Due to indiscriminate deforestation and approvals of construction projects without any analysis on balancing the eco-system has led to the development of concrete jungles in several metros in India.  Now spotting green in the areas is a rare occurrence thus leaving the city landscape in shades of grey.  Adding to this scenery is the smog caused due to intense air pollution which results in spreading of diseases and excess rise in temperature.  In cities where the humidity levels exceed 85%, this results in conditions very difficult to live resulting in spread of diseases, damage of electronic products, disappearance of bird species.  The heat envelope results in another 3-5 Deg C rise in temperature with respect to the outer greener surroundings.  This heat envelope is in general termed as the Urban Heat Island (UHI).

And as time proceeds, more of the available green land is used for real estate developments leaving the environment to the mercy of nature for its cure.  And nature has not been so merciful after all as we witness acid rain or rain water with reddish color which may be seen as nature?s own way of expressing the anger.    On the other hand, the cites have witnessed drilling of thousands of bore wells for water and this is gradually moving towards the depletion of ground water resources for human consumption.  Even the quality of ground water is questionable as traces of heavy metals, poisonous substances have been found in samples.  Several reports in the past have tried to convey the sad state of environment and effects due to UHI in many forums yet these reports are dumped and governments have not taken these so seriously.  The approaches thus far to beat this have been very slow paced and efforts by environmental conservation have always been overpowered by real estate development.  So, what these findings convey and when we will start to take these seriously?

The image captured below shows the green patches to be less than 10% of the overall map. This is alarming to note that the Urban Heat Islands are thriving at the cost of our eco-system and the urban heat map indicates the uncontrolled expansion of cities is to be blamed for the rise in temperature in cities.  Below is a summary of factors that influence UHI.

Factors supporting UHI:

?      Development projects led by real estates and other city expansion projects

?      Improper waste disposal

?      Uncontrolled sanction for new buildings in crowded areas

?      No law followed on minimum distance between buildings

?      No law followed on % of green vegetation around buildings

Observations collected between 1991 and 2016 indicate that heat islands in Chennai have grown rapidly with 2 to 3?C variation with the peripheries in 1991 growing to 5?C by 2016.  If left, unattended, UHI could compromise safe urban living as this negatively influences the balance with the ecosystem.  A few mitigation strategies are listed below and if implemented could benefit urban living.

?      Planting trees and developing new gardens

?      Garden roof to aid food production

?      Green building programs

?      Vertical farming techniques for urban living

Image credit:

1. https://scroll.in/article/811620/how-indias-concretising-cities-are-becoming-heat-islands (Image 1)

2. Findings of a recent study by Anna University supported by Regional Meteorological Centre, Chennai, India (Image 2)