Feb 18, 2020 Visualizing Data Through Thematic Mapping

By Justin Sorensen

What are some of the ways you express research data? Do you share your findings through text or perhaps a spreadsheet or visual graphic? If you look closely, you may notice that your data contains a geographic component representing a location or area around the world that can be visually depicted on a map. This location data along with categorical data about each location can be combined to create a Thematic Map – a type of map designed to show a particular theme connected with a specific geographic area. Not only are these maps visually engaging, they also have the ability to easily relay findings and conclusions to your viewers. In this post, I would like to touch on a few basic types of thematic mapping that our GIS Services department is available to collaboratively assist you in developing.

Basic Types of Thematic Mapping

Choropleth Mapping – choropleth mapping is one of the most common types of thematic mapping in which areas are shaded or patterned in relation to a quantitative statistic. In addition to depicting the extent of the geographic area, choropleth maps utilize a color progression ramp to easily depict high and low variables at a glance.

Proportional Symbol Mapping – proportional symbol mapping utilizes various sizes of map symbols to represent quantitative statistics. As the symbol sizing is easy to determine, this type of map allows viewers to quickly visualize large data quantity occurrences.

Contour Mapping – contour mapping relies on constructed lines of equal values to represent consistency over large areas. One of the most common uses for contour mapping are representations of elevation and meteorological data.

Chorochromatic Mapping – chorochromatic mapping, sometimes referred to as area- class or qualitative area maps, are utilized to portray regional data with different symbols or colors representing unique fields or categories such as climate classifications, vegetation, and soil types.

Dot-Density Mapping – dot-density mapping is an effective map visualization for depicting differences in distribution over large areas. An example of this type of map involves analyzing population statistics where a single dot represents a predetermined portion of the population. The geographic area becomes populated with the appropriate number of dots and allows viewers to easily determine high density populations of the study area.

Heat Mapping – heat mapping relies on point location data to visualize where high and low occurrences of your data take place. An example of this relates to plotting locations of tornados throughout the United States and returning a visualization depicting high and low occurrences over time. This type of visualization can be useful for identifying locations at higher risk or to convey the importance of allocating resources accordingly.

So whether you are new to GIS and thematic mapping or are a pro, know that our GIS Services department is here to collaboratively assist you through the development and visualization of your project.

To learn more about our collaborative services, please visit the GIS Services website @ www.lib.utah.edu/services/geospatial

Happy Mapping!

Justin Sorensen | GIS Specialist
Creativity & Innovation Services / GIS Services
justin.sorensen@utah.edu