Integrated Cadastral Management project cadastral data model.
The Canada Centre for Cadastral Management (CCCM) delivers, since 1870, the land survey component to support over 23 property rights systems in Canada. Property rights information integration projects have prompted CCCM to develop a cadastral data model that provides flexibility and interoperability. This paper presents the cadastral data model that was developed for the Integrated Cadastral Management (ICM) project in support for property rights information integration projects. The author will review some of the parcel data model principles recently presented by well known authors (Lemmen, von Meyer, Williamson, Kaufmann, etc) and will describe their application to ICM. The paper describes, with a focus on cadastral features, the legal land objects, survey objects and administrative area objects required to model the legal relationship between people and land. A legal land object addresses the spatial extent of rights and restriction on land. They include real property objects, limited right areas, sub-surface right areas, and public right and restriction areas. The elements required to geometrically define the above legal land objects compose the survey objects. The administrative area objects include the extent of the jurisdiction under which legal land objects are administered. Finally, all these cadastral features evolve over time and their state needs to be managed. The implementation of object evolution from project initiation to retired parcels will be presented. In conclusion, this paper provides a practical implementation of several parcel data model principles.
In recent years, agreements between the Canada Centre for Cadastral Management (CCCM) and departments responsible for the administration of lands has governed the content and type of boundary description or delimitation products that may be used to delineate parcels and interests recorded in the various registries. The Canada Lands Survey System has demonstrated both flexibility (to meet client needs) and rigor (to maintain system integrity) in its ability to adapt to the various needs for describing the extent of land interests.
A study conducted in 2003 to investigate various options for linking the Indian Land Registry with components of the Canada Lands Survey Records found that the current cadastral mapping did not adequately reflect the extent of all recorded interests on reserve lands. The complete picture only appears when the data from the registries is fully integrated and reconciled with the boundary (extent) information. With the ongoing devolution of land management functions to First Nations through legislation such as First Nations Land Management Act (S.C. 1999, c.24), there is a growing need to accurately reflect all land interests and to identify their geographic extent.
The study also found that while the business functions of CCCM regional offices are essentially the same, the data, business processes and technology used by each region to maintain digital cadastral mapping data was quite different. The key differences included:
* different data formats (CAD and/or GIS);
* different feature types and metadata;
* different technology and tools for data maintenance and validation; and
* different business processes for maintaining and updating the cadastral data.
The study made the following recommendations to CCCM:
* that a cadastral database be created that integrates the survey and registry data;
* that the data structure be flexible enough to accommodate various sources and accuracies for describing the location and extent of land interests; and
* that common data model and standardized maintenance processes be developed and implemented.
The Integrated Cadastral Management project was initiated in 2004 to review, develop and recommend improvements to the cadastral business processes, data models and GIS tools for a national delivery model for integrated cadastral management. This paper describes the national cadastral data model that was developed and implemented.
The Canada Centre for Cadastral Management (CCCM) manages, since 1870, the Canada Lands Survey System which supports over 23 property rights regimes in Canada such as the Indian Land Registry, mining rights, oil and gas rights, First Nations settlement Lands, offshore rights, titled lands in the territories, etc. The Canada Lands Survey System (CLSS) is present on Canada Lands (Figure 1), which include indian reserves, national parks, the territories and the offshore areas of Canada.
[FIGURE 1 OMITTED]
Rights and interests on Canada Lands are managed within a property rights infrastructure (Figure 2) which can be thought of as a triangle containing three systems for land survey, land registry and land management (Sullivan, 2006). It provides the functions for identifying, documenting, registering and protecting interests in land to support sustainable development and management of land.
[FIGURE 2 OMITTED]
The "What", in the centre of the triangle, is made of all rights and interests on land. The rights on land represent the integration element that all three systems use and contribute to. The Land Management System defines "Why", How" and "What" rights or interests are required within the property rights regime to ensure sustainable development and management of the land. The Land Registry System records "What" rights are active within the property rights regime, "Who" posseses these rights or interests and "When" they are effective. The Land Survey System describes "Where" and "How much" land is affected by "What" right as well as the relative position between them. The survey and registry systems together form the cadastral management component and must be tightly integrated to ensure the effective collection, management and dissemination of information about rights and interests on land for a specific jurisdiction. Within this model, the Land Survey System is primarily concerned with modeling the geometric representation of the extent of rights and interests on land to provide efficient and flexible solutions to the varied property rights regimes the Canada Lands Survey System supports.
