Mapping a City’s Health

Mapping Health


Schema worked with the Center for Public Health Nutrition (CPHN) and the Urban Form Lab at the University of Washington on visualizations of data from the NIH-funded “Seattle Obesity Study.” Two videos show data for 500 study participants in Seattle whose activities were tracked over the course of a week via GPS devices. The first video focuses on physical activity over 24 hours. As people move through the city, they leave traces—the blue traces are where they were traveling slow (e.g. walking, running or biking), the white traces are where they were traveling fast (e.g. driving or taking public transit). The second video visualizes proximity to supermarkets over the course of one week. As people get close to any of the supermarket locations in the Seattle metro area, bubbles representing the venues become increasingly larger to reflect the aggregate proximity.

Mapping Health: Fast/Slow Seattle
Mapping Health: Shopping for Health
The GPS traces build up over the course of 24 hours
Where were people were traveling fast and slow
The density of traces increases over time
Over the course of 24 hours the shape of the city emerge from the data
Data visualization of the areas of the city where people get more physical activity
Fast and slow traces accumulating over the course of the day


For this project we collaborated closely with researchers at the CPHN and the Urban Form Lab to identify the questions we were interested in investigating as well as what a resulting visualization might look like. We met frequently to review early prototypes using actual data before converging on the two final videos, which were rendered using Processing.


An observation from this project is that there is a high degree of mobility in the Seattle metro area. This challenges the concept of food deserts in places with similar geospatial and socio-economical characteristics. While the food deserts theory emphasizes the importance of having a supermarket close to an individual’s place of residence, CPHN’s research shows that people are willing and able to travel for groceries, motivated by factors such as cost and quality.


Collaboration Across Borders
Thanks 1,000,000
Mapping Public Transit in Cities
Transit Patterns