The sinking of a city
Nurjahan Begum is sitting on a plastic chair in front of her house in a densely populated settlement on the banks of Karnaphuli river in Chittagong. More than half of the chair is submerged in water. Today, hundreds of families in Begum's neighbourhood were once more trapped in floodwater for nearly five hours.
These days, the daily life of many people in Bangladesh's second largest city revolves around the tides and the rise and fall of the flooding. The sea is 16 kilometres away. Floodwater enters the canals of the city through the Karnaphuli river. During high tide, everyone is forced to stay indoors for five to six hours. All work, errands and other activities must be finished before the water returns.
More than half of Chittagong is now subject to regular flooding. According to a survey by the Public Works Directorate, a government agency in Bangladesh, about 69 % of the city is now more or less covered by flood tides.
Another study published in the scientific journal Geophysical Research Letters states that Chittagong lost 2.39 centimetres of land each year between 2015 and 2020. Simultaneously, according to the Intergovernmental Panel on Climate Change (IPCC), sea levels have been rising at a rate of about three millimetres per year since 1993.
Climate refugees face new climate risks
Many of Chittagong's some six million inhabitants have arrived in the city over the last few decades – migrants fleeing from the impact of other climate disasters happening elsewhere in the country. Most of them had lost all they owned due to cyclones, river erosion or floods.
Nurjahan Begum is one such example. Her house on the banks of Meghna River in Daulatkhan, part of the island district of Bhola, was swept away by a cyclone in 1991. The 60-year-old woman's life has been dominated by climate disasters. As a result, she has been forced to move 22 times. She arrived in Chittagong ten years ago with her three children, following the death of her husband and the renewed loss of virtually all her possessions.
Now, her family and many others are facing the impacts of the climate crisis yet again. In recent years, many people have been forced to shift repeatedly, living in high-rise areas with more expensive rents during the monsoon and moving back to low-rent houses in lower lying areas of the city once the monsoon is over.
Roksana Begum's family has ten members. In the past two years, they have moved three times because of the floods. The 55-year-old migrated to the city to escape economic hardship in her village. Mohammad Shahjahan also came to Chittagong in search of work when he was 20 years old.[embed:render:embedded:node:47413]
Until then, he had lived in a village called Dakshin Syedpur on the coast. His family had to shift their house seven times due to river erosion. These days, the place where Shahjahan's father once built their house lies in the middle of the river Meghna. Shahjahan once considered the centre of Chittagong to be a safe bet, but now he is worried about whether he can continue to live in the city at all.
Daily flooding
The more well-off neighbourhoods are not immune to flooding, either. The World Trade Center, the most important building in the Agrabad commercial area, is now surrounded by floodwater. The city's most elite residential area, the Chittagong Development Authority (CDA) housing estate, is located close to Agrabad.
In recent times, the popularity of the area has decreased massively. Abu Kalam is a CDA resident. Over the years, the 70-year-old has invested a lot in his home, the value of which has now dropped significantly. The ground floor is constantly under water. This is the case for the whole area for five to six hours a day. Most people can no longer use their ground floors and have been forced to build new houses elsewhere. Homeowners have no chance of renting out their houses in this formerly desirable area.
Some infrastructure projects have been initiated to improve the situation. Roads in the worst-affected areas have been raised by almost one metre – but at high tide the water is still 50 centimetres above the road. Locks are also being added to the canal outlets.
Rezaul Karim Chowdhury, acting mayor of Chittagong City, however, points to another problem: "Chittagong once had 76 canals. Now it is down to 57. Many canals have been taken over by land grabbers." He has requested the help of the ministry of local government, rural development and co-operatives to bring these canals back under the city's control.
Chittagong is not the only city facing these problems. In another study published in the journal Geophysical Research Letters, researchers measured the rate of land degradation in 99 coastal cities around the world between 2015 and 2020. In most cities, the land mass is sinking faster than the sea level is rising. If this decline continues, cities will be at risk of flooding much sooner than predicted in most models that focus on a rise in sea-level.
Human activities, especially groundwater extraction, are likely to be the main cause of this decline. Increased monitoring and policies are needed to reduce the rate of deterioration and minimise its impact.
Rafiqul Islam Montu