Implementation of Overlay Function Based on Fuzzy Logic in Spatial Decision Support System
Amirhossein Pirmoradi · 2008
3 Abstract: The overlay functions in GIS are well known and often needed tools for integrating different factors and generating useful information for decision makers. Both the integration model and the generated information usually rely on crisp set theory. In many cases, either the boundaries of classes are not clearly defined, or the classification of a feature into a class is not obvious. In such cases, overlay based on fuzzy set and fuzzy logic is unavoidable. The aim of this study is to develop overlay functions on the basis of fuzzy logic and to examine the usability of such functions in integrating data related to indeterminate aspects of a phenomenon. To implement and examine the idea, an application program is developed using VBA programming language and the available Arc Object library. Using this application, a user can generate fuzzy data and use different fuzzy overlay functions to integrate those data. To test the applicability of the model and application, the suitable locations for building commercial sites of oil products are determined using this application. In summery, data integration using fuzzy overlay functions can improve the reliability of decisions, when dealing with indeterminate phenomena.