Towards integration of 3D legal and physical objects in cadastral data models

Digital 3D cadastres are often envisaged as the visualisation of 3D property rights (legal objects) and to some extent, their physical counterparts (physical objects) such as buildings and utility networks on, above and under the surface. They facilitate registration and management of 3D properties and reduction of boundary disputes. They also enable a wide variety of applications that in turn identify detailed and integrated 3D legal and physical objects for property management and city space management (3D land use management).Efficient delivery and implementation of these applications require many elements to support a digital 3D cadastre, such as existing 3D property registration laws, appropriate 3D data acquisition 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 objects and their physical counterparts. Many jurisdictions have defined their own cadastral data models for legal purposes and have neglected the third dimension, integration of physical counterparts and semantic aspects.To address these problems, this paper aims to investigate why existing cadastral data models do not facilitate effective representation and analysis of 3D data, integration of 3D legal objects with their physical counterparts, and semantics. Then, a 3D cadastral data model (3DCDM) is proposed as a solution to improve the current cadastral data models. The data model is developed based on the ISO standards. UML modelling language is used to specify the data model. The results of this research can be used by cadastral data modellers to improve existing or develop new cadastral data models to support the requirements of 3D cadastres.     

Development of 3D underground cadastral data model in Korea: Based on land administration domain model

Underground space is being considered as a sustainable development resource, especially in heavily urbanized areas such as Seoul, in Korea. However, regarding 3D underground property, uncertainties and gaps exist between cadastral system and real property registration system. In Korea, cadastral system is able to deal with only 2D surface parcel, on the contrary, real property registration system is able to register and manage legal status of 3D underground properties. The mismatch between these two systems causes various types of problems for underground properties such as a vertical boundary disputes between aboveground and underground ownerships, administrative confusion and dual-compensation problems for new underground construction, reconstruction and haphazard development for underground space due to the lack of systematic registration procedure. In order to overcome these problems, this research proposes a 3D underground cadastral data model, which is associated and integrated with classes in ISO 19152 Land Administration Domain Model (LADM) developed by the Technical Committee 211 of the International Organization for Standardization. The proposed 3D underground cadastral data model comprises two packages: 3D underground parcel package, and 3D underground surveying and mapping package. It would support a better service for land administration by providing reliable and accurate spatial information on 3D underground property. In order to validate the proposed 3D underground cadastral data model, the prototype is developed and implemented in real-world situation for the first time. The proposed 3D underground cadastral data model can register various types of 3D underground properties including architectures such as shopping mall, public walkway, parking lot, and etc., and civil infrastructures such as subway, road, water supply, sewage, common utility tunnel, and etc. The results show that the proposed 3D underground cadastral data model could be applicable for other information system such as land valuation and taxation system, urban planning system, construction and facility management system.     

Initial 3D cadastre registration by cadastral resurvey in the Republic of Croatia

2D Land cadastre on the present territory of the Republic of Croatia has been continuously developed in the last 200 years. Throughout the years, survey methods, needs and purposes of cadastre have changed. This resulted in a variety of cadastral data with different accuracy and completeness. Today, we can collect an enormous amount of data and the need for cadastral data has never been greater. We need to find feasible solutions to make the initial acquisition of 3D cadastral data which would satisfy the needs of stakeholders involved in Land Administration System (LAS).This paper will present a historical background of the cadastral data acquisition which would help to understand circumstances on how this variety of available cadastral data has been produced and the data available nowadays. Based on the historical overview and the overview of the current state, we will upgrade the data model of a LAS used in Croatia to support the implementation of a 3D cadastre. The model will include its static components but also proposed improvements of cadastral resurvey related processes. The Land Administration Domain Model (LADM), which in 2012 became the ISO 19,152 standard, will be used as the formal basis.This paper offers a proposal for cadastral resurvey improvements, better registration of public rights and registration of separate parts of real properties. It will identify and explore critical points and make recommendations to bring Real Property Cadastre closer to a real 3D register.     