CADASTRAL DATA MODEL
The overall objective of ICM is to provide a flexible data model that allows the spatial representation of all rights on Canada Lands regardless of the property rights regime. To that end, it is essential that the model remains flexible enough to allow easy addition of new types of rights and that the combined rights from all property rights regimes do not impose unnecessary complexity on any given property rights regime.
The basic cadastral model presented in recent papers (Lemmen, 2003; Kaufman, 2004) provided the starting point for the ICM data model. This cadastral data model represents the legal relationship between people and land (who, what and where) as illustrated in figure 3. The rights on land that people can acquire or transfer are defined by the institutions that have jurisdiction over the lands. Depending on the mandate of the institution, these rights can take several forms. This simple model allows the representation of all types of rights for all property rights regimes on Canada Lands.
[FIGURE 3 OMITTED]
Land ownership is often considered the most fundamental right someone may have on land. In fact, ownership is made of a number of rights that among other things allows access, use, enjoyment and sale of a real property. The rights that someone can possess on land can be thought of as a "bundle of rights" with each defined right capable of being separated from the bundle and transferred individually (von Meyer, 2004). Thereby, it is possible for someone to possess limited rights on the real property of another. An owner can transfer a specific right to another individual such as a right of way or an agricultural lease over a portion of the property while keeping ownership of the land itself. The land rights may also be alienated by retaining some rights while transferring the ownership to someone else. An example is when the Crown grants ownership to land but retains the sub-surface rights. These may be granted separately under a different property rights system (mining).
Furthermore, a jurisdiction may impose, by legislation, some limitation and conditions to the use of a specific right. The Crown may limit the use of land to protect species at risk or apply building or land use restrictions. These limits and restrictions are referred to as public rights which are imposed for the benefit of the community as a whole.
In many jurisdictions, the rights, no matter the type, are recorded against the real property they affect. However, this approach does not allow for adequate spatial representation of the right or interest in the case where the extent is different than the real property (e.g. easement). In order to provide a better spatial representation of the legal situation of the land, one must clearly define the spatial extent of all rights to truly represent their location and size (Figure 4). In addition, it is important, to identify the type of rights which is likely to apply to an extent different than the real property. There is no need to create a separate spatial extent for every right that may exist if the right (e.g. mortgage, lease, etc.) applies to the same extent as an existing right (e.g. Ownership). The basic principle is that all rights associated to a specific spatial extent must apply homogeneously across the entire extent of the spatial object.
[FIGURE 4 OMITTED]
The objective here is to define the type of spatial objects that are required to spatially represent the extent of all rights and restrictions on Canada Lands. CCCM has determined that, for cadastral modeling purposes, all types of spatial objects can be organized, based on their spatial characteristics, into four main groups. These are the Real Property objects, Limited Rights Area objects, Sub-Surface Area Objects and Public Rights Area Objects. All these spatial objects can be further grouped under a generic term called Legal Land Objects (Kaufman and Steudler, 1998) providing a simple data model to link the Land Survey and Land Registry Systems
All rights and restrictions on land are inter-related and influence each other. For example, a limited right (e.g. easement) is always an encumbrance against one or more real properties (e.g. land parcel). Therefore, it becomes tempting in many situations to explicitly model these relationships within the cadastral data model. However, in most cases, these relationships can be established implicitly by comparing their respective geometry. If the extent of easement is properly represented and positioned, a simple polygon overlay will identify all real properties affected. Where possible, each legal land object should be completely independent (i.e. no explicit relationship) from other legal land objects. The principle of legal independence (Kaufman, 2004) allows the flexibility to adapt to the various and evolving needs of property rights regimes.
INTEGRATED CADASTRAL MANAGEMENT DATA MODEL
The Integrated Cadastral Management (ICM) data model (Figure 5) is comprised of three main groups of objects: The legal land objects, the survey objects and the administrative area objects. The legal land objects addresse the spatial extent of rights and restrictions on land. The features required to geometrically locate, define and support the above legal land objects are the survey objects. The administrative area objects include the extent of the jurisdiction under which legal land objects are administered. Other objects such as additional supporting data (ancillary objects) and annotation objects complete the data model. The main objects of the ICM Data Model are further subdivided as follows:
* Legal Land Objects
* Real Property Objects
* Land Parcels
* Internal Parcels
* Condominium Units
* Strata Parcels
* Limited Right Area Objects
* Indian Reserve Surface Oil & Gas Rights
* Indian Reserve Leases
* Cree-Naskapi Rights
[FIGURE 5 OMITTED]
* Sub-Surface Area Objects
* Mineral Claims
* Oil&Gas Sub-Surface Parcels
* Public Right Area Objects
* Indian Reserve Designations
* Protected Areas
* Survey Objects
* Survey Line Objects
* Cadastral Lines
* Limited Right Area Lines
* Sub-Surface Area Lines
* Public Right Area Lines
* Survey Point Objects
* Reference Points
* Survey Framework Objects
* Grid Areas
* Cree-Naskapi Blocks
* Survey Record Objects
* Surveys in Progress Extents
* Survey Record Extents
* Administrative Land Objects
* Administrative Areas
* Derived Administrative Areas
* Un-derived Administrative Areas
* Administrative Boundaries
* Modifications to Indian Reserve Extent
* Ancillary Objects
* Annotation Objects
Legal Land Objects
The Legal Land Objects on Canada Lands have been subdivided into four main categories of objects: Real Properties, Limited Right Areas, Sub-Surface Areas and Public Right Areas.
