An integrated decision aid system for the development of Saint Charles River alluvial plain, Quebec, Canada

We describe an integrated decision aid system designed to assist land-use planning and management of the alluvial plain of Saint Charles River, Quebec. The first stages of the development of the system consisted in building a georeferenced database managed by a geographical information system (GIS), and to elaborate eight different development scenarios along the Saint Charles River in a multiple decision-maker context. Multicriteria analysis (MCA) was then used to evaluate and compare the scenarios according to eleven criteria, using a combination of GIS analysis with Mapinfo and multicriteria processing carried out in PROMCALC & GAIA 3.5. This process leads to a partial ranking (PROMETHEE I) and a complete ranking of the scenarios (PROMETHEE II) for each individual decision-maker as well as for the whole group. We show that this approach helps multiple decision-makers to reach rational decisions based on scientific data and political considerations.