The 3D cadastre, one of the most fundamental components of the 3D LAS (Land Administration System), aims to provide an integrated 3D view of legal (Right, Restrictions, and Responsibilities–RRR) and physical boundaries in multi-storey properties; therefore, to extend the flexible and modular basis of LADM, which best represents legal boundaries and RRRs, some integrated models using technical standards (e.g., CityGML, IFC, InfraGML) are developed to represent the full 3D cadastre. However, since most of the developed 3D integrated data models are designed at the conceptual level, there is a knowledge gap in logical data model relationships, which is the next processing step in the fully integrated 3D data model stage. The main argument of this study is an innovative ADE 4D Cadastral Data Model to represent 3D cadastral objects registration with time attributes using LADM and CityGML. The data management and organization are done in an open-source database for the Turkish cadastral system. This research will discuss two main topics. The first is how to implement a suitable way of realising LADM-based 3D cadastral object registration by focusing on developing the presentation of those cadastral objects to 4D (3D + t), with time attributes in alignment with the jurisdictional framework in Turkey. The second is how the data is managed in an open-source PostgreSQL database. In addition, the usage type of cadastral objects is shown in a CesiumJS, a visualisation platform. Moreover, this study will contribute to eliminating the knowledge gap between the conceptual and logical models.

The concepts of three-dimensional cadastre (3D) and property ownership led to increased interest in land use management and research towards the end of the 90s. Within the scope of these studies, international standards and definitions have been realised. In Turkey, there are some academic studies available. However, there are not many studies conducted on an institutional basis. Turkey cadastre carried out by the General Directorate of Land Registry, and Cadastre (GDLRC) are kept. In this context, a 3D RRR (Right, Restriction and Responsibility) for Turkey-based cadastral data model design and development is essential in terms of not constitute a base for the study. The fact that these studies are in the context of LADM and ISO standards and OGC is very important in terms of the fact that the cadastral system is related to international standards. .

Nowadays, a very active research area is the 3D cadastre concept. In relation, 3D Cadastre is an essential component used in a land management system which is to manage and represent layered rights digitally, restrictions, responsibilities (legal models), buildings, public services and corresponding physical models (above or below the floor surface in 3D). The 3D Cadastre has a lot of capable of collecting, storing, organising, querying, analysing and visualising very intricate details within specific standards for all over the worlds. Besides, now in Turkey, 3D cadastre is to be designing and developing with academic studies. The cadastral concept was developed for the 3D Cadastral in the early 2000s from studies related to the world countries. The first workshop was held in 2001; the second workshop was held in 2011 and 2012 in the third. Temporarily, many theoretical and practical developments have emerged in these workshops. However, no 3D cadastre is currently being performed anywhere in the world (Oosterom et al., 2011). There are several reasons why successful implementation of 3D cadastre is legal, institutional and technical. These reasons can be listed as the necessary legal documents, missing data models, lack of technology and data format deficiencies. The 3D cadastre scope should be defined as ideal in legal and institutional systems for all of the cadastral systems. While waiting for these formalities, the development of a data model for 3D cadastre is a useful method to clarify the scope of 3D cadastre. A 3D cadastral data model is the most important for the introduction of standards (INSPIRE, OGC, LADM) and a common language within the user communities of the Land Administration. In this context, some countries (Netherlands, Australia) have developed cadastral data models (ePlan, Legal Property Object Model, LADM, 3D Cadastral Data Model) to improve their cadastral systems. Although cadastral data models differ between countries, 2D is based on the basic building block of a land parcel. The existing cadastral data models were developed based on the definition of a 2D land parcel for many countries. Besides land tenure recording system with related 2D cadastral systems also. In line with the developed models, Netherlands, Australia, Croatia and Israel improved their existing cadastral systems and carried out studies in the scope of 3D cadastre. In Turkey, the 3D cadastre scope is still working for an academic site. In this study, the first section comprises of the investigation for 3D cadastral systems. Turkey studies and cadastral systems will be discussed in section 2. The scope and principles of 3D cadastre are discussed for Turkey with section 3. Moreover, the obstacles to the implementation of 3D cadastre and international standards developed within the scope of 3D cadastre are discussed and also data models developed for Turkey cadastral system with related international standards (Land Administration Domain Model, INSPIRE and ISO) in section 4. Also, finally, discussion and results were assessed in this paper.

Physical and cadastral data management practices for underground facilities are insufficient to represent underground assets' Rights, Restrictions, and Responsibilities (RRRs) and their relationships with the cadastre. For this reason, developing a 3D integrated data (underground and above‐ground) model may be an approach to an effective land management system. This research aims to develop a creative data model by integrating Turkish National Geographic Information System (TUCBS‐AY in Turkish) with international standards (Land Administration Domain Model (LADM) and CityGML) as a holistic approach. The requirements determined for underground facilities using TUCBS‐AY were used. Since the data produced in Turkey were modeled according to the CityGML 2.0 version, the CityGML 2.0 UtilityNetwork version was used in the study to be compatible with the existing Turkish cadastral system. While some classes in the model are generalized, they are expanded using LADM's classes for legal rights and part information. In addition, the CityGML classes have been expanded within the model so that parcels, buildings, and independent sections are represented separately, thus providing the opportunity to represent the underground utilities associated with them, their RRRs, and ownership situations. Requirements for the proposed model were determined based on Turkey's cadastral system and underground data. The main purpose is to manage the legal and physical relations of underground and surface objects at the city scale, compatible with the current Turkish cadastral system, with a holistic approach. The proposed integrated conceptual data model shows how legal rights and ownership of underground structures can be logically represented with a 3D data model.