BMC zooms in on slums with satellite imagery …….Sharad Vyas
Mumbai: The first-time use of high-tech satellite imagery tracking the growth of shanties in Dahisar has helped the BMC realise the immense potential of slum mapping.
Inspired by the success,the corporation will undertake a full-fledged remote-sensing mapping with the help of Indian Institute of Remote Sensing (NRSA) in Dehradun.
A formal proposal has been submitted to municipal commissioner Swadheen Kshatriya,who last month directed all 24 ward officers to use Google Earth to map the mushrooming of illegal structures and hutments until the study is complete.First,the satellite images will help us in the spot verification of documents that the illegal dwellers provide as residential proof.Many times,the papers are fake and verification takes up a lot of time as we do not have a way to counter their proofs, said a senior civic official.
The exercise begins with the preparation of a drain-network map,which is done with the help of Ikonos data and SOI topographical sheets.Once that is done,other amenities and documents are taken into account.When the imaging exercise is over,they give a clear picture of the size of the shanties,how close they are to each other,the lopsided street patterns,structures along drains,railway tracks and also wasteland along a slum.
A sensing exercise throws up other interesting patterns as well that could help in conducting effective systematic demolition drives.With the help of these images,officials can see how the landscape of the city has evolved,that is,how illegal hutments have cropped up along drains and other uilities such as,water pipes and electricity poles.
This data could help us ascertain the timing and magnitude of action to be taken.For example,slums along drains face greater risks from flash floods than in other place, an official said.A pilot project using Google images has already been carried out at Dahisar.The local ward office showed how it used Google Earth imagery to trace the mushrooming of illegal shanties at Ganpat Patil Nagar in Dahisar.The difference in the number of huts in 2002 and those that got added by 2009 was marked by the demolition squad.There are 5,000 shanties in the slum,against 3,500 in 2002.