April 2004 Ontario DLI training
Mapping Census Data
in ArcView 3.x
Nancy Lemay
University of Ottawa
Barbara Znamirowski
Trent University
April 2004 Ontario DLI training
Workshop Outline
• Defining certain concepts and terms: Map scale,
coordinate systems, datum and projections.
We will try to
understand
these
concepts
April 2004 Ontario DLI training
Workshop Outline (cont’d)
• Understanding different file formats:
- “.e00”, “.shp”, “.shx”, “.dbf”, “.sbn” and “.sbx”.
• Introduction to ArcView and its components.
• Hands-on exercise using census data and cartographic
boundary files (CBF).
April 2004 Ontario DLI training
Map Scales
A defined dimensional relationship between reality and the map (Robinson et al., 1995):
a) Verbal: “one cm represents ten kilometers”
b) Representative fraction: 1:10,000
c) Graphic scale:
d) Area scale:
Represents square kilometers
5 0 0 0 0 5 0 0 0 1 0 0 0 0 M e t e r s
April 2004 Ontario DLI training
Calculate Map Scales
• For example, if 2 cm on a map represents 1 km on the
ground the scale would be 2 cm = 1 km, or...
• Scale is “unitless” because it is a ratio.
April 2004 Ontario DLI training
Examples small vs. large scale
Small scale: 1:250,000
Large scale: 1:50,000
April 2004 Ontario DLI training
Coordinate systems
• A coordinate system is a reference system based on
mathematical rules for specifying positions (locations)
on the surface of the earth. The coordinate values can
be spherical (latitude and longitude) or planar (such as
Universal Transverse Mercator).
• A coordinate system is usually defined by a datum,
ellipsoid and projection, and is specified in terms of
units (e.g. degrees, meters).
April 2004 Ontario DLI training
Types of Coordinate Systems
Geographic coordinate system:
– Uses latitude and longitude for locating positions
on the uniformly curved surface of the earth.
Rectangular/plane coordinate systems:
– Used to locate positions on a flat map.
– For example Universal Transverse Mercator
(UTM)
April 2004 Ontario DLI training
Geographic Coordinate System
• The Equator (latitude) and Prime Meridian (longitude) are the
reference points. Usually Greenwich, England is the Prime
Meridian.
• The Cartographic Boundary Files, the Road Network Files and
the representative points are disseminated in latitude/longitude
coordinates.
Prime meridian
Equator
April 2004 Ontario DLI training
Decimal Degrees (DD)
• Decimal degrees are similar to degrees/ minutes/seconds
(DMS) except that minutes and seconds are expressed as
decimal values.
• Decimal degrees make digital storage of coordinates easier
and computations faster.
60.34444 instead of 60º20'40"
April 2004 Ontario DLI training
Example: Converting DMS to DD
20 minutes.= 0.33333 (20/60)
40 seconds = 0.01111 (40/3600)
Add up the degrees to get an answer:
60º + 0.33333 + 0.01111=60.34444 DD
60º20'40" degrees
minutes
seconds
April 2004 Ontario DLI training
Ellipsoid (Spheroid) and Geoid
• Ellipsoid - used as a reference of the earth’s surface for the
mathematical model of the earth. Mathematical
approximation of the geoid.
• Geoid - estimates the earth’s surface using mean sea level
of the ocean with all continents removed.
April 2004 Ontario DLI training
Datum
• Geodetic reference system that specifies the size and shape of the earth.
• Base point from which the latitude and longitude of all other points on the earth's surface are referenced.
• Two types of datums: (1) Earth-centered (WGS84, NAD83), (2) Local (NAD27, ED50).
• The spatial data disseminated for the 2001 Census are based on the North American Datum of 1983 (NAD83).
http://www.geod.nrcan.gc.ca/index_e/geodesy_e/reference04_e.html
April 2004 Ontario DLI training
Map Projections
• Process of transforming and representing positions on the
earth's three-dimensional curved surface to a two-
dimensional (flat) surface.
• The process is accomplished by a direct geometric
projection or by a mathematically derived transformation.
For more information: http://mac.usgs.gov/mac/isb/pubs/MapProjections/projections.html
Use projected
spatial data to calculate
distance!!
April 2004 Ontario DLI training
Map Projections Examples
Lambert Conformal Conic Cylindrical Equal Area
Mollweide’s
Good for middle latitudes.
Good for directional and shape relations along large east-west mid-latitudes.
Preferred for world maps.
April 2004 Ontario DLI training
Different File Formats
Shapefile “.shp” is used in ArcView and ArcGIS and is accompanied by the following auxiliary files:
• “.dbf” the dBASE file that stores the attribute information of features. Required.
• “.shx” the file that stores the index of the feature geometry.
• “.sbn & .sbx” the files that store the spatial index of the features.
• “.prj” - the file that stores the coordinate system information.
• “.xml” - metadata for ArcInfo 8.0, for using shapefiles on the Internet.
