The Urban Problem 

According to a study by the United Nations, the number of inhabitants living in urban areas is 50 percent and is said to grow to 70 percent by 2050. It means two out of three persons will live in urban regions. The most change will be observed in China, India, and Nigeria which together account for 37 percent of total urban migrants before 2050. It puts forth one major problem, habitation. The easiest solution to this problem is the expansion of urban sprawl. 

The urban migrants look for cheap housing to join the workforce in the city center. It boosts housing demand in the city suburbs and catalyzes a greenfield development. The result of it is a misuse of existing green spaces that enclose the city.   

How do Cities Expand by Encroaching on Green Spaces? - Sheet1
Overcrowding is synonymous to the hustle bustle of cities ©Owen Barker 

The Gone Green spaces of Indian Metros  

At the start of the 20th century, there was only one metro city in India, Calcutta. Soon, Bombay, Madras, Hyderabad, and other cities followed. By 2011, the number of cities with over one million people rocketed to 52. 

People migrate to cities for better economic opportunities, education, infrastructure, and healthcare leading to rapid urban agglomeration. Metropolitan cities could grow in their cores (vertically) or through their periphery (de-densification by suburbanization).

Pallikaranai: The Lost Green Lung of Chennai

The 2015 floods in Chennai could have been averted if the wetlands of Pallikaranai were left untouched. Spread over a whopping 5500 hectares in 1965, the marshland dwindled to a meager 600 hectares in 2015, about 10 percent of the original size. Adjacency to city core areas like Guindy (a commercial hub post-independence) led to the misuse of the wetlands. 

Considered to be Chennai’s sponge, it is located strategically to absorb excess rainfall during monsoon and release them into the aquifer for surrounding areas in summer. Once a migration spot for endangered species is now squeezed by urban development. A total of 70 hectares of Pallikaranai is now dumping yards, toxic methane from incineration hovers the region. 

Land reclamation is also an issue as the area is “developed” into residential areas, IT parks, colleges and institutions. The story of Guindy National park follows similar lines. The 270-hectare national park, the smallest one in India, is a green space houses species like blackbucks, slender loris, deer, and jackals face a threat as the city expands.

How do Cities Expand by Encroaching on Green Spaces? - Sheet2
Pallikaranai land use map over the decades ©Spirit Of Chennai(dot)com

The case of Bangalore and Mumbai

The tale of Bangalore is not heartwarming either. During the IT boom in the early 21st century, the garden city was touted as the Silicon Valley of India. It did come at a cost. From 1973 to 2012, the areas under pavement multiplied 100 times while the green cover reduced from 68 to 25 percent. The surface cover of water bodies also drowned to just 1 percent from 3.4 percent. Researchers suggest that Bangalore will have a mere 3 percent of green cover in the near future.

How do Cities Expand by Encroaching on Green Spaces? - Sheet3
The land use map of bangalore shows the shrinking green spaces ©Bharath H Aithal-Vinay Shivamurthy-T V Ramachandra

Every city has experienced that stage of growing sprawl. Mumbai took over its mangrove lands. Not to mention the Aarey forest, a rift that sprang up between the government and its people as Mumbai wanted a metro that rides over the forest to decongest its traffic while reducing the burden on urban transport. 

Pune has also lost its green cover. The city in 1901 was just 5 square kilometers. It was all rapid urbanization, especially after Mumbai became a financial hub. Along the way, it has destroyed its green spaces and lands near lakes. For example, Lake Bhosari lost 90000 sqm of land around it in reclamation projects.

The Undeniable Connection Between Urban Sprawl and Green Space Reduction

There are international examples that follow the same pattern. The core city gets concentrated while the periphery grows as the population explodes. From London in the industrial ages to newly planned cities, growing suburbs tend to creep into forests and farmlands, eventually converting them into built spaces. 

