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Geo-referenced data and DLI aggregate data
sources
Chuck Humphrey
University of Alberta
ACCOLEDS 2007
Geo-referenced data
This presentation provides an introduction to
aggregate data sources, primarily from
Statistics Canada, that may be of value to
those using GIS to explore the spatial
distribution of Canadian socio-economic
characteristics.
To be of use to GIS researchers, these
aggregate products must contain geo-
referenced data.
Geo-referenced data
What are geo-referenced data?
Aggregate data, which are often organized
in multi-way tables, containing at least one
variable representing a specific spatial unit
in which the geo-codes are based on a
standard geographic classification and/or
have corresponding boundary files using
the same geo-coding system.
A spatial unit is the geographic area used
as the unit of analysis to structure the data.
The geography perspective
Geographic areas will define the spatial units and the geo-codes assigned to these spatial units are necessary to match geo-referenced data.
Spatial Unit
Geo-codes
The geo-referenced data
perspective
The unit of analysis, which defines the structure of a
data file, is in this case a spatial unit.
The Unit analysis makes up the rows in the
data file and is the object being described
by the other variables the file.
Geo-referenced data strategies
For a GIS user, we want aggregate data files
where the variables summarize social and
economic characteristics over spatial areas
and the data file is structured with the spatial
unit as the unit of analysis.
We want the spatial unit in the data file to
correspond with our GIS user’s boundary file.
We want the variable representing the spatial
unit to use the same geo-codes that match our
GIS user’s boundary file.
The Census
The Census is one of the most important sources of geo-referenced data. It is the largest survey conducted in Canada and, consequently, is the primary source of statistics for small areas.
To use geo-referenced data from the Census, you must know: The variety of spatial units used to disseminate
Census results;
The codes used to represent the various Census spatial units; and
The aggregate characteristics from the Census available for the various spatial units.
1: The variety of spatial units
Statistics Canada groups the variety of spatial
units associated with the Census into two
groups:
Source for the graphics: Illustrated Glossary, 2006 Census Geography, Statistics Canada
Administrative areas Source: Illustrated Glossary, 2006 Census Geography, Statistics Canada
Statistical areas Source: Illustrated Glossary, 2006 Census Geography, Statistics Canada
2: Census geo-codes
Statistics Canada has two categories of geo-
code systems:
Standard Geographic Classification (SGC)
Other geographic entities
Source for the graphic: Illustrated Glossary, 2006 Census Geography, Statistics Canada
Standard geographic
classification
Source: Illustrated Glossary, 2006 Census Geography, Statistics Canada
Standard geographic
classification, 2006
The link to
Definitions, data
sources and
methods on the
main page of the
Statistics Canada
website provides a
link to Standard
Classifications,
which includes
Geography.
Standard geographic
classification, 2006
From the link for
the province
codes, census
divisions can be
identified. For
example, click on
59 for BC and the
list of census
divisions is
presented.
Standard geographic
classification, 2006
Click on the link for
the census division
for Nanaimo (5921)
and the list of
census subdivisions
within this CD is
provided.
Standard geographic
classification, 2006
Click on the link for
the census
subdivision for the
city of Nanaimo and
the breakdown of
the SGC is
provided along with
other geographic
codes.
Other geographic codes
Under the information provided for the Standard
Geographic Classification, coding systems for
four additional spatial units are listed :
Census metropolitan areas and census
agglomerations;
Economic regions;
Health regions; and
Countries.
Source: Illustrated Glossary, 2006 Census Geography, Statistics Canada
Dissemination areas
Dissemination areas
Let’s add a DA-level to the SGC!
The geo-code for DA’s uses the
Standard Geographic
Classification and an added,
unique four digit numeric code.
For Nanaimo, the CSD code is:
59 BC
21 Nanaimo RD
007 Nanaimo City
5921007
Dissemination areas
Dissemination areas
The Census aggregate data at the DA level are available using two different geo-codes schemes (shown on the next slide).
For GIS users working with the spatial data files from the 2001 Census, caution them about these two different geo-coding schemes at the DA level. They will want to use the eight-digit code to be able to work directly with the spatial data files provided by Statistics Canada.
8-digit DA-level code
PR(2)-CD(2)-DA(4)
11-digit DA-level code
PR(2)-CD(2)-CSD(3)-DA(4)
8-digit DA
11-digit DA
Dissemination areas
3: Aggregate characteristics
Profile series and basic tabulations
Aggregate Census results are disseminated in two primary products: profile series and basic tabulations.