Coverages are often published in a compacted form with the extension “.e00”:
• Proprietary file format used to distribute Arc/Info datasets. Topology and attributes are properly maintained in this format.
April 2004 Ontario DLI training
ArcView Project File
• The ArcView “.apr” file contains the project information.
• Features are stored:
• view properties
• theme information
• layout information
• other types of information are stored.
• Return to the project without having to re-load all the
associated files.
April 2004 Ontario DLI training
StatCan Spatial File Naming
Convention First Character: projection of file: “g” if projection is Geographic
Latitude/Longitude and “l” if projection is Lambert Conic Conformal.
Next three characters: primary geographic boundary of file, for
example “csd”.
For example:
gcsd035b02a_e.exe
April 2004 Ontario DLI training
Next three Numbers: geographic code of coverage, for example 035.
Next character: file type (based on 1996 codes). a if digital boundary file (for Dissemination Warehouse only) (DBF in 1996)
b if Cartographic Boundary File, detailed coverage for large-scale mapping
c if detailed interior lakes hydrographic coverage
e Ecumene
r Road Network Files (RNF and SRNF)
For example:
gcsd035b02a_e.exe
April 2004 Ontario DLI training
Following two numbers: dissemination year (date stamp for versioning)
– The choices are: 01 if disseminated in 2001, 02 if disseminated in 2002, 03 if disseminated in 2003 etc.
Next character: file format:
– “a” ARC/INFO® ArcGIS Export File (e00), “m” MapInfo® Export File (mid & mif)
Final two characters: language
– _e English
– _f français
For example:
gcsd035b02a_e.exe
April 2004 Ontario DLI training
Introduction to ArcView 3.x
Button bar
Project window
Menu bar Tool bar
Document windows
Status bar
ArcView Documents View – display, query & analyze themes Layout – integrate documents to create presentation-
quality maps
Table – display attribute data
Script – program written in Avenue used to
customize the interface, automate common
functions or create applications
April 2004 Ontario DLI training
ArcView Projects
Views
Tables
Charts
Layouts
Scripts
Project window
Displays the names of all
project documents & acts
as a gateway to all
documents in the project.
April 2004 Ontario DLI training
Views and Themes • Theme: A GIS links sets of features and their attributes and manages
them together in units called themes. Each theme has a title and a
legend in the view’s Table of Contents.
Themes
April 2004 Ontario DLI training
Theme Operations
When a theme is
turned on, ArcView
draws it in the map
display area.
Active themes are raised
To make more
than one theme
active, hold
down the Shift
key as you
click on each
theme.
To invoke the
Legend Editor
Double-click on
active theme.
You can control
visibility and
change display
order (by
dragging)
April 2004 Ontario DLI training
Symbol Window Fill Palette Pen Palette
Palette manager Color Palette Font Palette Marker Palette
Legend Editor
April 2004 Ontario DLI training
Let’s Map 2001 Census Data…
Italian Mother Tongue Normalized by Total Population0 - 0.0050.005 - 0.0140.014 - 0.0310.031 - 0.0750.075 - 0.146
Hydrography
Streets
N
20 0 20 40 Kilometers
Source: Statistics Canada 2001 Census data and
cartographic boundary files
Author: Nancy Lemay
Projection: Lambert Conformal Conic
Proportion of Italian Mother Tongue by Census Tracts
April 2004 Ontario DLI training
Saving the Beyond 20/20 table
• Open the B20/20 table « .ivt » for:
– Profile of Citizenship, Immigration, Birthplace, Generation Status,
Ethnic Origin, Visible Minorities and Aboriginal Peoples, for
Census Metropolitan Areas, Tracted Census Agglomerations and
Census Tracts, 2001 Census - Cat. No. 95F0489XCB01005
• After subsetting the B20/20 table to include only Ottawa Census
Tracts, save the table as a « .dbf » file.
April 2004 Ontario DLI training
Importing the CBF .e00 file
a) Under Start then Programs, you will find under Esri:
April 2004 Ontario DLI training
Importing the .e00 file (cont’d)
b) Click on Browse… to find your .e00 file on your hard drive.
c) Click on Browse… and select where you want to save the new data
files and type a new filename in Output Data Source.
April 2004 Ontario DLI training
Open ArcView
• Open ArcView and double-click on Views in the project
view.
April 2004 Ontario DLI training
Set working directory…
When starting a project in which new data needs to be created, the
working directory has to be set so that ArcView knows where to
store the files.
File -> Set Working Directory
After this has been selected a dialog will appear where
the working directory can be set.
April 2004 Ontario DLI training
Load cartographic boundary file
To add a
new theme
click on
April 2004 Ontario DLI training
Make the theme active
Add a check
to make the
theme active
April 2004 Ontario DLI training
Add table to your new project
• Open ArcView 3.x make Tables active in the project
window, click on Add.
(1)
(2)
(3)
April 2004 Ontario DLI training
Information on Table Joins
• A join function is provided in ArcView so that the census
data can be appended to the attribute table of the CBF.
