When discussing climate change, attention usually turns to the rural coastal areas along rivers or the sea. However, a recent study on cities in the southwestern region has revealed that at least 22 of these cities are at high risk from climate change.
River erosion, salinity, cyclones, and water scarcity are severely affecting people’s livelihoods, health, social security, and future living conditions.
While the capital, Dhaka, faces the greatest pressure from migration, subdistrict towns in coastal areas have become the first destinations for migrants seeking new livelihoods. This influx has created immense population pressure in coastal urban centres. The risks posed by climate change are creating additional challenges for these cities in achieving sustainable development goals, particularly sustainable urban living.
Shireen Khatun once lived in Gabura, an island union of Shyamnagar upazila in coastal Satkhira. Her family faced repeated disasters due to annual storms and tidal surges. After losing her home, she took refuge three years ago in the Kukrali slum of Satkhira town with her two children. “I left my land for Satkhira, hoping to work and live better,” she said. “But during the entire monsoon, we had to live in water. There’s hardly any work in the city either.”
Another woman, Rokeya Khatun, from the same area, now lives in the Iteghacha slum of Satkhira town. “After the river took away my house, I came here hoping for a better life,” she said. “But now I live half the year surrounded by water. If I could find a place elsewhere, I’d move.”
According to Satkhira municipality, the town, which covers 31 square kilometers, now has a population of just over 200,000—up from 113,000 in 2011. Many displaced people from coastal areas have taken refuge in Satkhira city after losing their homes and jobs. There are now 47 slums in the municipality, each housing 50 to 60 families on average.
The Satkhira District Citizens’ Committee works on slum dwellers’ issues. Its convener, Azad Hossain, said, “People from coastal areas have moved to Satkhira slums hoping for a better life, but they are not doing well. The living conditions are poor; during the rainy season, the slums go underwater. There’s a lack of jobs, and many can’t even afford two full meals a day.”
Traffic congestion also plagues Satkhira city. The two-and-a-half kilometer stretch from Narkeltala to Boro Bazar or New Market intersections often takes over an hour to cross between 10am and 9pm. With no sidewalks, walking is nearly impossible. The main road, Shaheed Nazmul Sarani, in front of the municipal building, has broken pavement, making vehicle movement difficult. Poor waste management forces people to cover their noses, as garbage is dumped indiscriminately across the city.
The number of people like Shireen and Rokeya is increasing along Bangladesh’s coast. Many are being displaced from riverside and seaside settlements and ending up in coastal towns. Driven by the loss of livelihoods and the hope for a better life, migration has risen significantly due to climate change. The World Health Organization reports that by 2022, more than 7.1 million people in Bangladesh had been displaced because of climate change. This number could rise to 13.3 million by 2050.
22 cities at risk
A recent study titled 'Climate Vulnerability and Risk Assessment in Low-Lying Coastal Cities of Bangladesh Using Analytic Hierarchy Process' presents a data-driven picture of the risks faced by 22 cities. The research was published on 15 September in the Journal of Water and Climate Change.
Conducted by a team of researchers from Bangladesh University of Engineering and Technology (BUET), the study notes that the real impact of these risks on people’s daily lives cannot be fully captured in numbers.
The study was led by Professor AKM Saiful Islam of BUET’s Institute of Water and Flood Management. He told Prothom Alo that Bangladesh’s coastal regions face complex challenges from climate, environmental, and socio-economic factors.
Effective strategies require a combination of multi-dimensional risk assessment, development of climate-resilient livelihoods, and inclusive urban governance, which together ensure long-term sustainability. The research aims to highlight the often-overlooked issue of potential climate change damages in urban areas.
The suffering that numbers cannot capture
The life of Mobarak Hossain from Jorshing village in Koyra, Khulna, was upended by Cyclone Aila on 25 May, 2009. Mobarak was once a well-off person. He owned 22 bighas of shrimp farms, a large grocery store, and traded fish and honey from the Sundarbans. With a brick-built house and a happy family, his life was prosperous. But the tidal surge of Aila wiped away his world of happiness in an instant. The river embankment broke, and everything went underwater—his homestead, business, and even the graves of his forefathers.
