A cartogram is a diagram which uses the form
of a map to present numeric
information while maintaining some
degree of geographic accuracy.
An abstracted and simplified map the base of
which is not true to scale
Cartograms show information in a distorted way
while showing locations with some degree of
accuracy
Cartograms purposely distort to emphasize
information
For example, the above figure is a Cartogram of World Population
-notice countries are in accurate relative locations compared to
other countries
-color used here to simply distinguish continental areas, however,
color schemes may be used to differentiate data
This cartogram is “Gross Domestic Product per Country”
-largest countries have highest GDP
This is a cartogram showing Toy Exports per Country
(Asia—largest toy exporting area)
Where do you think the most toys are imported?
Toys Imported per Country
Was this what you thought?
Underweight Children per Country
-many variables may be mapped into a cartogram
Overcrowded Homes
For this activity, you are going to create a cartogram of U.S.
population
You will create the cartogram on graph paper, in which each
square of the graph will represent a unit of what is being displayed
For this activity, you will receive:
•Chart showing U.S. population by state
•Blank sheet of graph paper
Your task is to create a cartogram with the data from the
population chart
1st: Choose a scale for your map
•I suggest that one square on the graph paper equals
500,000 people (1/2 million per square)
•Or, you may use 1 square = 1 million
2nd: Use pencil to create your cartogram. Try to give states as
true of shape and relative location to other states as you can.
3rd: You will color each state using a choroplethic map-coloring
system (see next slide)
3rd: (continued)
-You will need to use 5 colors on your map. You should pick out
colors that go from a lighter to a darker shade. You need to show
this scale in a legend found somewhere on your cartogram. The
lightest color will represent states with lesser populations. Use
the following categories for your coloring:
•States with 3 million or less residents
•States with 3 million to 5 million residents
•States with 5 million to 10 million residents
•States with 10 million to 20 million residents
•States with over 20 million residents
4th: Title your map “U.S. Population by State, 2000”
Source is U.S. Census Data (this should be displayed somewhere
on your cartogram as well
Points for this cartogram:
Title: 1 point
Legend: 1 points
Source: 1 point
Choroplethic color scheme: 3 points
Accuracy of cartogram: 6 points
Accuracy of relative locations of states: 6 points
Neatness: 6 points
Summary paragraph: 6 points
TOTAL POINTS POSSIBLE: 30
SUMMARY PARAGRAPH: once you have completed your
cartogram, write a summary paragraph in which you make at least
three relevant inferences from your cartogram. These inferences
should address, “what can I learn from looking at this cartogram?”
You should make an inference, then write at least one supporting
statement for each inference using information from the
cartogram.
For instance, “states with higher populations tend to be toward the
fringes, while states with lower populations are found in the interior
regions of the United States.” This related to our previous discussions in
which I pointed out “4 out of 5 humans live within 500 miles of an ocean.”
So, observe the map and make inferences. Things you can look
at include:
•Is there relationship between largest states and largest
populations?
•Is there an area of the U.S. that seems to have a number of
darker shaded states? Why would this be?
•Why are some of the largest states lightest in color?
•Come up with your own, too!!