Choropleth maps have been used for a very long time because they allow the visualization of data in a geographical context.
Choropleth maps are versatile. For example, it is the simplest way to display election or census data. The color-coded regions give immediate insight by area.
These maps can display data in new and appealing ways. It may seem complex and, in the past, it used to require complex geographic information software.
It has become a very simple process with the availability of MapSVG making personalized choropleth maps more accessible.
What is a Choropleth Map?
The word “choropleth” is constructed from Greek; “choro” and “pleth”. “Choros” means “area”, and “plethos” means “multitude.” These thematic maps visualize statistical data in their geographical context. Proportional to the magnitude of the associated data, each area gets a different color or different shade of color. This representation simplifies how the data varies over a certain area and the extent of variation.
Maps similar to choropleth are the heat map and isarithmic map. Both use color-coding like the choropleth map, but do not use the geographical data in the same way.
Data is arranged by defined geographical boundaries, such as countries, states, and counties. The organization by these geographical units is relevant to the agencies that publish this data. This is the case for governments, but other sources also make use of this.
Choropleth maps are useful for displaying normalized and accumulated data. This data must be arranged by polygons. In this case, the polygons are counties, states, regions, or any area or region that can be geocoded.
Notes on Choropleth Maps
- A Choropleth map is an excellent tool for showing regional patterns. An example could be a striking unemployment level in a specific county compared to the surrounding area. If the data does not show geographical patterns, it is best to use a different method to present the data.
- Use the right colors to display the data. Colors determine how data is perceived, what message is conveyed, and the reliability of the data.
- Choropleth maps are clearest when only one variable is presented. In certain cases, two variables can be shown indirectly by showcasing the difference between the two variables. An example of this is the change in the unemployment rate from one year to the next.
- The patterns extracted from the data depend on the level of detail. A lower level of detail will reveal simplified patterns while using a high level of detail will show smaller trends.
- Choropleth maps give an overview of the data, rather than highlighting subtle differences. Small color differences are hard to perceive on a large map.
What is MapSVG?
MapSVG is a WordPress map plugin that allows the user to publish feature-rich maps. It is quick and uses a smart admin user interface.
Besides the interactive map feature, it can create diagrams, infographics, anatomies, and house plans. The user can also import Scalable Vector Graphics (SVG) files to edit and customize them. The wide range of colors, markers, popovers, tooltips, and other features allow the design of engaging interactive maps.
It is also possible to add external data, which is exceptional for making personalized weather maps, demographics, etc.
MapSVG is preloaded with nearly 200 geo-calibrated and uncalibrated vector maps covering both countries and regions. The plugin contains a complete set of tools for making a range of thematic maps.
These features include advanced custom fields, choropleth maps, customizable tooltips, integrated search, location filters, integration with other WordPress functionalities, map directory, and variable map detail. There are also many more features for customizing maps.
How to Make a Choropleth Map
To make a choropleth map, start with analyzing the reason for creating the map. Likely, there is location-related data that needs to be presented. Both are valid reasons for making a map with MapSVG. Whatever the reason, the ultimate purpose of a map is to present the data in a spatial setting.
MapSVG comes as a WordPress plugin. The plugin can be used to create thematic choropleth maps with the desired color scheme in an intuitive and simple way.
Choosing a map
After deciding on a choropleth map, you must then decide on the level of detail that is required. When a map of the United States is at its most practical, different levels of details are selected, for example, at the state level, the county, district court, or congressional districts. These details can also differ per year.
The first step is installing and activating the plugin in WordPress. Now, a new menu item will appear with the name “MapSVG.” By clicking the dropdown menu, a list of all available preloaded maps will appear. There is a map for every country in the world, as well as a complete world map.
Click on one of the maps to begin customizing. Then go to Menu > Database > Edit fields. Here, a new text field can be added and given any name, not limited to numbers:
To select the choropleth map option, go to Menu > Settings > Choropleth > On. Then, select the previously created field from the region dropdown menu:
Below the map, a gradient appears. The regions do not have colors yet. To add colors, values must be added to the “numbers” field.
To add the numerical values, go to Menu > Database > List. By clicking on a particular region, a box appears where the corresponding number can be typed. After adding the values for a couple of regions, the numbers start to appear.
Under Menu > Colors, the map colors can be changed. Gradients can be adjusted in Menu > Settings > Choropleth > Gradient labels.
An additional option is to add lists of objects with custom fields. This allows adding images coupled with text, which is useful if a person has to be connected with a specific location.
That is essentially how a choropleth map is made. MapSVG allows the user to manage the map in different ways. It can be done externally or via API calls to receive feedback for the map. The most practical option is managing it directly in the WordPress admin environment. That way, the map can be maintained without an additional code editor.
MapSVG is a complete map creation tool. Besides the features described above, it contains countless more common map functionalities.
Ending thoughts on how to make a choropleth map
With the MapSVG plugin, anyone can make their own choropleth map.
No matter the level of experience, creating stunning maps is simplified.
If you liked this article on how to make a choropleth map, you should also check out this article with map illustration examples.