Vertical Exaggeration for Dummies

Whether it's the classroom, a debate, or a press conference; you can usually tell when someone is trying desperately to conceal the fact that he or she doesn't know the answer to a question: the fumbling and restating are dead giveaways. On-line, self-proclaimed "freelancers" at sites like eHow are just about as obvious to those who know the topic under discussion. Our staff cartographer at the Antisocial Network caught eHow contributor Jennifer Fleming (multiple winner of the Dumbass of the Day) doing her best, and failing, to pretend she knows "How to Calculate Vertical Exaggeration" at Sciencing.com.

It took the cartographer to notice this, since vertical exaggeration is a "map thing." Vertical exaggeration is used on 3D and 2D maps to emphasize the shape of subtle changes in elevation that would be difficult to see on an unexaggerated map. It's easy to calculate, too: it's the ratio of the horizontal scale to the vertical scale. If the horizontal scale of a map is 1" = 500 feet and the vertical scale is 1" = 100 feet, the vertical exaggeration comes out to 5:1. Another way to look at the calculation is that 100 feet of vertical change covers one inch on this map, but 100 feet of horizontal change only covers ¹⁄₅th of an inch.

Jennifer, however, didn't want to do the math. Either she didn't know how or (more likely) she still didn't understand the concept after her "research." Her instructions, which follow eHow's demand that each step begin with "an action verb," consist of

1. Determine the area to be investigated. Duh. 
2. Acquire an elevation profile for this region. Consult a mapping tool such as Google Maps, MapQuest or Garmin for a topographical representation of this region. Insert the coordinates. "Acquire an elevation profile"? Does Fleming even know what a topographic profile is? How can you get them from those "mapping tools"? and "Insert" what "coordinates" where? What a maroon, as Bugs Bunny would have said!

3. Note the elevations. Document the current minimum and maximum elevations of the y-axis for the topographic profile. We're not sure where you're going here, Jennifer: enlighten us?
4. Calculate the vertical exaggeration. Using the formula of real units of horizontal scale solve for vertical exaggeration. For example, for a 1:500000 topographical map if 1 cm units on x-axis equals 500 real units...

It's that last that had our cartographer shaking his head. Normally, when one says to "use a formula," one provides said formula (unless one's a dumbass). And then there's Jennifer's obvious unfamiliarity with map scales: given a 1:500,000 topographic map, a unit - 1 cm, 1m, 1", 1 vara, whatever - never equals "500 real units." By definition, it equals 500,000 real units!  When she finally gets to her point - which, wonder of wonders, she got (or more accurately, transcribed and reworded) right, Jennifer's tortured prose -- a result of her unfamiliarity with the topic, we assume -- proves nearly impossible to unravel. "...if 1 cm units on x-axis equals 500 real units, and the vertical value is also 500, then no vertical exaggeration would exist; however if the vertical value were 100, the vertical exaggeration would be 5 indicating the topography is exaggerated five times the presentation in the original or real map"

Perhaps if Jennifer had had the foggiest notion of what vertical exaggeration is and why the concept exists, she'd have done a better job. And then again, perhaps not: that's how Jennifer Fleming collected yet another Dumbass of the Day award.

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