East Kolkata Wetlands & Green Space
The Ramsar site's legal boundary, its measured wetland cover in 1991 and 2023, and how much of the KMC area is green or blue space (2020)
The East Kolkata Wetlands are Ramsar site No. 1208. Their designated area is 12,500 hectares (125 sq km). That figure is a legal boundary, not a measurement of how much wetland is left. Inside that boundary, one satellite study (Yadav et al. 2024) finds that land classified as wetland fell from 91.2 sq km in 1991 to 33.4 sq km in 2023.
Inside the city, a 2020 mapping of the Kolkata Municipal Corporation area (Paul & Bardhan 2022) found green space covering 7.93% of the area and water bodies and wetlands another 3.58%. Divided by the Census 2011 population, that comes to about 5.08 square metres of green and blue space per resident.
About this data
What this page shows
Two things. First, the legal extent of the East Kolkata Wetlands Ramsar site, alongside one study's measured wetland land-cover class inside that boundary in 1991 and 2023. Second, the share of the KMC area mapped as green space and as water bodies or wetlands in 2020, and what that works out to per resident. Earlier versions of this page also showed a city-wide land-class breakdown, a built-up trend, conversion flows, a green-per-capita series and ward tree cover. None of those figures could be traced to a source, so they have been removed.
Where the data comes from
Designated area (12,500 ha) and fishpond area (about 4,000 ha): Ramsar Information Sheet for East Calcutta Wetlands, Site 1208, updated 19 August 2002. Wetland class for 1991 and 2023: Yadav, Jha, Joy & Bansal (2024), Ecosystem health assessment of East Kolkata Wetlands, India, Journal of Environmental Management 366:121809, doi:10.1016/j.jenvman.2024.121809. We took these figures from the published abstract. Green and blue space: Paul & Bardhan (2022), IRSPSD International 10(3):280-301, doi:10.14246/irspsd.10.3_280, text and Table I. Population: Census of India 2011, KMC total of 4,496,694.
Limitations worth knowing
The 125 sq km and 33.4 sq km figures measure different things and should not be compared as a loss. The first is a legal boundary. The second is one Landsat-based classification, and its “wetland” class may not include open-water fishponds, which the Ramsar sheet puts at about 4,000 ha (40 sq km). Only the 1991 and 2023 values are given in the abstract, so the chart shows no intermediate years. The per-person figure divides 2020 mapping by 2011 population, because Census 2011 is the latest count. Published per-person estimates for Kolkata differ widely. Another 2020 study (Springer chapter, doi:10.1007/978-3-031-06443-2_9) reports 12.46 sq m per person, about 2.5 times higher, using a different method.
On benchmarks
The widely repeated claim that “WHO recommends 9 square metres of green space per person” does not appear in any WHO document we could find. WHO's actual guidance is about access, not area per person: residents should live within about 300 metres of a green space of at least 0.5 to 1 hectare. This page does not measure that access, so it shows no benchmark line.
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