Wards located near Chennai dumpyards prone to extreme heat, says report

Chennai: At least 12 city wards, including those surrounding Kodungaiyur and Perungudi dumpyards, Chennai Airport, Koyambedu market, and Ambattur Industrial Estate, emerged as some of Chennai's extremely high heat zones under the state's latest urban heat assessment.Several of these wards were among the 25% of wards (50 wards) within Greater Chennai Corporation (GCC) limits classified as having a very high Heat Risk Index in 2024. These wards accounted for nearly 30% of GCC's total population while covering just 12% of the city's area. The Heat Risk Index was based on three components: hazard (high land surface temperature), exposure (population concentration), and vulnerability.The report attributed the high heat to dense urbanization marked by expansive impervious surfaces, decomposing waste generating additional heat, and limited green buffers around landfill sites. These conditions amplified land surface temperatures (LST) and intensified the Urban Heat Island effect. "This highlights the need to reduce landfill and convert existing landfills into green spaces through bio-remediation to reduce urban heat. Cooling infrastructure such as tree-lined buffers, reflective materials, cool roofs, and green roofs should be integrated into industrial development plans," said the report titled ‘Urban Heat Island Assessment and Strategic Guidelines for Urban Cooling' by Tamil Nadu Green Climate Company and NGO ICLEI, launched at the Tamil Nadu Climate Summit 4.0.Areas around the Kodungaiyur dumpyard (Ward 37) and the Perungudi landfill (Ward 189) recorded significant LST increases between 2016 and 2024. Maximum LST rose from 33.32C to 36.33C in Ward 37 and from 33.16C to 35.09C in Ward 189. The two dumpsites together hold nearly 94 cubic metre of legacy waste, with about 80% of newly generated waste still being dumped.Similar warming trends were observed near CMBT and Koyambedu market (Ward 127), where maximum LST increased from 32.37C to 34.37C. Around Ambattur Industrial Estate, maximum LST rose from 32.5C to 35.1C in Ward 84 and from 33.4C to 35C in Ward 86, coinciding with growth in MSME units.The report recommends tree plantations, micro forests, shading, reflective pavements and waterbody restoration.