It is an area that routinely gets hammered by severe cyclones. And then there is the problem of rising sea levels due to climate change. It is not only the people, but the Sundarbans itself that is under threat and things can only be said to be getting worse.
Following cyclone Yaas in May, residents of two islands, Ghoramara and Mousuni, are being being moved away to safety by the West Bengal government as tidal waters and rainfall pose grave risk to their lives while much of their property has already been claimed by the sea.
Caught between water and vanishing land
The Sundarbans has a unique geography. Formed by the confluence of the Ganga, Brahmaputra and Meghna rivers as they drain into the Bay of Bengal, it is the largest estuarine delta in the world. Dotted with islands, this area is girded by what is also the largest mangrove forest in the world. The delta, shared by India and Bangladesh, is home also to the famous Bengal tiger and the Gangetic dolphin apart from several other species.
Man and animal have cohabited these islands, but climate change has out a question mark on the existence of Sundarbans itself, which incidentally also features on the Unesco World Heritage List.
Formed by the heavy deposits of alluvium, or riverine silt, these islands had for decades held out against the sea, but since 2009, when cyclone Aila struck these parts, things have take a turn for the worse, experts say. In fact, Aila was followed by several other cyclones that brought water into these islands, Yaas being only the latest of those.
Why are the islanders being moved?
The islands of Ghoramara and Mousuni bore the brunt of Yaas, which tore away embankments that were built to keep the sea at bay. Taking stock of the damage from the cyclone, West Bengal chief minister Mamata Banerjee had said it had breached embankments at 317 places in the Sundarbans.
While work was taken up to repair the broken embankments, officials realised that the operation won’t be completed before another weather whammy appears on the horizon.
The fresh worry is of high tides even as monsoon clouds are headed towards Bengal.
According to reports, tidal activity on 11 June which will see a new moon surge, and around 26 June, when the spring tide will cause water levels in the sea and rivers to rise by as much as 1 metre than is normal, can badly hit these two islands.
Although the state government had said most of the 317 embankments would be repaired by 21 June, it will take them till the end of the month to cover some embankments on Mousuni and a few other islands. So, officials have already moved more than 4,000 inhabitants of Mousuni and Ghoramara islands to safety.
“So far, we have evacuated over 4,000 people from these two islands but more people need to be moved as per chief minister Banerjee’s direction. Over 1,100 families live in Ghoramara and 3,200 in Mousuni,” Sundarbans development minister Bankim Hazra had said on 9 June. The state government had earlier said up to 20,000 people would have to be moved out of harm’s way ahead of the tidal surge.
What is the level of threat facing the Sundarbans?
According to a climate threat assessment report released by the Centre last year, the Bay of Bengal area where the Sundarbans lies is one of the most climatically vulnerable zones in India with increase in sea levels and flooding presenting the greatest risk. An analysis of data between 1891 and 2018 showed that the Bay of Bengal region was struck by 41 severe cyclonic storms and 21 cyclonic storms during the given period. All these events had occurred in the month of May.
The report added that while the global average for rising sea temperatures was 0.7 degrees Celsius, surface temperatures in the tropical Indian Ocean rose by an average of 1°C between 1951 and 2015. This rise in ocean temperatures influences the intensity of thunderstorms and cyclones, the report noted.
And then there is the phenomenon of the sea swallowing up land.
According to a study cited by a report in the Deccan Herald, there are islands in the Sundarbans delta that have lost big chunks of land. Conducted jointly by the University of Exeter in UK and the Kolkata-based Jadavpur University, the 2018 study found that there was a 70 percent reduction in the landmass of the Ghoramara since the 1920s due to coastal erosion.
“The land loss has been attributed to flooding, cyclone activity, mangrove loss and sea-level rise, with climate change expected to play a greater role in the future,” says the studye entitled ‘Political Economy of Planned Relocation: A model of action and inaction in government responses’.