The next day, Mobarak took shelter in Khulna city with his family. Thus began the struggle to survive in an unfamiliar city. Years passed amid harassment, deception, hunger, and neglect. Yet life did not stop. Sixteen years later, he has rebuilt shelter in Dumuria upazila of Khulna. That small tin-roofed, fenced house is now his place of survival. Despite immense loss and pain, he was forced to leave his birthplace and seek a new means of living elsewhere.
Like him, many others—such as Haidar Ali Gazi of Kheona village and Ismail Sardar of Megharite—lost their homes to Aila and took refuge in towns. Some of these displaced people now drive rickshaws, pushcarts, or vans.
Due to one natural disaster after another, countless people from various villages of the coastal districts Khulna and Satkhira have been forced to leave their homes. Some moved to Khulna city, some to the capital, and others even to the hilly regions. Many have changed or lost their occupations. Those who remain have to fight nature to survive.
In the past 19 years, 13 cyclones—including Aila, Sidr, Amphan, and Remal—have hit the Khulna coast. According to government and non-government surveys, about 123,000 people have left Khulna and Satkhira after Aila. Around half a million people were displaced across the coastal region in 2009, many of whom still have not been able to return to their villages.
Bangladesh’s coastal region consists of 20 districts, with a total area of about 9,380 square kilometers. Most of the cities in the coastal districts lie between 1.2 and 4.5 meters above sea level. The southwestern coastal towns are known for their complex network of rivers, canals, estuaries, and mangrove forests.
For this study, 22 coastal towns in 10 districts—those facing rapid urbanisation and high risk—were selected. Continuous river flow, tidal activity, and sediment deposition have given this region a special character. Cyclones, seasonal floods, and riverbank erosion have further increased the risk to coastal towns.
How the damage was assessed
Considering the current situation and future climate change scenarios, vulnerability and risk indices were assessed for 22 coastal towns in the southwestern region. Both socio-economic and physical indicators were considered in this assessment.
The Intergovernmental Panel on Climate Change (IPCC) considers several indicators in vulnerability assessment. These include sensitivity, adaptive capacity, exposure, and hazard. Sensitivity includes population density, gender ratio, proportion of people with disabilities, and types of housing. Adaptive capacity was measured through literacy rate, water supply, sanitation facilities, and transport accessibility.
In terms of exposure, population size, agriculture, and coastal elevation were considered. For hazards, indicators included erosion rate, storm or tidal surge depth, wind speed, and maximum daily rainfall.
Socio-economic data were collected from the Statistical Yearbook of Bangladesh published by the Bangladesh Bureau of Statistics (BBS). In contrast, physical data were collected from different models, satellite images, the Bangladesh Water Development Board, and the Bangladesh Meteorological Department. Alongside data collection, group discussions and field surveys were conducted in high-risk areas.
Which towns are at what level of risk
Due to repeated cyclones and tidal surges, embankments in various coastal areas have broken, allowing saline river water to enter residential zones. Even after the embankments are repaired, salt remains in the soil. Shrimp farms are created by cutting or puncturing embankments under the Water Development Board’s jurisdiction. As a result, the embankments are damaged, homesteads are lost, livestock die, and forest and fruit resources are destroyed. Such scenes are regularly seen in different parts of the southwest.
Based on how incapable people in an area are in coping with disasters, vulnerability and risk indices were developed in the study. According to the current situation, the towns of Chalna, Morelganj, Kuakata, Char Fesson, Lalmohan, Kalaroa, Patharghata, Borhanuddin, and Paikgacha are classified as extremely high-risk or very highly vulnerable. On the other hand, the upazila towns of Nalchity, Mehendiganj, Muladi, Vedorganj, Zajira, Bakerganj, and Swarupkathi fall into the moderate vulnerability category. Betagi, Gournadi, Jhalakathi Sadar, Bagerhat Sadar, Banaripara, and Patuakhali Sadar are considered low vulnerability zones. Analysis suggests that in the future, the vulnerability indices of Chalna and Morelganj may remain unchanged.
Risk assessment shows that some towns with lower vulnerability have comparatively higher risk; whereas some towns with higher vulnerability have relatively lower risk. This difference depends on the presence or absence of hazard and exposure factors in each area. Under the current situation, Chalna, Patharghata, Mehendiganj, Morelganj, Muladi, Kalaroa, and Kuakata have been identified as very high-risk towns. Bhedorganj, Betagi, Nalchity, Char Fesson, Paikgacha, Borhanuddin, Swarupkathi, and Bakerganj fall under moderate risk. On the other hand, Jhalakathi Sadar, Lalmohan, Zajira, Bagerhat Sadar, Gournadi, Banaripara, and Patuakhali Sadar are in the low-risk category.
