The temperature is slowly rising in Chennai as winter bids goodbye and 2018 is likely to be hotter than the previous year, say weather experts. The heat that residents will experience is likely to be aggravated by the city's lack of natural defences such as the mandated 33% green cover.
A study conducted by the Care Earth Trust, which is a non-governmental organisation concerned over the conservation of biodiversity shows that only 15% of the city is covered by trees. That would mean that of the 426 sq km Greater Chennai Corporation (GCC) area, only 64.06 sq km possesses a green cover.
According to a report in the New Indian Express, the study was funded by the Tamil Nadu Urban Infrastructure Financial Services Ltd, which is a Public-Private Partnership operating in the urban sector. It is the first detailed zone-wise mapping of green cover conducted after Cyclonic Storm Vardah struck Tamil Nadu. It was initially estimated that the cyclone had uprooted at least one lakh of the estimated 4.5 lakh trees in the city.
To complete this fresh study, researchers have used the finest 1.5 metre satellite resolution and ground verification. That reportedly included measuring 9,000 trees, surveying 200 kms of road, 525 parks, medians, avenues, MRTS stations and institutions. The study took six months and the report which is 600 pages long has been submitted to the Greater Chennai Corporation (GCC). Resident associations of all 15 zones of GCC attended a stakeholders meeting and subsequently gave their suggestions. These were recorded and will be incorporated into the final report by retired Principal Chief Conservator of Forests (Head of Forest Force), S Balaji, who headed the project.
Speaking with TNM, Balaji says, “Trees can control the micro climate of an area and are extremely important for a city like Chennai which faces extreme heat in the summers. In the year 2000 we had 79 sq km of green cover. This reduced to 69 sq km in 2005 and has now come down to 64 sq km."
Was Cyclone Vardah the reason for this plunge?
"No, development work which is a necessary evil is one of the causes. We lost trees to the metro station, to the expansion of highways and to several other projects. What is done is done but now we must work towards replenishing the green cover," says Balaji.
Does your area have enough green cover?
According to the report that has been submitted, Adyar has the most green cover at 30%, this is followed by Anna Nagar (20.85%) and Teynampet (22%). Manali, Alandur and Perungudi have the least number of individual trees recorded.
Adyar also dominates in terms of the number of parks, followed by Perungudi and Alandur. This essentially means that there is space and potential for more trees to be planted.
Royapuram has the largest area under parks, followed by Teynmapet and Annanagar.
Thiruvotriyur, Manali and Madhavaram have the least number of parks as well as the least area stipulated for the same.
"Trees play a large role in absorbing heat. In addition to this the lack of green cover and increasing concrete means that heat reflects on the land increasing temperatures," Srikanth, the co-founder of Chennai Rains portal, a weather blogging site. "We are thus expecting a warmer summer than even last time. Chennai will see consecutive days of the temperature soaring above 40 degrees," he warns.
In 2017, the city already witnessed heat waves during the summer. The Indian Meteorological Department was forced to issue advisories, asking people to stay indoors. With experts now predicting the heat to become more unbearable in the wake of the lack of green cover, the fear is that summers will become hotter.
How do we tackle this?
According to the report, primary objectives of the study include preparing site specific strategies and structural plan for increasing green cover by creating multifunctional landscapes and appropriate vegetation to enhance urban resilience and human well-being. In addition to this they also want to prepare manuals for planting and maintenance of urban open spaces including medians and formulate a legal and institutional setup for sustainable maintenance.
“We have proposed a five-year greening strategy to increase the green cover to 40%," says Balaji. "A total of 10 lakh trees will be planted and that would mean 2 lakh trees a year. But even this is a conservative estimate. We will need the support of the government, NGOs and the communities residing in the city," he adds.
And this includes a strategy based on various local issues like availability of water, suitability, adaptability, maintenance, protection, etc.
"We have already identified areas where trees can be planted but what is also important is the species of trees we plant," he explains. "We are going to suggest the exact type that goes in various terrains - near waterbodies, near highways, etc. Species like bamboo can reduce temperatures upto five degrees but at the same time since the city is prone to cyclones we also have to plant wind firm species. On city roads, we can plant short trees that won't interfere with electrical wiring," he adds.
But one thing is certain, "If we don't act fast, the coming summers will be unbearable."