This study aims to improve the interoperability between the application domains of Building Information Modelling (BIM) and Geographic Information Systems (GIS) by linking and harmonizing core information concepts. Many studies have investigated the integration of application schemas and data instances according to the BIM model IFC and the GIS model CityGML. This study investigates integration between core abstract concepts from IFC and ISO/TC 211 standards for GIS—independent of specific application schemas. A pattern was developed for conversion from IFC EXPRESS schemas to Unified Modelling Language (UML) models according to ISO/TC 211 standards. Core concepts from the two application domains were linked in the UML model, and conversions to implementation schemas for the Geography Markup Language (GML) and EXPRESS were tested. The results showed that the IFC model could be described as an ISO/TC 211 compliant UML model and that abstract concepts from ISO/TC 211 standards could be linked to core IFC concepts. Implementation schemas for BIM and GIS formats could be derived from the UML model, enabling implementation in applications from both domains without conversion of concepts. Future work should include refined linking and harmonization of core abstract concepts from the two application domains.

<p><strong>Abstract.</strong> Standards from ISO/TC 211 are the foundation for modelling a universe of discourse in a geospatial context. UML models based on the standards, and in particular based on the UML profile defined in ISO 19103, have been developed and implemented in applications and databases for a wide range of geospatial information, from international to national and agency level. Amounts of information has been collected, maintained and made available based on the models, but mainly through specific services and exchange formats for geospatial information. To make the models and the information available in The Semantic Web, the geospatial UML models need to be transformed from UML to OWL ontologies, and the information needs to be transformed from UML-based structures to RDF triples. This paper investigates methods for transforming UML models of geospatial information to OWL ontologies, identifies challenges, suggest improvements and identifies needs for further research. Several methods for automated transformation from geospatial UML models to OWL handle basic concepts, but some concepts and context-closed restrictions from UML cannot be directly transformed to the open world of The Semantic Web. None of the analysed methods handles all of these issues, and suggested improvements include combining and improving transformation rules, as well as modifications in the UML models. To what degree and how these issues need to be handled will depend on whether the scope of the ontologies is to simply present geospatial information on The Semantic Web, or if they shall be used in a bidirectional information exchange.</p>

This study aims to improve the implementation of models of geospatial information in Web Ontology Language (OWL). Large amounts of geospatial information are maintained in Geographic Information Systems (GIS) based on models according to the Unified Modeling Language (UML) and standards from ISO/TC 211 and the Open Geospatial Consortium (OGC). Sharing models and geospatial information in the Semantic Web will increase the usability and value of models and information, as well as enable linking with spatial and non-spatial information from other domains. Methods for conversion from UML to OWL for basic concepts used in models of geospatial information have been studied and evaluated. Primary conversion challenges have been identified with specific attention to whether adapted rules for UML modelling could contribute to improved conversions. Results indicated that restrictions related to abstract classes, unions, compositions and code lists in UML are challenging in the Open World Assumption (OWA) on which OWL is based. Two conversion challenges are addressed by adding more semantics to UML models: global properties and reuse of external concepts. The proposed solution is formalized in a UML profile supported by rules and recommendations and demonstrated with a UML model based on the Intelligent Transport Systems (ITS) standard ISO 14825 Geographic Data Files (GDF). The scope of the resulting ontology will determine to what degree the restrictions shall be maintained in OWL, and different conversion methods are needed for different scopes.