A legal land object that represents the spatial extent of any land and appurtenances, including anything of a permanent nature such as structures including condominiums and strata parcels is defined as a real property. Real Property Objects include land parcels (Figure 6), internal parcels (Figure 7), condominium units, and strata parcels. Real property objects are usually created by the transfer of ownership. However, other types of transactions, such as long term leases (e.g. greater than 10 years on Indian Reserves) also cause the creation of a real property object. In this case, the long term lease on a portion of the original lot requires appropriate survey, demarcation and unique identification in the database. The ownership of the original land parcel is transferred onto the newly created parcels and a lease with appropriate grantee is recorded against the appropriate parcel. Real property objects are mutually exclusive from one another and therefore do not overlap each other. Land parcels form a continuous fabric throughout the jurisdiction. To that end, all pieces of land are uniquely identified whether or not they are privately owned. Land parcels owned by the Crown are recorded as such in the land registry system.
[FIGURE 6 OMITTED]
Internal parcels (Figure 7) are the result of a subdivision that does not cause the underlying land parcel to be retired. Both the original land parcel and the internal parcels are active and may be referred to for recording interests. This situation occurs when land parcels are transferred from one jurisdiction to another. The land parcel is identified in the originating jurisdiction for transfer purposes and subsequently subdivided in the destination jurisdiction. The parcel in the originating jurisdiction remains active and may be accessed.
Limited Rights Area Objects include legal land objects such as easements (Figure 8), leases, Indian reserve surface oil & gas rights and other rights which may overlap other interests. Limited rights are rights on a real property held by someone other than the lawful possessor of the real property. These limited rights area objects may overlap each other as it is possible for more than one right to cover portion of the same land (e.g. underground pipeline easement crossing surface right-of-way easement). In ICM, each limited right area object forms a separate feature class and no explicit relationships are created between these rights and the real properties they may affect. The relationship between the limited rights area object is established in real-time using a polygon overlay approach. Each feature class of limited rights does not form a continuous fabric within the jurisdiction and, therefore, to be meaningful, they must be used in conjunction with the real property objects.
[FIGURE 7 OMITTED]
[FIGURE 8 OMITTED]
Sub-Surface Area Objects are legal land objects that represent the spatial extent of sub-surface rights. They include surveyed and grid-based subsurface areas. Surveyed sub-surface area objects represent the extent of subsurface rights such as mineral claims affecting a real property for which the extent is described in a survey document. A grid based sub-surface area represents the spatial extent of a subsurface interest overlapping a real property object that is not surveyed but rather derived from a survey framework grid area such as the township/section fabric. Usually, CCCM does not manage grid based sub-surface areas. The extent of these features are created and maintained by external agencies (e.g. Indian Oil & Gas Canada) and are derived, if required, from sub-surface grids produced and maintained by CCCM. Sub-surface grid objects represent the extent of the smallest division that can be referred to in legal documents to define the extent of sub-surface oil & gas licenses and permits. Sub-surface grid objects include oil and gas surveyed sub-surface grid units and the Indian reserve subsurface oil and gas grid.
[FIGURE 9 OMITTED]
Public Right Area Objects are legal land objects that represent the spatial extent of a right or a restriction on the landscape as a result of the public interest or common good. For example, a wilderness area represents a public right area object. Public right area objects include indian reserve designations (Figure 10) and protected areas.
