3. How to use this product

Purpose of the product
Content
Limitations
Comparison with other products
Comparison to the 2001 Population Ecumene

Purpose of the product

The population ecumene is designed to allow users to thematically map data. By effectively masking non-ecumene areas of Canada, it enables users to display data only where population is concentrated (where there are ecumene pockets). Data that describes population characteristics can be assigned to and displayed within the ecumene permitting a more accurate representation.

Content

The 2006 Population Ecumene Census Division Cartographic Boundary File consists of four files: an ecumene mask file; a census division boundary file; a province/territory boundary file; and a hydrography (major internal lakes) file.

1. The ecumene mask file

The ecumene file is a mask consisting of pockets (polygons). Every polygon contains a Boolean value - either 1, being in the ecumene or 0, those sparsely populated areas that are outside the ecumene. There is at least one ecumene pocket in every census division of Canada.

2. The census division boundary file

The census division boundary file is a layer of polygons for each census division. Each census division polygon contains a unique identification code (the CDUID) and a name as an attribute. This file allows the display of census division boundaries on a map of the population ecumene.

3. The province/territory boundary file

The province/territory boundary file consists of polygons for each province. Each province/territory polygon has a unique identification code (the PRUID) and a name as an attribute. In addition, both English and French names, together with their abbreviations, are included as attributes. This boundary file is provided solely for displaying provincial and territorial boundaries on a map of the population ecumene.

4. The hydrography (major internal lakes) file

New to this product, the major lakes are included as a separate file. The file contains no attributes as it is provided for reference purposes only.

Figures 3.1 through 3.5 provide a visual representation of how these different layers are built up to provide a complete map. This map provides an accurate visual representation of the spatial distribution of population characteristics within Canada.

The use of an ecumene mask is particularly recommended for dot and choropleth maps. If an ecumene is not applied to dot maps, the dots may be randomly spread over the spatial extent of a unit. This approach defeats the main attributes of dot mapping (i.e., showing correct location, extent and density of various characteristics). Similarly, one of the inherent limitations of choropleth maps is that the statistical distribution is assumed to be homogeneous or uniformly spread over each unit area, and is consequently represented by a single tone or colour covering the entire unit. Using an ecumene limits the display to only those areas where population is found and results in a more accurate depiction of the spatial distribution of data.

Limitations

The data used to create the 2006 Population Ecumene Census Division Cartographic Boundary File are based on source data with a wide range of scales. Maps produced from this source will not be precise if plotted at a larger scale than the scale of the source material used in its creation.

The 2006 population ecumene, together with the surrounding shoreline and major internal lakes, is generalized to render it suitable for cartographic display at a small scale (1:20,000,000 to 1:25,000,000). Because of this generalization, the position of the boundaries and shorelines are not compatible with the 2006 Census Cartographic Boundary Files, Road Network File or Road Network and Geographic Attribute Files. Similarly, the product does not support cadastral, surveying or engineering applications.

Comparison with other products

• Due to the extensive generalization and the use of a different generalized coastline, the 2006 Population Ecumene Census Division Cartographic Boundary File is not compatible with other 2006 Census Boundary File products or other spatial files.
• Due to the changes in boundaries and the use of a different generalized coastline, the 2006 Population Ecumene Census Division Cartographic Boundary File is not compatible with the 2001 Census Boundary File products or other spatial files.

Comparison to the 2001 Population Ecumene

The 2006 Population Ecumene Census Division Cartographic Boundary File is derived in the same fashion as the 2001 ecumene, using the dissemination block. However, there are a few significant changes worth noting. The coastline and the large interior lakes are generalized using the hydrography created for the 2006 Census Cartographic Boundary Files.

In 2001, census division boundaries were integrated into the ecumene pockets of the mask. In the 2006 product, the mask is separate from the census division layer to facilitate thematic mapping.

The census division boundaries within the 2006 Population Ecumene Census Division Cartographic Boundary File are updated to reflect boundary changes and are not compatible with the census division boundaries contained in the 2001 Population Ecumene Census Division Cartographic Boundary File.