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

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

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