Cartography

Categories of Maps and Map Uses

Throughout human history, maps have been created for a variety of uses and purposes. One of the earliest uses of maps was for navigation or wayfinding purposes, and this remains a common use of maps today. For example, a nautical chart used by the crew of a ship for navigation by sea and a subway map used by a tourist to travel around a city are both examples of maps used for navigation purposes. In addition, maps are commonly employed for displaying or visualizing [Page 340]geographic trends or patterns in data. For example, a map of population density for provinces in a country would display geographic patterns of high- and low-density population in the country. Some maps depict geographic change over time, such as weather maps on television that forecast trends in daily temperature change over a week for a location. Other maps are used primarily for the management of resources, for example, maps used by employees of a city to manage infrastructure such as utility or water lines. Maps are also commonly used to assist in the decision-making process, such as a map that displays possible building locations for a new business based on proximity to prospective customers.

Figure 1 Example of a reference map

Source: Map created by author based on data from Environmental Systems Research Institute. (2008). ESRI data and maps 9.3. Redlands, CA: ESRI Press.

Maps produced by cartographers may be categorized in many different ways depending on their purpose or use. One common classification is to divide maps into two categories, reference maps and thematic maps. Reference maps (Figure 1) display the location of major geographic features such as cities, political boundaries, transportation networks, or physical features (e.g., rivers, lakes, and mountain ranges). Examples of reference maps include the topographic maps published by the U.S. Geological Survey and the British Ordnance Survey. Thematic maps (Figure 2), commonly referred to as statistical maps, display a particular theme, topic, or attribute. Examples include a map of per capita income for states in the United States and a map of languages spoken in countries within a region of the world. Thematic maps are constructed from a base map (e.g., state boundaries) and thematic or statistical data (e.g., per capita income for each state). Maps may also be classified in any number of other ways, such as by specific theme or topic, map scale, time period, or geographic area.

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