A study carried out by the Bombay Natural History Society (BNHS) has cautioned the City And Industrial Development Corporation (CIDCO) of “ high risk of bird strikes at the proposed Navi Mumbai International Airport (NMIA) site” at Panvel.
At the proposed site, maximum number of birds, around 4,500, were seen in February and very few birds were seen from June to December in 2013, the report recently submitted to the CIDCO states. “Population of congregating birds in different roosting areas around the proposed site changed seasonally. Such kind of bird movement within airport influence zone would be a concern for air safety in the future,” said Sujit Narwade, co-investigator of the report.
Around 253 bird species belonging to 55 families were observed within 10 kilometres of the proposed site since December 2011. The 2,054-hectare area at Panvel is demarcated as the airport zone and the 10 kms around the site comprises creeks, rivers and mangroves, which serve as a good habitat for congregating birds along with the Karnala Bird Sanctuary located closeby.
According to the report, flocking water birds were seen congregating in shallow water pools in grasslands and paddy fields near human habitation, instead of inland wetlands and seashore. “This suggests that birds may get attracted to temporary water pools formed during the monsoon in the vast open patch of land, at the proposed NMIA site,” states the report.
Moreover, population of Lesser Sandplover, Greater Sandplover, Curlew Sandpiper species rising to a few thousands during October-November and April-May indicates that some bird populations use wetlands in the vicinity of the proposed NMIA as a stopover site, the report states.
Explaining the danger of bird-hits, Captain Mohan Ranganathan, an aviation safety expert and former Boeing commander, said, “ A 30-lbs goose striking the windscreen of a plane flying at 200 knots (in circuit speed) creates a relative impact of 20 tonnes, which could cause serious damage to aircraft and pose a risk to lives of passengers.”
Ranganathan believes the problem is the lack of proper understanding of bird behaviour near the ground by pilots and aviation authorities.
“Roosting and migratory bird paths are important. The danger exists wherever these sites are close to airports but the authorities never pay attention to environmental issues when it comes to airline operations near such areas.”
The other species sighted in the area include eastern cattle egret, painted stork, black-headed Ibis, a near-threatened species, lesser flamingos, brown-headed gulls and blue rock pigeons.
The BNHS report is part of the conditional clearance given to the CIDCO project by the Ministry of Environment and Forests. This is the second annual report of a five-year study that began in December 2011.
To avoid bird hits, BNHS has recommended that the proposed site and adjoining area be made unattractive for the birds as well as develop bird sanctuaries on the coast and in the mangroves, away from the influences of air traffic, as compensation.
Developing proper garbage disposal system in the area to avoid attracting birds, strictly regulating the extent and spread of stone quarries and construction work were the other recommendations.