Dot Density Maps using Winnipeg's Open Data

Ed Manley, an urban researcher in the UK, decided to take open data from Winnipeg and make dot density maps. One shows variation in ethnicity, one shows linguistic variation, and another shows income disparity.

As Ed explains on his blog, "These maps are often used to map Census statistics, where single points equate to actual individuals. For each Census area, you generate points for the population in the area – you have 500 people, you generate 500 points – colour the points according to some population indicator, and then distribute them randomly across that area.

There are flaws, of course, it is a bit more artistic than functionally informative, and the random distribution of categorised points within an area doesn’t always make sense, but at small region sizes it generally works well."

Read more about Ed's density mapping process here:



Thanks for sharing!

I remember seeing some of Ed Manley's maps for a variety of American cities, but I didn't know he'd done the same thing for Winnipeg. Some interesting patterns show up in this way of showing the data, for sure.

I had some fun doing some dot density maps of a different variety using CDP data for a presentation on Mapping the Ethnicity of Toronto's Older Adult population. I used the 2011 NHS Target Group profile for the population aged 65+, assigning dots in our GIS software based on Census Tract level data, and randomizing the location of the dots within the residential areas of each Census Tract.

People had a lot of fun trying to guess some of the specific ethnicities based on their distirbution throughout the city. It was a fun an engaging way to get people thinking about which communities live where in the city and why.

For the interested, you can look at the resulting maps on the City of Toronto's website. Important tip: This was for an event where we knew the participating groups ahead of time, so we made sure that there was a map for everyone attending. You want to make sure everyone sees themselves and their communities reflected somewhere in this exercise.