/ population

Fast food and supermarket density in Germany

During January a couple of students of mine started working on a small project with the goal of visualizing locations of McDonald's fast food restaurants in Germany. This was a beginner's course, so I had no concern that it would basically result in a population density map.

When browsing through my twitter stream, I came across a blog hosted by John Nelson: Adventures In Mapping. Coincidentally, he had just done the same thing, except for the US and for a larger number of franchises. And he went on with a nice turn on things: normalization.

Instead of simply plotting franchise locations, he calculated the ratio between the number of locations and population per-capita of 14 different fast food chains and visualized them as bubbles.
After I hinted my students at normalization, I started to pursue my own little project of visualizing fast food and supermarket distributions in Germany. Here's the result:

Density of fast food locations in Germany

Fast food density in Germany
Click image for larger version

Density of supermarket locations in Germany

Supermarket density in Germany
Click image for larger version

So how is it done?

  1. Fetch all the franchise and supermarket locations from OpenStreetMap via overpass turbo
  2. Get some census and geometry data for Germany and it's municipalities here
  3. Write an R script that
  • reads the data
  • counts locations inside of geometries
  • calculates the ratio between number of locations and population inside of municipalities
  • categorizes the results (for reasons of readability)
  • plots a circle at the geometries centroid with size based categorized ratio
  1. Optional: Put everything in a neat, responsive webpage with interactive maps

Animated, interactive, responsive webmap

Thanks to John Nelson for being a huge inspiration!