Modeling and manipulating fuzzy regions: strategies to define the topological relation between two fuzzy regions

Topological relations between geographic objects are among the most important kinds of relations to manage in Geographic Information Systems (GIS). However, it its very expensive in storage space to keep these relations explicitly stored. Therefore, the relations are usually not directly stored, but they are inferred from the geometry of the objects. Furthermore, the inference of the topological relations is very expensive in processing time, especially when managing complex geographic objects such as fuzzy regions, or regions with multiple alpha-cuts. In this paper the authors argue that the topological relations between two regions with multiple alpha-cuts can be defined using the topological relations between the crisp regions that compose these two regions. In addition, they present strategies to define the topological relation between two regions with multiple alpha-cuts, with the intent to minimize the number of overlays of crisp regions to be executed to define the topological relationship between the two regions.