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Third International Workshop on "Geographical Analysis, Urban Modeling, Spatial Statistics"
Citation preview
Valerio [email protected]
The periphery as a spatial The periphery as a spatial patternpattern
Working on the edge Working on the edge of townof town
The International Conference on Computational Science and its Applications
Università di Pisa - Dipartimento di Ingegneria Civile________________________________________________________L.I.S.T.A. – Laboratorio di Ingegneria dei Sistemi Territoriali e AmbientaliL.I.S.T.A. – Laboratorio di Ingegneria dei Sistemi Territoriali e Ambientali
ICCSA 2008 – Perugia, June 30th- July 3rd
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
In the common sense, the notion of periphery generally refers to several different meanings
marginalization
physical distance
landscape uniformity
functional weakness
poor land values
few public facilities
economic depression
segregation
physical distance
criminality
The notion of The notion of peripheryperiphery
References like that appear to share nothing but a negative meaning
The periphery as an urban disease
The periphery as a problem
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
Here, the notion of periphery will be approached in a configurational mode
A configurational approach to A configurational approach to peripheryperiphery
Such a view, though partial and not exhausting, allows a better comprehension of several questions
The periphery as a spatial process, depending on the configuration of the urban grid
How do urban areas get peripheral
How can we do to redevelop such areas
Which urban areas can be said peripheral
Which spatial pattern characterises such areas
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The thesis we aim at verifying is that
The The thesisthesis of this research. 1 of this research. 1
Not only the position of an urban area with reference to the located activities,
spacedoes matter
but also its spatial pattern with reference to the whole urban grid
and even its intrinsic spatial features
actually influence the way the space itself is used, and concur in determining its level of marginality
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The base of configurational theory
Configurational analysis could hardly be considered as a general urban theory
We’d better regard it as a complex of techniques based
on two different points of view over urban phenomena
The assumption of the urban grid as the primary factor
in the formation of movement
in the location of activities
valerio cutini
The interest towards the urban grid with regard to its configuration
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
It’s the structure of the paths of an urban settlement what dictates the distribution of traffic flows and then, as a consequence, the preconditions for the activities location
The urban grid, hence, implicitly contains the vocation of each area to house activities, according to the benefit they derive from the presence of traffic
The base of configurational theory.The urban grid
valerio cutini
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The urban grid merely provides the spatial impedance between couples of activities
Configurational vs interactional logic
Configuration of the urban grid
Distribution of movement and activities
input output
The urban grid is the primary element in movement production and in activities location
Consistency and position of the located
activities
Flows distribution and intensity of mutual
interactions
valerio cutini
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
To analyse the configuration of an urban grid means to define the characteristics of each of its spaces as resulting from the
relations connecting it to all the other parts of the grid
In a configurational approach, each space in a settlement is appraised on the base of its connections to all the others
Down to the facts, it means to define, for each single element of the system, a set of numeric values correspondent to its configurational indices
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The base of configurational theory.The configuration
The relation between any two spaces depends on their relations to all the other spaces in the system
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The solution of the configurational problem
The solution of the configurational problem follows the following logic
The model is processed
The configurational indices, output of the model, are determined
The urban grid is reduced into a system
axial map
visibility graph
Axial analysis
V.G.A.
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XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The axial analysis
In axial analysis the system to analyse is the axial map
A complex of lines (the longest and fewest ones) that connect all the convex spaces of the grid
The most significant configurational parameter, that we recognise capable to reproduce the distribution of natural
movement (and hence the attractiveness towards activities), is the integration value
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The mean depth of a line from all the other lines of the axial map
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The solution of the configurational problem. An example : Siena
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From the urban grid ... to the axial mapto the distribution of integration value
Siena
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
A different configurational technique: the VGA
As a matter of fact, the operational Space Syntax techniques show some limits
some subjectivity in the construction of the system
the invariability of each configurational index all along the line
Since the late ’90s a different configurational technique has gone arising, so as to overcome such limits: the Visibility
Graph Analysis
the insensitivity towards the role of the open spaces
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XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
On the basis of the same configurational approach, the VGA is characterised by the way the system to analyse is actually constructed
In Space Syntax, the system is assumed as a set of intersected elements (lines), which connect the convex spaces of the grid
In VGA, the system is constructed as a mesh of points (vertices) in mutual visual connection