• In order to join the two tables, a common field containing
the same values must be identified. Please note that the
name of the field does not have to be the same, but the
values in the field must be of the same type (string vs
number).
April 2004 Ontario DLI training
Prepare census table for a join
• To Edit the census table click under Table –> Start
Editing
• Under Edit click Add Field…
• Type « CTUID » for Name, select « String » as a Type
and « 10 » for Width.
• Click under Table –> Stop Editing
April 2004 Ontario DLI training
• We need to convert these census tract labels to recreate the common
field in our profile data.
• Click Calculate in the Field menu. The calculation is based on the
following instruction: CTUID=505.AsString+[Geography].Left(7),
which means that the CTUID string is created by adding the Ottawa
CMA code as a string to the left-most 7 characters in each of the
Geography labels.
April 2004 Ontario DLI training
Open CBF table
To open the
CBF table go
back to the
View and click
the table icon
on the button
bar
April 2004 Ontario DLI training
Identify common field Find the common field, it should be
left justified (string).
April 2004 Ontario DLI training
Join the census data with CBF
Source table
Destination table
April 2004 Ontario DLI training
• In the attribute table click on the field you will use to
join. You know the field is selected when it is sunken
and darker than the surrounding fields.
• In the shapefile table click on the same field. Click
Table in the menu and then Join or click on the
following button:
Source table Destination table
April 2004 Ontario DLI training
Calculate the ratio
Open the destination table
and under Table select Start
Editing
April 2004 Ontario DLI training
Add a new field to calculate ratio
Once the table is in edit
mode, select Add Field
under Edit.
April 2004 Ontario DLI training
Define the new field
• Give the new field a proper name.
• Select Number as Type.
• Type “4” for number of Decimal Places.
April 2004 Ontario DLI training
Calculate the new variable
• Under Field select Calculate…
• Let’s calculate the ratio of people who have Italian as a mother tongue
and the total population.
April 2004 Ontario DLI training
Map the new variable
• Go back to the View and double-click on the active theme.
• We will select Graduated Color as a Legend type.
April 2004 Ontario DLI training
Select a classification field
• Select your newly created variable called Ratio for the Classification Field.
Click Apply.
April 2004 Ontario DLI training
Choose a projection
• A projection is needed for publication purposes and for calculating
distances.
• Under View select Properties.
• Select kilometers as Map Units and Distance Units.
• Click on Custom and select Lambert Conformal Conic.
April 2004 Ontario DLI training
Optional: add hydrography
• Click on the to add the hydrography shapefile.
• Remember to make it active by adding a checkmark.
Double-click on the
active theme to
activate the Legend
Editor and double-
click on the the color
box below Symbol.
Click on the paint
brush to select a new
color. Click Apply.
April 2004 Ontario DLI training
Final results
April 2004 Ontario DLI training
Comparing ArcView 3.x and
ArcGIS 8.x
• Same basic functionality as 3.x
• Separate software modules for organizing files
(ArcCatalog), accessing tools (ArcToolbox) and working
with data (ArcMap).
• Projection-on-the-fly
• Direct read of more data formats
• Can import 3.x project files and legend files
April 2004 Ontario DLI training
Terminology
• Project files (*.apr) become map documents (*.mxd)
• Projects become maps
• Views become data frames
April 2004 Ontario DLI training
Interface
• No more project window
• Table of contents
– Display view
– Source view
• Map display
• Toolbars
April 2004 Ontario DLI training
Importing
• Simple to do, but it has been known to cause problems.
– Primarily, cannot import all 3.x views
• Import 3.x project files (*.apr)
• Import 3.x legend files (*.avl)
April 2004 Ontario DLI training
Project file problem…
• ArcMap allows the storing of relative path names.
• Use “Set Data Source” to find lost layers or simply remove
and re-add the lost layer.
April 2004 Ontario DLI training
New terminology
• http://www.esri.com/news/arcuser/0402/files/talking.pdf
April 2004 Ontario DLI training
References
• Robinson, A.H., et al., Elements of cartography. 6th ed. 1995, New York:
John Wiley. 674.
April 2004 Ontario DLI training
Partial Credits for Stolen Slides
• http://tdr.tug-libraries.on.ca/HELPS/gishelp.htm
• http://prod.library.utoronto.ca:8090/maplib/ArcMap_Guide.pdf
• http://www.ideal.forestry.ubc.ca/cons340/Lecture03.pdf
• http://maps.nrcan.gc.ca/maps101/scale.html
• http://www.uottawa.ca/academic/arts/geographie/lpcweb/web2320/
April 2004 Ontario DLI training
More info on making your projects portable:
• http://www.wlu.ca/~wwwgeog/special/geomatics/pdf/tra
nsportable.pdf
• http://www.esri.com/industries/k-
12/download/docs/transapr.pdf
Importing ArcView GIS Projects into ArcGIS
• http://www.esri.com/news/arcuser/0701/avconvert.html