How to make a choropleth map with Google Fusion Tables

10
7048
Choropleth map of cycling in Hackney wards

Data mapping is becoming an increasingly popular way of visualising information. It’s quite straightforward to make a choropleth map and in this post I’m going to show you how to make one using Google Fusion Tables.

A fortnight ago I made a choropleth map to go alongside this story for the Hackney Post.

Choropleth map of cycling in Hackney wards
Choropleth map of cycling in Hackney wards

The map was designed to show the increase in the number of Hackney residents commuting to work by cycling over the last decade. I thought I’d use a map as it is more visual and quickly tells the story. Stating that “Dalson had a rise of 10.9%, whereas Hoxton’s increase was only 5.3%, unlike Clissold…” would undeniably bore the reader.

I’m briefly going to show you how to create your own choropleth map.

The data that I used is from the Greater London Authority’s website and was published in October.

First of all I created a Google Docs spreadsheet showing the percentage increase of every Hackney ward:

Percentage point increase for cycling in Hackney by ward

Once I had manually entered these data, I put them on to a map using Google Fusion Tables. Once you load up Fusion Tables, all you need to do is import your Google Docs spreadsheet:

Importing a spreadsheet to Google Fusion Tables
Importing a spreadsheet to Google Fusion Tables

Now you need to find the map data to visualise the cycling data on a map. What you’re looking for here is a “KMZ Shapefile”. Thankfully, Ændrew Rininsland (former City Uni hack, now News Developer at The Times) uploaded a shapefile of all Hackney ward map data. If you download any shapefile of the area that you’re trying to map, that should work fine. Next, upload the .kmz file to your Google Drive.

Now, go back to the Google Fusion Table and click:

Merging in Google Fusion Tables

Select the correct .kmz file and merge it based on the field name “ward”, as this will be the same in each table.

This will show you something like this:

merged map in Google Fusion Tables

Now, to shade it in different colours dependent on intensity, go to feature map > change feature styles > buckets:

Colour shading on Google Fusion Tables

This will end up with something like this:

Unmarked choropleth map of Hackney Wards

Then all I did was add the ward names using Adobe Photoshop.

Once you get used to using Google Fusion Tables, they are a fast and easy way to visualise your data.

10 COMMENTS

    • I followed a similar process to create a choropleth map of the U.S. states. However, I don’t to import KML for the shapes. However, even I can create a legend with different colors, colors were not shaded on the polygons, and each state has a marker within a uniform color. What have I missed?

  1. Hi, thank you for the tutorial. I would like to know if there is a way to let users interact with colors theme, like a color picker for the map.

  2. When I choose Merge, I don’t see the KMZ file I’ve uploaded to my Google Drive, even though it’s sitting right next to the xls file I’m using for the data table. 🙁

    Google did, however, georeference the column to centroids, which is cool–it only missed one location–but that didn’t help me make a choropleth map.

      • I know I was able to get around it, but I don’t remember how. If memory serves, I either unzipped the KMZ file and used the source files inside of it, or I gave up and used an ESRI shape file which I converted to KML. Either way, I was not able to get KMZ files to work.

Leave a Reply