Boundary Files, Reference Guide, Second edition, Census year 2021

This reference guide is intended for users of the 2021 Census Boundary Files. This guide provides an overview of the files, the general methodology used to create them, and important technical information.

What's new?

• Each boundary file now includes the Dissemination Geography Unique Identifier (DGUID) for geographic areas.
• Each boundary file contains only the information relative to its specific geographic level. The new 2021 Dissemination Geographies Relationship File allows linking all geographies to their higher levels.
• Due to methodology changes in the delineation of the census metropolitan areas and census agglomerations (CMA/CA) geographies, the “CMA/CA Boundary Files” and “Census Tract (CT) Boundary Files” releases were moved to February 9, 2022.
• As of 2020, all the boundaries maintained by Statistics Canada have been adjusted to the more current, accurate and consistent CanVec hydrographic features (Topographic Data of Canada – Natural Resources Canada), which comply with international geomatics standards seamlessly across Canada.
• The 2021 Census Boundary Files are now available in File Geodatabase (.gdb), Esri® REST and Web Mapping Service (WMS) formats.
• The 2021 Census Boundary Files are no longer available in MapInfo (.tab) format.

1. About this guide

This reference guide does not provide details on specific software packages that are available for use with the 2021 Census Boundary Files. Users are advised to contact the appropriate software vendor for information.

This data product is provided ‘as-is,’ and Statistics Canada makes no warranty, express or implied, including but not limited to, warranties of merchantability and fitness for a particular purpose. In no event will Statistics Canada be liable for any direct, special, indirect, consequential or other damages, however caused.

2. Overview

The 2021 Census Boundary Files depict the boundaries of all standard geographic areas established for the purpose of disseminating census data. See Figure 1.1, "Hierarchy of standard geographic areas for dissemination, 2021 Census” from the Dictionary, Census of Population, 2021.

They contain information such as unique identifier (UID), name and type where applicable, as well as land area and province or territory unique identifier (PRUID). Each boundary file can be linked to all higher level geographic areas using its DGUID and the new 2021 Dissemination Geographies Relationship File.

They are available for download or viewing in two types: cartographic and digital. Both cartographic and digital boundary files are portrayed in Lambert conformal conic projection (North American Datum of 1983 [NAD83]).

3. About this product

Purpose of the product

The purpose of the 2021 Census Boundary Files is to provide a framework for mapping and spatial analysis, and to support Geographic Information System (GIS) applications used for land use and demographic studies, or social, economic and market research. Geographic unique identifiers permit linkage of statistical data to geographic areas depicted in the boundary files. Boundary files can also be used to create new geographic areas by combining standard geographic areas.

The boundary files are positionally consistent with the 2021 Road Network File, which provides additional reference for geographic context for mapping applications.

Definitions and concepts

Geographic terms and concepts are briefly defined in the Dictionary, Census of Population, 2021.

Content

Each 2021 Census Boundary File contains the UID, DGUID, name and type where applicable, and land area of the geographic level the file represents. It also contains the PRUID. A 2021 Census Boundary File is available for each of the following geographic areas:

• Provinces and territories (PRs)
• Census divisions (CDs)
• Federal electoral districts (2013 Representation Order) (FEDs)
• Census subdivisions (CSDs)
• Designated places (DPLs)
• Economic regions (ERs)
• Census agricultural regions (CARs)
• Census consolidated subdivisions (CCSs)
• Census metropolitan areas and census agglomerations (CMA/CAs)
• Census tracts (CTs)
• Population centres (POPCTRs)
• Dissemination areas (DAs)
• Dissemination blocks (DBs)
• Aggregate dissemination areas (ADAs)

General methodology

The National Geographic Database (NGD) is a joint Statistics Canada-Elections Canada initiative to develop and maintain a spatial database that serves the needs of both organizations. The focus of the NGD is the continual improvement of quality and currency of spatial coverage using updates from provinces, territories and local sources. The source files used for the creation of the boundary files reside on Statistics Canada's Spatial Data Infrastructure (SDI), which was derived directly from data stored in the NGD.

Creation of the 2021 Census Boundary Files

Digital

For the digital boundary file creation, spatial and attribute information were extracted for each level of the geographic hierarchy. Primary data manipulation of the product layers included preserving the geographic hierarchy of the attributes inherent within a geographic level and ensuring spatial alignment between layers. The native files were copied into SDE feature datasets and stored as feature classes to facilitate geo-processing (e.g., projecting, joins, transforming and verification operations).

