GEOG 486
Cartography and Visualization

Types of Maps


Types of Maps

Maps are generally classified into one of three categories: (1) general purpose, (2) thematic, and (3) cartometric maps.

General Purpose Maps

General Purpose Maps are often also called basemaps or reference maps. They display natural and man-made features of general interest, and are intended for widespread public use (Dent, Torguson, and Hodler 2009).

example of an OpenStreetMap Basemap of Toronto area showing streets and toll roads
Figure 1.2.1 OpenStreetMap Basemap.
Credit: OpenStreetMap © OpenStreetMap contributors.
The data is available under the Open Database License (CC BY-SA).

Thematic Maps

Thematic Maps are sometimes also called special purpose, single topic, or statistical maps. They highlight features, data, or concepts, and these data may be qualitative, quantitative, or both. Thematic maps can be further divided into two main categories: qualitative and quantitative. Qualitative thematic maps show the spatial extent of categorical, or nominal, data (e.g., soil type, land cover, political districts). Quantitative thematic maps, conversely, demonstrate the spatial patterns of numerical data (e.g., income, age, population).

Color coded US map: median houshold income in 2015; states are shown in shades of pale blue to purple representing various income levels.
Figure 1.2.2 A Thematic Map from the US Census Bureau

Cartometric Maps

Cartometric Maps are a more specialized type of map and are designed for making accurate measurements. Cartometrics, or cartometric analysis, refers to mathematical operations such as counting, measuring, and estimating—thus, cartometric maps are maps which are optimized for these purposes (Muehrcke, Muehrcke, and Kimerling 2001). Examples include aeronautical and nautical navigational charts—used for routing over land or sea—and USGS topographic maps, which are often used for tasks requiring accurate distance calculations, such as surveying, hiking, and resource management.

example of a nautical chart from NOAA showing islands and water with superimposed grid features
Figure 1.2.3 A Nautical Chart from NOAA
Credit: NOAA (click the link for a larger image!)

In theory, these map categories are distinct, and it can be helpful to understand them as such. However, few maps fit cleanly into one of these categories—most maps in the real world are really hybrid general purpose/thematic maps. 

colorful hybrid map of Orange County, CA showing roads as well as color blocks showing fire hazard severity
Figure 1.2.4 A hybrid map of fire hazard severity zones from Orange County, CA

Advancements in technology and in the availability of data have resulted in the proliferation of many diverse types of maps. Some, as shown in Figure 1.2.5, are embedded into exploratory tools intended to inform researchers and policy-makers.

Dark world map with several data categories bordering it, color coded dots scattered on the map
Figure 1.2.5 A Screenshot of the Geovisual Analytic tool MapSieve.
Credit: Robinson, Anthony C., and Sterling D. Quinn. 2018. "A Brute Force Method for Spatially-Enhanced Multivariate Facet Analysis." Computers, Environment and Urban Systems 69 (June 2017). Elsevier: 28-38. 
Reproduced with permission from Dr. Anthony Robinson, Penn State University. 

Other maps are intended for a wider audience but share the goal of uncovering and visualizing interesting relationships in spatial data (Figure 1.2.6).

example of a map that represents relationships in spatial data (in this case, places where one can view both bigfoot and a solar eclipse)
Figure 1.2.6 Places to see both bigfoot and the solar eclipse
Credit: Sightings map by Joshua Stevens (

Maps also are not limited to depicting outdoor landscapes. Some maps, such as the one in Figure 1.2.7, are designed to help people navigate complicated indoor spaces, such as malls, airports, hotels, and hospitals.

example of an indoor map: Washington DC Marriott from the 2017 International Cartographic Conference
Figure 1.2.7 Indoor map of the Washington DC Marriott from the 2017 International Cartographic Conference
Credit: Cary Anderson and Cindy Brewer. In-hotel walk throughs and detailed floor plans at

For a map to be useful, it is not always necessary that they realistically portray the geography they represent. This map of the public transit system in Boston, MA (Figure 1.2.8) drastically simplifies the geography of the area to create a map that is more useful for travelers than it would be if it were entirely spatially accurate. 

example of a simplified public transportation map from Boston, MA showing color coded routes
Figure 1.2.8 A Public Transportation Map from Boston, M.A.
Credit: Boston MBTA 

Maps that show general spatial relationships but not geography are often called diagrammatic maps, or spatializations. Spatializations are often significantly more abstract than public transit maps; the term refers to any visualization in which abstract information is converted into a visual-spatial framework (Slocum et al 2009).

example of a spatialization, clusters of red and blue dots by year, gradually polarizing
Figure 1.2.9 A spatialization by Andris et al., (2015) that demonstrates the increasing polarization between members of the US House of Representatives. Each dot represents a member of a congress (blue for democrat, red for republican); connections represent vote-based agreement above a threshold determined by the authors. For more details, see (Andris et al. 2015).
Credit: Andris, Clio, David Lee, Marcus J. Hamilton, Mauro Martino, Christian E. Gunning, and John Armistead Selden. 2015. “The Rise of Partisanship and Super-Cooperators in the U.S. House of Representatives.” PLoS ONE 10 (4). doi:10.1371/journal.pone.0123507. Available under the Open Database License (CC BY-SA).

Though there are many different types of maps, they share the goal of demonstrating complex spatial information in a clear and useful way. Rather than attempt to place maps into discrete categories, it is generally more productive to see them as individual entities designed to suit a particular audience, medium, and purpose. We will discuss this more in the next section.

Recommended Reading

  • Chapter 1: Introduction to Thematic Mapping. Dent, Borden D., Jeffrey S. Torguson, and Thomas W. Hodler. 2009. Cartography: Thematic Map Design. 6th ed. New York: McGraw-Hill.
  • Wood, D., and Fels, J. (1992) The Power of Maps. New York: Guilford.