Dictionary, Census of Population, 2021
Thematic map

Release date: November 17, 2021


A thematic map shows the spatial distribution of one or more specific data themes for selected geographic areas. The map may be qualitative in nature (e.g., predominant farm types) or quantitative (e.g., population percentage change).

Reported in

2021, 2016, 2011, 2006, 2001, 1996, 1991, 1986, 1981, 1976, 1971, 1966 and 1961


A thematic map is also called a special-purpose, single-topic or statistical map. It focuses on the spatial variability of a specific distribution or theme, such as population density or average annual income. It can be used for conducting exploratory spatial data analysis, confirming hypotheses, synthesizing spatial data by revealing patterns and relationships, and visualizing data.

A thematic map is composed of two elements: a base map showing locational or reference information, such as place names or selected bodies of water; and statistical data, which overlay the base map.

The statistical data can be symbolized with a variety of methods. Some common thematic maps produced at Statistics Canada are choropleth, graduated symbol, and dot maps. For the first two types, the data are classified into ranges, then displayed for a particular geographic area as either a colour or a symbol. In general, lighter colours or smaller symbols mean smaller data values, while darker colours or larger symbols mean larger data values. These maps use standardized data (ratios or percentages), rather than absolute values, to avoid the size of the geographic area influencing the data interpretation.

Dot maps use absolute data values, where one dot represents a certain number of units of the data. More dots within a particular geographic area indicate higher values of data. At Statistics Canada, this method of data visualization has been used to display where people live and work.

A smaller-scale thematic map may use the population ecumene, which shows only the parts of geographic areas where people actually live.

To ensure confidentiality, all census data are subject to random rounding or data suppression.

Refer to the related definitions of Ecumene and Reference Map.

Changes prior to the current census

Not applicable

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