Three different conceptual and theoretical issues are at stake in this research program:
- What is an inhabitant in a given place ? The inhabitated space is approached through an adequate measure of the density of population. In order to measure density of inhabitants we need to overcome one of the problems of classical census data in a society of mobile individuals: they give information on mere residential density. More than ever, an inhabitant of a city is not only a dweller nor an employee, but also a consumer, a tourist, a stroller, a congress attendant, a student, and so on. The notion of "density" needs to be explored, in order to be used as in a comprehensive approach of density, by measuring not 'bodies' but different spatial roles a given individual can play successively. The hypothesis tested here is thus the possibility of constructing a synthetic indicator of density, theoretically more consistent than the classical density conceptualisation. It allows implementation in cartogram representations. [module 1]
- How to represent cartographically the contemporary inhabitated space ? The choice of the cartographical representation is crucial. It guides the interpretation of the processes of urbanisation in terms of sustainable development. Here, the cartogram principle (non-Euclidean anamorphoses of the background based on a given series of data) will be used to design a general, versatile software supposed to be implemented in any geographical situation. [module 2]
- How to model the human acting with the city ? The basic idea is to open up the 'black box' of actors' strategic perspectives in order to model urban dynamics. The hypothesis is that of a small number of consistent ideal-types of individual strategic schemes whose concrete choices in terms of location and mobility will modify urban areas. This means that economic and political factors that compose the context of individual decisions must be taken into account, but precisely as a context. The theoretical basis is that of an actor-centred perspective, in which the various alternatives explored by the model should distinctly encompass, on the one hand, the different possible configurations of this societal context and, on the other hand, the diversity of individual attitudes and responses. Indeed, context changes affect the inputs of the actors' decisions but not directly. These external inputs are always filtered and interpreted inside one of the actors' ideal-typical strategic schemes.