3D cadastres for densely occupied informal situations: Necessity and possibility

Much of 3D cadastre research and development targets high valued urban land, including condominiums, apartment buildings, and office complexes. The value of the land and the economic activity generated from transactions in this urban space potentially support the cost and time spent on establishing and maintaining a 3D cadastre. Methods for data acquisition and for construction and maintenance of the 3D cadastre are also simpler in the regular and formally planned and surveyed structures of the high value urban environment. Low-income, urban areas of informal tenure and informal development, however, also need and can benefit from a land administration system supported by a 3D cadastre but are neglected in the 3D cadastre research. Mechanisms are required for quick and cost effective construction of a 3D cadastre in this type of area to support land management and regularisation procedures, and to provide security of tenure. Light Detection and Ranging (LiDAR) is one technology that may be examined to differentiate structures in densely occupied environments where limited information and limited resources must be able to be used for managing the land and also protecting informal rights.This paper initially posits the need for 3D cadastres in low-income but densely structured urban settlements. It then tests the ability of an existing LiDAR dataset together with orthoimagery, derived to be low cost so therefore having limited specifications, for capturing sufficient definition of 3D occupation in the low-income, densely structured case study area of Laventille in Trinidad and Tobago.The difficulties of manually or automatically discriminating between close and overlapping structures and boundaries are highlighted and it is found that there is still a need for adjudication and verification of boundaries on the ground, even when physical features can be discerned from the software.     

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.     

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.     

A technical solution for 3D crowdsourced cadastral surveys

The development of 3D property registration systems is indispensable for the spatial determination of property Rights, Restrictions and Responsibilities (RRR), the sustainable operation of property markets and the safeguarding of ownership in the highly urbanized world. Several developments in computer graphics, 3D modelling and rendering techniques have attracted the growing global interest in 3D cadastre. Since 2012, the Land Administration Domain Model (LADM ISO 19152) is adopted as the international standard for 2D and 3D cadastral data modelling. Developed legal procedures and prototype systems for 3D property rights registration provide interesting solutions for data acquisition and visualization but such approaches are time and cost demanding. In parallel, 2D cadastral surveying procedures have progressed significantly in reducing required time and cost, utilizing crowdsourcing methodology and mobile services.This paper presents a technical solution under development, aiming to provide the beginning for a new era in the initial acquisition, registration and representation of 3D crowdsourced cadastral data, appropriate for both the developed and the developing world. The proposed solution consists of two complementary parts, the technical framework and the crowdsourced methodology to be followed. The technical framework consists of two interconnected parts, the server-side and the client-side. The server-side refers to the Database Management System (DBMS) where the collected data are stored. The client-side refers to the data capturing tool, which in this case is the mobile device. For the server-side, a prototype system based on model driven architecture practices and LADM is developed; while for the client-side, an open-source mobile application for the acquisition of 3D crowdsourced cadastral data, 3D modelling and visualization of 3D property units as block models (LoD1) on a mobile’s phone screen in real-time, is developed.This research is focused on investigating technical aspects for capturing and integrating data about legal rights on physical objects. Detailed investigation of legal issues is not within the objectives of this research. Two case-studies for testing the proposed technical solution are made. An assessment of the current stage of development of the technical solution is presented. The main conclusions converge that the proposed technical solution has huge potentials for the fast, economic implementation of 3D cadastral surveys as it can produce an accurate and reliable 3D information model, depending on the accuracy of the available basemaps. The developed application is easy-to-use as users may not have the necessary level of 3D modelling skills in order to contribute to the registration procedure.     

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.     

土地产权三维界定的技术路线及其评论

研究目的：对已有研究文献涉及土地产权三维界定的技术路线进行结构性把握,梳理研究脉络与趋势,以期为土地产权三维界定在研究方法和范式上的改进提供思路。研究方法：文献分析法、比较分析法。研究结果：从理论基础、界定起点和界定方案看,国内外学界对土地产权三维界定大致存在三条技术路线：基于空间分离原理的技术路线、基于空间区分原理的技术路线和基于三维地籍原理的技术路线,分别反映了法学和地籍学对土地产权形态和产权客体进行三维界定的技术方案。研究结论：未来应将土地产权形态与产权客体三维界定统一起来,厘清其内在逻辑与生成路径,深化三维土地产权客体特定化实现机制、国家公权力植入三维土地产权实现机制和三维土地产权排他性支配机制研究,加快构建三维土地产权范式。     

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.     

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.     

重庆一小时经济圈土地适宜性评价与整理三维可视化研究

研究目的:科学地开展土地资源评价和规划,实现土地合理、有效利用。研究方法:以重庆长寿湖周边地区为例,利用RS与GIS技术,借助地质、地球化学、遥感等多源信息,运用层次分析法选取评价指标,通过专家打分确定权重,使用多指标评价模型、模糊数学和叠加分析相结合的方法,建立了一套土地适宜性评价指标体系。以土地的社会属性为重点,结合当地政府对研究区在一小时经济圈的具体定位,对其土地利用现有结构进行了科学调整。研究结果:遥感影像与评价结果叠加实现三维可视化,让决策者简单直观的了解土地利用情况,为土地规划提供科学依据。研究结论:以土地自然属性为基础的适宜性评价,和以社会属性为重点的土地结构调整方法,可很好的结合研究区自身的发展特点,对其未来的发展制定合理的土地规划,可为重庆一小时经济圈内其他地方的土地评价与规划提供思路。