The classification of some towns has changed position; for example, Patharghata, Morelganj, and Paikgacha have dropped to relatively lower categories. In the future, the risk indices of Chalna, Bagerhat Sadar, and Gournadi may remain the same.
In addition, the vulnerability indices of Bagerhat Sadar, Paikgacha, Banaripara, and Gournadi may increase by 8 per cent, 7.9 per cent, 12.4 per cent, and 11.3 per cent respectively — the highest growth rates among the 22 coastal towns.
Eight problems increasing urban risk
Economic condition: Nazem Uddin of Char Fesson in Bhola drives a battery-run rickshaw on a busy road in Barishal city. Once, his family lived off farming and river fishing. But when the Meghna’s erosion devoured his land, he moved to the city in search of livelihood. His wife and children still live in the village, while Nazem stays in a slum mess in Barishal city with 15 other rickshaw drivers. The government’s new poverty map shows that the highest poverty rates in the country are now in the coastal Barishal division.
The number of battery-run rickshaws in Barishal city is rising every day, increasing traffic congestion and civic suffering. Five years ago, there were at most 5,000 such rickshaws; now the number has exceeded 15,000. Most of the drivers are working-class people from coastal districts like Bhola, Patuakhali, and Jhalakathi.
Thus, poverty in areas like Barishal and Khulna is increasing day by day. Dipankar Roy, joint secretary of the Statistics and Data Management Division of the Planning Ministry, told Prothom Alo, “We observe poverty in terms of consumption, migration, and unemployment. The recurring disasters in coastal regions could be a cause for worsening poverty conditions.”
Salinity and drinking water crisis: Due to salinity in soil and water, the availability of drinking water is decreasing, cultivable land is being damaged, and many fish species are disappearing. Because of excessive salinity, many farmers have left agriculture and taken up shrimp farming. With cultivable land shrinking, many have turned to construction work, which is not a year-round occupation.
The study mentions that in Paikgacha, Chalna, and Morelganj, intrusion of saltwater into groundwater has created a drinking water crisis. In Bagerhat Sadar, some water is supplied, but it is not enough to meet demand. The lack of safe water has also increased the spread of waterborne diseases. People in Chalna and Morelganj collect water from distant ponds—during summer, they have to walk 2–3 kilometers. The absence of well-maintained ponds in rural areas is worsening the crisis.
The salinity levels in rivers of the Khulna coastal region are rising rapidly. Normally, water with salinity over 5 dS/m becomes unsuitable for irrigation. But according to a survey by the Soil Resources Development Institute, in April last year, salinity in Koyra Canal water was 42.9 dS/m—almost equal to seawater (50 dS/m). Salinity in the Rupsha River was 23.7 (up from 18.56 in 2023), in the Shibsha River of Paikgacha 35.9 (up from 26.64), in Mongla’s Pashur River 33.3, and in Bagerhat’s Daratana 22.8 dS/m.
Soil salinity has also reached alarming levels. In March this year, salinity was recorded at 5.97 in Gutudia, Dumuria; 5.84 in Phultala-Batiaghata; 12.2 in Digaraj, Mongla; and 5.98 dS/m in Paikgacha fish farms.
To Amena Begum, a resident of Hodda village in Maheshwaripur union of Koyra, saline shrimp farms are a curse. She said, “Because of these saltwater farms, the trees on our homestead are turning red and dying. Earlier the river water stayed outside the embankment; now it enters our locality directly through the shrimp enclosures.”
River siltation and erosion: In these densely populated and land-scarce towns, river erosion is a major curse. People have to relocate repeatedly due to erosion. Riverbeds are filled with silt, causing regular inundation during tides. The Kapilmuni section of the Kopotakkho River has lost its former depth and width. Recent dredging has increased the river’s flow, but severe erosion has appeared in the bends of the Shibsha, Chunkuri, Rupsha, and Panguchi rivers. Many lands and road segments along the Panguchi River at Gabtala village have been swallowed by the river. Three embankments along the Rupsha River have already collapsed, and a fourth is at risk. The retaining walls and protective structures in Chalna and Morelganj are also damaged and weak.
