Chennai Flood Map, an app that visualises the impact of last year’s devastating floods in the city, has been selected for presentation in the Visualising Cities exhibit at the prestigious United Nations Habitat III conference in Quito, Ecuador.
The app was jointly developed by five colleagues at Mapbox, Bangalore, in the last week of November 2015, as torrential rains started hitting Chennai.
Says Aruna Sankaranarayanan, who conceptualised the idea, “Mapbox had their monthly hackathon that weekend. Incidentally, Chennai’s monsoons with severe thunderstorms had battered the city, flooding many parts, so we thought of developing an app based on that.”
The result was Chennai Flood Map, an app that displays an interactive map of the city, and allows anyone to mark a street as flooded. Other users can then visualise the city with the flooded areas marked out. Says Arun Ganesh, interface designer and cartographer for the app, “The app was completed in a day. The affected parts were marked in pink. We posted the link on our respective social media pages.”
However, there were only a few visitors. All that changed as the flooding turned critical in the first week of December 2015. The app went viral on social media and started getting heavy traffic.
Says Arun, “Our personal server couldn’t handle the load, so we roped in Sajjad Anwar and Sanjay Bhangar to scale up the infrastructure.” Says Sanjay, “At peak load, we received 1,500 requests per second. We moved the application to our company’s server and used its technology. Soon, the situation was under control.”
The technology for Chennai Flood Map lies at the intersection of three revolutionary changes. First, since the app allows crowdsourcing, it enables ordinary citizens to contribute their local knowledge to the application. While each citizen might know of the flooding situation only in their locality, by pooling together the knowledge from thousands of citizens, the app is able to piece together the flooding status across the entire city in real time.
What about authenticity of the data? Arun says, “Users were free to mark and update information. Due to the number of users, if someone has entered wrong information, somebody else would correct it. Prasanna Loganathar helped with design visual improvements. We also continuously monitored the feedback.”
The second revolution is the rise of open source mapping technology. Mapping is everywhere in our lives today. Whether it is checking directions or hailing a taxi or locating restaurants nearby, maps have become indispensable. However, writing apps based on maps can be an expensive affair, as you need to purchase them from a map provider.
Open source mapping technology changes all that. Chennai Flood Map used a technology called Open Street Map (OSM). When asked about the reason for using OSM against Google maps, Arun replies, “The data in OSM is completely community-driven. It is free of cost for an enterprising individual to build on top of it, while Google maps has restrictions and is also costly to use in a customised application.” The final revolution, and potentially the most impactful, is the way such apps enable civic participation by ordinary citizens on a massive scale. While it will take a long time for the residents of Chennai to forget the devastating floods, a lasting image of that time is one where the residents of the city came together for rescue efforts. Enabled by the Chennai Flood Map app and coordinated over social media, several teams and NGOs were able to identify high-risk areas, coordinate relief supplies and deliver them to those in need. A very satisfied Aruna says, “We also received great feedback from volunteering groups and NGOs, who told us that it gave them real insight about the affected areas.” What the response to the floods has shown is that citizens are ready to participate in civic issues on a large scale, if they have technology enablers to make it easy.
The app has seen global awareness via social media. Arun wraps up, “We have received many enquiries from universities, research students and technologists from around the world, who are interested in doing similar apps.” They have further plans on the existing link for this year’s monsoon. With 15,000 reports of flooded streets and over a million views, the Chennai Flood Map app has shown how open source mapping technology can be a positive enabler for citizen participation in urban habitats.
