Center for Technology and Teacher Education

Map Projections

Procedures:

Step 1 Introduce students to the topic.

Step 2 Show students or have them view examples of four map projections.

Step 3 Students should record their impressions about the differences between the map projections.

Describe these projections according to the shape of the continents.
How do the lines compare?

Step 4

Review with students some of the general uses of different map projections.

Have students think of some specific types of maps. Generate a list of map types and write them on the board. Some examples may include maps of cities, states, countries, continents, road maps, topographic maps, etc.

Step 5

Review with students some of the differences in the four map projections,

Mercator

Because of the angular nature of Mercator maps they are useful for:

topographic maps,

navigational charts and,

world general reference maps.

Robinson

Because they maintain true areas Robinson projections are useful for comparing distributions like:

world maps of population density,

per capita income and,

various other human-oriented statistics.

Conic

Conic maps like Mercator maps they are useful for:

topographic maps and

navigational charts.

Azmuthal

Azmuthal projections are called equidistant projections because they maintain equal distance between the lines of latitude. This feature makes azmuthal projections useful for:

small scale maps like maps of cities and,

general reference maps of countries.

Have students determine which of the maps would be different if different projections were used. For example, a map of a mall would not be influenced by different projections. Ask students which of the four projections are best suited for the maps where projection is an issue.

Step 6 Give students an opportunity to practice with the map projections by proposing the following map types and asking students what type of maps would be best for the map.

Map type	Ideal projection
A map of districts for the U.S. House of Representatives.	Robinson
A map of Antarctica	Conic
An interstate road map of the city you live in.	Azmuthal
A map showing the world's oceans	Mercator
A map showing the population distribution in a state.	Robinson

Step 7 Download a freeware program that will allow student to view various map projections. The program is available for download

Center for Technology and Teacher Education, University of Virginia, This module was created by John K. Lee University of Virginia