C. Lemmen

The core cadastral domain model

Abstract A standardized core cadastral domain model (CCDM), covering land registration and cadastre in a broad sense (multipurpose cadastre), will serve at least two important goals: (1) Avoid re-inventing and re-implementing the same functionality over and over again, but provide a extensible basis for efficient and effective cadastral system development based on a model driven architecture (MDA), and (2) enable involved parties, both within one country and between different countries, to communicate based on the shared ontology implied by the model. The second goal is very important for creating standardized information services in an international context, where land administration domain semantics have to be shared between countries (in order to enable needed translations). This paper presents an overview of the core cadastral domain model and its developments over the last 4 years. The model has been developed in a set of versions, which were each time adjusted based on the discussions at workshops with international experts and the experience from case studies in several countries of the world (Netherlands, El Salvador, Bolivia, Denmark, Sweden, Portugal, Greece, Australia, Nepal, Egypt, Iceland, and several African and Arab countries). Important conditions during the design of the model were and still are: should cover the common aspects of cadastral registrations all over the world, should be based on the conceptual framework of Cadastre 2014, should follow the international ISO and OGC standards, and at the same time the model should be as simple as possible in order to be useful in practise. Besides presenting the CCDM itself this paper represents an important new wave in geo-information standardization: after the domain independent basic geo-information standards (current series of ISO and OGC standards), the new standards based on specific domains will now be developed. Due to historical differences between countries (and regions) similar domains, such as the cadastral domain, may be modeled differently and therefore non-trivial harmonisation has to be done first. The presented CCDM is a result of this harmonisation and one of the first presented examples of semantic geo-information domain standards. Besides the three well-known concepts, Parcel, Person and Right, at the class level the model also includes immovables such as Building and OtherRegisterObject (geometry of easement, like a right of way, protected region, legal space around utility object, etc.) and the following concepts: SourceDocument such as SurveyDocument or LegalDocument (e.g. deed or title), Responsibilities, Restrictions (defined as Rights by other Person than the one having the ownership Right) and Mortgages. At the attribute level of the model the following aspects are included: SalePrize, UseCode, TaxAmount, Interest, Ranking, Share, Measurements, QualityLabel, LegalSize, EstimatedSize, ComputedSize, TransformationParams, PointCode, and several different date/times. The heart of the model is based on the three classes: (1) RegisterObject (including all kinds of immovables and movables), (2) RRR (right, restriction, responsibility), and (3) Person (natural, non-natural and group). The model supports the temporal aspects of the involved classes and offers several levels of Parcel fuzziness: Parcel (full topology), SpaghettiParcel (only geometry), PointParcel (single point), and TextParcel (no coordinate, just a description). The geometry and topology (2D and 3D) are based on the OGC and ISO/TC211 standard classes. The model is specified in UML class diagrams and it is indicated how this UML model can be converted into and XML schema, which can then be used for actual data exchange in our networked society (interoperability).

Spatial data management on a very large cadastral database

Abstract An overview is presented of spatial data management in the Netherlands Cadastre. As a result of more than three years research a major improvement in the accessibility and maintenance of 50 Gb available geometric data has been introduced. Quality assurance of topological relationships, maintenance of historic spatial data and flexible data access by a query tool is supported. The ‘Spatial Location Code’ used for spatial clustering and spatial indexing guarantees excellent performance of the relational database. This opens the possibility to develop new products, which can be delivered efficiently via networks.

Solutions for 4D cadastre-with a case study on utility networks

The increasing complexity and flexibility of modern land use requires that cadastres need to manage information on the third and temporal (fourth) dimension. This article considers the registration of legal space of utility networks in cadastre in this 3D + time (=4D) context. A requirement analysis in three countries that have methods to register utility networks complying with their legal, organizational and technical structure (Turkey, the Netherlands and Queensland, Australia) is the basis for three alternatives for 4D cadastre to register utility networks. The three alternatives are analysed with respect to legal, organizational and technical cadastral requirements. This article presents a case study and a prototype from the Netherlands. In this country by law utilities are considered to be real estate objects with obligatory registration of ownership and geometry. This study shows that the 3D space and separate temporal attributes approach (state-based model) is a very promising solution to maintain temporal changes of utility networks and that this approach is to be preferred above the current practice, where the 3D and temporal aspects are not considered when registering a network.

