Crowd-sourcing initiative to map Bellandur lake's black spots

Crowd-sourcing initiative to map Bellandur lake's black spots

Fire, trash, polluting industries to be identified, mapped with phone pics

Crowd-sourcing initiative to map Bellandur lake's black spots

Fire in the city’s Bellandur lake had sparked a frenzied call to save Bengaluru’s biggest water body. To keep that attention riveted to the lake’s survival, the local community has a plan: Crowd-source the evidence of every fire, locate every garbage dumping and burning site on a GPS-enabled map through smartphone photography.

The project’s objective is also to identify the polluting industries around the lake. The Karnataka State Pollution Control Board had blamed inflow of untreated domestic sewage for the froth that erupts periodically in the lake. The attribution to industries was general, limited to numbers without elaboration.

The mapping process is expected to pinpoint the location of these industries and identify their role in large-scale pollution of the lake. As environmentalist Nagesh Aras informs, the highly toxic effluents from these units are directly let into the drains leading to the lake. Every litre of electrolyte solution with high lead and zinc content can pollute 10 lakh litres of water.

So how does this crowd-sourcing work? Using mobile apps such as Mapillary’s Openstreetmap or Mapunity, photographs are taken from the sites and uploaded to a map, accessible to all. The photos taken with GPS tracking are overlaid onto Mapillary, showing the black spots in the lake as animated pictures. The app’s timeline feature allows multiple images of the same site.

But extensive local mapping will be required to get the complete picture. According to Aras, this process begins on Saturday. The data so collated and overlaid on maps will be part of reports to be submitted to the National Green Tribunal. Rationale: Evidence-backed reports have better chance of enforcing remedial action.

To improve the reliability of the maps, data gathering will be on the lines of Mapillary’s Humanitarian OpenStreet Map Team (HOT). This is an initiative designed to provide accurate maps for use in humanitarian work. Often when a natural disaster strikes, changes to the human and natural landscape reduce the accuracy of maps. The HOT team then works both physically and remotely to boost reliability.

Mapillary allows people on the ground with a smartphone to capture images in the area which can then be used by people with GIS experience to update the OpenStreetMap. This tool was extensively used for relief measures during the 2015 earthquake in Nepal.