Chennai - Immediate value of crowdsourced data collection
The Chennai floodmap was instrumental in allowing Chennai's residents to take disaster response into their own hands
Mapbox Bangalore created a crowdsourced visualization of Chennai’s flooded streets after the strongest monsoon rains of the century hit and disrupted the life of over 6.7 million people. No up-to-date map of flooded streets as a measure of the devastation was available to residents and local media. The easy-to-use digital tool built on top of OpenStreetMap lets users zoom in, discover which streets are reported as flooded (pink), or click on a street that they know is flooded to report it.
Stakeholders involved
Mapbox Team reacting to the escalating situation using the tools they’re familiar with
Local Media - frustrated with insufficient data provided by local government, such as an excel sheet with addresses of flood relief centers
Government - unprepared to handle the escalating situation
People of Chennai - ease of use, albeit not accessible for all groups of the community
Types of data handled
OpenStreetMap data - ODbL
Topographic elevation data- Inundated areas (Nov 28) Flood Waters Over Chennai Area UNITAR - UNOSAT (USGS)
Inundated areas (Dec 3) ISRO RISAT 1
Low lying locations: ISRO Cartodem3 and SRTM 30m
Crowdsourced data
Technical solutions
Map to highlight low altitude areas of Chennai prone to flooding
Functionality to mark road segments as flooded via browser without login using Mapbox GL JS and Datasets API. Mapbox GL JS allows to select individual features on the front-end, and selected roads are posted to a Dataset backed via the Datasets API.
Subsequent outcome
Map was picked up by an humanitarian organization working with the city for relief operations
Within 24 hours after major media outlets picked up word about the map, over 2,500 streets were reported to be flooded by the citizens of Chennai
Map available as open source tool on Github
Further reading
Last updated
Was this helpful?
