Stay updated with the latest - Click here to follow us on Instagram
Journalism of Courage
Kolkata’s concrete boom has made it hotter, the city must rethink where it grows: IIT Kharagpur study
Study says 60+ sq km of tree cover wiped out, 20 sq km of agricultural farmland lost, and 10 sq km of ponds, pukur, and wetlands filled in
Researchers identified several Kolkata neighbourhoods where rising urbanisation has intensified the city's heat island effect. (Image for representation: Unsplash)
Kolkata’s rapid urban expansion over the past two decades has come at a cost: higher temperatures, shrinking green cover and growing pressure on wetlands and water bodies, according to a new study by researchers at IIT Kharagpur, who have also identified where the city should and should not expand in the future.
Published in Environmental Science and Pollution Research, the study analysed changes across the Kolkata metropolitan region between 2000 and 2020 and found that built-up areas now account for nearly 86% of the metropolitan area, up from 72% two decades ago.
The researchers found that more than 60 sq km of tree cover, around 20 sq km of agricultural land and nearly 10 sq km of ponds and wetlands disappeared during the period as residential townships, commercial projects and transport infrastructure expanded.
The loss of natural cover has intensified Kolkata’s urban heat island effect, with pre-monsoon temperatures in several neighbourhoods rising by 4°C to 6°C above surrounding areas. Residential hubs including Behala, Bansdroni, Dum Dum and New Town are warming by nearly 0.15°C every year, the study said.
It also identified traffic-heavy areas such as Esplanade, Park Street, Dalhousie and Bowbazar as persistent pollution hotspots because of dense smog loads and limited greenery.
Rather than allowing further expansion into agricultural land and wetlands, the IIT Kharagpur team recommended prioritising redevelopment of brownfield and industrial land in areas such as Dankuni and Maheshtala, as well as vacant plots within existing urban limits.
The study called for strict protection of ecologically sensitive areas, including the East Kolkata Wetlands, agricultural land in Bhangar and Sonarpur, and the Hooghly river floodplain, warning that continued construction in these areas would worsen flooding, heat stress and environmental degradation.
Story continues below this ad
It also urged authorities to create more urban forests, green corridors and neighbourhood parks in central Kolkata, particularly around Esplanade, Park Street, Dalhousie, Bowbazar, New Town and the Howrah industrial belt.
“Every tree and wetland protected today becomes tomorrow’s natural air conditioner for the city,” Prof. Jayanarayanan Kuttippurath, who led the study, said.
The researchers noted that towns such as Kalyani, Halisahar and Kanchrapara showed that urban growth and environmental conservation can coexist by strictly preserving trees and opening green spaces. As Prof. Kuttippurath emphasizes: “The smartest place to build is on land already disturbed, not on ecosystems that naturally cool and protect Kolkata.”
© The Indian Express Pvt Ltd
Advertisement
Loading Recommendations...
Advertisement
Live Blog
Advertisement