Cadastral data as a source for 3D indoor modelling

Despite the rapid development of indoor spatial data acquisition technology, there are currently no solutions that enable large-scale indoor spatial data acquisition due to several limiting factors that characterize the indoor space. This fact, together with the rapidly growing need for indoor models, is the main motivation for our research. The focus is on the study of the appropriateness of existing cadastral data for 3D indoor modelling. Within the study, a framework for 3D indoor modelling has been developed, comprising a chain of processes, starting from initial cadastral data and ending with the OGC IndoorGML compliant document. The process chain is divided into three parts, which are described individually and supported by UML activity diagrams. The Slovenian Building Cadastre data represents the basis for the framework design and data assessment. The IndoorGML standard is used for final outputs, as it provides a standardized data model for the representation and exchange of indoor spatial information designed for indoor navigation and location-based services. The data storage options using a spatially enabled database are presented for storing 2D and 3D geometries. The stored data enables fully automatic IndoorGML document generation on request, while also taking advantage of all spatial database functionalities. The proposed approach is software independent and can be implemented with various spatially enabled software packages. In addition to 3D indoor data modelling, the framework represents a comprehensive method for assessing the usability of input data for the purpose of 3D indoor modelling. The assessment is done for the case of the Slovenian Building Cadastre. The assessment of the cadastral data suitability for 3D indoor modelling can be used for decisions regarding future steps towards a multi-purpose 3D real property cadastre. The presented concept can be applied in many countries worldwide that have a similar condominium registration system.     

3 Dimensional data research for property valuation in the context of the LADM Valuation Information Model

Property valuation is a process that promotes sustainable development as it supports and forms several land management activities. Access to information on the legal, geometric, physical, locational and environmental characteristics of property units together with the economic indicators are required for an effective property valuation system. Traditional cadastral systems generally provide only two-dimensional (2D) legal and geometric information about property units, however, today’s valuation practices would benefit significantly from three-dimensional (3D) information in order better to estimate and explain values of property units. The purpose of this paper is to examine how 3D spatial datasets and spatial analyses have been used in property valuation, and to develop 3D valuation unit profile(s) in line with the examination results for the recently proposed Valuation Information Model that extends the ISO 19152:2012 Land Administration Domain Model (LADM) from the valuation point of view. The study focuses more on 3D locational and environmental characteristics of property units; particularly visibility and especially viewshed analysis in terms of property valuation. By using open topography, building and height datasets of the Netherlands, a number of viewshed analyses are conducted to show how it can be utilized using different 3D data sources. The main contribution of the article is to present how 3D datasets and spatial analyses could be used to support property valuation activities and to investigate to what extent it is possible and meaningful to include derived 3D characteristics of property units in valuation registries.     

4D cadastres: First analysis of legal,organizational, and technical impact—With a case study on utility networks

The increasing complexity and flexibility of modern land use requires that cadastres need an improved capacity to manage the third dimension. As the world is per definition not static, there also will be needs in relation to the representation of the temporal (fourth) dimension either integrated with the spatial dimensions or as separate attribute(s). In this paper, registration of utility networks in cadastre are considered in this 3D + time (=4D) context. A number of countries in the world have developed methods to register utility networks complying with their legal, organizational, and technical structure. We researched the different approaches of three specific countries: Turkey, The Netherlands and Queensland, Australia. These are analysed to evaluate a solution that matches legal, organizational, and technical cadastral requirements in the most optimal way.     

三维地籍形态分析与数据表达

研究目的：建立三维地籍模型,描述三维地籍产权体并兼容二维地籍宗地,实现不同维度土地权属的统一管理和登记。研究方法：结合中国城市发展的实例和地籍管理需求,分析三维地籍基本形态,比较各类三维空间数据模型。研究结果：提出适应三维地籍管理功能需求的三维地籍空间数据模型及其相应的数据自动组织方法和思路。研究结论：三维地籍通过地理空间坐标这个“基因”来管理不动产,为土地和房产的统一登记提供了统一的技术框架,是对现行不动产管理技术的升级和超越。     

The Land Administration Domain Model – A literature survey

The international standard for land administration, LADM, ISO 19152, has been the subject of numerous research activities during the last one and a half decade, with topics ranging from technical implementation issues and the registration of real property to legal and organisational aspects. However, some areas have been more researched than others.The aim of this study is to provide an overview of the research as evidenced by research publications 2001–2015 to discuss the distribution of interest areas within LADM research.In total 184 publications on LADM have been analysed in the study. The result shows that technical and real property registration issues have been in focus throughout the surveyed period, whereas there has been less focus on research on legal and organisational matters. There has, however, in recent years been an slight increase in legal research, whereas research on organisational matters, such as efficiency and how to organise and manage interests in land and the benefits and costs for implementing the standard, still is lacking in comparison with the other investigated fields of research, and should be an important area to research now during the implementation phase of LADM.     

