Project 5 Thematic Maps

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Project 5Thematic Maps

• Aaron Henning Carl Sherlock

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Thematic Maps Basics

• Transfer geographic data into geographic
  information
• Highlight one attributes geographic distribution
• Single purpose or theme in mind
• Review Reference maps portray many attributes
  and features

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Reference vs. Thematic
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Thematic Maps

• Use abstract, graphic symbols that represent the
  quantities and qualities that make locations
  meaningful
• The use of colors and symbols to project
  attribute data
• Attribute data examples density, counts, rates,
  etc.
• Cynthia Brewers presentation

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Remember
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Thematic Mapping

• Counts
• Showing a symbol for each individual or group of
  individuals
• Fails when many individuals or groups are present
  and/or when location is unknown

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Thematic Mapping

• Porportional Symbol Maps
• Also called graduated symbol maps
• They represent classes of counts not individual
  counts
• Useful for counts that lack location

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Thematic Mapping

• Chloropleth place value
• Involves coloring geographic areas to represent
  categories of rates or densities
• Most common type of thematic map

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Thematic Mapping
Pie Chart

• Rates and densities
• Simply one count divided by another count
• In densities, the divisor is the magnitude of a
  geographic area
• Can be in various formats

Bar Graph
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Starting the Project

• Go to factfinder.census.gov
• Left side menu, hover cursor over DATA SETS
• Click on Decennial Census

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• Making sure you are selecting Census 2000
  Summary File 1, choose Thematic Maps on right
  hand menu
• Select county under geographic type
• Select your state, then select your county, and
  hit Next
• This will display all of the data themes that can
  be displayed on a map ? pick one and click Show
  Result

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(No Transcript)
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• Directly above map where it says Display map
  by, select Census Tract from drop-down menu
• Adjust zoom and pan to make data as visible as
  possible

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• At top of left side menu under Change, select
  data classes
• From here you can change classing method, color
  scheme, and number of classes

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Classing Methods Review

• Quantile (percentile)
• Equal number of features in each class
• Equal Interval
• Equal range of values in each class
• Natural Breaks
• Divides features and/or range of values according
  to pre-existing groupings or divisions

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• When finished customizing, right click map and
  select Save picture as... (repeat for legend)

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• You have now successfully found and downloaded
  all data for your first map
• For this project, you need a total of 3 maps
• At least one needs to be of ACS Data
• From FactFinder homepage, hover over Data Sets
  and click on American Community Survey and
  follow same process

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• Take a moment to analyze your map why is the
  data how it is?
• Why does the tract that corresponds to campus and
  downtown have the lowest percent of persons under
  18?

Think about this, it will help you with the
write-up
Map 1 Percent Persons Under 18 Years of Age
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Finding Map Scale

• In bottom left corner of your map image, it will
  tell you distance across (Dg)
• The actual width of the image is 6 (Dm)
• Remember the formula?
• S Dm / Dg

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Review

• Thematic Mapping
• Attribute data transformed into useful geographic
  information
• Designed with a central purpose or theme
• Different types of data are represented in
  different ways

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References

• Baxter, Ryan. Census Mapping and Thematic Maps.
  GEOG 121 Lecture. 11/20/06
• Brewer, Cynthia. Cartographic Inspirations for
  Designing Better Data Visualizations. GEOG 121
  Guest Presentation. 10/11/06
• Census Bureau FactFinder. Accessed 11/20/06.
  http//factfinder.census.gov
• ESRI Virtual Campus Module 6. Accessed 11/19/06.
  http//training.esri.com
• The Pennsylvanian Marketing and Planning Center.
  Accessed 11/20/06. http//www.mapcenter.org/index.
  html

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Help

• Aaron Henning amh334_at_psu.edu
• Carl Sherlock cfs5000_at_psu.edu
• http//www.personal.psu.edu/cfs5000/geog121_lab5.h
  tml
• Course Example
• http//www.geog.psu.edu/courses/geog121/projects/p
  roj5_example.html