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Jun 11Pairing VAC Benin Data with Mapbox and TileMill
For the first month of the summer I worked with Plan Benin on their effort to use Ushahidi to collect and visualize reports of violence. Ushahidi is great for crowd-sourcing reports via a variety of channels and offers visualization capabilities for browsing data on the deployment’s website. I thought it would be neat to visualize the VAC Benin data on a custom map that isn’t on the list of supported basemaps in Ushahidi, most of which don’t provide very good local data for Benin. While it’s possible to add map overlays to your Ushahidi deployment, I decided instead to run everything through through MapBox, which provides a suite of tools for creating and hosting custom maps. MapBox comes from the team at Development Seed, where I’m spending the remainder of the summer break.
Using TileMill, MapBox’s open source custom map studio, I created a map that includes only the data relevant to Plan Benin’s activities on this project. In particular, it includes GIS data for Atacora and Couffo, the two “Program Units” where Plan operates. Those are in light blue on the map in the northwest and southwest corners of the country, respectively. I also included labels for the important cities in both Program Units. The red dots indicate the reports of violence and if you mouse over a dot you can see a summary of the incident. If you click on the incident, you see more information. This interactivity is baked right into TileMill. The reports were geolocated by hand using information in the text messages. The map also incorporates the World Bright basemap, which includes country borders, custom labels, population centers (in light yellow/brown tones), and other information.
Though this is really the tip of the iceberg in terms of what TileMill can do — it would also be possible to add multimedia-rich interactivity, use a choropleth scheme to indicate hotspots of violence, cluster reports, etc . — I think it is easy to see how this custom map improves the experience of interacting with data collected through Ushahidi. Highlighting the Program Units draws the eye to the important areas, adding custom map labels solves the problem of local data being absent from the major map providers, and the built-in interactivity means that visitors don’t need to browse to multiple pages (a killer in low-bandwidth environments) to view information on individual reports. Plus the map is super fast!
Finally, TileStream hosting makes it easy to host the map and generates embed code so the map can be widely shared. Take a look at the map below and feel free to click over to the VAC Benin Ushahidi site to see the difference for yourself.