Developing a new framework based on solid models for 3D cadastres

3D cadastres aim to record, manage, and visualise spatial dimensions of volumetric legal objects in a 3D digital information environment. Definition of the geometry and topology of volumetric representations of legal objects is predicated on solid modelling approaches which are widely used in 3D modelling applications. Some solid modelling approaches are more user friendly for constructing legal objects while others enable the creation of 3D legal objects with a higher level of spatial complexity. This study aims to assess the capabilities of solid models in managing the geometry and topology of 3D legal objects with various spatial complexities. The assessment was conducted based on identification of the fundamental principles for defining geometry and topology in 3D cadastres. Various 3D legal objects with different geometric shapes were examined according to the topological principles for ensuring both internal and external validity of 3D legal objects. The identified geometric and topological principles were used to propose a new framework based on solid modelling for 3D cadastres. Our suggested framework would provide the basis for modifying land subdivision policies to adopt solid models in upgrading current cadastral systems into 3D digital environments.     

Geometrical data validation in 3D digital cadastre − A case study for Victoria,Australia

Data ambiguity and invalidity can cause significant expensive issues in the cadastral domain (e.g. legal disputes). An automated data validation can significantly help to reduce the potential issues. Quality assurance has been comprehensively investigated in various domains, however, the validation of 3D cadastral data is still in its early development. The availability of various regular and irregular shapes for 3D cadastral objects and modern building designs has resulted in a critical need for developing validation rules to ensure data validity and quality.The land registry in Victoria, Australia, is investigating the technical requirements for implementing a 3D digital cadastre. The study of 3D cadastral data validation requirements has been part of this ongoing investigation. This study is being undertaken in three main phases including 1) developing geometrical validation rules, 2) developing non-geometrical validation rules, 3) implementing an online service to validate 3D cadastral data.This paper aims to discuss the initial outcomes of the first phase of the aforementioned study which has focused on developing geometrical validation rules for 3D cadastral objects. The paper reviews the development of four geometrical validation rules which have been formalised using mathematical expressions to check the individual 3D parcels and their relationships with adjoining or neighbouring parcels. The first validation rule checks the compatibility of the cancelled parcel against the created parcels. The second rule deals with parcel collision detection which is required for flagging unacceptable intersection of 3D objects. The third rule ensures the faces forming a 3D parcel are flat. The fourth validation rule assures 3D objects are watertight. The paper concludes with a discussion around the impacts of the proposed validation checks on the subdivision process and future research for the Victorian 3D digital cadastre.     

3D Cadastres in India: Examining the status and potential for land administration and management in Delhi

Urbanization and the trend towards complex infrastructure development challenges the traditional two-dimensional (2D) cadastral representations used in conventional land administration. Three-dimensional (3D) representations are argued to serve as the future basis upon which to spatially define rights, restrictions and responsibilities (RRRs) in these environments. In Delhi, the capital city of India, where horizontal expansion via new settlements in peri-urban areas, and vertical expansion by densification of city infrastructure, are both prevalent, the need to manage this increasingly complex 3D infrastructure environment presents a great challenge for land administration and management agencies. This paper explores both the current and potential future application of 3D representation in Delhi, with respect to land use planning, development and management. A cross-cutting thematic case study analysis is undertaken: policy drivers, legal frameworks, organizational aspects, and technical standards are considered. For each aspect a separate analytical approach is used. Based on the results, it is concluded that current practices related to 3D representation are somewhat immature and not adequate for capturing the future vertical growth of Delhi. This could lead to legal and physical boundary inconsistencies and irregularities, and dispute cases. However, by learning from international developments and standards-based approaches, agencies have the potential to enhance and support processes in their respective land administration systems. To realize this potential, internal and external policies, institutional settings and, technical and financial arrangements need to be reformed. In the short term it is recommended to focus on raising awareness for the widespread adoption of 3D representations in relevant agencies in Delhi.     

LADM-based modeling of the unified registration of immovable property in China

In China, the types of immovable property objects cover not only land (a typical immovable property object) but also buildings, sea areas, forests, etc., and the general idea of unified registration of immovables (as the newest development and hottest topic in field of land administration in China) proposed by Property Law of the People’s Republic of China (2007) is not detailed until 2014 when “Interim Regulations on Real Estate Registration” was enacted and would come into force in 2015. This paper focuses on modeling of unified registration of immovables in China whose cores rely on “4 unifications” (i.e., unification of registering basis, unification of registering authorities, unification of information management platform, unification of registering books) using the world-wide advanced standard LADM (Land Administration Domain Model). In detail, the typical 8 immovable property rights (right to use construction land/forest land/sea area, ownership of houses/forests/marine structures, right to contractual management of arable land/grass land) are firstly introduced; then change of register types before and after unified registration (as one important component of “unification of registering basis”) is described; later, comparison of register procedures reflecting “unification of authorities”, “unification of information management platform” and “unification of registering books” is modeled using LADM where parties, 3R, spatial units package are greatly referenced which is followed by elaboration of a newly proposed URDMIPO (Unified Registration Data Model for Immovable Property Object). However, the complete implementation of unified registration in China will still take a long time.     