The land administration domain model (LADM) as the reference model for the Cyprus land information system (CLIS)

In this paper, the enhancement of the data model of the Cyprus land information system (CLIS), with the adoption of the land administration domain model (LADM) is examined. The CLIS was established in 1999, within the Department of Lands and Surveys, to support the operation of the Cyprus cadastral system and has met the majority of its initial set goals. It is however now broadly accepted that the CLIS should be improved and upgraded, and a new data model should be introduced to facilitate the manipulation and provision of data to internal and external users/ customers in a more effective way. The need to enhance the CLIS coincides with the introduction of the LADM, which is under development within the Technical Committee 211 of the International Organization for Standardization and identified as ISO 19152. The LADM provides an abstract, conceptual schema with three basic packages: parties (such as people and organisations), administrative rights, responsibilities and restrictions (such as property rights) and spatial units (such as parcels, buildings and networks), with the latter having one subpackage: surveying and spatial representation [6]. [Note: In this moment (January 2012), the LADM is at the development stage of Final Draft International Standard]. In this paper, the basic entities of the CLIS are presented and restructured, in a way to comply with the LADM. After analysing the characteristics of LADM, it is concluded that this is compatible with CLIS, and can be used as a data model framework for CLIS’s upgrade. Thus, the Cyprus country profile is proposed. The adoption of the LADM is a great opportunity for the Department of Lands and Surveys to introduce an International Organization for Standardization standard model, based on model driven architecture, and to gain all the benefits derived from such a movement. Such benefits include the improvement in the effectiveness and the efficiency of the current system and the expansion of the services provided by CLIS to the broader land administration system and to the Cyprus community. The new functionality includes: better structuring of the rights, responsibilities and restrictions (and related source documents); better fitting in the information infrastructure, both national (e.g. valuation, taxation, building, address and person registrations) and international (e.g. INSPIRE cadastral parcels); and future capabilities for representing three-dimensional spatial units (e.g. legal spaces related to apartment or utility infrastructure).

The point cadastre requirement revisited

Abstract Certain countries need to establish a faster, cheaper and more fit-for-purpose cadastre than those offered by conventional strategies. This paper reintroduces the strategy of the point cadastre: a cadastral system where geographic points are used to represent land parcels. When point features are combined with satellite imagery, freely available topographic maps (e.g. OpenStreetMap) and managed using cloud based geographic information services, a simple cadastral solution becomes apparent. This paper concentrates only on defining drivers and requirements for point cadastres. Three discrete studies were used to generate the requirements: expert group meetings, a pressure cooker meeting and an online questionnaire. The requirements are classified under preparation, functional, quality and architectural categories. Preparation requirements illustrate the need for contextual awareness before commencing any point cadastral project. Functional requirements are found to be similar to the requirements of parcel based cadastres; however, the necessity for parcel boundary identification is removed. Quality requirements promote the need for ‘ease of use’ and ‘low cost’: ‘accuracy’ is found to rank lowest out of six quality requirements. Architectural requirements provide various options for collecting, storing, maintaining and visualising the cadastral point information. Together, the requirements provide a basic blueprint for cadastral practitioners considering point cadastre solutions. Further work is required on development of indicators for assessing achievement of the requirements in practice.

Constructing a seamless digital cadastral database using colonial cadastral maps and VHR imagery – an Indian perspective

A Land Administration System (LAS) with its cadastral component is the infrastructure that facilitates the implementation of land policies to attain sustainable development. Therefore, the availability of a digital, up-to-date and easily accessible cadastral database has become a primary requirement for undertaking efficient land administration and/or spatial planning decisions for any country. In this paper, the authors demonstrate a method for constructing a seamless digital cadastral database (DCDB) based on colonial cadastral maps using Geographic Information System (GIS) and image interpretation techniques for an area of about 326 km2. Geo-Eye1 (pan-sharpened) data were used for this purpose in combination with limited on-site survey. The proposed approach could be considered as an alternative to a complete cadastral resurvey. It is important to mention here that the quality of these colonial maps is quite high and can be proven as a basis for spatial planning. A cadastral resurvey may be required in the future where there is an urgent need for higher accuracy, but the approach would be time consuming and potentially bring unrest in villages and urban neighbourhoods. Hence, an alternative is, therefore, to respect the contents of the existing maps and records combined with a quality upgrade: make the existing records and maps up-to-date as a basis for a spatial planning.

A procedure for semi-automated cadastral boundary feature extraction from high-resolution satellite imagery

Abstract Fit-for-purpose land administration aims to align cadastral policies, administration and technology selection with the prevailing societal needs and capacity within a country context. It seeks to support delivery of more rapid and low-cost cadastral boundary mapping – and ultimately more widespread land tenure security. The philosophy suggests that when high positional accuracies are not the primary concern, but when time pressure is, high-resolution satellite images can serve as a source for creating cadastral boundary information. This paper explores the potential of mean-shift segmentation plug-in in QGIS to semi-automatically extract cadastral boundaries in rural areas – based on the land cover information from WorldView-2 satellite images. The segmentation gives a vector file satisfying many cadastral boundary requirements and ready to be used in a GIS environment. The buffer overlay method was used to assess the quality of extracted boundaries. For a non-vegetated terrain having visible boundaries, the approach could be taken as an alternative to support existing, relatively slow, boundary mapping approaches by minimizing the effects of manual digitization and surveying.

