Some implications of fuzzy set theory applied to geographic databases

Present geographic database design is based on Boolean logic. The inadequacy of this logic for representation and manipulation of inexact data has recently become a major topic of debate. This is a first attempt at formulating a consistent model for handling inexactness in geographic information systems by introducing a logic of inexactness. Fuzzy logic serves as the basis for representing and manipulating inexactness in a relational geographic database. Four distinct cases of nonfuzzy schema/nonfuzzy data, nonfuzzy schema/fuzzy data, fuzzy schema/ nonfuzzy data, and fuzzy schema/fuzzy data are presented. Two models of managing fuzzy data within a nonfuzzy schema are presented.