[FIGURE 10 OMITTED]
Legal Land Objects are all identified using a parcel designator commonly found on survey plans. On Canada Lands, this designation may take several forms ranging from a simple lot number (e.g. Lot 167) to more complex descriptions (Lot 119-67-4, Concession V, Township of Tuscarora). These parcel designations are usually used in legal documents to identify and associate the respective rights and interests to the appropriate Legal Land Object. To facilitate integration and ensure unique identification, all Legal Land Objects are also assigned a 7-digit number (e.g. 1234567) which is unique across all Canada Lands. A global unique identifier (GUID) is also used in ICM to ensure unique identification when integrating the cadastral data within the Canadian Spatial Data Infrastructure (CGDI) or other spatial data infrastructures such as the Global Spatial Data Infrastructure (GSDI).
Survey Objects represent the surveyed and un-surveyed elements required to support the Canada Lands Survey System. Survey objects include survey points, survey lines, survey frameworks and survey records.
Survey Points consist of the active monumented and unmonumented locations with known locations and accuracy. The survey points are compiled from Canada Lands Survey Records Plans (CLSR), Registration Plans (RS; formerly called RSP) and location sketches (LS) in the Canada Lands Survey Records.
Survey Lines consist of the lines required to form the boundaries of the legal land objects. Survey lines include provisional lines, cadastral lines, limited right area lines, public right area lines and sub-surface area lines. COGO attributes are associated to the lines and depict the adjusted framework of the legal land objects. The survey lines are compiled from Canada Lands Survey Records Plans (CLSR), Registration Plans and Field Notes recorded in the Canada Lands Survey Records.
Under the conceptual data model, survey lines should be managed as one feature class as all lines are integrated together to maintain the relative position of legal land objects. However, in the ArcGIS physical data model, a separate line feature class has been created for each associated legal land object. This was done to avoid the introduction of unnecessary vertices where legal land objects overlap. These extra vertices are inserted into features as a result of maintaining topology rules between legal land objects and the supporting survey lines. The additional vertices create "pivot" points in the survey lines and legal land objects which make it very cumbersome when spatial adjustments are required as a result of new more accurate legal surveys.
The conceptual data model also called for having all the data organized in one national database. However, legal surveys are carried out in local projections (Universal Transverse Mercator, Modified Transverse Mercator and Double Stereographic projections). Therefore, to maintain the original intent of the survey, updates to the cadastral database must be performed in the local projection to establish straight lines and circular curves where required. Since, in ArcGIS, the coordinate system is maintained at the feature class or feature dataset level, it is not possible to manage the appropriate mathematical definition for each cadastral feature using one national coordinate system. To resolve this issue, several GeoDatabases were created to support the various projection requirements.
The Survey Framework Objects data provide the spatial representation of primary survey frameworks such as the Township/Section system and Grid Area system.
Survey Record Objects provide information on the spatial extents of a proposed, on-going or completed survey project. Survey record objects include plan envelopes and project envelopes (Figure 11). A project envelope represents the spatial extent of a proposed or on-going survey project. The project envelope extent is derived from existing data or is created through redlining approximate boundaries of a project. Project envelopes are deleted and replaced by a plan envelope when the survey project is completed. A plan envelope represents the spatial extent of the "Lands or boundaries dealt with" shown on Canada Lands Survey Records (CLSR) plans, Registration Plans (RS; formerly called RSP), Field Notes and Location Sketches (LS) archived in the Canada Lands Survey Records. Plan envelopes allow a spatial query of all plans archived in the Canada Lands Survey Records.
[FIGURE 11 OMITTED]
Administrative Land Objects
Administrative Land objects represent pieces of land managed under a single governance or statistical reporting structure. Administrative area objects include derived and un-derived administrative areas, administrative boundaries and modifications to administrative areas (Indian Reserves only).
Administrative areas are managed as derived and un-derived area objects. A derived administrative area (Figure 12) represents the spatial extent of a jurisdiction that is created and managed as a composite of Land Parcels through an automated process. Derived administrative areas include indian reserves, indian lands, settlement lands, national parks and territorial parks. An un-derived administrative area object represents the spatial extent of a jurisdiction that is created and managed as a separate entity within the ICM database. Un-derived administrative areas include QUADs, groups, subdivisions, municipalities, block land transfers, settlement areas, districts and regions. Un-derived administrative areas also include the spatial extent of site that do not have a specific administrative boundary such as indian settlements and national historic sites.
[FIGURE 12 OMITTED]
Administrative boundaries represent the spatial limits of a jurisdiction that is created and managed as a separate entity within the ICM database. Administrative boundaries are available for the Yukon, Northwest Territories and Nunavut and may include international, provincial and territorial boundaries.
Modifications made to an existing indian reserve such as additions to reserve or dispositions of land are also managed within the ICM data model. Normally, these result from of an order in council or ministerial order and are maintained as separate entities to record the change in the spatial extent of a jurisdictional area of an indian reserve.
