the convergence of patterns in the city: (isolating) the effects of architectural morphology on...

The convergence of patterns in the city:

(Isolating) the effects of architectural morphology on movement and activity

Vinicius NETTORenato SABOYAJulio VARGASLucas FIGUEIREDOCássio FREITASMaíra PINHEIRO

Universidade Federal Fluminense (NEPHU-UFF)Universidade Federal de Santa Catarina (UFSC)Universidade Federal do Rio Grande do Sul (UFRGS)Universidade Federal da Paraíba (UFPB)Escola Nacional de Ciência Estatística (ENCE-IBGEUniversidade Federal Fluminense (NEPHU-UFF), respectively. Brazil.

CNPq sponsors this research.

This research is about the relationships of distinct urban patterns that constitute the city...

...the city as the result,a synthesis of pattern relations

We shall approach pattern relations in two ways:

FIRST, we shall examine how they converge (or diverge)

SECOND, we shall have a closer look into the effects of a particular pattern over others – namely, the patterns of urban form constituted by ARQUITECTURAL FORM

Theoreticalframework

Key geographical and urban theories have approached cities as relations of patterns

Spatial EconomicsVon Thünen (1826) Agricultural location [regional]A. Weber (1909) Industrial location and distance [regional] time-distance and locationHansen (1959) "How accessibility shapes land use" [intra-urban]Alonso (1964) bid-rent model [intra-urban]retail location theory, etc

Configurational studiesHillier and Hanson (1984) The social logic of space – encounter, solidarities and spatial configurationHillier et al (1993) Pedestrian movement and urban configurationKrafta (1994) Acessibility, centrality, distribution of attractorsHillier (1996) Cities as movement economies, configuration and retail distribution, etc

Alonso’s bid-rent model (1964)

Spatial Economics

These approaches imply that cities acquire intrinsic properties as signs of a successful convergence of patterns.

Global Integration – Berlin [reunified 1999][Desyllas, 2000]

Space syntax

Office location in Berlin [1991-1997] [Desyllas, 2000]

Each pattern may be seen as an emergence in its own right.

They have distinct roles, from the material conditions of daily actions in social reproduction to spatial production.

they have a dual relation to each other, being influenced by them on the one hand, and changing and shaping them on the other.

Relations look like a teleological process: cities seem geared to pattern.

The convergence of patterns in the form of the city

The production of street networks internally differentiated into accessibility patterns – a highly durable and stable structure

The slow temporality of built form production and replacement – Densities which express and support activities

The occupation of buildings finds its own distribution pattern: Activity location. Activities last from days to years, even centuries

Patterns of actions unfolding in a city are recognizable as movement patterns connecting activity places. Emergence is fast – similar patterns of pedestrian movement emerge everyday and adapt quickly to changes in location, densities or streets

The convergence of patterns in the form of the city: TEMPORALITIES

These theories were successful in bringing to light the convergence of these four patterns.

Theories seem to assume that interrelations and mutual dependences would lead to progressive convergence in time.

Patterns mutually related in a meta-pattern – emerging in the form of the city itself.

The convergence of patterns in the form of the city: the CONVERGENCE ASSUMPTION

Spatial studies highlight aspects of convergence … to a point that convergence is taken for granted…

Behind theses assumptions lie risks of a non-dynamic understanding of the different materialities and processes at play in the city creation process.

The complex tension of mutual dependence and conflict between patterns is overlooked… differences are rendered unproblematic.

However…

Does convergence happen all the time for every city or area? What if patterns were prevented from full convergence? Is there any room for divergence or “dissonance” between

patterns?…what if we focus on what lies before or beyond convergence…?

Dissonance between accessibility and pedestrian levels

USUAL REASONS FOR SUCH DISSONANCE:

…Weaker densities in areas with high accessibility may reduce movement allowed by the grid.

….specific architectural types could offer poor support for retail activities potentially demanded by pedestrians.

Growing cities may have shifts in accessibility cores along with slower changes in density patterns.

Souce: Linconl Institute

these questions provide a framework for further analysis

We would like to challenge usual theoretical positions.

Our work addresses the differences between patterns – their non-correspondence – and aims at explaining which factors may be active there.

Our hypothesis is that, despite a potential trend to alignment in such dimensions, dissonance is always already at work, preventing full convergence

We propose a methodology able to indicate the stage of convergence / dissonance of patterns and allow the analysis of their behaviour in time. a thought experiment on convergence bringing the relation between time of urbanization and urban patterns in a theoretical city. Hypothesis examined through sets of correlations between distributions of accessibility (Acc), densities (Dens), pedestrian movement (PM), activities (Act) along with Age of different areas.

correlations could help clarifying states of pattern convergence.