Waterlogging: Waterlogging is a major problem in coastal towns, especially in markets and low-lying areas. During the monsoon months, many areas flood with even light rain or tidal flow. In Morelganj, areas like Krishi Bank Road, Kuthibari, and the surroundings of Boira Bazar regularly experience waterlogging. The Morelganj market remains submerged twice a day for two to three hours during high tide. In Chalna’s Asabhua village and the residential areas near the upazila office, the absence of drainage causes waterlogging even after light rain. In Bagerhat Sadar, rainwater stagnates due to poor drainage. This waterlogging severely disrupts daily movement, trade, healthcare, and education.
Drainage problems: The absence of a proper drainage system is the main cause of waterlogging. In almost all areas, there is no effective drainage for stormwater or rainwater. Many drains are too narrow or clogged. There are no drains in residential areas of Chalna and Morelganj, and the canals are filled with silt. In Bagerhat Sadar, the drains from Rahater Mor, Muniganj, and Sadhan Mor towards the river are narrow and filled with waste. The canal beside Doratana Bridge is also blocked. The drains in Morelganj’s Sheresta Bridge and main market areas are small and insufficient, causing water accumulation during heavy rain. The lack of regular cleaning and maintenance has rendered the drainage systems ineffective.
Solid waste management problems: Most towns have no permanent system for solid waste collection or disposal. In Bagerhat Sadar, waste is collected on a very limited scale, which is inadequate. Other towns have no collection system or designated dumping sites. As a result, people dump waste indiscriminately, which ends up in drains and canals. This waste blocks the drainage system and stops water flow. The increasing amount of plastic and non-biodegradable waste makes the situation worse, putting pressure on the natural environment.
Canal siltation: Canal siltation and dead flow have become common in all towns. The main causes are waste dumping, lack of maintenance, and no dredging. In Chalna town, the Asabhua, Gaurkhali, and Baroikhali canals have become filled with silt. In Bagerhat Sadar, canals beside PC College, Jadunath School, and Muniganj Bridge are almost completely closed. In Morelganj, the number of canals is insufficient, causing prolonged waterlogging during monsoon rains. The canal near Naboirshi bus stand is completely closed, and shops have been built over it. The canals near Sheresta Bridge and Kamarpatty are in similar condition. However, the canal beside the fire service station in Chalna is still functional, so there is no waterlogging there. Similarly, canals in Baroikhali and Bhaijura areas remain active and help irrigation for farming.
Sluice gate problems: All coastal towns—such as Paikgacha, Chalna, Morelganj, and Bagerhat Sadar—are situated on tidal rivers. Hence, sluice gates play an important role in flood control, water management, and maintaining river–plain connectivity. But broken and ineffective sluice gates are severely damaging the towns’ flood control capacity. As a result, low-lying areas get flooded during heavy rainfall or tidal surges, disrupting agricultural and commercial activities. The sluice gate in Chalna’s Baroikhali area has completely collapsed; locals have blocked it with wood, but the authorities have taken no action. The widths of old sluice gates are also too narrow to handle current water flow. With climate change increasing water volume and frequency, this problem will worsen.
Koyra upazila in Khulna is surrounded by 155 kilometers of embankments along three rivers — the Kapotakkha, Shakbaria, and Koyra. Recently it was found that over 400 holes and cuts have been made in the Water Development Board’s embankments to install pipes that supply saline river water to shrimp farms. In some places, thick pipes have tube wells attached at both ends. On one side of the embankment is the river; on the other side, shrimp enclosures.
Infrastructural weakness: Prolonged waterlogging and tidal water are damaging roads, culverts, and drains. The road beside the Gaurkhali canal in Chalna and parts of the culvert in Baroikhali village are damaged. During cyclones Sidr and Reshma (2007 and 2008), roads in Chalna’s gas company and shipyard areas were destroyed, and they still have not been repaired. Roads in Rahater Mor and Sadhan Mor in Bagerhat have been elevated several times but are again submerged due to poor drainage. The sluice gate of Mazar Canal has broken, and the one beside Muniganj Bridge is nonfunctional. Prolonged waterlogging weakens road foundations, causing roads and culverts to deteriorate rapidly. In any disaster, these weak infrastructures will be easily damaged, further reducing the area’s disaster resilience.
(Report prepared with assistance from Kalyan Banerjee in Satkhira and M. Jasim Uddin in Barishal)