CHENNAI: The heat in the city has been unbearable all through this month and it could be linked to the depleting green vegetation that has been making way for infrastructure like metro rail and roads.
According to the draft City Climate Action Plan prepared by the Chennai Corporation, the green space per capita, an indicator to assess urban green infrastructure in the city, is 8.75 square metre per person, which is unhealthy against the prescribed 9.5 sq.m. per person for healthy living as per World Health Organisation.
Urban green infrastructure is considered a key element in improving quality of life and creating an appropriate framework for sustainable cities. In Chennai, it is a negative relationship with vegetation and water bodies. Higher temperatures are observed in areas with lower vegetation and waterbodies.
From 1991 to 2021, Chennai has seen a threefold increase in the built-up area (from 102 sq.km to 295 sq.km), while the vegetation cover has reduced from 23% to 17% (from 101.9 sq. km to 74.35 sq. km). Additionally, a significant decrease has also been observed in the area of water bodies, from 8% to 4%, the draft report accessed by TNIE stated.
The temperature is observed to be significantly higher in areas where the land surface is covered by materials such as concrete, asphalt, metal and sand, compared to areas with water bodies and vegetation. Higher temperatures have been recorded in industrial areas such as Sidco industrial estate and integral coach factory, while parks, gardens, forests and waterbodies are comparatively cooler, says the report.
The impact of increased heat is higher on urban poor communities, as they live in thermally uncomfortable built environments with higher densities, low vegetation cover and limited choice over roofing materials, the report states. In Chennai, 27% of the slum houses use asbestos sheets as a roofing material, which heats much faster than cement roofs.
Limited access to fresh water adds to this dilemma by increasing the risk of dehydration. The report quoting Rajiv Gandhi Government General Hospital states that 30 to 50 patients with heat-related symptoms are reported between April and June each year.
However, to increase the green cover, CMDA has partnered with The Nature Conservancy India to implement ‘Greenprint for Chennai’ under the third masterplan, to enhance the city’s green cover, protect its rivers, waterbodies and coastal wetlands.
Shrinking Greenery
The green space per capita in the city is 8.75 sq.m/person, against WHO prescribed 9.5 sq.m/person