GEOG 486
Cartography and Visualization




Welcome to Lesson 5! In previous lessons, we discussed and designed several types of thematic maps, including proportional symbol, dot, and choropleth maps. Here, we discuss a more specialized type of thematic map - flow maps. In this lesson, we'll integrate our knowledge of visual variables, map symbolization, and levels of measurement into our discussion of these flow maps: maps that show movement between locations. 

Before diving into our flow map discussion, however, we introduce another topic integral to cartography: map projection. We explore the different ways in which we define locations on Earth's surface, the process of creating a map projection, and how our choice of projection alters readers' interpretations of our maps. By the end of this lesson, you should understand the different classes and cases of projections, as well as popular map projections and their characteristics. In Lab 5, we use this knowledge to create custom projections for flow map-based advertisements - a twist intended to emphasize the vast variety of clients and audiences for whom cartographers design thematic maps.

Learning Outcomes

Lesson 5 Objectives, see text description in link below
Lesson 5 Learning Outcomes
Click for text description of objectives. 

By the end of this lesson, you should be able to:

  • explain the relationship between the geoid, a reference ellipsoid, and a datum, as well as the importance of these elements in cartography;
  • classify projections based on their class, case, and aspect;
  • describe projection properties and their respective utility for different mapping tasks;
  • integrate knowledge of a map’s purpose, scale, and location into the projection selection process;
  • describe the use of visual variables and levels of measurement in flow maps.

Lesson Roadmap

Lesson Roadmap


To Read

In addition to reading all of the required materials here on the course website, before you begin working through this lesson, please read the following required readings:

  • Chapter 6 in How to Lie With Maps.
    Monmonier, Mark. 2018. How to Lie with Maps. 3rd ed. The University of Chicago Press.
  • Pages 223-233 in Cartography: Thematic Map Design.
    Dent, Borden D., 1999. Cartography: Thematic Map Design. Fifth Edition, Boston: WCB McGraw-Hill.

If you want to dive into the material a bit further, a good place to start with map projections and learning about their influence on map design, check out this article: Hsu, Mei-Ling. "The role of projections in modern map design." Cartographica: The International Journal for Geographic Information and Geovisualization 18, no. 2 (1972): 151-186.

Additional (recommended) readings are clearly noted throughout the lesson and can be pursued as your time and interest allow.

The required reading is available in the Lesson 5 module.
To Do
  • Submit Lesson 5 Quiz.
  • Complete Critique #3.
  • Complete Lab 5.
  • Contribute to class discussion.
  • Submit Lesson 5 Quiz.
  • Submit Critique #3.
  • Submit Lab 5.
  • See Discussion Participation for ideas and contribute accordingly.


If you have questions, please feel free to post them to the Have a question about Lesson 5? Ask here! forum. While you are there, feel free to post your own responses if you, too, are able to help a classmate.