ABSTRACT
Semantic interoperability among heterogeneous geospatial sources is a key research issue for Geographic Information Science (Vckovski 1998, Goodchild et al. 1999), as in various other domains. The semantic aspects of interoperability are also considered highly relevant and important to GIScience (Shepherd 1991, Bishr 1998, Frank & Raubal 1998, Gahegan 1999, Harvey 1999, Sheth 1999, Uitermark et al. 1999, Kuhn 2002, Rodríguez & Egenhofer 2003, Kokla & Kavouras 2005). However, despite the criticality of the research issue, not many solid approaches exist.
