Land area

Part A - Short definition:

Number of square kilometres of land in a given geographic area (e.g., a province, a territory, a city).

Part B - Detailed definition:

Land area is the area in square kilometres of the land-based portions of standard geographic areas. Land area data are unofficial and are provided for the sole purpose of calculating population density.

Census years:

2011, 2006, 2001, 1996, 1991, 1986, 1981, 1976, 1971, 1966, 1961

Remarks:

Land area data for the standard geographic areas reflect the boundaries in effect on January 1, 2011 (the geographic reference date for the 2011 Census of Canada). The data are available for all standard geographic areas.

The data are derived from the Spatial Data Infrastructure (SDI), including water polygon layers used in the process for calculating land area. The area calculations are computed from data that are transformed from a Lambert conformal conic projection to an Albers equal-area projection, since the properties of an equal area projection are indispensable for calculating land area. The same projection parameters (two standard parallels, central meridian and latitude of projection origin) are used for each province or territory.

Land area is calculated using ArcGIS^® software. There is a two-stage aggregation procedure. First, the data are calculated and stored in square kilometres at the census block (CB)^{Footnote 1} level to eight decimal places and then aggregated to the dissemination block (DB) level and rounded to four decimal places. Second, the DB data are individually aggregated to each higher level standard geographic area.

Since the Spatial Data Infrastructure (SDI) is a digital base using three input map scales (1:50,000, 1:250,000 and 1:1,000,000), greater land area accuracy is achieved at larger scales – that is, there is less generalization regarding the symbolization and number of hydrographic features. Land area errors may occur due to digitizing or linkage discrepancies, and when water polygons do not line up or are symbolized differently between different map scales.

The source layer for water has changed in British Columbia for 2011. This may result in varying land area calculations as compared to previous censuses. Users should note that even where the boundaries of standard geographic areas did not change between censuses, the land areas may differ due to geometry shifts. The shifts are caused by a change in the underlying database architecture and by improvements in the absolute positional accuracy of some of the roads.

Refer to related definitions of dissemination block (DB); geographic reference date; population density and Spatial Data Infrastructure (SDI).

Changes prior to the current census:

For 2006, the data were derived from the Spatial Data Infrastructure (SDI) geospatial layers, including selected water polygons. Land area data were calculated using ArcGIS^® software. The data were calculated and stored at the basic block (BB)^{Footnote 2} level at eight decimal places and then aggregated to the dissemination block (DB) level and rounded to four decimal places. The DB data were then individually aggregated to all higher level standard geographic areas. Land area data were not disseminated for basic blocks.

For 2001, land area data were calculated using ArcGIS^® software. Separate projection parameters (two standard parallels, central meridian and latitude of projection origin) were used for each province or territory. As well, there was only a one-stage aggregation procedure. The data were calculated and stored at the basic block (BB) level at eight decimal places and then aggregated to all higher level geographic areas and rounded to four decimal places. Land area data were not disseminated for basic blocks.

Prior to 2001, land area was manually calculated using a planimeter. Measurements were normally taken three times for each geographic unit and then averaged. The map scales generally varied between 1:50,000 and 1:250,000. In densely and sparsely populated regions of Canada, larger or smaller scales may have been used. Only discernible bodies of water found on the maps were excluded. The planimeter gave accurate readings for only small zones – and consequently, large geographic units were subdivided into smaller ones and measured individually; the individual parts were then added together.

Boundaries that changed from one census to another were not measured in their entirety. Only the land area gained or lost due to a boundary revision/update was measured, and then added to or subtracted from the original figure.

Land area measurements for census subdivisions (CSDs) were aggregated to obtain the land areas for the higher level geographic units – namely, primary census metropolitan areas/primary census agglomerations (PCMAs/PCAs), census metropolitan areas/census agglomerations (CMAs/CAs), census consolidated subdivisions (CCSs), census divisions (CDs), economic regions (ERs), and provinces/territories. Land area measurements were done separately for urban areas (UAs), designated places (DPLs) and census tracts (CTs). Data were not available for enumeration areas (EAs) and federal electoral districts (FEDs).

The land area data were subject to a number of errors, including measurement, coding and transcription, and processing errors – and overall, cumulative historic errors. As well, a limited number of tests revealed logical inconsistencies; for example, there were cases where the land area was greater than the total area.

Prior to 1996, some CSDs had land areas of zero (0) because their official limits were unknown.

For 1991, land area was called 'net land area.' Prior to 1976, land area data were expressed in square miles only.