HYPOTHESIS OF CONVERGENCE / DISSONANCE


Quantifying normalized levels of Acc, Act, PM and Dens in an urban system allows comparison of patterns and assessment of STATES OF CONVERGENCE / DISSONANCE

Results may show whether convergence is or is not an evolutionary process.

process may happen in cycles, consistent with descriptions of self-organized criticalityconvergence is likely to increase and fall in cycles in time, without ever becoming complete

distance

IN TIMEIN SPACE


CONVERGENCE IN SPACE:Distributions normalized in intensity indexes [0-1] as a function of decreasing accessibility in three levels

distance

Visible forms of dissonance Distinct curves amounting into different patterns

Different intensities: similar curves, different peaks.

distance

EMPIRICAL CASE:1. Overall strong dissonance between accessibility and other patterns.

2. Areas within the first range have higher dissonance (low densities and high accessibility). Reversion in the third range

distance


CONVERGENCE / DISSONANCE IN TIME:Correlations of patterns varying as cities or urban areas age

The problem of Time and Convergence

Pearson’s correlations between pairs of urban patterns show a complex tendency to increase as urban areas age. Correlations peak in Copacabana, with decrease in areas around 120 years…

…Dissonance perhaps due to accessibility levels higher than density, changing or approaching criticality.

dissonance X convergence: complex interplay

intraurban densification X peripheral growth areas reach stability and others decay; areas or whole cities may go through fast change.

The city as convergence of patterns: observations

A perfect overlapping of patterns could only be the case if:

SOCIALLY: agents were capable of complete coordination of collective actions, and capable of shaping the physical world accordingly.

COGNITIVELLY: agents were capable of perfect diffusion of information (omniscient agents) and optimal distribution in urban space.

SPATIALLY: spaces were able to change continuously as the arrangements of practice and urban activities changed and demanded changes in location and density.

Of course each of these conditions is ontologically impossible. It could only be possible in a liquid world, where materially different systems

could shape one another all the time.


Distinct urban processes fail to fully project themselves into each other – inexorably.

Full convergence is never completely achievable:

complex social-spatial interactions

collisions of materialities and temporalities of distinct urban processes

Contextual contingencies [geographical constrains, culture]



In different cities:

Convergence asserts similarities among cities.

Dissonance, on the other hand, emerges from contingencies of misinformation, decisions about architectural form, land uses; it relies on lesser or greater coordination. Emergent dissonances are related to whatever prevents cities from looking alike; they produce idiosyncrasies we identify in every city

DISSONANCE BRINGS ABOUT DIFFERENCES– IT IS KEY TO THE IDENTITIES OF CITIES

This method analyses relations of patterns in the city and explores possibilities in modelling and isolating them

It raises questions about major axioms of spatial approaches: Looking at the empty spaces in between patterns, we suggest that

dissonances are as important as the unproblematically assumed telos of convergence.

rather than seen unproblematically,

the relationship between patterns in the city creating process

should be held as a key theoretical problem.


examining dissonances: a particular set of relations of patterns

We intend to address a classic question in architecture and urban studies and design:

can buildings affect what happens around them? Would distinct architectural morphologies have

distinct effects over local social and economic processes?

Or more broadly: does architecture matter to the vitality of streets and public life in the city?

[Rio de Janeiro: Centre

Fonte: Google Street View

[Rio de Janeiro: Barra da Tijuca

The dissolutions of pattern of urban and architectural form

Similar thinning out of streets’ social uses(pedestrian movement, microeconomic activities)

Potential undesirable consequences to the city(vehicular dependence, empty streets, spatial segregation, insecurity])

Rio de Janeiro: Centro, Jardim Oceânico,Barra da Tijuca Fonte: Google earth

HYPOTHESES

Local positive effects:•Nearer interface relationships among pedestrians and microeconomic activities.

Local effects:•Promotion of retail activities;•Interface with street weaker than (a)

HYPOTHESES

(a) Contiguous buildings (b) Detached buildings (c) Hybrid buildings

Local negative effects•Increase in distances between buildings:•Dispersion of ground floor retail and services.

Different typologies have different effects on the urban vitality of public spaces

More specifically, our hypothesis is that, properties like accessibility and density being equal, type (a) would respond more adequately to both social and microeconomic life at the local scale.

Our hypothesis also points to the possibility that type (b) would have opposite effects to (a) as a function of how large are the setbacks from the plot’s limits, distances between buildings and from buildings to the sidewalks.

