Valerio Cutini and Giovanni Rabino on "The urban growth: development, sprawl and spatial configuration"

1. Valerio Cutini
Giovanni Rabino
The urban
growth Development,
sprawl and spatial configuration
Seventh International Conference on Informatics and Urban and Regional Planning
Cagliari, 10-12 May 2012

2. Contents
valerio cutini
giovanni rabino
Introduction
The configurational approach, in short
Urban development and configuration
Some case studies
Conclusions

3. Would you draw a city?
valerio cutini
giovanni rabino

4. Our thesis
valerio cutini
giovanni rabino
The connections are assumed as the primary
to be assumed as the
raison d’etre ofd’etre of the city
primary raison the city
The relation between the activities and the
urban grid is its actual making mechanism
The genesis of an urban grid appear to follow
appears to follow
some constant and recurring dynamics, which
materialize in its spatial relations
Such dynamics can be revealed by
means of a configurational approach

5. Configuration and morphology
valerio cutini
giovanni rabino
Lorini
In a configurational approach, as focused on the
relations between spatial elements, any
geometric and morphologic feature vanishes
system graph
Scamozzi

6. Contents
valerio cutini
giovanni rabino
Introduction
The configurational approach, in short
Urban development and configuration
Some case studies
Conclusions

7. The configurational approach
valerio cutini
giovanni rabino
Three assumptions can be recognized at the root of
the configurational approach to the analysis of
urban settlements
The decisive influence of urban structure on the
phenomena occurring inside
The importance of the perceptive appraisal of
space in the behavioural choices of its users
The assumption of the urban grid as the primary
element of the urban structure

8. The configurational analysis
valerio cutini
giovanni rabino
The configurational analysis of an urban settlement
can be summarized as follows
Definition of the urban grid
Reduction of the urban grid into a system of
connected spatial elements
Computation of the spatial relation between the
elements
Determination of the parameters that represent
the relational state of the system
configurational indices

9. Some configurational indices
valerio cutini
giovanni rabino
connectivity
The number of spatial elements connected to the
observed one
integration
The mean topologic distance (depth) from all the
other elements of the system
global integration local integration

10. The configurational techniques
valerio cutini
giovanni rabino
The way of reducing the urban grid into a system is the
distinguishing element of the several operational techniques
axial analysis visibility graph analysis
spatial
lines vertices
elements
connection elements points uniformly distributed all
between convex spaces over the grid
relation intersection mutual visibility
system axial map visibility graph

11. Axial analisys and VGA: Siena
valerio cutini
giovanni rabino
The integration value in the lines
of the axial map
The urban
grid
of Siena
The integration value in the
vertices of the visibility graph

12. Configuration and activities
valerio cutini
giovanni rabino
Siena
The configuratrional analysis is
The results show a
hence proved suitable for
narrow(esponential)
reproducing the distribution of
correlation between the
Volterra the levels of centrality within
density of activities and the
an urban settlement
integration value

13. Contents
valerio cutini
giovanni rabino
Introduction
The configurational approach, in short
Urban development and configuration
Some case studies
Conclusions

14. A small example
valerio cutini
giovanni rabino
Integration value
64 lines
Correlation of
local integration
versus
global integration
3.88512
3.11819
3.02162
2.83209
4.60934 R² = 0.999461
0.628534
0.787503
0.866043
0.941414
1 line
32 lines
16 lines
256 lines
128 lines
Integration [HH] R3
0.422392
0.824669
0.795544
0.617794
0.590638
0.624947
0.872037 Integration [HH] 2.50006
2.33192
2.27936
2.48376
4.60934

15. Contents
valerio cutini
giovanni rabino
Introduction
The configurational approach, in short
Urban development and configuration
Some case studies
Conclusions

16. The diachronic genesis of Grosseto
valerio cutini
giovanni rabino
Distribution of integration
value in Grosseto in the
period 1825-2005
(axial analysis)
1935
date 1825 1910 1950 1980 2005
nr. lines 78 109 367 487 629
CM 15.5 11.6 7.2 7.0
1825 5.7 1975 1960
Imin/Imax 0.28 0.34 0.38 0.40 0.42 2005
R2 (Iglo/Iloc) 0.89 0,83 0,82 0,76 0,59

17. The diachronic genesis of Pisa
valerio cutini
giovanni rabino
Distribution of integration
value in Pisa in the
period 1825-2005 1910
1980
(axial analysis) 1950
1825
2005
date 1825 1910 1950 1980 2005
nr. lines 371 455 637 936 1159
CM 9.65 8.43 8.30 7.13 6.64
Imin/Imax 0.28 0.28 0.34 0.33 0.37
R2 (Iglo/Iloc) 0.87 0.82 0.64 0.64 0.57

18. Findings. 1
valerio cutini
giovanni rabino
As the system dimension increases from its primigenial
core, the connectivity mean value decreases
As the system dimension increases, the ratio Imin/Imax too
increases
As the system dimension increases, the R2 value in the
correlation of local integration versus global integration
progressively decreases
Grosseto Pisa
Any development of the grid involves the addition of new
lines, mostly in the outer ring, whose main features are
poor values of connectivity and global integration, but not
necessarily poor values of local integration
nr. lines nr. lines

19. Findings. 2
valerio cutini
giovanni rabino
The growth of a settlement involves the development of an
inner core, generally characterized by high values of global
integration and connectivity, as well as new development
areas, characterized by poor values of the same indices
If we assume connectivity and R2 as indicators of the
resilience of the system, we can regard the inner core as
the place of urban resilience, while the edges of the
urban area can be regarded as the place of urban frailty
Such spatial notions appear changing right along as the
settlement grows, in that the edges get progressively
more resilient as new development areas are added

20. Contents
valerio cutini
giovanni rabino
Introduction
The configurational approach, in short
Urban development and configuration
Some case studies
Conclusions

21. Conclusions
valerio cutini
giovanni rabino
Cities appear as dendritic systems, irradiating from their
inner core to the farthest development areas
Their spatial structure seems to be induced by a general
principle of optimization, aimed at urbanizing new areas
and connecting them to the existing settlement
Some configurational features appear so recurring as to
characterize the new areas with respect to the pre-
existing ones
In such view, even the common notions of periphery and
sprawl can be interpreted as the material appearance of
a system of spatial relations in its ongoing evolution

22. valerio.cutini@ing.unipi.it
giovanni.rabino@polimi.it
Thank you