Abstract. The paper proposes a methodology for fuzzy multi-criteria analysis of decisions in a raster-based geographical information system (GIS) to determine the optimal locations for territorial objects. Recommendations about the stages of choosing alternatives for spatial and non-spatial constraints are given. It is shown that the fuzzyfication of criteria, that is, the conversion of their attribute values into a fuzzy set, based on expert evaluation of a fuzzy membership function, allows screening alternatives by determining thresholds of alpha-cut of fuzzy sets for each criterion, followed by combining criteria attributes using aggregation operators: minimum, maximum, weighted sum, OWA operator Jager. Adding to the procedure of multicriteria analysis of the additional stage of filtration of alternatives gives the opportunity to reduce the number of alternatives, and in the future and the processing time of the criteria layers by aggregator operators. The proposed algorithm for screening alternatives can be performed in a GIS environment using Fuzzy Membership, Overlay and raster calculators tools.
Keywords: geographic information systems;multiple-criteria decision analysis; fuzzy set theory; alpha-cut; site selection