A city of fading greenery

Sylhet, a city over 700 years old, has been facing a major crisis over the last 20 years where it has been steadily losing its greenery and turning into a concrete jungle like many other parts of the country.

Experts say this change is triggered because of the conflict between the existing environment and the rapidly expanding urbanisation of the city.

From a GIS (geographic information system) and RS (remote sensing)-based hybrid image classification technique conducted by Sanjoy Roy, a researcher and GIS/RS analyst, on the greenery of Sylhet City Corporation area, it has been found that the green cover of the city has reduced by half between 1995 and 2016.

The study shows that the city area's total green cover was 1,347 hectares in 1995, which declined to 1,066 hectares in 2005 and 673 hectares in 2016.

The city has thus lost a staggering 674 hectares of green cover over the last two decades. The study also reveals that among four different land-use or cover types -- the green coverage contributed to about 49.64 percent of total city area in 1995, which has since reduced to 24.81 percent in 2016.

The key causes of this reduction in greenery, revealed by the study, show that the built-up area -- which mainly represents buildings and infrastructures of Sylhet City Corporation -- increased from 927 hectares in 1995 to 1,799 hectares in 2016.

Therefore, built-up area of the city has shown an exponential expansion of 32.13 percent in 2016 from 1995. In addition, the open land area, which is commonly used as playgrounds, recreation or pasture land, has also diminished by 171 hectares in the last 21 years.

Sanjoy Roy told The Daily Star that the reason behind this is the fact that Sylhet is a rapidly growing city where urban expansion is the main factor behind green surface loss.

This is happening in order to meet the need of an ever-increasing population. Huge infrastructures and buildings are being developed but there is little to no prior planning about city standards.

He said, “It is needless to say that such reduction of green coverage will have a very adverse impact on urban environment and its scenic beauty. Expansion of impervious surface along with vegetation reduction will hamper rainwater penetration to the ground, which is a large source of ground water recharge.”

As a result, ground water levels will also deplete gradually resulting in deficit in ground water extraction for the city dwellers, he said.

“Besides, vegetation reduction will also affect the urban biodiversity and urban micro climate pattern by increasing surface temperature and decreasing rainfall.”

Moreover, city dwellers are losing recreational facilities that have a long-term negative impact on human psychology. It is urgently needed to undertake a proper conservation action for the remnant green spaces in the city along with a more sustainable city development plan to reduce further degradation, he stressed.

Abdul Karim Kim, general secretary of Bangladesh Paribesh Andolon (Bapa), Sylhet chapter, said a proper planning is needed to protect urban greenery. “The demand for protecting the greenery of Sylhet remains part of a long movement run by Bapa.”

“For example, we demanded that an urban park be developed in place of Sylhet Jail, which is being transferred to another place. But that didn't happen.”

“Also, offences like cutting hills and felling trees must be punished,” he said.

Dr Md Jahir Bin Alam, professor of civil and environmental engineering department of Shahjalal University of Science and Technology, said the city is dramatically losing its greenery due to unplanned and rapid urbanisation.

“A workable plan is required to ensure the protection of greenery in the city. Alongside this, the government has to take up plans with the local governing administration to protect the existing greenery.”

Contacted, Enamul Habib, chief executive officer of Sylhet City Corporation, said the corporation is planning to start a tree plantation campaign from the next season. Under the initiative, they would plant 10,000 trees per year to keep the city green.

Ariful Haque Chowdhury, mayor of Sylhet city, said they now have a master plan for the development of the city. “It is environment friendly and could prevent further greenery reduction in the coming years.”

“We are also consulting with experts to implement projects for protecting the green cover of the city,” the mayor said.