The only discretionary element in the construction of the system is the density of the vertices, that’s to say the detail
level we expect on the results
The VGA: featuresvalerio cutini
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
The configurational techniques.A small example: Palmanova
From the urban layout… … to the urban grid
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
An example:the linear analysis of Palmanova. 1
From the urban grid … … to the axial map
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
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An example:the axial analysis of Palmanova. 2
From the axial map … to the distribution of integration value
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
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An example:the VGA of Palmanova. 1
to the distribution of integration valueFrom the visibility graph…
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
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An example:the VGA of Palmanova. 2
to the distribution of clustering coefficientFrom the visibility graph… to the distribution of neighborhood size
K < 1.01.0 < K < 2.02.0 < K < 3.53.5 < K < 5.0
5.0 < K
to the distribution of interaction value
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
Some previous results. The correspondence integration vs activities
SienaThe results show an excellent
exponential correlation between the density of the located activities (resulting
from direct observation) and the integration value, resulting
from the processing of the map
Volterra
Such results prove configurational analysis capable to reproduce, by means of the
integration value, the distribution of the levels of
attractiveness within a settlement
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The thesis is that an edge urban area, commonly recognised as peripheral, is actually characterised by a specific
spatial pattern
The The thesisthesis of the research. 2 of the research. 2
Those features, setting aside any social, historic, economic functional and architectural aspect, allow to recognise such
areas as peripheral
Configurational analysis, as based on merely spatial elements, allows an easy identification of those
elements
Moreover, on such basis we can identify the possible ways
of removing the spatial factors of marginalization, so
as to mitigate them
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
As our case studies, we’ve here selected the urban settlements of Pisa and Leghorn, with reference to their edge areas
valerio cutini
Our case studies
More in detail, we’ve analysed the social housing areas, focusing with specific attention on those commonly
recognised as suffering from segregation and urban disease
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
The first case study: Pisa and its social housing settlements
1925-1940 1950-1965 1965-1980 1980-1995
“I Passi”
“Gagno”
“CEP”
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
The axial analysisof Pisa. 1
to its axial mapFrom the urban grid of Pisa…
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
The axial analysisof Pisa. 2
to the distribution of integration valueFrom the axial map of Pisa…
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
Pisa: the selected areas and their configurational pattern
“CEP”social housing area
Axial map of Pisa Distribution of global integration value Distribution of local integration value
“I Passi”social housing area“Gagno”
social housing area
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
Pisa: the selected areas and theirlocal configurational pattern. 1
valerio cutini
“CEP”social housing area Axial map of Pisa
“I Passi”social housing area
“Gagno”social housing area
Distribution of integration value
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
Pisa: the selected areas and theirlocal configurational pattern. 2
K < 1.01.0 < K < 2.02.0 < K < 3.53.5 < K < 5.0
5.0 < K
“Gagno”
Distribution of interaction value K
“I Passi”“CEP”
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
The second case studies: LeghornThe axial analysis. 1
to its axial mapFrom the urban grid of Leghorn…
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
The axial analysis of Leghorn. 2
to the distribution of integration valueFrom the axial map of Leghorn…
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
Leghorn: the “Corea” area. Global and local configurational pattern
Distribution of global integration valueAxial map of Livorno
“Corea”social housing area
“Corea”social housing area
Distribution of local integration value
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
valerio cutini
Leghorn: the “Corea” and “La Rosa” areas. Local configurational pattern. 1
Distribution of integration valueAxial map of Livorno
“Corea”social housing area
“La Rosa”social housing area
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
Leghorn: the “Corea” area. Local configurational pattern
valerio cutini
Distribution of interaction valueAxial map of Livorno
“Corea”social housing area
K < 1.01.0 < K < 2.02.0 < K < 3.53.5 < K < 5.0
5.0 < K
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
Leghorn: the “La Rosa” area. Local configurational pattern
valerio cutini
Distribution of interaction valueAxial map of Livorno
“La Rosa”social housing area
K < 1.01.0 < K < 2.02.0 < K < 3.53.5 < K < 5.0
5.0 < K
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
The The configurational patternconfigurational pattern of the edge areas of the edge areas
On the basis of the results so far, the analysed edge areas appear to share some configurational features
Poor mean values of global integration
The lack of strong local integrators
A weak hierarchy in the distribution of local integration (sameness of IR3 values)
The lack of strong interaction spaces (poor K values)
on a global on a global scalescale
on a local on a local scalescale
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
ConclusionsConclusions
Such results give use a hint for possible lines we can guess, while discussing redevelopment plans on urban edge
areas
To increase their mean global integration
To set up some strong local integrators
To modulate the distribution of local integration so as to establish a marked hierarchy
To set up some prominent interaction spaces
on a global on a global scalescale
on a local on a local scalescale
XXV Conferenza Nazionale A.I.S.Re. - Novara, 6-8 ottobre 2004
Thank youThank you
[email protected]@ing.unipi.it