Can Dhaka be made less hot?

Dhaka people are having their hottest days in recent memories. The temperature, which crossed 40 degrees on Sunday, highest in 58 years, is still lower than in southwestern Chuadanga district seeing over 42 degrees. But the feeling of heat in Dhaka is 5-6 degrees Celsius more than the actual reading.

What makes Dhaka people feel more heat than the recorded temperature?

The additional heat feeling is man-made – a gift of thoughtless infrastructural building destroying natural open water sources and green spaces, global and local studies suggest.

A field survey of the Centre for Atmospheric Pollution Studies (CAPS) found in 2017 that summertime temperature in Dhaka was 3-5 degrees Celsius higher in heavily urbanised areas than in areas with more green coverage and water bodies.

"That means the more trees we have around us, the less heat we feel in that environment," said CAPS Director Dr Ahmad Kamruzzaman Majumder.

Does the sprawling capital city have enough greenery and water bodies to keep the weather cool for its 1.3 crore population?

The answer is a clear no. The city has already lost much of its greenery and open water bodies like canals, floodplain, water retention zones.

More than two-thirds of the global population will live in cities by 2050. In Bangladesh, Dhaka city remains the biggest growth engine, attracting the most influx of people, requiring more infrastructures and thus causing more destruction to nature.

As the city grows, it needs to become a healthier place to breathe. But a growing number of studies say the city needs to let nature back in. It needs more green spaces. It needs to prevent water bodies from depleting fast as unending construction of roads, flyovers, expressways and buildings are turning Dhaka into a perfect "urban heat island".

Where we stand in liveability index

We are at the same low place for years in the Economist Intelligence Unit index. Dhaka stands 166th among 172 cities, seventh least liveable city in the world, ahead of cities like Karachi, Algiers, Lagos and Damascus. Since 2016, its overall score has remained at the 38-39 level out of 100, with infrastructure remaining the same and culture and environment score dropping.

It indicates that despite big infrastructures being built one after another, there is no qualitative improvement. Rather the city sinks in quality of culture and environment – one of the five categories for measuring how liveable a city is.

With 39.2 score, Dhaka is a sea away from the world's most liveable city Vienna scoring 99.1.

But all is not yet lost.

Though water bodies and greenery are depleting fast, studies suggest, still the rest can be saved if development plans incorporate the environment protection.

There are instances to follow. In neighbouring India, Kerala state sets an example how a city can be developed without ignoring the conservation of water bodies. Rather, Water Bodies were used as a Catalyst to Growth and Development in Kodungallur Town,sustaining its ecosystem, enhancing the social and recreational value and livability.

Why do cities need water bodies?

Water bodies are required to protect ecological balance, enhancing a city's beauty, discharging rainwater to reduce water-logging, recharging groundwater tables and balancing city temperature. All these contribute to the socioeconomic value of a city, brighten its image and make it more liveable.

The groundwater table of Dhaka has been depleting 2-3 metres every year.

AKM Shahid Uddin, director (Technical) at Dhaka Wasa, said, "Extreme hot weather this season has caused water table depletion to 2-3 feet more, making water pumping more challenging."

Bangladesh University of Engineering and Technology (Buet)'s water resource engineering department faculty Prof Md Ataur Rahman blames blanket concrete coverage over Dhaka for less groundwater recharge.

"Rainwater drains down as it cannot infiltrate into underground reservoirs. Moreover, the water retention points across the city have been shrinking," Ataur observed.

Urban planners think a city needs water bodies on 10-15% of its total area. In 1999, water bodies accounted for over 14% of Dhaka city area, which shrank to little over 4% in 2019, according to a study of Bangladesh Institute of Planners (BIP).

Between 1999 and 2010, an average 5,757 acres of water bodies were lost every year in Dhaka metropolitan area and surrounding upazilas.

The study shows how water bodies vanished along the Dhaka-Mawa highway, Bashundhara residential area, Uttara Sector-18, Basila, Beraid, Aminbazar in Savar, Baktar Char of Narayanganj between 2004 and 2019.

As per the Detailed Area Plan, Dhaka city area lost 22% of over 1 lakh acres of water bodies covering floodplain, water retention area, canals, rivers and other open source of surface water between 2010 and 2019.

In Dhaka metro alone, over a third of water bodies were filled by both government and private development works. In the suburbs, Rupganj took the biggest blow of massive residential, road and commercial complex works that depleted 41% of natural water bodies, followed by Keraniganj (21%), Savar (15%), Gazipur (17%).

Even in Dhaka city, to construct an elevated expressway and build apartments for government staff, the authorities have filled up the water bodies from Banani to the airport, especially along the railway tracks. Water bodies were also filled up while constructing Kuril flyover. A site office for Purbachal New Town has been built by filling up a low-lying land near Kuril Bishwa Road.

"This is frustrating that all the wetlands around Uttara (Diyabari) and Mirpur have been filled, particularly after the inauguration of the Metrorail," former General Secretary of BIP Professor Adil Mohammed Khan said.

What about Dhaka's greenery?

It is not good. The city's nearly 82% area was covered by concrete structures in 2019, up from 64% two decades ago, according to the BIP.

Though the filling of water bodies and cleansing of greenery for infrastructural works have not stopped, and more areas must have been lost by the time since the study period, hopes are still there. Much of the rest of the water bodies and greenery can still be protected.

There are ways

Urban planners suggest that development plans must keep rivers, canals and other water bodies in mind.

At least three laws have either been enacted or amended since 2000 to protect natural water bodies. Those must be enforced to prevent land developers from illegal land-filling, the planners' body says.

The BIP stresses the need for making economic analysis of water bodies. It refers to countries that take into account economic, social and cultural values or water bodies to sensitise people.

It shows how Malaysia, China, Myanmar, Sri Lanka and Taiwan have protected their water bodies through promoting ecotourism.

A water budget can be framed, like the one in China, to ensure recharging of groundwater in normal course and preserving soil moisture balance.

Government agencies must be made accountable using their own land and water bodies, transfer of development rights can be practised like that in South Korea to shift owners' right on water bodies to elsewhere, it suggests.

Why Dhaka matters

Accommodating more than a third of Bangladesh's urban population, Dhaka has been the country's engine of economic growth and job creation.

As Bangladesh moves forward to become an upper middle income country, development plans mainly focus on the capital Dhaka, attracting more and more crowds, and making it increasingly less liveable.

Dhaka's low liveability disproportionately affects vulnerable populations, says a World Bank blog series article, stressing that a liveable capital city is a must for the upper middle-income journey.

Dhaka accounts for one-third of the country's total population, one-fifth of national GDP and one-third of all jobs. Low-income people, who mostly live in a city's congested areas, live 10 years less than high-income ones living in open, leafy areas, says a 2008 study published in The Lancet.

These low-wage workers are the main drivers of the city's life and business, and they need to live healthier to serve the city better.

Bangladesh's path to upper-middle-income status will hinge particularly on leveraging Dhaka, its economic and political centre, says the post, explaining how planned and efficient development make major cities in US, Europe and Asia as global growth engines.