Dictionary, Census of Population, 2021
National Geographic Database (NGD)

Definition

The National Geographic Database (NGD) is a spatial database that contains attributed roads (names and addresses) and boundaries used to delineate administrative and statistical geographic entities such as provinces, municipalities, census tracts and health regions. The fundamental components of the NGD include a road and boundary line layer fully integrated with a polygon layer. The road and boundary line layer defines polygons, which are then aggregated into the various statistical and administrative geographies. Road attribution from the line layer, specifically road name and address range, is also used to determine the location of buildings and place them into specific geographies based on the road and line layer relationship to the polygons. The collection and dissemination of socioeconomic data can therefore be organized into a geographic framework as a result of the NGD line and polygon relationships. The NGD is a shared database between Statistics Canada and Elections Canada, as both agencies have shared requirements for an attributed road network to conduct their respective business, and collective maintenance reduces costs.

Reported in

2021, 2016, 2011 and 2006

Remarks

The National Geographic Database (NGD) began in 1997 as a joint Statistics Canada and Elections Canada initiative to develop and maintain a national road network geospatial database serving the needs of both agencies. Initialization using spatial data from Statistics Canada, Elections Canada and Natural Resources Canada occurred from 1998 to 2000. Statistics Canada and Elections Canada then reconciled their respective digital boundary holdings to the NGD road network geometry so that operational products could be derived.

From 2001 to 2008, the NGD focused on data quality improvements related to the content and currency of road network coverage, including road names and civic address ranges. In 2009, a major redesign of the NGD was undertaken that updated the underlying technology, improved the data model, and enhanced maintenance concepts and activities.

From 2009 to 2015, the NGD improved road network geometric accuracy by aligning GPS-compliant provincial road network sources. This activity was completed for British Columbia and six census divisions in Ontario, specifically Halton, Hamilton, Ottawa, Peel, Toronto and Waterloo, for the 2011 Census. Yukon, Nunavut and the Northwest Territories were also aligned to more accurate geometry, where available, during this time. For the 2016 Census, the remainder of Ontario was completed, as were the provinces of Prince Edward Island, Nova Scotia, Alberta, New Brunswick and Quebec. By 2018, the remaining provinces of Newfoundland and Labrador, Manitoba, and Saskatchewan had their road alignment completed.

Prior to 2020, the NGD maintained its own version of hydrography for boundary reference and alignment based on data from the original build, with periodic improvements such as hydrographic name improvements, adoption of the National Hydrographic Network in British Columbia in 2009, and the move from 1:1M to 250K representation in the north. In 2018, to facilitate data interoperability, the decision was made to adopt Natural Resources Canada's Topographic Data of Canada CanVec 1:50K hydrography representation. From 2018 to 2020, the NGD aligned boundaries coincident with hydrography to the more current, accurate and consistent CanVec hydrographic features.

The NGD road network is constantly improved based on external data sources and geocoding feedback of administrative files to ensure road network currency and address range accuracy. Sources include provincially sourced datasets, field operation activities, and municipal and private sector licensed holdings. Priorities for road network file maintenance are determined by Statistics Canada and Elections Canada, enabling the NGD to meet the joint operational needs of both agencies in support of census and electoral activities.

The data are maintained and stored in the Lambert Conformal Conic projection based on the North American Datum of 1983 (NAD83).

Refer to the related definitions of Coordinate System; Datum; Map Projection and Spatial Data Infrastructure (SDI).

Changes prior to the current census

Not applicable