But researchers suggest that if we could contain a city within the core, the environmental impact due to land use, emission of Greenhouse Gases (GHG) could all be reduced, thanks to Transit-Oriented Development (TOD). TOD enables buildings to go taller, reducing sprawl. 

Improved Mass Rapid Transit Systems ensures connectivity while demoting the use of personal vehicles like cars. For example, Barcelona has 103 road junctions per square kilometer, compared with Brasilia’s 47 and Shanghai’s 17. Yet, it is one of the best cities to live in because of the preference provided to pedestrians, frequent public transport that makes the city well accessible, urban green areas, and provision for housing in the core.

Principles of TOD ©ITDP (dot)org

Sustainable Urban Agglomeration

Densifying urban centers will prove viable in terms of environmental conservation and sustainable growth. A large population in a small area reduces road infrastructure while shared public transport will be adequate. It is also time-saving and financially a better option for both the city planners and the users. 

In recent years, people prefer to stay within city limits over suburbs, making it easier for city officials to push policies to densify the cores to reduce suburbanization. Seoul’s mayor bulldozed an eight-lane road to pedestrianised the city, and it worked. More apartments and taller structures were constructed in the center, allowing cheaper housing within the city core. Many European cities are in that process by introducing bike-sharing systems and lanes, non-motorable days of the week, pedestrianizing roads, and adding green spaces. 

It leads to one conclusion, cities are GHG hotspots and account for large carbon emissions. But this is being shifted. More and more cities are committing to turning greener. Singapore is a front runner. Though it is the densest places to live in, it is dubbed as the greenest city in Asia, thanks to initiatives that promote pockets of green spaces on land such as parks and gardens (like the gardens by the bay) along with collaborative efforts by architects who add greenery on to their buildings to reduce urban heat island effect and make the city more livable. 

If a city like Singapore with heavy border constraints and fewer open spaces can pull off such a humongous feat, other existing metros could too. All it needs is a push from the government and the city planning authority. 

References

https://www.academia.edu/33533895/Growth_of_Metro_Cities_in_India_Trends_Patterns_and_Determinants

https://www.thehindu.com/news/cities/chennai/pallikaranai-marsh-has-shrunk-to-a-tenth-of-its-size-in-1965-amicus-curiae/article29164755.ece

https://timesofindia.indiatimes.com/city/chennai/Welcome-to-wild-wild-Chennai/articleshow/9523758.cms

https://science.thewire.in/environment/chennai-pallikaranai-marsh-dredging-ecologicall-bad-idea/

https://www.researchgate.net/publication/268690352_Urban_green_space_planning_for_climate_adaptation_in_Indian_cities

https://researchmatters.in/article/satellite-images-show-green-cover-bangalore-reducing-alarmingly-fast

https://www.researchgate.net/publication/259389464_Prediction_of_Land_use_Dynamics_in_the_Rapidly_Urbanising_Landscape_using_Land_Change_Modeller

https://timesofindia.indiatimes.com/city/mumbai/authorise-forest-officials-to-take-action-on-mangrove-destruction-on-private-land-aditya-thackeray-to-centre/articleshow/80370561.cms

https://www.bbc.com/news/world-asia-india-47959685

https://www.academia.edu/5696568/Effects_of_changed_urban_land_use_pattern_and_loss_of_wetlands

https://www.theguardian.com/cities/2016/jul/12/urban-sprawl-how-cities-grow-change-sustainability-urban-age

https://www.researchgate.net/publication/280304507_Challenges_and_strategies_for_urban_green-space_planning_in_cities_undergoing_densification_A_review

https://earthobservatory.nasa.gov/images/144807/sizing-up-the-carbon-footprint-of-cities

https://spiritofchennai.com/city/pallikaranai-marsh/

Author

Vignesh Esakkinathan is a final year architecture student from chennai. He blogs about climate change and productivity with the hopes to become an architectural journalist. When he's not playing cricket, you can see him philosophising life at his rooftop.

Write A Comment