Geoscience Reference
In-Depth Information
cell for which transition is being considered. In other works, it is the geometry of the
cells itself, with the construction of polygons with varied shapes, that is adapted to
the empirical cases being studied. Such is the case of the models developed by
Benenson et al. [BEN 02] and Moreno et al. [MOR 09] to simulate the emergence
and the evolution of a segregation process, in the case of Yaffo for the first, and of
Pau for the second. Used in the environmental field, CA have also been adapted in
order to be applied to empirical cases. Thus, Douvinet et al. [DOU 08] use the
RuiCells model to study the influence of the morphology on the hydrological
behavior of watersheds. In this model, the transition rule simulates the displacement
of a stream from one surface to another, depending on the morphology of the terrain
that creates a “roadway” following the principles governing liquid flows (water or
mud). This model has been used to construct, from simulations, synthetic indices of
the potential dynamics of a watershed [DOU 08].
Finally, the CA are often coupled with other methods. Already in the 1990s,
Couclelis [COU 97] stressed upon the benefits of coupling CA with geographical
information systems (GIS). Some environments of development of CA are coupled
with GIS and incorporate their leading features, which makes it possible to import
the geography of observed situations for designing the initial state of the studied
system. This coupling also helps to evaluate the different states produced during the
simulation by comparison with the states of the analyzed territory. In this case, the
applications have operational objectives. This is the example developed by Dubos-
Paillard et al. with the SpaCell automaton (©Langlois 9 ) [DUB 03], to analyze the
urban evolution around Rouen between 1950 and 2000. Three maps are integrated in
the CA: 1950, 1966 and 1994, that describe the land occupation in 15 categories on
a grid of resolution of 150 m. The authors identify two distinct processes of urban
growth: densification over the first period, and urban sprawling over the second
period. The CA is developed with the objective to reproduce as precisely as possible
the observed spatial organizations and, thus, bring out specific types whose
behaviors escape the logic of change integrated in the CA. This is the case of some
major public housings, for which the CA does not reproduce the implementation.
Phipps and Langlois proposed, on their part, coupling the CA with an aggregated
dynamic model [PHI 97]. Engelen et al. [ENG 99] combine these two forms of
coupling by inserting their initial CA model between a GIS providing the initial
situation of the land use at a fine scale and a dynamic model at an aggregate level
managing the change of land uses at the macrogeographical level. Once the total
number of cells of a certain land use is known, the geographical distribution of this
stock is then governed by the CA.
9 Langlois P. http://www.spatial-modelling.info/cellular-automata-spacelle.
Search WWH ::




Custom Search