Toward an Integration of the Fuzzy Logic and MCDA to GIS: Application to the Project of the Localization of a Site for the Implantation of Chemical Products Factory

The implementation of a new urban infrastructure causes more and more conflicts mainly because of the correlation of actors coming often from opposed different domains, such as the political, the social, the economic, and the spatial one. To help the decision makers in the territory management, several actors have shown the adequacy of the association of the geographical information systems (GIS) and the multicriterion decision aid (MCDA) methods. This association not only permits to manage the spatial reference information but also to apply new analysis methods permitting to have the most pertinent and most profitable information. However, most problems of MCDA take into account not only the traditional quantitative criteria, but also the qualitative and imprecise criteria, which make their use difficult for the decision and analysis. We propose in this paper, a hybrid model of MCDA for the localization of a site for the implantation of a chemical products factory. This model enables us to combine the use of the multi-representation geographical information systems (MRGIS) and the MCDA methods, such as AHP (analytic hierarchy process). Then, to facilitate the interpretation of the qualitative data in our model, we propose an approach of data modelling based on the fuzzy set theory, which makes it possible to interpret the qualitative values by precise values rather than by classical intervals.