From Fractal Urban Pattern Analysis to Fractal Urban Planning Concepts - Computational Approaches for Urban Environments - page 12

remained constrained (Bairoch 1985 ). It was the introduction of railways and later
of tramways and suburban railway systems that made it possible to live in one
place and work in another (Rodrigue 2013 ). The outcome was tentacular growth
along public transportation network routes. Motorization changed accessibility
dramatically. Road networks are being improved continuously covering space
ever more uniformly. Increasing areas have come to be affected by that what
is currently called “urban sprawl.” So, if we speak here of “urban sprawl,” we
refer to the phenomenon of more or less uncontrolled urban growth in Western
countries generating mainly low density zones consisting of individual housing,
often localized in former rural areas which have developed since the use of private
cars predominates. Town planners often deplore that growth like this cannot readily
be controlled and that the patterns generated look rather “chaotic,” more like ink
splashes than compact shapes such as circles or squares, which are often thought of
as the geometric paradigms of ancient cities.
Compact forms like circular or square-like patterns minimize boundary lengths
and so are optimal for protecting cities against attack. Yet, even in the Middle Ages,
poorer households often settled outside the city walls along the highways. Within the
walls, land was often reserved with the result that the actual urban fabric looked less
regular than might be claimed. But, of course, this remained a local phenomenon
whereas nowadays urban fabrics form a patchwork of complex clusters connecting
several ancient nuclei.
This contribution focuses first on the spatial distribution of built-up space in
contemporary settlement patterns in Western Europe. We look how built-up space
fills up surface across scales. Only in the last part we consider, in the context of
planning strategies, the intensity of soil occupation, i.e., the degree of concentration
of population in buildings. Hence, except in the last part, we restrict discussion to a
two-dimensional approach.
In particular, we are interested in the extent to which these patterns are organized
around a certain ordering principle. Indeed, despite their irregular shapes, some
research since the late 1980s has shown that, at the macroscale, urban patterns
obey rather precise distribution laws corresponding closely to fractal geometry.
Much basic work on fractal investigations of urban patterns has been done since
the 1980s, in particular by Batty and Longley ( 1986 , 1994 ), by Goodchild and
Mark ( 1987 ), Lam and de Cola ( 2002 ), as well as by White and Engelen ( 1994 )
and the present author Frankhauser ( 1994 ). Subsequent publications have deepened
the methodological aspects and confirmed the value of this approach (e.g., Batty
and Kim 1992 ; Batty and Xie 1996 ; Frankhauser 1998 ; Benguigui et al. 2000 ;
Shen 2002 ; De Keersmaecker et al. 2003 ; Frankhauser 2004 , 2008 ; Thomas et al.
2008a , b , 2010 , 2012 ;Chen 2009 , Chen and Feng 2010 ).
Thereafter, the focus shifts to particular features of fractal geometry liable to
provide a better understanding of the spatial properties of such urban fabrics. This
leads us to ask to what extent the emerging fractal shape of urban patterns cannot
inspire planning concepts designed to manage peripheral urbanization intelligently
without dismissing it a priori (Frankhauser 2008 ; Frankhauser et al. 2011 ). This will
be done by introducing a planning concept inspired by fractal geometry.