Hierarchical fuzzy pattern matching for the regional comparison of land use maps

The evaluation of the spatial similarities and land use change between two raster maps is traditionally based on pixel-by-pixel comparison techniques. However, a pixel-by-pixel comparison can register a small displacement in pixels as land use disagreement even though the land use patterns may be essentially the same. The techniques of unique polygons mapping and hierarchical fuzzy pattern matching, where the maps are compared on both a local and global level, are combined to provide a more robust alternative approach. Local matchings determine the degree of containment of each unique polygon in the template map in terms of fuzzy areal intersections. Formally, the local agreement values are based on polygon property containments and are calculated from a fuzzy logical Max-Min compositional algorithm. A global agreement value is derived by the fuzzy summation of the local matchings. The uses of these basic methods are discussed and further refinements and modelling possibilities are outlined.