Layer approach to ownership in 3D cadastre in the case of underground tunnels

The paper focuses on approaches to the registration of real property rights in the case of underground or subway tunnels in different EU countries: Austria, Bulgaria, Czech Republic, Croatia, Greece, Poland, Slovenia, and Sweden. The authors conducted analysis on the registration of rights to subway tunnels in the chosen countries, including its effectiveness in ensuring appropriate property rights to construct and exploit tunnels. Special attention was given to limitations related to the lack of legal provisions vertically dividing space, i.e. into layers, and referring to the ownership right to the layers. Benefits which might be achieved by the introduction of a 3D real property subdivision were pointed out. The analysis of the available data concerning the geometry of subway tunnels in particular countries was presented. The authors tried to answer the question whether the accessible data concerning the geometry of subway tunnels allows to generate a 3D geospatial model of a constructed object, and to specify the space which should be determined as a 3D parcel in the 3D real property cadastre, for the purpose of registering property rights for the object (the tunnel).     

A geometric and semantic evaluation of 3D data sourcing methods for land and property information

Urbanisation, the development of high-rise apartments and the advent of complex building structures creates unique challenges that cannot be met by 2D land and property information. These include inter-related titles and complex plans relating to (i) the land parcel and (ii) the building, both internal (indoor plans) and external attributes (roof and façade). Incorporating the third dimension into the land development cycle can potentially address such challenges by providing data that describes both the land parcel and building in 3D. This move towards 3D data administration requires the development of new 3D data processes, including 3D data sourcing, which forms the focus of this research. Following an examination of current 2D methods in land and property information registration, a framework of the requirements for sourcing 3D land and property information is suggested and potential methods are discussed. Focussing on the geometric and semantic components an evaluation of the methods is developed and applied. The results highlight methods based on photogrammetry, laser scanning, mobile mapping, Unmanned Aerial Systems (UAS) and Building Information Modelling (BIM) to source integrated 3D information for both the internal and external attributes of a building and corresponding land parcel.     

A structured framework for 3D cadastral data validation − a case study for Victoria,Australia

There are a wide variety of cadastral objects, ranging from simple 2D entities such as a land parcel, to complex 3D objects such as multistory/multi-owned buildings. The complex infrastructures development happening above and below the ground complicates the processes required for defining rights, restrictions and responsibilities in 3D (3D RRRs). Even in the current, predominantly, 3D analogue cadastral system which relies on 2D drawings and representations, defining 3D RRRs is still a complicated task. With the widespread use of 3D geospatial information technologies, it is increasingly becoming easy to realise and interpret a 3D digital cadastre system. As part of the process of transition from the 2D representation of cadastre towards a 3D digital cadastre, not only will 2D representations be replaced with 3D models, but the examination workflow and its principles also need to be able to manage 3D models. Developing principles and validation rules is a critical requirement to guarantee that the diverse cadastral data is trustable and contains enough detail to define the spatial and legal extents of ownership. This paper proposes a structured framework to define validation rules for 3D cadastral models. The paper’s methodology utilises a case study approach where a plan examination process in Victoria, Australia has been analysed to investigate the principles of examining cadastral plans, and further expanded on for validating 3D digital plans. The paper concludes with a discussion on the implications of the proposed 3D validation rules and proposes future research within the topic of 3D cadastral data validation.     

