1. Workshop on Land Accounts and urban morphology, ETC-CE, 12 july 2006
A classification of European urban areas on a double scale of compactness
Marianne Guérois
Université Paris 12, C.R.E.T.E.I.L.
Associated to UMR Géographie-cités, Paris

2. Ph-D in 2003 : How to characterise the compactness level
of European agglomerations in a comparative way ?
> A unique model of « compact city »
VS diversity of urban shapes throughout Europe ?
CLC well-suited to staging comparisons often impeded
by heterogeneous nature of source of information

3. What are the main determinants of areal extent contrasts ?
Built-up surface =
an elementary and relevant
estimate of the
absolute degree of sprawl
Urban areas
> inh. in 1990

4. How does areal extent vary when population size increases?
Strong correlation with population size, even within a cross-national frame
Linear fit : +1,5 km² per inh.
Residual values highlight trends towards sprawling or compact extensions

5. Tendencies to compactness, tendencies to sprawl
On a European scale,
a south-to-north gradient
Predilection for urban values
inherited from Latin culture?
Spatial diffusion process
of peri-urbanisation?
National determinants :
Dutch agglomerations
A careful link to national planning features
Local « perturbations »
Influence of topography but not
only…

6. A second dimension of morphological compactness :
The urban « footprint »
To complete areal extent and population density approach,
a comparison of built-up global design (> inhab. in 1990)
Three significant features :
Elongation Digitation Indentation
How to convert qualitative descript°
into numeric expressions ?

7. How to quantify shape variations ?
A selection of indices
> Ratios between elementary
parameters (area, perimeter,
Longest axis …)
> Values range from
0 (linear or digited shape) to
1 (circular shape)
Limits ?
> Circle as an absolute reference
> Some measures remain
ambiguous

8. The need for a combinaison of indices
A test on schematic shapes
Results of the multivariate analysis (PCA) :
> Axis 1 (79%) = global distance to the circle feature
> Axis 2 (16%) = linear VS digital shapes
=> Each specific pattern can be identified by a set of indices

9. Extreme positions of agglomerations for each index

10. A typology of agglomerations extension patterns
Cluster analysis
6 relevant types of shape
No regional consistency
Strong influence of
topography, but also…

11. 2 dimensions of compactness

12. 2 dimensions of compactness
No correlation
between those two
dimensions of compactness
Must be crossed

13. CONCLUSION Crossing these two dimensions of morphological
compactness provides original framework to compare
the shape of European agglomerations
CORINE Land cover potential regarding urban
analysis at this scale
… A careful link between morphological features
and normative discourses about sustainable cities
… what description for suburban extents ?
… The need for a state of the art about classification of European cities shapes