The Profile series is available at all levels of geography disseminated by Statistics Canada and consists primarily of counts for all the response categories to questions in the 2B form. In 2006, the 2B form consisted of the eight questions asked on the 2A form plus an additional 53 questions. This series is the most frequently used by GIS researchers on our campus.
Profile series breakdown
Spatial Unit Number of Characteristics
CSD 1709
DA 1490
CMA/CA 1709
CT 1709
FSA 1706
Federal District 1716
Health Regions 1236
Basic tabulations
Basic tabulations are n-way tables showing
the results for combinations of Census
questions. The more the variables included
in the table, the higher the level of
geography that is reported. Few of these
tables are below the CSD, CMA/CT level,
although always check. For example, in
2001 Religion (13) by Age (8) is available at
the DA level.
Aggregate Census data
Want data at the CT-level or higher?
E-STAT has these data in Beyond 20/20, DBF,
CSV, Tab-delimited format.
Available in Beyond 20/20 format on the
Statistics Canada website with level 2 access
and from the DLI FTP site.
Want data at the DA-level?
Available through the DLI FTP site or local DLI
member aggregate Census file servers.
Other Geo-referenced data
Other important aggregate data sources
from Statistics Canada include Health,
Justice, Education, Business, Environment
and some customized products.
Not all of these, however, have compatible
spatial boundaries with the Census.
Some may make reference to metropolitan
areas but not use the Census geo-codes for
Census Metropolitan Areas.
Health
Health Region is the administrative area in
which health care is delivered in Canada.
As administrative areas, Health Regions are
determined by the provinces. Statistics
Canada creates a customized product from
the Census aggregating results using
Health Region boundaries.
Health Indicators and Community Profiles
are the two key sources for Health Region
aggregate data.
Health
CIHI is responsible for disseminating
statistics about the health care system at
the Health Region level. The CIHI site
provides maps without the data for a few
indicators. The database, Regional
Contextual Information for Health Regions with over 75,000 Population, appears to be the only data source on
the CIHI site for Health Regions.
Justice
The table may refer to jurisdiction instead of geography.
Justice tables
Table 253-0004 - Homicide survey, number and rates (per 100,000 population) of homicide victims, by census metropolitan area
Refer users to http://www.statcan.ca/english/sdds/3315.htm
Report homicides according to four population sizes: 500K +, 250-499K, 100-249K and < 100K
Group metropolitan areas under these categories
Justice
Justice
Justice
Justice tables
Police Administration Survey - Municipal Police
Force Administration Character, 1986 - 2006
866 municipal police force jurisdictions
The geo-code for municipalities consist of the
standard geography classification for provinces
(2-digit codes) followed by 3-digit codes that
don’t correspond to Census geography but do
correspond with the Uniform Crime Report police
force codes
Justice
Nanaimo 59904
Justice
Justice tables
Uniform Crime Survey – Crime Statistics, All
Police Services, 1977 - 2003
“There are approximately 1,200 separate police
locations responding to the survey, comprising
about 220 different police forces.” Canadian
Crime Statistics, 85-205-XIE, p. 73.
This table contains 2,711 police detachments,
some no longer operational.
The geo-code corresponds to the Police
Administration Survey: 2-digit province code and
3-digit detachment code.
Justice
Nanaimo 59904 and 59905
Education
The Education tables on the DLI FTP site provide provincial level summaries and for some post-secondary related tables, institution names are provided. No Census spatial units, other than province, are used among this tables.
The Statistics Canada website contains the Report of the Pan-Canadian Education Indicators Program. Includes the use of CMA and non-CMA reporting for some tables. Names and not geo-codes are used to identify CMA’s.
Business
Canadian Business Patterns reports the
number of establishments by industrial
classification and size of workforce. These
aggregate data are available for CD, CSD
and CMA/CA levels of Census geography.
The data also provide a time series at these
geographic levels since 1998 for both the
NAICS and SIC industry classifications.
CANSIM
CANSIM is primarily a time series database
but every time series is placed in the
context of some level of geography. One
can search table titles for geography terms
but cannot currently search just the
geography field within each series.
Odds and ends
Survey of Household Spending Equipment (62F0041XDB): 17 metropolitan areas
Spending (62F0031XDB): 17 metropolitan area
Canada Revenue Agency Provincial level statistics summaries from tax
returns.
Environment Canada data sources use postal codes in some instances
Environment Human Activity and the Environment: Annual
Statistics Product (16-201-XWE)
Available in CANSIM series, too