Like many cities in the global south, Kigali is rapidly growing and urbanizing. Rwanda’s capital and largest city has seen its population more than triple since 2000. While development brings modern amenities and opportunities, it also has a cost. As vehicle usage and development have surged in the country, concerns about air quality have grown.
This interactive map from Peter Pihlmann Pedersen at open-seneca visualizes air quality patterns in Kigali. It’s based on more than six million measurements from a network of local sensors.
The map shows how areas around the city vary in air quality. Pedersen describes it as a hot spot map for air pollution. Cells in green have less measured PM2.5 than the city as a whole. Shades of orange represent areas where air quality is worse than the city baseline. As you hover around the map, you can see each how each cell deviates from the Kigali average. You can also see how often and how many measurements were recorded in each place.
Clicking a cell provides access to all the recorded data for that place. Charts show measurements over time and break down patterns by day of the week and time of day. Cells with more measurements have more reliable data, and you can even filter the map to focus on cells with more measurements over time.
The default map shows major roads on top of the cells, but the imagery basemap provides more context. Given the role vehicle emissions play in air pollution, it’s not surprising that cells with the highest PM2.5 values are on or near major roads in Kigali. Conversely, many of the cells with less relative PM2.5 are in or near places with significant amounts of green space.
The map reveals how the city’s road network and other features influence air quality on a granular scale. But green cells do not necessarily signal good air quality. While these places show lower PM2.5 levels relative to the Kigali baseline, Kigali’s baseline is still too high. Overall, PM2.5 levels across Kigali range around 30 micrograms per cubic meter. This is well above the World Health Organization’s guideline of 5 micrograms per cubic meter.
More to Explore
- Revisit a live map of air quality in the US.
- Discover more air quality maps for places around Earth.
