Collaborative Cartography Project Using Excel

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Collaborative Cartography Project Using Excel

• Jonathan F. Lewis
• Benedictine University

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Shaded relief can make contour lines difficult
to see
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Basic BW works well. Probably will need to blow
it up a bit
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Use a ruler to draw a grid
Put letters across the top and bottom and numbers
down both sides
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The numbering and lettering correspond to Excels
spreadsheet layout
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The procedure

• Students are assigned sets of lines (e.g. one
  student does A, B, and C while the next does D,
  E, and F)
• They determine the elevation of the point where
  lines intersect (A-1, A-2, A-3, etc) and enter
  the value into the appropriate part of an Excel
  spreadsheet
• These are then combined to create a very large
  data set

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Consider

• Might want students lines to overlap (first
  student does A, B, and C, while second does C, D,
  and E) as a check
• Keep track of which sets of lines were assigned
  each student (some forget while others enter the
  data into the wrong part of the spreadsheet)
• Points falling between contours
• Let them decide how to interpolate and ask them
  later to explain the basis for their decisions,
  or
• Discuss it in class in order to ensure consistency

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Also

• Some students dont get this done in time,
  leaving gaping holes in the data set
• Another benefit of the overlapping lines
• Should probably have done the entire project
  yourself first (a pain, but hey, thats part of
  the job)
• A surprising number of students have no idea how
  to read contour maps, so devote some time to
  explaining them

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Many students already understandthe principle
behind contour lines

• Make this more interesting to them in the context
  of a presentation covering the various ways
  cartographers have attempted to convey elevation
  information

Shaded Relief
Hachuring
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Not surprisingly

• The greater the number of points
• The more detailed and accurate the information
  and the cooler the final image (like surveying
  everyone, not 1 of every 1,000 people)
• The greater the effort older machines and earlier
  versions of Excel will have to exert to create
  the image. It will still work, but when you
  later want to manipulate the image, it may take
  some time to redraw

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Typical data files look like this
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Select all the cells, click on the chart wizard
tool, and select Surface
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Youre then given several options
such as labeling axes and titling the image
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Customizing the image
You can change the number of elevation levels
and their color
You can add a picture to the floor of the
image. This makes it possible to depict the
original contour map with the 3-D surface
hovering above it
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Like this
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Manipulating the image
Clicking once on a gray side creates boxes at the
corners. Click and hold the mouse button down,
then move the image.
Initially, the 3D surface may disappear until you
release the button, then the surface will be
redrawn from the new perspective
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In Office 2007, Excel works differently
This is the floor of Yosemite Valley as shown in
Excel 2007. Not a bad look, really.
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In Office 2007, the design tool permits selection
from color ranges. Image rotation works
differently, too.
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A background image makes it a little harder to
read but allows comparison with actual photograph
of the location
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Future possibilities

• I want to try this in conjunction with a
  historical project the attack on Savannah,
  Georgia during the American Civil War
• Can utilize a map of the Savannah Rivers depths
  created in the late 1850s
• Students can use it to pass judgment on whether
  or not a naval assault on the city was feasible
• Theyll need to know seasonal variations in the
  rivers depth, the draft of Union vessels,
  location of defense emplacements, possibly lunar
  phases