Supporting Indoor Navigation Using Access Rights to Spaces Based on Combined Use of IndoorGML and LADM Models

The aim of this research is to investigate the combined use of IndoorGML and the Land Administration Domain Model (LADM) to define the accessibility of the indoor spaces based on the ownership and/or the functional right for use. The users of the indoor spaces create a relationship with the space depending on the type of the building and the function of the spaces. The indoor spaces of each building have different usage functions and associated users. By defining the user types of the indoor spaces, LADM makes it possible to establish a relationship between the indoor spaces and the users. LADM assigns rights, restrictions, and responsibilities to each indoor space, which indicates the accessible spaces for each type of user. The three-dimensional (3D) geometry of the building will be impacted by assigning such functional rights, and will provide additional knowledge to path computation for an individual or a group of users. As a result, the navigation process will be more appropriate and simpler because the navigation path will avoid all of the non-accessible spaces based on the rights of the party. The combined use of IndoorGML and LADM covers a broad range of information classes: (indoor 3D) cell spaces, connectivity, spatial units/boundaries, (access/use) rights and restrictions, parties/persons/actors, and groups of them. The new specialized classes for individual students, individual staff members, groups of students, groups of staff members are able to represent cohorts of education programmes and the organizational structure (organogram: faculty, department, group). The model is capable to represent the access times to lecture rooms (based on education/teaching schedules), use rights of meeting rooms, opening hours of offices, etc. The two original standard models remain independent in our approach, we do not propose yet another model, but applications can fully benefit of the potential of the combined use, which is an important contribution of this paper. The main purpose of the combined use model is to support the indoor navigation, but could also support different applications, such as the maintenance and facility management work, by computing the cleaning cost based on the space floor area. The main contributions of this paper are: a solution for the combined use of IndoorGML-LADM model, a conceptual enhancement of LADM by the refinement of the LA_Party package with specialization for staff and student (groups), and the assessment of the model by converting sample data (from two complex university buildings) into the model, and conducting actual access-rights aware navigation, based on the populated model.

The LADM based on INTERLIS

Both the conceptual schema language INTERLIS and the land administration domain model (LADM) share the same model driven architecture (MDA) principles. In this paper we explore how INTERLIS and LADM complement each other in actual implementation of land administration system based on the LADM using INTERLIS tools. In Switzerland, the requirement for a clearly defined data model that can be adapted in flexible ways resulted in a conceptual schema and object oriented language INTERLIS. The cadastral core data model and many other models (i.e. utility services, urban planning, etc.) have been defined with INTERLIS in Switzerland. The concept of the data description language INTERLIS is compatible with international standards like UML or GML/XML. The language is widely used in the country. Constraints for comprehensive data quality checking can be formulated easily. This is one of the main reasons to keep INTERLIS. INTERLIS tools are available for QGIS, FME and other systems. There is also an INTERLIS aware graphic UML editor, GML can be generated, web services (WMS) are supported, etc. The Land Administration Domain Model (LADM, ISO 19152) has been formulated in INTERLIS now. The result is a layered INTERLIS model description: ISO191xx base model, generic LADM and finally country model specific model expressed in INTERLIS. From this, using INTERLIS tools database schemas (Oracle, PostgreSQL) can be generated and also a foundation for data exchange format (XML) of the specific LADM country profile is available. Specific attention will be paid to expressing the LADM constrains (expressed with pseudo OCL in ISO 19152) into INTERLIS. The paper first introduces the INTERLIS concepts and supporting documentation. Some examples are included. Then the integration of LADM is expressed. Pros and cons are analyzed (compared to not using INTERLIS and applying just standard UML, OCL, XML). Finally, future work is presented: support of volumetric 3D primitives, more advanced constraints, etc. Briefly stated, INTERLIS brings one more option to implement LADM (with support from Switzerland) in an efficient manner, and supporting a range of actual target platforms (GIS, DBMS, etc.).

A LADM-based temporal cadastral information system for modelling of easement rights – A case study of Turkey

Type people to land relations are dynamic and, as a consequence, the nature of land title and cadastral data is of a dynamic nature. Land title and cadastral data are core components for a lot of property applications (e.g. taxation, valuation, mortgage). Those applications require up to date, complete and reliable data – including temporal data as in use in application forms and transactions. In this paper, the modelling of Rights, Restrictions and Responsibilities (RRR) is discussed with a focus on the modelling of easement rights in a case study in Turkey. Functional requirements with respect to the characteristics of easement rights are investigated based upon interviews with professional experts in the public and private sector. Then a prototype model was built based on a simple implementation of the Land Administration Domain Model (LADM) RRR classes and by conforming to the national cadastral data management standards related to land registration systems. This new proposed model includes temporal cadastral attributes related to easements. This is materialised in the ‘Administrative Package’ and illustrated in the Turkey LADM country profile. We show that the LADM can be used to describe for the time dimension of cadastral information in Turkey, but that there are semantic differences, similarities and mismatches of classes and attributes between the LADM and the cadastral information system in Turkey. Proposed LADM-based model for the time dimension of cadastral information will be of immense advantage to land administrators, the governments and land users in Turkey.