Cartographic

In contrast to digital boundary file creation, the spatial and attribute information for the cartographic boundary file creation were extracted at the lowest level of geography, the basic block. The spatial and attribute information of the hydrography component were extracted and the basic block and the hydrography spatial components were copied into SDE feature datasets and stored as feature classes to facilitate geo-processing (e.g., projecting, joins, transforming and verification operations).

To create the cartographic boundary files, a subset of the full hydrography, the coastal layer, was created. This subset of coastal hydrographic features was then used to erase the portions of the basic block that are covered by coastal waters. After erasure the basic blocks were dissolved to create each higher level geographic layer.

Post-processing

Both the digital and cartographic files were verified for their spatial and attribute content, translated into French and English, and appropriately named according to the file naming convention. Final data processing consisted of the conversion from the SDE feature dataset feature class format, using FME® (Safe Software), into the following file formats supported by Geographic Information System (GIS) software: Shapefile (.shp), Geography Markup Language (.gml), and File Geodatabase (.gdb).

The Shapefile, Geography Markup Language and File Geodatabase files were compressed into WinZip® files (file extension .zip) and made available for download from the Internet.

Limitations

The input data used to create the files was originally obtained from several sources having a wide range of scales. The 2021 Census Boundary Files will not be precise if plotted at a larger scale than the scale of the source material used in their creation. Maps created from the boundary files should not be used to determine the precise location of boundaries.

The positional accuracy of the files does not support cadastral, legal, surveying, digitizing or engineering applications.

Comparison to other products or versions

Each 2021 Census Boundary File is compatible with other 2021 Census Boundary Files and the 2021 Road Network File. Boundary files are derived from the same native sources and the attributes found in each of the boundary files are compatible.

The 2021 Census Boundary Files are similar but not necessarily consistent with the boundary files released prior to the 2021 Census.

The 2021 Census Boundary Files can be linked to other 2021 Census data products using the UID and DGUID for each geographic area. The new 2021 Dissemination Geographies Relationship File also allows the 2021 Census Boundary Files to be linked to higher geographic levels through their DGUIDs.

Use with other products

When considering using the 2021 Census Boundary Files, users should be aware of the compatibility of these files with those that are available from other sources. They may not be consistent with Statistics Canada files.

Reference date

Population counts

The population count data used to create the “2021 Designated Place Boundary Files”, the “2021 Census Metropolitan Area and Census Agglomeration Boundary Files” and the “2021 Population Centre Boundary Files” refer to the 2021 Census of Population which was conducted on May 11, 2021.

Standard geographic areas

The geographic reference date is a date determined by Statistics Canada to finalize the geographic framework for which census data are collected, tabulated and reported. The reference date for the geographic area boundaries in cartographic and digital boundary files is January 1, 2021.

4. Technical specifications

Record layout and data descriptions

Province and territory

For more information on provinces or territories, refer to the “Province or territory” definition from the Dictionary, Census of Population, 2021.

Census division

For more information on census divisions, refer to the “Census division (CD)” definition and “Census division types by province and territory, 2021 Census” table from the Dictionary, Census of Population, 2021.

Federal electoral district

For more information on federal electoral districts, refer to the “Federal electoral district (FED)” definition from the Dictionary, Census of Population, 2021.

Census subdivision

For more information on census subdivisions, refer to the “Census subdivision (CSD)” definition and “Census subdivision types by province and territory, 2021 Census” table from the Dictionary, Census of Population, 2021.

Designated place

For more information on designated places, refer to the “Designated place (DPL)” definition and “Designated place types by province and territory, 2021 Census” table from the Dictionary, Census of Population, 2021.

Economic region

For more information on economic regions, refer to the “Economic regions (ER)” definition from the Dictionary, Census of Population, 2021.

Census agricultural region

For more information on census agricultural regions, refer to the “Census agricultural region (CAR)” definition from the Dictionary, Census of Population, 2021.

Census consolidated subdivision

For more information on census consolidated subdivisions, refer to the “Census consolidated subdivision (CCS)” definition from the Dictionary, Census of Population, 2021.

Census metropolitan area and census agglomeration

For more information on census metropolitan areas and census agglomerations, refer to the “Census metropolitan area (CMA) and census agglomeration (CA)” definition and “Census metropolitan area and census agglomeration types by province and territory, 2021 Census” table from the Dictionary, Census of Population, 2021.

Census tract

For more information on census tracts, refer to the “Census tract (CT)” definition from the Dictionary, Census of Population, 2021.

Population centre

For more information on population centres, refer to the “Population centre (POPCTR)” definition from the Dictionary, Census of Population, 2021.

