Revisit Polygon Overlay Method to Explore an Innovative Solution

摘要

Polygon overlay is a major tool for the GIS analysis. McHarg and others may be responsible for its wide spread use in environmental planning and GI Science. It has limitations and often multiplies error in data resulting in vacuous analysis. This paper explores ideas and approaches that are beyond traditional polygon overlay method. McHargian traditional polygon overlay method is briefly reviewed. The method's contribution and limitation are summarized. The fundamental goal of doing polygon overlay is to find the result of environmental interaction, determine the spatial distribution of the opportunities and constraints, and therefore, make recommendation to policies and decisions. Bearing the goal in mind, different ideas and approaches are explored from two levels: improving the traditional method by applying more sophisticated algorithms and concepts, and seeking for different approaches to achieve the same goal as the traditional method. Polygon overlay is discussed in the context of fuzzy logic and soft computing, pattern recognition, computational morphology and computational geometry. An innovative way to use polygon overlay method is presented: the mathematically complicatedly multiplicatively weighted Voronoi diagram can be easily solved by topological polygon overlay.