About this product

Purpose of this product
Definitions and concepts
Content
General methodology
Limitations
Comparison to other products/versions
Using with other products
Reference date

Purpose of this product

The agricultural ecumene is designed to assist users in thematically mapping data. By effectively masking non-ecumene areas of Canada, it enables users to display data in areas where agriculture is concentrated.

An ecumene mask is useful for dot and choropleth thematic mapping. In dot map applications, if an ecumene is not applied, the dots may be spread over the spatial extent of a geographic area. This approach defeats the main attributes of dot mapping (i.e., showing correct location, extent and density of various characteristics).

In choropleth map applications, one of the inherent limitations is that the statistical distribution is assumed to be homogeneous or uniformly spread over each geographic area, and is consequently represented by a single tone or colour covering the entire area. Using an ecumene limits the display to only those areas where agriculture is found and results in a more accurate representation of the spatial distribution of data.

Figure 3.1
Example of an ecumene mask with the provinces and territories generalized cartographic boundary file

Description of Figure 3.1

Figure 3.1 Example of an ecumene mask with the provinces and  territories generalized cartographic boundary file

Definitions and concepts

Geographic terms and concepts are briefly defined in the glossary (Appendix A). More details can be found in the 2011 Census Dictionary(Catalogue no. 98-301-X) and the 2011 Illustrated Glossary (Catalogue no. 92-195-X).

Content

The Agricultural Ecumene Boundary File consists of four spatial files:

  1. Ecumene mask file
    The ecumene mask consists of polygons flagged with a value: 1, being in the ecumene; 0, outside the ecumene. All non-amalgamated census divisions with reported agriculture are represented in the ecumene.
  2. Census division boundary file
    The census division boundary file contains census division boundaries. Related attribute information is available for each census division polygon, including a unique identifier, name and type.
  3. Province and territory boundary file
    The province and territory boundary file contains the boundaries of the provinces and territories. Related attribute information is available for each province and territory polygon, including a unique identifier, English name, French name, English abbreviation and French abbreviation.
  4. Hydrographic reference file
    The hydrographic reference file contains a selection of lakes. Each hydrographic feature contains a unique identifier.

All spatial files are available in English and in French, in three formats: ArcGIS® (.shp), Geography Markup Language (.gml) and MapInfo® (.tab).

General methodology

The National Geographic Database (NGD) is a joint Statistics Canada-Elections Canada initiative to develop and maintain a spatial database which serves the needs of both organizations. The focus of the NGD is the continual improvement of quality and currency of spatial coverage using updates from provinces, territories and local sources. The native files used for the creation of the Agricultural Ecumene Boundary File, Census year 2011, reside on Statistics Canada's Spatial Data Infrastructure which was derived directly from data stored on the NGD .

The reference files that make up the agricultural ecumene were created using the following processes:

Agricultural Ecumene Boundary File

A) Ecumene mask file

The ecumene mask file was created by using the land area and the current census agricultural data to calculate the importance of agricultural activity in each dissemination area (DA). Every DA was then classified as either being an ecumene area (meeting the agricultural activity criteria based on land use and sales) or being a non-ecumene area (those without significant agricultural activity). The resulting ecumene outline was smoothed and buffered to facilitate small scale mapping.

The dissemination areas included in the agricultural ecumene boundary layer were selected according to three separate, but complementary, indicators of agricultural intensity. The primary indicator was the ratio of total agricultural land to total DA land area. Agricultural land included all land in the DA devoted to crops (including Christmas trees), summerfallow, tame or seeded pasture, and natural land for pasture. This ratio was calculated for each DA within a province and the DAs sorted in descending order, starting with the largest ratio. DAs were selected for inclusion in the agricultural ecumene until the cumulative total area of the selected DAs exceeded a pre-determined percentage of the total agricultural land area for the province.

The second indicator of agricultural intensity was the ratio of total agricultural receipts to total DA land area. This is particularly important for DAs containing farms with large sales on a relatively small land base, such as greenhouses or feedlots. This ratio was also calculated for all DAs in a province and the DAs sorted in descending order. Using the same principle as for the previous indicator, DAs were selected for inclusion in the ecumene until the cumulative total area of the selected DAs exceeded a pre-determined percentage of the total agricultural land area for the province.