Dissemination area

The digital boundary file contains the boundaries of all 57,936 DAs which combined cover all of Canada. The cartographic boundary file contains the boundaries of 57,932 DAs. DA 24690104 in Quebec as well as 35010386, 35010377 and 35010392 in Ontario fall completely in coastal water and are not included in the cartographic boundary file.

For more information on dissemination areas, refer to the “Dissemination area (DA)” definition from the Dictionary, Census of Population, 2021.

Dissemination block

For more information on dissemination blocks, refer to the “Dissemination block (DB)” definition from the Dictionary, Census of Population, 2021.

Below is a list of the 239 DBs which are not included within the cartographic boundary file. These DBs are located entirely within coastal waters and were therefore removed during the production of the cartographic boundary file.

Aggregate dissemination area

For more information on aggregate dissemination areas, refer to the “Aggregate dissemination area (ADA)” definition from the Dictionary, Census of Population, 2021.

Attribute domain values

Census division type (CDTYPE)

For information on census division types, refer to the “Census division type (CDTYPE), 2021 Census” table.

Census subdivision type (CSDTYPE)

Census subdivisions are classified according to designations adopted by provincial/territorial or federal authorities.

For information on census subdivision types, refer to the “Census subdivision type (CSDTYPE), 2021 Census” table.

Census metropolitan area and census agglomeration type (CMATYPE)

For information on census metropolitan area and census agglomeration types, refer to the “Census metropolitan area and census agglomeration type (CMATYPE), 2021 Census” table.

File specifications

Not applicable

Software formats

Boundary files for the 2021 Census are available for download from the Statistics Canada website in the following formats:

• Shapefile
  File extension: .shp
• Geography Markup Language (GML) 3.1.1
  File extension: .gml
• File Geodatabase
  File extension: .gdb

The 2021 Census Boundary Files are also available as map services from the Statistics Canada website in the following formats:

• Esri® REST service
• Web Map Service (WMS)

This reference guide does not provide details on specific software packages available for use with the 2021 Census Boundary Files. Users should contact the appropriate software vendor for such information.

File extension and accented character information

The Shapefile, Geography Markup Language and File Geodatabase files are compressed into WinZip® files (file extension .zip).

Some of the 2021 Census Boundary Files contain attributes with accented characters. They were successfully tested on desktop versions of ArcGIS® 10.5.1, File Geodatabase and FME Data Inspector 2015.1.

Metadata

The downloadable compressed packages (.zip) include a metadata file (.xml) that describes and validates the structure and content of the 2021 Census Boundary Files.

The same metadata are applied to the Esri® REST service and Web Map Service.

Geographic representation

The 2021 Census Boundary Files are available on the Statistics Canada website in the following geographic representation:

• Projection: Lambert conformal conic
• False easting: 6200000.000000
• False northing: 3000000.000000
• Central meridian: -91.866667
• Standard parallel 1: 49.000000
• Standard parallel 2: 77.000000
• Latitude of origin: 63.390675
• Linear unit: metre (1.000000)
• Datum: North American 1983 (NAD83)
• Prime meridian: Greenwich
• Angular unit: degree
• Spheroid: GRS 1980

The North American Datum of 1983 (NAD83) is an adjustment of the 1927 datum (NAD27) that reflects the higher accuracy of geodetic surveying.

Users of 2021 Census Boundary Files can transform the files into the representation that best satisfies their needs, knowing the effects these representations have on angles, areas, distances and direction. Users have the option to choose the best projection in concert with display objectives.

File naming convention

Spatial product file names follow a file naming convention. The file projection, the geographic level, geographic coverage, file type, geographic reference date, file format and language are embedded within the file name. Standardizing the names of the files facilitates the storage of compressed files, all having the extension .zip.

Each file name is 13 characters in length. All alphabetic characters are in lower case to maintain consistency.

First character: projection of file

• l - projection in Lambert conformal conic

Next three characters: primary geographic level of file

• pr_ - province/territory
• cd_ - census division
• fed - federal electoral district
• csd - census subdivision
• dpl - designated place
• er_ - economic region
• car - census agricultural region
• ccs - census consolidated subdivision
• cma - census metropolitan area/census agglomeration
• ct_ - census tract
• pc_ - population centre
• da_ - dissemination area
• db_ - dissemination block
• ada - aggregate dissemination area

Next three numbers: geographic code of coverage

• 000 - Canada

Next character: file type

• a - digital boundary file
• b - cartographic boundary file

Next two numbers: geographic reference date

The geographic reference date is a date determined by Statistics Canada for the purpose of finalizing the geographic framework for which census data are collected, tabulated and reported. For 2021 Census products, the geographic reference date is January 1, 2021.

