A semantic 3D city model for underground land administration: Development and implementation of an ADE for CityGML 3.0

Abstract

Current practices of managing and communicating underground physical and cadastral (legal) data are based on fragmented and silo-based 2D methods, which cannot provide unambiguous, coordinated, and reliable representations of assets and their rights, restrictions, and responsibilities (RRRs) in subterranean environments. There is also no link between underground physical and legal data in current practices, resulting in ineffective Underground Land Administration (ULA). A single 3D integrated model of underground assets associated with the cadastral data at a city-scale can improve understanding and interpretation of underground legal and physical aspects. Extending a 3D city model to include underground legal data requirements can potentially provide a viable approach for developing a 3D integrated model. This research aims to develop a new Application Domain Extensions (ADE) for CityGML 3.0 (called VicULA ADE) to manage underground data using a single 3D integrated legal-physical model at a city-scale. The VicULA ADE proposes semantic entities for underground legal spaces, enabling the model to define spatial and semantic relationships between different types of legal spaces. The proposed approach comprises identifying requirements based on the Victorian state of Australia, developing the conceptual and logical data models in UML, and implementing the XML schema as the physical data model. The viability of the VicULA ADE is tested in a complex real-world case study that has various underground legal and physical objects, shifting this data model from a conceptual level to the implementation level. The proposed ADE of the CityGML 3.0 standard revealed how underground legal data elements can be logically embedded in this 3D data model.