1. Creating Historical Digital Census Boundary Maps for  Canada - a pilot project
Andrey Petrov, Laine Ruus,
Data and GIS Services,
University of Toronto
Presented at CAPDU & IASSIST 2007 (r3)

2. Outline
Background
The project
The result

3. Background
The basic building block of all larger census geographic areas in Canada has until recently (1996) been the enumeration area (EA)
EAs are defined as the geographic area canvassed by one census enumerator during the population census
EAs have not been geostatistically stable over time.

4. EAs are stackable, therefore can cover >100% of the land area
Bg contd
EAs are stackable, therefore can cover >100% of the land area
EAs are the smallest geographic area for which census statistics have been released since 1961
The number of EAs changes from census to census

6. Bg contd
EA-level aggregate statistics have been produced and disseminated by Statistics Canada since 1961

8. Availability of census boundary files & reference maps
Reference maps (raster/print) at the EA-level are available for the following census:
1971, 1981, 1986, 1991, 1996, 2001, 2006
STC scanned to tiff: (EAs and urban CTs)
Boundary files (vector files) at the EA-level are available for the following census:
1981 (at STC, some lost), 1986, 1991, 1996, 2001, 2006
Canadian Land Inventory EA boundaries from 1971 & 1976

9. summary of availability:
descriptive and
boundary data
availability:

10. Bg contd
Demand for historical census data revitalized with release of each new census

12. STC has previously done tests of:
bg contd
STC has previously done tests of:
Calgary – 1981 census
Kitchener-Waterloo – 1981 census
Québec – 1981 census

13. Our project
Create a historical digital census boundary files for province of Saskatchewan at EA level for 1976 & 1981 (projected to NAD83)
Why Saskatchewan?
simple geometry, only 2 CMA/CAs
modest census-to-census boundary changes
no changes to Representation Order (Federal electoral district boundaries)

14. Proj contd
Objectives
Test alternative methods of re-creating historical EA boundary files
Assess problems and advantages of each method
Evaluate feasibility of extending the project to create a national coverage of historic census maps

15. Resources used: Proj contd
Canadian Land Inventory boundary files for 1976 (rural boundaries only)
STC digital boundary files of Regina & Saskatoon
Geography attribute files 1976 & 1981
EA conversion file
Area master file/road network files
Scanned raster/analog maps of EA boundaries for Regina, Saskatoon, and rest of Saskatchewan, 1976 & 1981

16. Proj contd
Design requirements
Use only existing data available for the entire country
Develop a repeatable, time & resource efficient method
Miminize manual components
Provide GIS-ready digital output
Ensure compatibility with other STC datasets (1996 geographic base)

18. And the result Vectorizing from raster maps proved not feasible
Project successfully produced EA boundary files for 1976 and 1981 for
Regina and Saskatoon CMAs
Remainder of the province:
58 CSDs missing in 1976
78 CSDs missing in 1981

19. Inadequate and varying quality of scans
Cluttered with secondary features (lines, labels, grid, etc.)
Dashed lines
All made successful automated vectorization extremely difficult

20. Scope of changes:

21. Extent of changes in Regina and Saskatoon 1976-1981

24. Resources required
Hardware: minimum 3.4 GHZ processor, 2GB RAM, 80 GV hard drive, 256 MB multi-port video card
Software: ArcGIS 9.x or higher, full package
Wetware: 155 hours, intermediate to advanced GIS skills
(average 3.0 to 5.0 minutes per EA)

25. Where does the project go from here?
Whatever Paula Hurtubise said this morning………..

26. Project materials Report:
Zip file of all project files, including outputs: