A Grassroots Mapping Of Mumbai
O’Reilly author and true map scholar Schuyler Erle just gave a talk at Where 2.0 about how one of the world’s largest cities was mapped in stunning detail using only free software, accessible consumer devices and a lot of walking.
At 14 million people and growing, Mumbai, India is a true “Maximum City.” Almost half of Mumbai’s residents live in slums, and a group of local architects have been working on public housing projects to improve the living conditions of the city’s poor. One of the many problems they faced is that to build in Mumbai, you need detailed maps of your project, and there is no freely available accurate map data for the city.
The team solved the map problem with the help of a group called Collective Research Initiatives in Trust. The architects had given CRIT heavily detailed but flawed maps created in AutoCAD. The maps had street names, waterways and building-level data, but they were created without actual land-based reference points. CRIT sent a group of surveyors out onto the streets with cheap, off the shelf GPS units. They collected dozens of land reference points in Mumbai, then plotted them on the map using free software. Buildings and rivers were stretched on the map to match real-world points in space, locations were tagged and everything was open-sourced on the web at mumbai.freemap.in.
Most of the maps in the world have the same problems — noisy data, gaping holes in collection practices and a lack of tagging consistency from region to region. In other words, there’s a lot of work still to be done. Check out the continuing efforts at publicgeodata.org.
