Guide to the Census of Population, 2021
Chapter 11 – Census geography

Introduction

There is a geographic component in every stage of the census cycle, from consultation, through collection, processing and dissemination. Users are consulted about the geographic concepts used by Statistics Canada and about various options for disseminating standard geographic information. Geographic areas are defined and mapped in detail so that every dwelling can be located during the collection phase. During the processing phase, the collected data are coded to the appropriate geographic areas within the geographic hierarchy of standard geographic areas for dissemination. Finally, census data are disseminated by a variety of geographic areas designed specifically for dissemination, along with supporting reference maps and other geographic data products.

National Geographic Database

The standard geographic areas that Statistics Canada uses for census and survey collection and dissemination activities are constructed, maintained and supported by detailed geographic information which are stored in a precise geographic database called the National Geographic Database (NGD).

The NGD is a joint Statistics Canada-Elections Canada initiative which develops and maintains a geospatial database that serves the needs of both organizations. The focus of the NGD is the continual improvement of quality and currency of geographic coverage using updated geospatial data provided by provinces, territories and local sources.

The NGD includes a digital representation of the boundaries of standard geographic areas and their attributes, such as names, types and codes, which are necessary for uniquely identifying each individual geographic area.

The NGD also contains additional geographic features, including a detailed road network, various hydrographic features such as lakes, rivers and coastal waters, and other selected visible features, for example, railroads.

The road network also has associated attribute data, such as street names, types, directions and address ranges.

To take full advantage of census data, users are encouraged to develop a basic understanding of the geographic dimensions.

Hierarchical model of geographic areas for collection

The geographic areas used for census data collection are illustrated below in Figure 11.1, Hierarchy of geographic areas for collection, 2021 Census, and are different than geographic areas used for dissemination.

The geographic areas used for census data collection are designed to serve two purposes: the organization of the materials and workforce required to conduct census collection and the assignment of each dwelling to the lowest possible level of geography that can be linked to the dissemination geography used for publishing census data.

The geographic areas used for collecting census data range in size from Canada, groupings of provinces and territories, all the way down to collection blocks, and are organized in a hierarchical model to illustrate the nature of their relationships to one another.

Figure 11.1
Hierarchy of geographic areas for collection, 2021 Census

Data are not published for collection geographic areas and therefore are not represented in Figure 1.1, Hierarchy of standard geographic areas for dissemination, found in the Dictionary, Census of Population, 2021, Statistics Canada Catalogue no. 98‑301‑X.

Administrative areas

• Province or territory
• Previous census – Census division (PC CD): The Census division (CD) of the previous census; for the 2021 Census, therefore, the PC CD is the 2016 CD.

Collection areas

• Regional Census Centre (RCC): A senior management office within a region. For census collection purposes, Canada is divided into three regions, which are groupings of provinces and/or territories. The Montreal region comprises the provinces of Newfoundland and Labrador, Prince Edward Island, Nova Scotia, New Brunswick and Quebec. The Toronto region comprises only the province of Ontario and the Vancouver region comprises the provinces of Manitoba, Saskatchewan, Alberta and British Columbia and all three territories: Yukon, Northwest Territories and Nunavut.
• Field operations manager district (FOM): A geographic area defined by a group of field operations supervisory districts for which a field operations manager is responsible.
• Field operations supervisor district (FOS): An area comprised of a group of crew leader districts and is the geographic area for which a FOS is responsible.
• Crew leader district (CLD): A geographic area defined by a group of zones. They are the geographic area for which a crew leader (CL) is responsible.
• Non-response follow-up zone: A grouping of collection units (CUs) that create an assignment area for one enumerator.
• Delivery zone (DZ): An area comprised of a group of CUs to which an enumerator is assigned for dropping off census materials to dwellings that Canada Post cannot send mail to. It contains a combination of mailable and non-mailable dwellings. Non-mailable dwellings are those that contain insufficient address information for Canada Post to use to deliver mail directly to the dwelling. As such, these dwellings will receive their census materials from a census enumerator.
• Collection unit (CU): The primary collection geographic area used to assign and monitor work in the various collection activities. Approximately 73% of CUs in Canada received their census materials in the mail during the 2021 Census, 18% received their materials in person from a census enumerator, and 9% of CUs used a combination of mail and enumerator delivery.
• Collection block (COLB): Like a dissemination block (DB), a COLB is an area bounded on all sides by roads and/or non‑visible boundaries of standard geographic areas. Unlike a DB, a COLB must respect the boundaries of both dissemination and collection geographic areas, not only the boundaries of dissemination geographic areas.

Hierarchical model of geographic areas for dissemination

Just as one can subdivide a population by sex, or into age and language groups, one can subdivide a population by different geographic areas. The geographic areas used for disseminating census data range in size from Canada, provinces and territories, all the way down to dissemination blocks, and are organized in a hierarchical model to illustrate the nature of their relationships to one another.

