Beware! Dangerously rising sea level could submerge Mumbai in 100 years

What makes this is a possibility, according to a PhD scholar from JNU, is that the current annual sea level rise is between 2.5 and 3 millimetres (mm).

The city could lose 25.32 sq km — roughly 1,700 Wankhede stadiums (0.0148 sq km) — of its urban sprawl to coastal inundation caused by a 1m sea level rise over the next 100 years, according to a study.

Picture for representation(HT File)

The author also said the protection of mangroves play a significant role in protecting the city.

The ‘Impacts of predicted sea level rise on land use/land cover categories of coastal areas of Mumbai megacity’ study by a research scholar from Jawaharlal Nehru University (JNU) identified urban areas including housing societies, commercial complexes, roads, infrastructure such as flyovers, bridges etc., ports, slum settlements and few open spaces, that could be affected by coastal inundation.

What makes this is a possibility, according to Malay Kumar Pramanik, author of the paper and PhD scholar, JNU, is that the current annual sea level rise is between 2.5 and 3 millimetres (mm).

“Mangroves and wetlands are a natural protection that can absorb a large quantum of the excess water during inundation and protect the shoreline from tidal currents,” he said.

According to the study, the entire coastal belt from Gorai to Mira Bhayander will be the worst affected owing to the Arabian Sea and Vasai creek.

Areas such as Andheri to Dahisar in the western suburbs, right from Sewri, Trombay, Govandi, Wadala, Chembur, parts of Mulund, in the eastern suburbs, all the way up to Thane due to rise in water level from the Thane creek.

Some low-lying parts of the central and south Mumbai, including Haji Ali, Worli, and some areas around Nariman Point to Marine Drive, could be completely submerged.

“The evidence of global rise in temperatures with 2016 being the hottest year on record, melting of glaciers and ice caps with recent evidence of the splitting of the Antarctic ice shelf, population expansion of Mumbai city and rising infrastructure development makes the city vulnerable to probable inundation,” he said.

The conclusion of the study revealed that sea level rise would reduce the drainage gradients that promote flooding condition to rainstorms and subsequently increase saltwater intrusion into coastal regions. “Alterations in the coastal features and landforms correlated with inundation characteristics make the coastal region more vulnerable in the coming decades due to huge development activities and population pressures in Mumbai,” the study concluded.

HT had reported in December last year that a National Institute of Oceanography (NIO) study had estimated a 1.5m sea level rise by 2100, which could inundate 40% (190 sq km area) of Mumbai. Both studies factor in the impact of climate change and global warming through the melting of glaciers, rise in temperatures over the next century as a result for sea level rise.

Researchers from the NIO said that Mumbai has an average elevation above sea level of 14 m with some areas as low as 6 to 8 metres along the low-lying coastline.