Thematic maps are maps based on topographic maps that represent any geographical phenomenon on the Earth's surface.

They pursue well-defined objectives. They refer to the representation of certain characteristics of distribution, relationship, density or regionalization of real objects (vegetation, soils, geology, etc.), or abstract concepts (indicators of violence, economic development, quality of life, etc.).

To represent numerical variables they use all types of visual resources, such as surfaces of different colors or patterns (choropleths), arrows to indicate the movement of a phenomenon (flows - sometimes they have a thickness proportional to their magnitude), the drawing of lines that join points of equal value (isolines), non-symbol circles of size proportional to the numerical value, or even deformed maps so that each geographical unit is represented with a size proportional to its numerical value (cartograms or anamorphic maps).

• - Muehrcke, P. et al. (2005). Map Use, The University of Chicago Press, 4th Edition.

• - Robinson, Arthur H., et al. (2000). Elements of Cartography, Wiley, 6th Edition.

• - Slocum, T. et al. (2003). Thematic Cartography and Geographic Visualization, Prentice Hall, 2nd Edition.

• - Thrower, (B. 1991). Maps and Civilization: Cartography in Culture and Society, The University of Chicago Press. cola university.

• - Wikimedia Commons hosts a multimedia category on Thematic Map.