Fuzzy techniques for multiple criteria decision making in GIS

Spatial decision making is a fundamental function of contemporary geographic information systems (GIS). One of the most fertile GIS development areas is integrating multiple criteria decision models (MCDM) into GIS querying mechanisms. The classic approach for this integration has been to use Boolean techniques of MCDM with crisp representations of spatial objects (features) to produce static maps as query answers. This paper examines a prototype system, FOOSBALL which addresses many of the inherent weaknesses of these systems by implementing: 1) fuzzy set membership as a method for representing the performance of decision alternatives on evaluation criteria; 2) fuzzy methods for both criteria weighting and capturing geographic preferences; and 3) a fuzzy object oriented spatial database for feature storage. This makes it possible to both store and visually represent query results more precisely. The end result of all of these enhancements is to provide spatial decision makers with more information so that their decisions will be more informed, and thus, more correct.