Standard geographic areas used for data dissemination and their relationships to one another are depicted in Figure 1.1 Hierarchy of standard geographic areas for dissemination, and can be found in the Dictionary, Census of Population, 2021, Statistics Canada Catalogue no. 98‑301‑X.

• Each box in the hierarchy chart represents an individual geographic level, which is composed of one or more geographic areas.
• The relative position of each geographic level in the chart shows how it can be subdivided or aggregated to form other geographic levels. For example, the national level can be subdivided into 6 regions which comprise 13 provinces and territories, which, in turn, are subdivided into 338 federal electoral districts, which comprise more than 400,000 dissemination blocks, the lowest level of standard geographic areas.
• The lines that join the boxes in the geographic hierarchy chart illustrate the relationship between the geographic areas that comprise each geographic level. In general, this is a ‘one-to-many’ relationship when moving from one geographic level down to a lower geographic level, for example, moving from 13 provinces and territories down to 338 federal electoral districts. From bottom to top, the relationship is ‘many-to-one.’
• Each branch of the geographic hierarchy illustrates how different geographic levels relate to the geographic areas of lower geographic levels. For example, the geographic hierarchy chart shows that dissemination areas (DAs) group together to form census subdivisions (CSDs); they also group together to form census tracts (CTs). However, there is no exact fit relationship between CSDs and CTs, and therefore, there is no line joining the CSD and CT boxes of these geographic levels within the geographic hierarchy chart.

The hierarchy of geographic areas: Understanding the hierarchy, how geographies are related and data analysis

The geographic hierarchy illustrates how one can carry out geographic analysis starting with higher-level geographic areas and moving to the lower-level geographic areas (a top-down approach). For example, one can start with Canada, and then look at each of the 13 provinces and territories, and continue by looking at individual or groupings of census divisions (CDs) and census subdivisions (CSDs). Conversely, using a bottom-up approach, one can start by examining specific individual lower-level geographic areas, CSDs for example, by comparing them with each CSD within a particular CD, and then comparing CDs within the same province or territory, and eventually within or among regions and Canada as a whole.

Geographic areas for dissemination

In Figure 1.1, Hierarchy of standard geographic areas for dissemination, found in the Dictionary, Census of Population, 2021, geographic areas used for disseminating data are depicted as being either administrative areas or statistical areas.

Administrative areas are defined, with a few exceptions, by federal, provincial or territorial statutes, and are adopted for the purposes of the census. Statistical areas, on the other hand, are defined by Statistics Canada in cooperation with stakeholders for the purpose of disseminating census data and complementing the structure of administrative areas.

The number of geographic areas by province and territory for the 2021 Census is presented in Table 1.1, Geographic areas by province and territory, of the Dictionary, Census of Population, 2021, Statistics Canada Catalogue no. 98‑301‑X.

Refer to the Introduction to the geography universe section of the Dictionary, Census of Population, 2021, Statistics Canada Catalogue no. 98‑301‑X, for definitions and more detailed information on each of the following administrative and statistical areas.

Administrative areas

• Canada
• Province or territory
• Federal electoral district (FED)
• Census division (CD)
• Census subdivision (CSD)
• Designated place (DPL)
• Forward sortation area (FSA)©
• Postal Code^OM

^OM: Postal code is an official mark of Canada Post Corporation.

Statistical areas

• Region
• Census agricultural region (CAR)
• Economic region (ER)
• Census consolidated subdivision (CCS)
• Aggregated dissemination area (ADA)
• Dissemination area (DA)
• Dissemination block (DB)
• Statistical Area Classification (SAC)
• Census metropolitan area (CMA) and census agglomeration (CA)
• Census tract (CT)
• Census metropolitan influenced zone (MIZ)
• Population centre (POPCTR)

Other

• Place name (PN)
• Blockface
• Census subdivision—previous census

Non-standard or user-defined geographic areas for dissemination

In most cases, the standard geographic areas for dissemination satisfy data user requirements for census data tabulations. However, there are also data users who require that data be tabulated for specific geographic areas that are not available for any of the standard geographic hierarchy depicted in Figure 1.1, Hierarchy of standard geographic areas for dissemination, Dictionary, Census of Population, 2021.

There are two basic types of non-standard or ‘user-defined’ geographic areas: areas that are customized aggregations of individual standard geographic areas, and areas that do not match the standard geographic areas at all. An example of the first type could be user-created sales regions within a metropolitan area, where the sales regions are created by combining one or more specific census subdivisions. An example of areas that do not match standard geographic areas could be user-defined market areas, school districts, or transportation and utility corridors. When data users require that census data be tabulated for non-standard geographic areas, they may turn to the Custom Area Creation Service provided by Statistics Canada (see Chapter 10 – Dissemination).

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