Development of process model for Serbian cadastre

Identifying the processes in the cadastre enables understanding the principles on which the cadastre works. Processes in cadastre define the way how the cadastre manages information and what are the prerequisites for the data to be stored in the appropriate data structure. In order to explicitly specify cadastral procedures and workflows to support their automatization, we developed a process model for Serbian cadastre. The main reason for developing the process model is to ensure the framework which will provide possible integration and interoperability with other systems outside traditional cadastral system and between cadastral subsystems themselves. The process model is based on hierarchical decomposition of two basic groups of processes: processes for changing cadastral data and processes for displaying cadastral data. Each group of processes is further decomposed step by step until the workflow of a single process is shown. The developed process model is an abstract model, i.e. it is independent of the implementation. However, in order to instantiate such process model, it is necessary to provide binding of the abstract process model to its underlying implementation. Cadastral registration of spatial units may be beneficial for activities that relay on land administration, such as taxation, spatial planning, obtaining a building permit or legalization of buildings. This relation to the processes under jurisdiction of other organizations justifies the use of cadastral process model and its implementation into SOA environment. Traditionally, cadastral processes include alphanumeric data and 2D spatial data on cadastral maps that contain 2D borders of parcels and buildings. However, recent advancements in 3D technology bring the opportunity to enhance such processes with 3D information. In particular, the aim is to extend current 2D process model to support data maintenance and transactions in the upgrade towards 3D cadastre. Therefore, these 3D data supported workflows are introduced to the process model. For the processes that include 3D information the choice has to be made which specifications will be used and how representations of 3D spatial units will be resolved. In this paper, we first develop an abstract process model of Serbian cadastre. After that, we extend the process model to include 3D information, discuss the options for using the encodings of 3D spatial units (legal spaces) and select buildingSMART openBIM IFC standard for this purpose.     

Associating land use/cover information with land parcels represented in LADM

LADM design requires the association of external land use/cover information with cadastral land parcels. In addition to model design, related specifications are to be defined in the implementation. Yet, there are many severe obstacles against defining such specifications that are applicable to all cases. In this context, there are many different types of land use/cover classification systems for different purposes in different data quality, scale and content, which are either designed internationally or nationally. FAO Land Cover Classification System (LCCS), CORINE land cover, INSPIRE land use/cover themes, land use capability classification and Land Parcel Identification System (LPIS) are common international examples.In this study, management of spatial land use/cover data in association with cadastral land parcels represented by LADM was studied in a pilot study area in Turkey. In this context, association of spatial information as sub-divisions of land parcels (sub-parcels) was studied. Different land use/cover data sets (four types) were specifically produced for this study with an LPIS like digitization method. For the association, special overlay operations with and without predefined XY tolerances were carried out. Effects of similar yet different data sets, spatial data consistency between the produced sub-parcel data sets and land parcels, and also errors were analyzed based on the results. It is found (1) that the level of detail (base production scale) of external land use/cover data set increases spatial association errors, (2) that using XY tolerances to reduce these errors causes data inconsistency and (3) that direct spatial harmonization of two data set may be a robust solution when it is possible. In this context, in order to contribute to the implementation of LADM in terms of spatial association of land parcels and external land use/cover data, together with these data processing and analysis work, LADM modelling abstraction, availability and data quality issues of external land use/cover data, updating and maintenance issues were also discussed.     

Assessing the environmental impact of 3D public law restrictions

The needs of modern societies require, on the one hand, the most efficient exploitation of land by individual stakeholders and, on the other hand, have set up a variety of restrictions and regulations for the public benefit. Such restrictions are steadily growing in number and apply in various areas. Given the technological development in the construction sector, complex proprietary relations emerge in overlapping private and public rights. Cadastres constitute the core of land administration systems, gradually evolving to development tools that provide multi-purpose land related information. Within this context, incorporation of Public Law Restrictions (PLRs) to cadastral systems is considered a step towards the development of integrated land administration systems. Internationally, PLRs are usually registered in separate registries, under different types and formats, depending on the competent body/authority. These PLRs include, among others, restrictions regarding environment and nature protection, water protection, spatial and land use planning zones, cultural heritage, public infrastructure corridors and zones, public easements/servitudes and mining rights. Until today 3D registration and visualisation of such PLRs is mostly discussed at research level, mainly due to the variety of fields related to each PLR, the need of quantifying qualitative components or “translating” physical attributes to legal restrictions and 3D volumes, as well as to the variety of responsible authorities and types of regulations. This paper focuses on identifying PLRs that pertain either explicit or implicit 3D characteristics, emphasising on the PLRs related to the development of the Trans Adriatic Pipeline (TAP) project. This paper aims to identify the nature of 3D PLRs, based on the legal requirements regarding environmental components’ analysis and mapping defined in Environmental Impact Assessment (ESIA) studies, and to investigate the possibility of compiling 3D environmental models from recorded ESIA data. Economic implications of 3D PLR approach is also considered, at qualitative level, in terms of impact on land value when 3D restrictions are imposed, and regarding the cost-effectiveness of drafting ESIA studies showing 3D PLRs.