A research paper, titled ‘Landscape and Urban Planning’, conducted in Bengaluru showed that urban green spaces (UGS) provided cooling effects up to 347 metres to any buildings and other infrastructure.
The research — Quantifying the local cooling effects of urban green spaces: Evidence from Bengaluru, India — authored by one post-doctoral student, his professor at Indian Institute of Management-Ahmedabad and a faculty member from the Indian Institute of Technology-Gandhinagar, published in January this year, showed the declining cooling effect on buildings and other spaces in proportion to the distance from the green spaces.
“The average UGS was 2.23 degrees Celsius cooler than the point where it ceased to provide cooling effects. Cooling effects reduced with distance from the UGS, and were impacted by the greenness, size, and shape of the UGS,” the research paper stated.
The authors used remote sensing to understand the cooling effects and the study pointed to the need for conserving green spaces in rapidly growing cities in India. They also focused on the local cooling effects of 262 UGS in Bengaluru in 2017.
Arpit Shah, one of the co-authors of the research paper, said that higher distance between the green spaces and concrete structures also caused higher dependence on electronics like air conditioning and refrigeration.
The paper stated that increased urban temperatures were also a cause for higher secondary air pollutants and their resultant impact on health. Green spaces could also reduce ambient heat at the local scale, reduce air and noise pollution levels and better absorb rainwater.
The findings come at a time when temperatures in Bengaluru have soared on account of declining green spaces in one of the country’s fastest growing cities. While its prowess in technology and other sectors has grown, the city’s administration has failed to keep its green cover intact, experts and activists said.
The Bruhat Bengaluru Mahanagara Palike (BBMP, the city’s civic body) on Saturday earmarked ₹214 crore towards the maintenance of around 1,200 parks in the city, up from ₹84 crore the previous year. In its 2020-21 budget, the civic body has also decided to set up air quality management centres at the cost of ₹279 crore. Another ₹39 crore has been earmarked to the forest department as well as plans to plant another 10 lakh saplings in the current year.
“To cool down buildings, you need green spaces at the local level and that is what is disappearing in Bengaluru over a period of time. The same is true across India,” Arpit Shah said.
According to the study, built-up area in Bengaluru accounted for 58% of the total land use in the city in 2017 while green cover (including grasslands) was just 10.5%. Water bodies constituted for 3.9% and bare land accounted for 19.2%.
The findings come at a time when the civic administration in Bengaluru has gone on a rampage, cutting fully grown trees to make way for concrete structures like flyovers, buildings and other works under the guise of “development”, activists and environmentalists said.
“They claim that they are going by due process since it is developmental work and that an underpass is coming there,” Vinod, an activist and resident of the locality said. This road connects East and Central Bengaluru to Whitefield and other IT corridors of the city.
He added that since there is Work from Home, there is no real traffic and no urgency required to carry out this project in such a hurry by cutting down fully grown trees.
At HAL (Hindustan Aeronautics Limited), residents have been protesting against the felling of fully grown trees to make way for an underpass that, experts said, would only shift the bottleneck a little further.
Residents of the locality, just off the Old Airport Road in East Bengaluru, on Sunday alleged that the contractors had poisoned the trees to justify the felling of trees.
“As you are aware of the tree cutting issue on the Old airport road, we the residents of HAL surrounding area are opposing and pleading you to help us by at least saving the remaining trees by minimal restructuring the plan of the service road used for underpass,” Swathi Damodhar, a resident of the locality wrote to top BBMP officials on Sunday.
She added that it was “disheartening” to see that the trees have been poisoned, which was absolutely “inhumane”.
“We had done a human chain last Sunday and this week we have had a small rally there to safeguard these heritage trees. What is marked as number one and two are over 100 years old,” Vinod said.
At least two senior officials from the BBMP could not be reached for comment.
Activists said that around 48 trees were marked to be cut, of which 10-12 were cut without consultation with the locals.
They added that some volunteers were performing Raksha Bandhan and tree hugging to help save the trees.
With the boom in Information Technology (IT), Bengaluru has seen a sudden shift in its fortunes where it has earned reputable tags like IT and startup capital of India but has steadily eroded the sheen of its earlier monikers like ‘garden city’.
“There are so many lakes in Bengaluru, so many green spaces. But now construction and built-upareas have expanded over it,” Professor Amit Garg, another co-author of the paper, said.
The research found that green spaces that were spatially dispersed across the city could be useful in providing cooling effects and that city administrations should embed these spaces at various locations.