1. Mapping Census Data in ArcView 3.x
Nancy Lemay
University of Ottawa
Barbara Znamirowski Trent University
April 2004
Ontario DLI training

2. We will try to understand these concepts
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

3. 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
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4. Map Scales
A defined dimensional relationship between reality and the map (Robinson et al., 1995):
Verbal: “one cm represents ten kilometers”
Representative fraction: 1:10,000
Graphic scale:
Area scale:
Represents square kilometers 5 1 M e t r s
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5. 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
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6. Examples small vs. large scale
Small scale: 1:250,000
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7. 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
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8. 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)
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9. 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
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10. 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.
instead of 60º20'40"
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11. Example: Converting DMS to DD
60º20'40"
degrees
minutes
seconds
20 minutes.= (20/60)
40 seconds = (40/3600)
Add up the degrees to get an answer:
60º = DD
April 2004
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12. 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
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13. 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).
April 2004
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14. 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.
Use projected
spatial data to calculate
distance!!
For more information:
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15. Map Projections Examples
Cylindrical Equal Area
Lambert Conformal Conic
Preferred for world maps.
Mollweide’s
Good for directional and shape relations along large east-west mid-latitudes.
Good for middle latitudes.
April 2004
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16. 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
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17. 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
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18. 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
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19. 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
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20. 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
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21. Introduction to ArcView 3.x
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22. Tool bar
Menu bar
Button bar
Project window
Document windows
Status bar

23. ArcView Documents
Layout – integrate documents to create presentation-quality maps
View – display, query & analyze themes
Table – display attribute data
Script – program written in Avenue used to customize the interface, automate common functions or create applications

24. ArcView Projects Project window Views Tables Charts Layouts Scripts
Displays the names of all project documents & acts as a gateway to all documents in the project.
Tables
Charts
Layouts
Scripts
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25. 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
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26. Theme Operations
You can control visibility and change display order (by dragging)
Active themes are raised
To make more than one theme active, hold down the Shift key as you click on each theme.
When a theme is turned on, ArcView draws it in the map display area.
To invoke the Legend Editor Double-click on active theme.
April 2004
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27. Symbol Window Legend Editor Fill Palette Pen Palette Marker Palette
Font Palette
Color Palette
Palette manager
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28. Let’s Map 2001 Census Data…
Proportion of Italian Mother Tongue by Census Tracts
Source: Statistics Canada 2001 Census data and cartographic boundary files
Author: Nancy Lemay
Projection: Lambert Conformal Conic
April 2004
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29. 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
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30. Importing the CBF .e00 file
Under Start then Programs, you will find under Esri:
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31. Importing the .e00 file (cont’d)
Click on Browse… to find your .e00 file on your hard drive.
Click on Browse… and select where you want to save the new data files and type a new filename in Output Data Source.
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32. Open ArcView
Open ArcView and double-click on Views in the project view.
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33. 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.
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34. Load cartographic boundary file
To add a new theme click on
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35. Make the theme active Add a check to make the theme active April 2004
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36. Add table to your new project
Open ArcView 3.x make Tables active in the project window, click on Add.
(2)
(1)
(3)
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37. 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
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38. 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
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39. 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
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40. Open CBF table
To open the CBF table go back to the View and click the table icon on the button bar
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41. Identify common field
Find the common field, it should be left justified (string).
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42. Join the census data with CBF
Destination table
Source table
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43. In the attribute table click on the field you will use to join
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
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44. Calculate the ratio
Open the destination table and under Table select Start Editing
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45. Add a new field to calculate ratio
Once the table is in edit mode, select Add Field under Edit.
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46. Define the new field Give the new field a proper name.
Select Number as Type.
Type “4” for number of Decimal Places.
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47. 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.
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48. 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.
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49. Select a classification field
Select your newly created variable called Ratio for the Classification Field. Click Apply.
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50. 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.
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51. 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
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52. Final results
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53. 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
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54. Terminology Project files (*.apr) become map documents (*.mxd)
Projects become maps
Views become data frames
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55. Interface No more project window Table of contents Display view
Source view
Map display
Toolbars
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56. 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
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57. 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.
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58. New terminology
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59. References
Robinson, A.H., et al., Elements of cartography. 6th ed. 1995, New York: John Wiley. 674.
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60. Partial Credits for Stolen Slides
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61. More info on making your projects portable:
Importing ArcView GIS Projects into ArcGIS
April 2004
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