Mayor Subrata Mukherjee’s decision to update the city’s maps, made by British surveyors during the Raj, has sparked off a controversy among the civic engineers and Opposition leaders. The mayor intends to update the maps after conducting an aerial survey with British grants.
According to civic engineers in the survey department, more than 800 maps of the city, left behind by the British, are absolutely accurate, drawn on the basis of actual measurements. It is impossible to update them by conducting a high-cost aerial survey.
“An aerial survey always gives a bird’s eye-view of the topography and it is generally conducted to prepare a first-hand rough map of an uncharted area,” the engineers pointed out.
The mayor, however, argued that “the latest maps with the Calcutta Municipal Corporation (CMC) date back to 1909-13. An enormous amount of changes have taken place in the city landscape and skyline since then.”
He said the geographical information system (GIS) software was an integral tool to manage a modern city effectively and the preparation of this software required up-to-date data. So, the CMC is now in search of experienced GIS consultants to prepare base maps on a 1:500 scale, based on aerial surveys by the National Remote Sensing Authority.
The CMC is getting a grant of Rs 212.25 crore, in terms of both technical and financial support, from the British department for international development for a capacity-building programme over the next six years. “A portion of this fund will be utilised for the aerial survey and to develop a GIS software for the city,” Mukherjee explained.
“The mayor, perhaps, is not aware that Calcutta had pioneered the preparation of city GIS during the Raj and the CMC had updated the data on its own, according to the changing face of the city, till 1975,” pointed out CPM leader Sudhanshu Sil, who had been a mayoral council member in the former CPM-led civic board. In 1996, added Sil, Delhi granted a fund of Rs 1 crore and asked National Atlas and Thematic Mapping Organisation (Natmo) to update and digitise the GIS. The programme was flagged off on August 1, 1996, and completed in 1999. “The mayor’s decision for an aerial survey of the city topography is nothing but a high-cost gimmick,” Sil said.
The maps made by Col Smart between 1909 and 1913 are still regarded as the touchstones by the CMC’s survey department. They are still consulted to verify road alignments, encroachments and even plot boundaries.