HYPOTHESES

Method

Architectural, economic and social variables

KEY: In order to test these hypotheses, we needed a way of disentangling the effects of accessibility on local socioeconomic variatbles from those of the architectural typology.

Some alternative methods were considered:

(a) Differential of accessibility(b) Analysis of aggregated effects(c) Accessibility ranges(d) Statistical variance

METHOD

CONTROLLING ACCESSIBILITY

We try to maintain accessibility as constant as possible in our samples in order to minimize the effects of the grid…

….while examining distributions of typologies and socioeconomic variables [correlations].

METHOD

Nevertheless, controlling for the influence of accessibility in urban vitality features is not an easy task:

Accessibility is a complex property active on a number of scales

and can be measured in several different ways.

Space syntax measures seem adequate as proxy for accessibility at the fine scale we are interested in.

But which measure, radius and spatial unit should be used?

METHOD

Choice

Integration RR

METHOD

Integration RR Integration R3

METHOD

Local integration ranges were more scattered over the system than global ones.

three dilemmas shared a same underlying issue: the degree of clustering of spatial units within one given accessibility range.

Hypothesis included synergies of architectural form, acessibility and local socioeconomic events – a certain degree of clustering was desirable.

We opted for:

Measure: IntegrationEntity: Axial lineRadius: RR

Local radii was explicitly considered as an independent variable and statistically tested.

METHOD

Which accessibility range(s)?:

FIXING ACCESSIBILITYLEVELIntegration values sliced in 20 levels from which we chose three different and nearly constant levels (high, medium and low).

Which accessibility range(s)?:

Rio de Janeiro

Accessibility Ranges Population

Range 7 Range 11 Range 17

Control for density: each accessibility range was subdivided into three (broad) ranges of density.

High Medium Low

Rio de Janeiro

Rio de Janeiro: assessing the effects of architectural form on urban vitality

In order to define the set of axial lines to be analysed empirically, we divided areas defined through accessibility ranges in sectors with a minimum number of segments, and picked randomly a sample statistically appropriate.

Our study involves twenty-four areas in Rio de Janeiro. A number of segments should be analysed in each combination of accessibility and density ranges

9 Setups:3 Accessibility Ranges x 3 Density Ranges

RANGE 7104 segments1574 plots



Rio de Janeiro

Effects of building typology on local socioeconomic processes

PRELIMINARY RESULTS

Accessibility range 7 – Pearson’s correlation coefficient for 101 segments.

All accessibility ranges – Pearson’s correlation coefficient for 249 segments

Three variables seem to contribute most positively with movement, controlling for accessibility:

retail on the ground level window density open plot

Other strong variables are:

retail plus services economic unit density building height diversity in upper floors

Mostly associated with the Contiguous building type

PRELIMINARY RESULTS

The most negative variables in relation to movement, controlling for accessibility:

residential activity on the ground level Front walls Low window density garage door density

Mostly associated with the Detached building type

PRELIMINARY RESULTS

Correlations of architectural types to social dependent variables decrease in higher accessibility levels.

However, there is the problem of dissonance: in Rio, the core of higher accessibility changed due to recent expansion towards north and west.

So we can neither assert that distinct levels of accessibility are forces at play in reducing the effects of types, nor that dissonance is an exclusive factor in lowering correlations.

We need to analyse more cities.

PRELIMINARY RESULTS

We attempted to “collide” – statistically – a large number of urban components in order to see what combinations may correspond to the chemistry of urban vitality.

Although analysis is still ongoing, preliminary results seem to point to consistencies in the relation of certain architectural features and local socioeconomic variables.

different architectural types tend to have nearly reversed effects

Results suggest that the contiguous type is not an exclusive factor of urban vitality, as it may support both commercial and residential activities (the latter has strong negative correlations with dependent variables), but it is a condition for architectural features that matter.

conclusions

conclusions

severe implications for current trends in cities in Brazil and elsewhere, where architectural types poorly related to urban life become dominating

Whole areas in our cities become less walkable due to growing distances and the progressive disappearance of local activities that support daily life.

Our work hopes to contribute to the diagnosis of problems in urban performance, i.e. the relation of urban processes to architectural form…

...in other words, which architectural types are more efficient in supporting the diversity of activities and uses of public spaces – key

issues in the urban sustainability debate.

Porto Alegre

Florianópolis

Rio de Janeiro

João Pessoa

FURTHER EMPIRICAL WORK

the convergence of patterns in the city: (isolating) the effects of architectural morphology on...

Documents

movement patterns

city slide

patterns of urban form

accessibility patterns

arquitectural form slide

activity location

centuries patterns of

distribution pattern