until 1960. Its shallowness and linkage to the borderline allowed Uruguayans and Brazilians even accessibility to workplaces.

SANTANA DO LIVRAMENTO / BR CONFIGURATION ANALYZIS

FAST CHOICE displays the importance of ring roads system to regional and international transit inside and through the city, concentrating accessibility and also the road system ringness from where tree like residential suburbia spread.

SYNERGY & INTEGIBILITY are low, while Mean Depht is high as a typical Brazilian (MEDEIROS & HOLANDA, 2007) city might be, displaying: economy of lines, patchwork resemblance grid. Configuration reproduces the uneven Brazilian social and economical structure: subject to property development speculation logic which forces the increase of urbanized perimeter with low density rates (BRAGA AND RIGATTI, 2009).

CENTRALITY Movement equity along the low hierarchy / control city core allows fuzzy centrality and even co presence of locals and tourists. Social investments target segregation and urban spread patterns deconstruct the once accessible (inclusive to diversified co presence) orthogonal grid structure.The emergent hierarchy is lead by axes that capture movement in and out of the city, favoring new centralities intrinsically linked to vehicular transportation and the suburbia is discontinuous and clustered into up and low market neighborhoods.

The urban structure reproduces complexity, fragmentation and clustering that reflect the weaknesses of national city governance parameters, either subject to political struggles, market laws or discontinuity of urban planning policies.

AXIAL GRAPHS PROCESSED USING MindWalk © Figueiredo, 2002 software

RIVERA / UY SYNTATIC MEASURES (742 axial lines)

The system is smaller and more compact than Santana do Livramento / BR, covering a continuous area through longer axial lines. It spreads by the extension of its longer lines parallel to the border, keeping the orthogonal grid pattern despite local topography.

RN graph RR graphs display similar measures, therefore accessibility is non-hierarchical, the configuration is shallow and permeability is high on local and global scales, what characterizes the orthogonal grid dominating the spatial system. Co presence between locals and strangers (HILLIER & HANSON, 1984) and indistinctive locational patterns of land use are consequent to the configuration non-hierarchical character (FIGUEIREDO & AMORIM, 2007) what allows fuzzy centrality along the urban area.RN and RR distinctions are credited to the system longer lines that connect the urban core to the road network and its new suburbs.

RIVERA / UY CONFIGURATION ANALYZIS

FAST CHOICE highlights a centrality hierarchy given by the system’s cross-shaped longer axes: one perpendicular to the borderline (symbolic uses, duty free shops), the other parallel to the borderline provides main access to newer and peripheral housing estates and is a local centrality . It also highlights the most important international road connection linking Livramento “dry port” to Montevideo.

SYNERGY & INTEGIBILITY are high, while the system’s mean depth is lower. These data are consistent Latin America cities typology (MEDEIROS & HOLANDA, 2007), which is based on the orthogonal grid.

CENTRALITY is scattered amidst the whole orthogonal grid due to its indistinctive locational patterns and functions as the city social life core. New peripheries, designed to absorb migrant rural population answers to a segregative spatial logic, where social differentiation comes from the opposition rural / urban recent background.

Urban planning focuses mostly in the improvement and qualification of public places within the orthogonal grid and improvement of periphery infrastructure and governmental housing expansions. Unlike its Brazilian counterpart, its centre is not emptied or degraded, land plots and dwellings being more valuable than ever on the city core.

CONURBATION SANTANA DO LIVRAMENTO/ BR-RIVERA / UY

No Axial Lines

Rn max Rn min RR max RR min Integibility Synergy Mean Depth

Santana do Livramento / BR

1128 1,49 0,43 1,66 0,32 0,39 0,62 7,58

Rivera / UY 742 1,31 0,47 3,04 0,35 0,64 0,84 4,97CONURBATION 1889 1,31 0,47 2,15 0,33 0,48 0,67 7,33

Comparative Space Syntax measures / correlations(data: by the author, already published in SSS7, Stockholm, 2009)

AXIAL GRAPHS PROCESSED USING MindWalk © Figueiredo, 2002 software

COMPARING BOTH CONURBATIONS

Santana do Livramento / Rivera conurbation CI < 1 The cities systems are better understood separately due to the morphological contrast

between both urban grids.Rivera has the typical Latin American grid: orthogonal & compact

XLivramento has the typical Brazilian grid: deep, fragmented and disperse

=The conurbation performance is weakened due to contamination by Brazilian typology

CAUSESDifferences on urban spread (RIGATTI, 2011) turn the systems interpenetration weak outside the cores, concentrated on few axes (ring road system);Blurred city limits are only noticeable in the cores, while on both towns newest parts morphological and structural changes become clear, even if the systems interpenetrate. The street system running along the borderline is able to connect the cities without interpenetration, Rivera concentrating most part of the conurbation integration core.

(data: the authors)

CONURBATIONS Mean Rn Subsystem 01

Mean RnSubsystem 02

R - Mean Rn conurbation

CI - Conurbation Index

Integibility Synergy

Santana do LIVRAMENTO / BR RIVERA / UY

0,78142693 1,04 0,850749101 0,930725 0,48 0,67

CHUí / BR CHUY / UY

1,245928 1,572854 1,426498 1,0121378 0,58 0,94

COMPARING THE CONURBATIONS

CHUÍ / CHUY conurbation CI > 1 The strong Conurbation Index validates the systems codependency:

They must be understood as a whole = a conurbation and a continuous urban fabric

CHUÍ / BR RN and RR measures approach Latin American patternsX

CHUY / UY=

CAUSESThe systems interpenetration is high and the conurbation core spreads along both cities.

The axes along the borderline, connecting both settlements grants a large interface between systems. The small size of the system and urban dynamics contribute to reinforce the conurbation character. Rn and RR higher than Brazilian average ones are also important: despite the fact that morphological differences between both cities are noticeable, Chuí / BR is closest to the Latin American samples than to the Brazilian ones, allowing us to think that if we were to pick up a sample from Mercosul borderline conurbations, certainly Chuy-Chuí would set typological parameters.

The cities systems are better understood separately due to the morphological contrast between both urban grids.

Rivera has the typical Latin American grid: orthogonal & compactX

Livramento has the typical Brazilian grid: deep, fragmented and disperse