These fundamental cadastral objects are supplemented with additional supporting features such as ancillary features and cartographically placed annotations. Ancillary data objects represent features that provide auxiliary information to better define the location of boundaries. They consist of features such as traverse and construction lines, topographic features (shoreline, contour, etc.) and other survey lines (archived, field notes, etc.).
Finally, all these cadastral objects evolve over time and their state needs to be managed from project initiation to archived survey lines and retired legal land objects (Figure 13).
[FIGURE 13 OMITTED]
Survey lines may exist within the ICM Database in one of the following four Line States: Provisional, Boundary, Field Notes or Archived. Provisional lines represent boundaries within the approval process. During the approval process, legal land objects are only represented as lines and no polygon is created. Once a survey plan is approved and recorded in the Canada Lands Survey Records (CLSR); the line status is changed from provisional to boundary. A topological relationship between boundary lines and legal land objects ensures that the later remain aligned with the survey fabric. Field notes are surveyed lines that have been recorded in the CLSR but that were never approved. These lines cannot be used to define the limit of a legal land object. Archived lines are lines that are recorded in the CLSR but that have been superseded by a new survey.
Legal land objects may exist within the ICM Database in one of the following three basic Parcel States: "Created", "Active" or "Retired". The "Created" state indicates that a new legal land object has been described on a recorded survey plan and is awaiting registration to become active. The registrar activates legal land objects when the appropriate legal documents are registered and that all active rights have been dealt with (i.e. transferred from the land parcel to be retired to the land parcel newly created). All legal land objects with a state set to "Active" form the current cadastral fabric. Interests can only be registered against active legal land objects. Objects with a state of "Retired" are historical objects that have been superseded by new active legal land objects. Additional Parcel States such as "Other", Unresolved", "Inconclusive" and "Unrecorded" are used for specific purposes. Parcel states are implemented within the ICM physical data model as feature class sub-types. This implementation allows to easily moving a legal land object from one state to the other thus allowing an effective integration between the land survey and land registry systems.
The Integrated Cadastral Management data model was developed and implemented to provide a national delivery model for integrated cadastral management. The data model is based on emerging cadastral data models which provide a solid base to facilitate interoperability with other cadastral systems in Canada and internationally. The implementation of a simple concept of the legal relationship between people and land allows for a straight forward integration with various land registry systems the Canada Lands Survey System supports. The management of a legal land object parcel state provides additional flexibility to ensure that the appropriate land registry system can activate and retire the required legal land object at the most opportune time. The modeling of all types of public and private rights on land, with their specific location and extent, ensures a flexible cadastral environment that can support various property rights regimes to give a complete and accurate picture of the legal situation of the land. Finally, the creation of independent feature class for each type of right provides an environment which can meet multiple property rights requirements and evolve over time to meet emerging needs without imposing an unnecessary complex data structure on any given property rights regime.
With the implementation of the Integrated Cadastral Management data model, the Canada Centre for Cadastral Management continues to demonstrate its commitment to deliver flexible solutions to support the property rights infrastructure on Canada Lands to meet constituent needs while maintaining rigor for describing the extent of land interests and in maintaining robust land survey system.
Kaufman, Jurg, and ESRI, 2004, "ArcGIS Cadastre 2014 Data Model Vision", Printed in USA
Kaufman, Jurg, and Daniel Steudler, 1998, "Cadastre 2014: A vision for a future cadastral system", Working Group 7.1 of FIG Commission 7
Lemmen, Christiaan, Paul van der Molen, Peter van Oosterom, Hendrik Ploeger, Wilko Quak, Jantien Stoler, and Jaap Zevenbergen, 2003, "A modular standard for the cadastral domain" in the 3rd ISDE: Digital Earth--Information Resources for Global Sustainability, pp 399-419
MacNeil, Terry, 2004, "Integrated Cadastral Information Management for the Canada Lands Survey System", Edmonton, AB, AGP Geomatics and Forte Consulting Ltd.
Sullivan, Peter, 2006, "Introducing the Canada Centre for Cadastral Management", Edmonton, AB, Natural Resources Canada
Von Meyer, Nancy, 2004, "GIS and Land Records--The ArcGIS Parcel Data Model", Redlands, CA, ESRI Press
Canada Centre for Cadastral Management
Natural Resources Canada
615 Booth Street, Room 528
Ottawa, ON, K1A oE9
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|Publication:||Urban and Regional Information Systems Association Annual Conference Proceedings|
|Article Type:||Technical report|
|Date:||Jan 1, 2006|
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