The third indicator was to include all DAs in a province that exceeded not only a specific agricultural land total but also a certain ratio of total agricultural land to total DA land area. The final list of selected DAs in a province consisted of all DAs meeting the criteria for one or more of the three indicators, and ensured that the ecumene reflected those areas of significant agricultural activity in a province.

This DA selection process was successful in all provinces except Newfoundland and Labrador. The poor results in this province were due primarily to a combination of many large DAs in the province and a limited and localized pattern of agricultural activity. As a result, the DA selection process was replaced with a procedure that identified and selected smaller areas of significant agricultural activity within dissemination areas. The territories were not included in the delineation of the agricultural ecumene.

A base ecumene layer was created by integrating the selected DAs in nine provinces with the selected DA components in Newfoundland and Labrador. Every DA or DA component polygon was classified as either being an ecumene DA (meeting the agricultural activity criteria) or not being an ecumene DA. This base layer was divided into three component layers: main ecumene, other ecumene pockets (outside the main ecumene) and non-ecumene pockets (within the main ecumene). Three subsequent steps generalized the base layer into an agricultural ecumene boundary layer suitable for small-scale mapping of census division data.

First, internal non-ecumene pockets and external ecumene pockets too small to be visible at small scale were eliminated. Second, the detailed boundaries of the remaining external ecumene pockets were smoothed (generalized) and enlarged to increase their visibility on small-scale maps. Third, the detailed boundaries of the large internal non-ecumene pockets and main ecumene were smoothed. The smoothing process incorporated the use of satellite imagery within large marginal DAs in order to give a more realistic ecumene.

The ecumene was also extended to include at least one portion of each census division that contains Census of Agriculture data for 2011.

B) Creation of the generalized cartographic boundary files

To create the generalized cartographic boundary files, a subset of the full hydrography, the coastal layer, was created.

Using the source hydrography file, all generalized coastal water features were extracted. Hydrography features were then dissolved to create one coastal file used in the creation of the generalized province and territory and census division boundary files included in this product.

The coastal hydrographic features were then used to erase the portions of census divisions that are covered by coastal waters. Subsequently, the province and territory file was derived from the census division file.

C) Creation of the hydrographic reference file

The hydrographic reference file contains a selection of water features from the National Geographic Database's hydrographic reference layer. These reference data were sourced from the National Topographic Data Base (1:50,000 and 1:250,000) and the Digital Chart of the World (1:1,000,000). In British Columbia, information was supplemented with data from the National Hydro Network. All small islands were transformed into water polygons.

Final data processing consisted of the conversion from the File Geo Database format, using FME® (Safe Software), into the following Geographic Information System (GIS) file formats: ArcGIS® (.shp), Geography Markup Language (.gml) and MapInfo® (.tab).

Limitations

The positional accuracy of these files does not support cadastral, surveying, digitizing or engineering applications.

The input data used to create the files were obtained from several sources having a wide range of scales. Maps created from the Agricultural Ecumene Boundary File should not be used to determine the precise location of boundaries.

Comparison to other products/versions

The Agricultural Ecumene Boundary File is generalized to render it suitable for cartographic display at a small scale (i.e., 1:20,000,000 to 1:25,000,000). Due to this generalization, the position of the shoreline is not necessarily consistent with the suite of census cartographic boundary files.

The Agricultural Ecumene Boundary File is similar but not necessarily consistent with ecumene boundary files released prior to the 2011 Census.

Using with other products

The Agricultural Ecumene Boundary File can be linked to other 2011 Census statistical data products using the unique identifier (UID) for each geographic area.

The Agricultural Ecumene Boundary File is generalized to render it suitable for cartographic display at a small scale. Due to this generalization, the position of the shorelines are not necessarily consistent with the suite of 2011 Census Cartographic Boundary Files or 2011 Census Road Network File.

When considering using the Agricultural Ecumene Boundary File, users should be aware of the compatibility of these files with those that are available from other sources. They may not be consistent with Statistics Canada files.

Reference date

The geographic reference date is a date determined by Statistics Canada to finalize the geographic framework for which 2011 Census statistical data are collected, tabulated and reported. The reference date for 2011 Census standard geographic areas is January 1, 2011. More specifically, the census reports data according to the geographic areas (e.g., municipalities and equivalents referred to as census subdivisions) that are in effect on January 1, 2011, provided that Statistics Canada receives the information on the changes by March 1, 2011 (see 2011 Census Dictionary – Geographic reference date for more details).

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