Introduction to the geography universe

The geography universe defines terms related to geographical concepts, infrastructure, products and services. The following summary denotes changes made to the geographic program for the 2011 Census. For further details, refer to the individual definitions of terms.

Geographic areas

Census data are disseminated for a number of standard geographic areas. These areas are either administrative or statistical. Administrative areas are defined, with a few exceptions, by federal, provincial and territorial statutes. Statistical areas are defined by Statistics Canada as part of the spatial frame for disseminating census data. Figure 1 shows the hierarchy of all standard geographic units for dissemination and Table 1 shows the distribution of geographic units by province and territory.

Updates for 2011

• Improved coverage and quality of Statistics Canada's geographic infrastructure
  
  The National Geographic Database (NGD) is a joint Statistics Canada/Elections Canada initiative to develop and maintain a national road network file which serves the needs of both organizations. Since 2001, the focus of the NGD has been on improving the quality and currency of its road network coverage using all provincially-sourced data. However, the following provincially/locally-sourced data have been used for geometric realignment: Digital Road Atlas (DRA) in British Columbia and Ontario Road Network (ORN) in six census divisions in Ontario (Halton, Hamilton, Ottawa, Peel, Toronto and Waterloo). Yukon, Northwest Territories and Nunavut now contain territory-sourced data. The result of this effort is a significant expansion of road names, civic address ranges and improved geometric accuracy.
  
  The NGD also contains separate reference layers comprising physical and cultural features such as water features, railway lines and power transmission lines.
  
  These improvements and expansions have been incorporated into Geography Division's Spatial Data Infrastructure (SDI). The result is that users of 2011 Census geography products such as road network files, boundary files and reference maps can geographically reference census data more accurately than before.
  
  
• Standard geographic areas
  
  For 2011, the term 'population centre' (POPCTR) replaces the term 'urban area' (UA). A population centre is defined as an area with a population of at least 1,000 and a density of 400 or more persons per square kilometre. All areas outside population centres continue to be defined as rural areas.
  
  Population centres are divided into three groups based on the size of their population to reflect the existence of an urban-rural continuum:
  
  
  • small population centres, with a population of between 1,000 and 29,999
  • medium population centres, with a population of between 30,000 and 99,999
  • large urban population centres, with a population of 100,000 and over.
  
  Users of the former urban area concept are able to continue with their longitudinal analysis using population centres.
  
  The terms 'core,' 'fringe' and 'rural area' replace the terms 'urban core,' 'urban fringe' and 'rural fringe' for the 2011 Census. Likewise, the term 'secondary core' replaces the term 'secondary urban core.' These terms distinguish between population centres (POPCTRs) and rural areas within a census metropolitan area (CMA) or a census agglomeration (CA).
  
  The 2011 delineation criteria for inclusion in the designated place (DPL) program have changed. The two 2006 delineation criteria which remain are the requirements that the area must be 10 square kilometres or less and that it not overlap the area of a POPCTR.
  
  New for 2011 is the removal of the requirement for a DPL to have a minimum population of 100 and a maximum population of 1,000. As well, there is no longer a requirement for a minimum population density of 150 persons per square kilometre. If, however, the population of the DPL exceeds 1,000 and the population density is at least 400 persons per square kilometre, then the DPL continues to be eligible to become a POPCTR. Population centres that are retired for 2011 due to population decline will still be assessed to determine if they are eligible to be DPLs. Finally, DPLs are no longer required to respect census subdivision (CSD) boundaries.
  
  
• Adjustment of population counts
  
  Statistics Canada is committed to protect the privacy of all Canadians and the confidentiality of the data they provide to us. As part of this commitment, some population counts of geographic areas are adjusted in order to ensure confidentiality.
  
  Counts of the total population are rounded to a base of 5 for any dissemination block having a population of less than 15. Population counts for all standard geographic areas above the dissemination block level are derived by summing the adjusted dissemination block counts. The adjustment of dissemination block counts is controlled to ensure that the population counts for dissemination areas will always be within 5 of the actual values. The adjustment has no impact on the population counts of census divisions and large census subdivisions. Population counts of federal electoral districts will be within 5 of the actual values. Dwelling counts are unadjusted.