In the past three decades, the rate of destruction of ecosystem in five largest cities of the country has accelerated fast.

Water bodies and forestlands in these cities have been destroyed along with biodiversity.

Owing to this, residents of these cities have been deprived of services worth around Tk 600 billion from 1991 to 2021. This information surfaced in a research done on Dhaka, Chattogram, Rajshahi, Khulna and Sylhet cities.

Nine researchers from UK’s Oxford University, Australia’s Newcastle University, Curtin University, Canada’s Calgary University, Chattogram University, Chattogram University of Engineering and Technology and Noakhali University of Science and Technology conducted this research. The research got published in the international science journal Ecological Informatics in the beginning of the current month.

The research stated, all five of the cities have flourished on the river banks. Among them, Dhaka thrived on the banks of Buriganga, Chattogram on Karnaphuli, Rajshahi on Ganges, Khulna on Rupsha and the city of Sylhet grew on the banks of Surma river.

The rivers and wetlands in these cities were put under pressure due to the rapid growth of population. The population of Dhaka city is increasing by 11.5 per cent every year. Meanwhile, the rate of growth in Rajshahi is 5 per cent and in Chattogram it is about 3.75 per cent.

Ashraf Dewan, a member of the research team and an associate professor at Australia’s Curtin University, said to Prothom Alo, “Water bodies and greeneries crucial for the ecosystem of these cities including Dhaka is being destroyed.”

“However, these natural elements help us with temperature control, food supply and healthy atmosphere. We are failing to reap the benefits due to constructing concrete buildings, roads and various other infrastructures through the destruction of these. This is causing the temperature in these cities to go up rapidly, making them unlivable,” he added.

Under such circumstances, ‘World Nature Conservation Day’ was observed in the country on Thursday. This year the theme of this day is to reduce plastic use for the conservation of nature.

In the research ecosystem services mean human beings and other animals receive a number of services if important features of a natural environment remain intact.

Such as the temperature in the concrete surrounded area is one to three degree Celsius higher than that of the area with water bodies. People use many appliances including electric fans and air conditioners if the temperature is high.

If there are green trees somewhere, it helps with the reduction of temperature and supplies fruits, medicinal plants as well as habitats for birds and animals. These are considered as ecological facilities.

It was said in the research that Sylhet city has lost wetlands the most in the past thirty years. Meanwhile, Dhaka dwellers were deprived of financial benefits the most due to the decrease of wetlands.

In 1991, there were 27 per cent of greeneries in Dhaka. This reduced to 10.14 per cent in 2021. Apart from that, forest lands in Sylhet decreased to 20 percent from 50 per cent, in Khulna it dropped to 32 per cent from 40 per cent and in Chattogram it became only 18 per cent going down from 28 per cent.

A member of the research team and a teacher at Chattogram University of Engineering and Technology, Md Sarfaraz Gani, said to Prothom Alo, “The ecosystem of our cities is being destroyed in the interest of some influential quarters.”

16 types of ecological facilities were financially evaluated in the research. This included issues like pure air, arrangements for entertainment, carbon emission control, water supply, soil protection and waste management.

City residents have to pay extra money on these facilities as the ecology has been destroyed.

The research stressed on planned urbanization to reduce the financial loss caused by the destruction of ecology.

At the same time, it also provided guidelines regarding what kind of preparations should be taken to deal with the risk of damage related to climate change.