Résumé : For a little over twenty years, researchers have worked on integrating multi-criteria aggregation procedures (MCAP) to GIS. Several notable contributions have brought this field to what it is today. After studying the course of MCDA-GIS integration through several works, we question the future of such an attempt. Indeed most works that aim for an integration do not survive long after their direct purpose has been fulfilled. We end up understanding through a critical review of the existing systems that technical integration means nothing if it is not visible to the user on an operational level.

We therefore propose several contributions to improve the usability of MCDA methods in a geographic context. One of our works consists in adapting the PROMETHEE-GAIA methodology to be used on maps for spatially referenced problems. To do so, we define symbols/glyphs that display select parts of the results obtained through the PROMETHEE and GAIA methods. This allows for the comparison of alternatives' profiles and characteristics based on their geographic location which wasn't possible before. This adaptation helps us combine multicriteria and geographic aspects in an entirely new way.

We also propose some extensions of the GAIA method to improve the quality of the results and reduce the risk of wrong interpretations to be made due to losses of data.