An IFC-based database schema for mapping BIM data into a 3D spatially enabled land administration database

There are different processes in 3D urban land administration in which spatial analysis plays an underpinning role.Among 3D data models,Industry Foundation Class(IFC)provides the potential capabilities for modelling legal and physical dimensions of urban properties.However,performing spatial analysis using IFC files cannot address the on-demand spatial analysis requirements of 3D urban land administration.In response to this limitation,3D data needs to be stored in a spatial database to enable spatial analyses required by different stakeholders.Therefore,in this paper,by considering spatial analysis requirements in 3D-enabled urban land administration,an IFC-based database schema is designed.Moreover,a methodology for transforming Building Information Modelling(BIM)data into the proposed schema is provided.This methodology includes seven steps:designing the architectural model and adding legal data,georeferencing,IFC data validation and cleaning,mapping process,database data validation and cleaning,spatial analysis,and visualisation.To demonstrate the feasibility of the proposed database,three datasets are implemented in the database.Moreover,a new method for modelling legal spaces with oblique structures and two applications of spatial analysis in 3D urban land administration are provided.

Managing underground legal boundaries in 3D-extending the CityGML standard

Legal boundaries are used for delineating the spatial extent of ownership property’s spaces.In underground environments,these boundaries are defined by referencing physical objects,surveying measurements,or projections.However,there is a gap in connecting and managing these boundaries and underground legal spaces,due to a lack of data model.A 3D data model supporting underground land administration(ULA)should define and model these boundaries and the relationships between them and underground ownership spaces.Prominent 3D data models can be enriched to model underground legal boundaries.This research aims to propose a new taxonomy of underground legal boundaries and model them by extending CityGML,which is a widely used 3D data model in the geospatial science domain.We developed,implemented,and tested the model for different types of underground legal boundaries.The implemented prototype showcased the potential benefits of CityGML for managing underground legal boundaries in 3D.The proposed 3D underground model can be used to address current challenges associated with communicating and managing legal boundaries in underground environments.While this data model was specifically developed for Victoria,Australia,the proposed model and approach can be used and replicated in other jurisdictions by adjusting the data requirements for underground legal boundaries.