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With the growing dominance of multi-storey buildings and other infrastructures, 2D-based cadastral systems are facing new challenges in recording, managing and visualising the spatial extent of vertically stratified cadastral spaces. In Malaysia, surveying and cadastral measurements are currently stored in the National Digital Cadastral Data Base (NDCDB), which is a 2D-based database in the form of planimetric coordinates (X, Y). However, in reality, cadastral objects are three dimensional and 2D-based approaches provide a fragmented view of these 3D spatial objects. Another challenge is that multiple pages of 2D drawings, which are used to show all the spaces of multi-storey buildings and surroundings, imposes a significant amount of cognitive effort for inexpert stakeholders who cannot easily understand the accurate location of cadastral boundaries obscured within physical structures. Therefore, the methods of data collection, calculation and adjustment of existing survey and processing data needs to be upgraded for the purposes of implementing 3D cadastral database and producing 3D digital certified plans. The international land administration domain model (LADM) standard provides a formal conceptual model for recording and managing land administration data. It provides an extensible basis for the development and refinement of efficient and effective land administration systems, based on a Model Driven Architecture (MDA), and enables involved parties, both within one country and between different countries, to communicate, based on the shared vocabulary (that is, an ontology), implied by the model. The latter is required for the sharing and exchange of data. There have been several research and development activities in the past to model 3D cadastre in Malaysia. However, these investigations mainly remain at the theoretical level and yet to be implemented in the real context of Malaysian jurisdiction. Therefore, the motivation for this paper is to discuss the cur

A 3D cadastral data model (3DCDM) was developed to support integration of legal and physical information that are required for 3D cadastral applications. The 3DCDM model has twelve sub-models or modules including 3DCDM Geometry Model, 3DCDM Root Model, 3DCDM LegalPropertyObject Model, 3DCDM InterestHolder Model, 3DCDM Survey Model, 3DCDM CadastralPoints Model, 3DCDM Building Model, 3DCDM Land Model, 3DCDM Tunnel Model, 3DCDM UtilityNetwork Model, 3DCDM PhysicalPropertyObject Model, and 3DCDM Terrain Model. Sub-models are selected based on the user requirements and the application. For example, if the purpose of using the 3DCDM model is to model a building and visualise its ownership boundaries, only 3DCDM Building Model and 3DCDM Root Model are used. The 3DCDM Root Model must be used in each implementation of the 3DCDM model. This paper aims to develop a physical data model of the 3DCDM model. It is developed as an application schema of the Geography Markup Language 3, version GML3.2.1. GML is an XML grammar defined by the Open Geospatial Consortium (OGC) to express geographical features. Each module has a separate schema that support implementation of the 3DCDM model.

The need for more ‘space’ resulting from population growth, urbanisation and industrialisation has increased the pressure on land-use planning and development. As a result, space above and below ground level is increasingly used. Examples include underground developments, infrastructure facilities, high-rise buildings, and apartments. To extend the use and functionality of the land, complex infrastructures are being built, both vertically and horizontally, layered and stacked. These three-dimensional (3D) developments affect the interests attached to the underlying land. 3D cadastres will assist in managing the effects of 3D development and increase the functionality of a multipurpose cadastre. 3D cadastres are digital representations of real property ownership rights, restrictions, and responsibilities (legal objects) and their corresponding physical objects such as buildings, utilities, on, above or under the ground surface. They are equipped with 3D data storage, 3D visualisation, and 3D spatial analysis functions. They facilitate management of property rights; registration of strata plans; and reduction of boundary disputes between owners and Owners Corporations. They also enable a wide variety of applications, which in turn create a demand for detailed and integrated 3D legal and physical objects. To successfully implement the 3D cadastre and efficiently deliver the above-mentioned objectives, many elements must support a digital 3D cadastre, such as existing 3D property registration laws, appropriate 3D data collection methods, 3D spatial database management systems, and functional 3D visualisation platforms. In addition, an appropriate 3D cadastral data model can also play a key role to ensure successful development of the 3D cadastre. A 3D cadastral data model needs to reflect the complexity and interrelations of 3D legal and physical objects. Many jurisdictions, organisations and software developers have developed their own cadastral data model. Examples of

The importance of managing properties and people’s interests in complex multi-level developments is increasing, due to population growth and shortage of land in urban areas. As a result, cadastral systems are under pressure to change the way they capture, register and visualise 3D data of these multi-level scenarios. However, interests in land and properties in Australia are registered and visualised through subdivision plans. This visualisation method is often paper-based and includes 2D floor plans, cross-sections and isometric diagrams. These drawings are used to represent 3D properties and associated rights. Although this has been a common practice for experts such as land registration officers and cadastral surveyors, non-expert users such as the public, lawyers and real-estate agents often find these methods difficult to understand and interpret particularly in complex high rise buildings. In order to visualise and represent properties and associated rights in 3D, a web-based prototype system was designed and developed utilising various technologies to enable a wide variety of users to explore 3D ownership rights. The prototype system’s architecture is based on a three-layer framework including, data access, process and presentation layers to represent cadastral data such as Rights, Restrictions and Responsibilities (RRRs). For developing the prototype system, the subdivision plan components and the electronic surveying and subdivision plans (ePlan) were studied and analysed. In this web-based prototype system, 3D LandXML files are converted to KML data format using Extensible Stylesheet Language Transformations (XSLT) and are visualised in the Google Earth API. Furthermore, attribute information such as bearing and distance, attached to subdivision plans, is also represented in this system. Although this prototype system is not able to visualise underground RRRs, it has potential to represent interests in land and properties through the Internet. This paper c

Current cadastral data models use a 2D land-parcel definition and extend it to cover 3D requirements. This approach cannot adequately manage and represent the spatial extent of 3D land rights, restrictions and responsibilities (3D RRRs). This paper aims to develop a 3D Cadastral Data Model (3DCDM) to configure 3D cadastral frameworks, manage and represent 3D RRRs, and facilitate 3D cadastre implementation. Three underlying principles have been proposed to develop the 3D Cadastral Data Model (3DCDM). These principles are: • Principle 1: The 2D cadastral data model is a sub-set of the 3D cadastral data model, • Principle 2: The 3D cadastral data model should not only accommodate 3D RRRs and their association with physical objects: the data model should also represent the spatial extent of 3D RRRs, and; • Principle 3: The 3D cadastre data model should cater for a broad range of land administration functions including land tenure, land value, land use, and land development with sufficient detail. These principles are used to assess and modify the core cadastral data model. Additionally, principles related to the legal property object are also used to modify the 3DCDM. The legal property object combines interests and its spatial dimension into a single entity. This creates more flexibility and enables inclusion of complex commodities and all kinds of RRRs. The first version of a 3D Cadastral Data Model (3CDM_Version 1.0) is provided at the end of this paper. 3DCDM maintains both legal and physical parts of 3D objects. The data model has wider application than the traditional requirements of cadastral systems: it is also usable in applications such as urban planning and disaster management.