Thematic knowledge for the generalization of land use data

Knowledge, especially the special knowledge about land use itself, is an indispensable component for guiding the whole process of land use data generalization. In this study, such knowledge is classified into two broad types, i.e. general knowledge and thematic knowledge. General knowledge covers the basic and common restrictions and specifications for generalization of geographic data. Thematic knowledge describes the special restrictions and specifications for a specific geographic data or application. The paper emphasizes the use of thematic knowledge in detail for land use data generalization. Three main types of thematic knowledge are identified, i.e. nature-based, culture-based and application-specific. Such thematic knowledge is then represented using the so-called production-rule method to become generalization rules. These rules are built in a prototype system to guide the implementation of land use data generalization. Real-life data have been used for testing and very promising results have been obtained from this system.