Geography 222 The Power of Maps

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Geog 222 Exercise 5: Map Projections

Revised: 2/29/08

Exercise 5 not assigned, Spring 2009

Introduction:

The process of map projection transforms the 3D surface of the spherical earth into a flat, 2D surface. As discussed in lecture, there are an infinite number of ways to project maps, and every different map projection distorts something: areas, angles, directions, distances, etc.

With the increase in WWW-based mapping and GIS applications, you may someday have to make a decision about which map projection to use. Exercise 5 asks you to select an appropriate map projection given a specific defined use of a map.

Sources of additional information on map projections which may be useful for this project can be found in the class readings and at the following sites:


Goals:

Imagine the following situation for this exercise: You graduate from OWU with a C average and a few extra pounds (from dorm food and beer) and get a job at Dubious Enterprises in Dodo, Ohio (located about 60 miles west of Delaware). The best part of this job is that you get to live in lovely central Ohio.

Your boss, who also had his share of well-deserved mediocre grades while an undergrad, finds out that you took a Map and GIS course while at OWU and assigns you the task of selecting world & regional maps to accompany various company projects. Please select an appropriate map projection, create it, and explain why it is appropriate, for the five scenarios listed at the end of this exercise.

What is Due: Turn in one page for each map application (1 through 5 below): include the question (so I know which one you are answering), a paragraph justifying your choice for each of the five applications, and embed the map you create in the page (if you are having trouble with this please ask me for help).


Procedure:

The first thing you do is get on the WWW and find a Web site that generates maps of the world: Interactive Album of Map Projections from Penn State University is exactly you want.

After you arrive at the site, note that it shows a map of the world with a bunch of different mysterious, yet fascinating, options.

Choose a map projection

Redraw the map button: punch this each time you make a change in any of the options on the page to generate the new map projection.

View projection documentation provides some details about the current selected map projection. Potentially useful for answering the questions below!

Define projection parameters varies based on the map projection selected; any information you need to enter here will be noted below with the list of map projections.

Define map extent (decimal degrees) allows you to zoom in by defining the North / South / East / West boundaries of the map (so you show less than the entire earth at a more detailed scale.

Plot a Location (decimal degrees) allows you to include a point symbol and name at a particular location.

View/hide distortion ellipses allows you to add those saucy distortion circles to the map, to show distortion of size (area) or shape (angles). Please turn the circles on for your maps in this exercise.




Lettuce recenter a map on Dodo, Ohio (84 degrees W, 40 degrees N) and plot that metropolis, using decimal degrees.


Select Plate Carree from the menu if it is not already selected.

Under Define projection parameters type in -84 for the central meridian. This means the 84 degree West meridian (a line of longitude) is at the center of the map.

Under Plot a location enter 40 for latitude and -84 for longitude. Put Dodo in for the place name.

Hit redraw the map to see your work.




Map Projection Options and their parameters

Below find a list of the correct options for the different map projections available at the Interactive Album of Map Projections WWW site (with some additional information on the projection's characteristics, useful when providing answers to the questions at the end of this exercise).

Remember to hit redraw the map any and every time you change any parameter to see your changes.


To get a map that focuses on the contiguous US, enter the following map extents if digital degrees are called for:


Plate Carree


Mercator


Transverse Mercator


Cylindrical Equal Area


Robinson


Lambert Conformal Conic


Albers Equal-Area Conic


Azimuthal Stereographic


Azimuthal Equidistant


Azimuthal Orthographic




Below find a series of map applications from your boss. You will use the WWW site Interactive Album of Map Projections from Penn State University to generate the map with the proper map projection. For each application provide the following


Map Application 1: The CEO of Dubious Enterprises and your boss, Gaston Bacon III (affectionately known as "Gassy"), was messing around on eBay and came upon a few passenger airliners up for bid at ridiculously low prices, due, of course, to the recent bankruptcy of numerous US airlines. "Dubious Airlines" (known as "Dubi Air" around the office) plans to start flights between Dodo, OH and Bogota, Columbia soon, as no other airline currently connects these two vital locations. Gassy storms into your cramped cubicle one morning, requesting that you create a map projection which can show the route between Dodo, Ohio and Bogota, Columbia for the Dubious Airlines brochure. You recall that your boss is fond of globes, and has a collection of over 600 in his home (including a rare globe of Ohio). Choose a map projection which can show both Ohio and Columbia: it need not preserve areas or angles (shape), nor does it need to show all of the earth at once, but should look just like a little globe.


Map Application 2: Global warming is happening, and we will really start to sizzle in the near future. But Gassy and his political cronies have been told to play the whole thing down until investment opportunities, created by global warming, can be secured. Gassy and his cronies plan to move their headquarters to the South Pole, along with Gassy's fleet of airliners. Gassy wants a map projection to plot out distances from the South Pole to any other location on the earth accurately (thus he needs a distance preserving map projection) centered on his future headquarters at the South Pole.


Map Application 3: Dubious Enterprises is considering getting into the lucrative deforestation business, given the weakening of US environmental laws over the last seven years. To assess the viability of this plan, Gassy needs a map projection of the United States which shows and allows accurate comparisons of the size of different areas of untouched forests (which he will map out later).


Map Application 4: Gassy's rather complicated and self-involved wife Maive Pelham Bacon, affectionately called Ma-pel by her friends, is a bit bored and has decided to save the rainforests. She has set up the Ma-pel Bacon Foundation to this end. Plans are afoot for her and her friends to send petulant letters to politicians, business leaders, and common folk in those countries with rainforests, urging them to knock it off with regards to cutting down the rainforests. As an inducement, the Foundation will include a gift basket of trinkets, carved from exotic rainforest woods, with each letter. Problem is, Ma-pel does not quite know where the rainforests are, so she would like you to generate a world map projection that does not distort areas, so she can plot out the areas of rainforests.


Map Application 5: Gassy is having a big company meeting, and wants to impress his international business partners by having a world map tattooed on his chest, thus implying that he and Dubious Enterprises think globally. For the tattoo, your boss has to do a bit of shaving (the Griswalds are uncommonly hirsute) and needs a map projection of the entire earth that looks the best and "normal" to people but it need not preserve areas or shapes (angles) or distances. Remember, tatoos are forever, and if you choose the wrong one you will be dispatched forthwith to the new South Pole headquarters.


Hand in one typed sheet with the best map projections for each of the five requests and your justification for each of these choices, along with the actual map you generated.


E-mail: jbkrygier@owu.edu

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