• 21 - geographic reference date is 2021

Next character: file format

• a - Shapefile (.shp)
• f - File Geodatabase (.gdb)
• g - Geography Markup Language (.gml)
• s - Services (Esri® REST and Web Map Service [WMS])

Final two characters: language

• _e - English
• _f - French

5. Data quality

Spatial data quality elements provide information on the fitness-for-use of a spatial database by describing why, when and how the data are created, and how accurate the data are. The quality elements include an overview of lineage, positional accuracy, attribute accuracy, logical consistency and completeness. This information is provided to users for all spatial data products disseminated for the census.

Lineage

Lineage describes the history of the spatial data, including descriptions of the source material from which the data were derived, and the methods of derivation. It also contains the dates of the source material, and all transformations involved in producing the final digital files.

All data in the 2021 Census Boundary Files were originally extracted from Statistics Canada's SDI.

Positional accuracy

Positional accuracy refers to the absolute and relative accuracy of the positions of geographic features. Absolute accuracy is the closeness of the coordinate values in a dataset to values accepted as or being true. Relative accuracy is the closeness of the relative positions of features to their respective relative positions accepted as or being true. Descriptions of positional accuracy include the quality of the final file or product after all transformations.

The NGD is not fully Global Positioning Systems (GPS)-compliant. However, every possible attempt is made to ensure that the standard geographic area boundaries maintained in the NGD respect the limits of the administrative entities that they represent (e.g., CD and CSD) or on which they are based (e.g., CMA/CA). The positional accuracy of these limits is dependent upon source materials used by Statistics Canada to identify the location of limits. In addition, due to the importance placed on relative positional accuracy, the positional accuracy of other geographic data (e.g., road network data) that are stored within the NGD is considered when positioning the limits of the standard geographic areas.

Within the NGD, DB representative points were generated using ArcGIS® software in conjunction with their respective cartographic boundaries. The most detailed hydrography available was used in identifying cartographic boundaries and calculating representative points in Statistics Canada native format. Efforts were made to ensure that representative points do not fall in water, where possible. After geo-processing (e.g., projecting, appending, transforming and verification operations), the “2021 Dissemination Block Cartographic Boundary File” is converted into Shapefile (.shp), Geography Markup Language (.gml) or File Geodatabase (.gdb) files. These manipulations may have caused slight shifting of some of the underlying land and hydrographic features resulting in representative points falling in water.

Attribute accuracy

Attribute accuracy refers to the accuracy of the quantitative and qualitative attribute information attached to each feature (e.g., CSD name, UID).

As noted under the General methodology section, the attributes (names, types and UIDs) for all standard geographic areas are sourced from Statistics Canada's SDI. The names and types of standard geographic areas have been updated using source materials from provincial, territorial and federal authorities.

The attribute data associated with the polygons in the 2021 Census Boundary Files were verified against the data in the SDI and found to accurately reflect them.

Logical consistency

Logical consistency describes the fidelity of relationships encoded in the data structure of the digital spatial data.

The 2021 Census Boundary Files were verified against data in the NGD and found to be logically consistent.

In each boundary file, all geographic areas have been verified to have a UID and DGUID that is valid for the 2021 Census.

Consistency with other products

The position of the boundaries in the 2021 Census Boundary Files is not necessarily consistent with previous editions of boundary files or road network files as a result of updates made using provincially and territorially sourced data.

Topology checks were performed with the 2021 Road Network File and the 2021 Census Boundary Files to measure the degree of integration amongst these products. The results indicated the degree of integration was within the default tolerance parameters as defined below.

• Tolerance: 0.00001 metres
• Resolution: 0.000005 metres

Completeness

Completeness refers to the degree to which geographic features, their attributes and their relationships are included or omitted in a dataset. It also includes information on selection criteria, definitions used, and other relevant mapping rules.

In both digital boundary files and cartographic boundary files, a geographic area may be depicted by more than one polygon. In the digital boundary files there are some geographic areas that have two or more parts. This is particularly the case for some CSDs. In cartographic boundary files, this is also due to having removed the coastal water area from the digital boundary files, thus creating several polygons for one geographic area. In the cartographic boundary files, this impacts only geographic areas that are situated in coastal areas.

Appendix

See Table 1.1, “Geographic areas by province and territory, 2021 Census,” from the Dictionary, Census of Population, 2021.