Section 3 About this product

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Purpose of the product
Definitions and concepts
Content
General methodology
Limitations
Comparison to other products/versions
Using with other products
Reference date

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Purpose of the product

The purpose of the 2011 Census Boundary Files is to provide a framework for mapping to support Geographic Information System (GIS) applications used for land use and demographic studies, or social, economic and market research. Geographic 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 2011 Census 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 glossary (Appendix A). More details can be found in the 2011 Census Dictionary, to be released February 8, 2012. Supplementary information is provided in the appendices.

Content

Each boundary file contains the unique identifier (UID), name and type (where applicable) of the geographic level the file represents, as well as the UID, name and type of all higher level geographies where available at time of release.

In addition to containing UID and name, the Province/Territory boundary file contains English name, French name, English abbreviation and French abbreviation.

In addition to containing UID and name, the Federal Electoral District boundary file contains English name and French name.

Geographic areas are portrayed in parts where the geographic area straddles a provincial or territorial boundary. For example, the census metropolitan area/census agglomeration geographic areas are portrayed in parts.

All files are available in English and in French, in three formats: ArcInfo^® (.shp), Geography Markup Language (.gml), and MapInfo^® (.tab).

General methodology

The National Geographic Database (NGD) is a joint Statistics Canada-Elections Canada initiative to develop and maintain a spatial database which 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 native file used for the creation of the spatial files resides on Statistics Canada's Spatial Data Infrastructure and was derived directly from data stored in the NGD environment.

To produce the files, the following processes were applied:

Creation of the 2011 Census Digital Boundary Files

For digital boundary file creation, spatial and attribute information wereextracted using the lowest level of geography, the dissemination block. Primary data manipulation of the product layers included preserving the geographic hierarchy of the attributes inherent within a geographic level. The dissemination block native file was copied into a File Geo Database to facilitate geo-processing (e.g., projecting, joins, transforming and verification operations). The spatial component of the file was reprojected from Lambert Conformal Conic into latitude and longitude coordinates (NAD83) using the ArcGIS^® ArcCatalog (Feature-Project) tool.

All of the higher level geographies were created from the dissemination block level. The files were verified for their spatial and attribute content, translated into French and English, and appropriately named according to the file naming convention (see section 4). Final data processing consisted of the conversion from the File Geo Database format, using FME^® (Safe Software), into the following file formats supported by Geographic Information System (GIS) software: ArcInfo^® (.shp), Geography Markup Language (.gml), and MapInfo^® (.tab).

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

Creation of the 2011 Census Cartographic Boundary Files

As with the digital boundary file creation, the spatial and attribute information for the cartographic boundary file creation were extracted at the lowest level of geography, the dissemination block. The spatial and attribute information of the hydrography component were extracted. The dissemination block and the hydrography spatial components were copied into a File Geo Database to facilitate geo-processing (e.g., projecting, joins, transforming and verification operations). The spatial component of the files were reprojected from Lambert Conformal Conic into latitude and longitude coordinates (NAD83) using the ArcGIS^® ArcCatalog (Feature-Project) tool.

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 dissemination block that are covered by coastal waters.

The files were verified for their spatial and attribute content, translated into French and English, and appropriately named according to the file naming convention (see section 4). Final data processing consisted of the conversion from the File Geo Database format, using FME^® (Safe Software), into the following file formats supported by Geographic Information System (GIS) software: ArcInfo^® (.shp), Geography Markup Language (.gml), and MapInfo^® (.tab).

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

Creation of the 2011 Hydrographic reference files

The inland water layer was created by selecting water features from the National Geographic Database's hydrographic reference layers. These reference data were sourced from the National Topographic Data Base (1:50,000 and the 1:250,000 maps) and the Digital Chart of the World. In selected areas, information was supplemented with data from the National Hydro Network.

Coastal file

The coastal file was created by selecting a subset of hydrographic features which represent the coastal water bodies surrounding the land area of Canada for use with the suite of cartographic boundary files.

Inland lakes and rivers (polygon)

The inland polygon lakes and rivers file contains a selection of internal water bodies and islands not found in the coastal layer.

Inland rivers (line)

The inland river file contains a selection of linear water features such as rivers and streams.

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

Limitations

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

The input data used to create the files was obtained from several sources having a wide range of scales. Boundary files will not be precise if plotted at a larger scale than the scale of the source material used in its creation. Maps created from the boundary files should not be used to determine the precise location of boundaries. They are not intended to serve as a legal or cadastral representation of the geographic areas.

Comparison to other products/versions

Each 2011 Census Boundary File is compatible with other 2011 Census Boundary File products. It portrays its respective geographic area boundary, as well as selected attributes for all higher level geographies that respect the geographic hierarchy, available at the time of release. Boundary files are derived from the same native sources. The attributes found in each of the boundary files are compatible. Where applicable, boundary files contain the same unique identifier, name and type.

The 2011 Boundary Files are similar but not necessarily consistent with the boundary file products released prior to the 2011 Census.

2011 Boundary Files can be linked to other 2011 census data products using the unique identifier (UID) for each geographic area.

Using with other products

When considering using the 2011 Census Boundary Files, users should be aware of the compatibility of these files with other similar files. Boundary files are available for download on the Internet from other websites; however, they may not be consistent with Statistics Canada files.

Reference date

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, 2011.