Latest news with #TamilNaduStateLandUseResearchBoard
New Indian Express
2 days ago
- Climate
- New Indian Express
Tamil Nadu's first block-level heat stress mapping rings alarm bells
CHENNAI: Tamil Nadu released the state's first-ever block-level spatial analysis of heat exposure, on Monday. The decadal study, conducted by the Tamil Nadu State Land Use Research Board and State Planning Commission confirms that rising urbanisation and loss of natural land cover are driving a dangerous surge in local temperatures across the state. Out of 389 development blocks, the study found that 94 have experienced significant decadal increases in heat stress, while 64 blocks are currently enduring higher-than-state-average temperatures, even if they haven't seen long-term trends. Critically, 25 blocks which fall under 10 districts -- Chennai, Chengalpattu, Karur, Madurai, Pudukkottai, Ramanathapuram, Sivagangai, Tiruchy, Tirunelveli and Tiruvallur -- fall under the 'extremely heat-stressed' category in both assessments. The study found that many of the blocks that fall under both critical categories are associated with intensive urban development or proximity to industrial belts. "These blocks are of particular concern as they represent areas where temperatures have both increased significantly over time and are currently above the state average, indicating persistent and intensifying thermal stress," the report states. The findings draw a direct link between land use change -- especially built-up area expansion -- and temperature rise. For instance, Chennai's built-up area grew from 48% of its total area in 1985 to 74% in 2015. St. Thomas Mount in Chengalpattu district saw a staggering fivefold increase in built-up footprint, surpassing even the capital in relative growth. In these urban and peri-urban zones, temperatures have risen by up to 2 degree Celsius above the state average in just two decades.
The Hindu
2 days ago
- Climate
- The Hindu
T.N. State Planning Commission's report shows increase in built-up area over 30 years has fuelled heat stress
An analysis by the Tamil Nadu State Planning Commission (SPC) reveals that rising temperatures, driven by urban sprawl, deforestation, and changing land use, are putting people, ecosystems, and infrastructure at increasing risk. Titled, 'Urban Growth and Thermal Stress: A Decadal Assessment of Built-Up Area and Climate Interactions in Tamil Nadu', the study builds on the Tamil Nadu Heat Mitigation Strategy (2024) and integrates three decades of data, using satellite imagery, elevation models, and climate reanalysis to present, possibly for the first time, a block-level understanding of heat exposure across the State. The study report, submitted to Chief Minister M.K. Stalin on Monday, confirms what many urban residents have long felt — cities are becoming hotter, faster. Blocks such as Chennai (with 74% built-up area as of 2015), Coimbatore, and Tiruppur have seen significant urban sprawl that directly correlates with rising land surface temperatures. These changes not only worsen thermal discomfort but also strain infrastructure and energy systems. Out of 389 blocks analysed, 94 showed severe long-term increases in temperature, while 64 currently experience extreme heat stress. Significantly, 25 blocks — including parts of Chennai, Karur, and Ramanathapuram — fall into both categories, making them the most vulnerable hotspots in Tamil Nadu. Traditionally cooler high-altitude regions such as Kodaikanal, Udhagamandalam, and Yercaud are no longer climate refuges. These regions have recorded noticeable warming, up to 0.7°C in Kodaikanal and 1.2°C in Tiruttani, due to forest degradation and tourism-driven development. Seventeen of the highly heat-intensified blocks are in hilly terrain, raising urgent concerns about biodiversity and habitat loss. Under future climate scenarios (RCP 4.5 and 8.5), Tamil Nadu could experience annual air temperature increases of 0.9°C to 2.7°C by 2050. Such changes threaten crop viability, water security, and public health — especially for vulnerable groups such as outdoor workers and the elderly, the report points out. The Universal Thermal Comfort Index for Tamil Nadu now registers 'strong heat stress' in multiple districts, signalling not only rising temperatures but also the direct impact of heat on human health and daily life. According to the SPC report, over 3,025 sq. km. of forest cover has been lost in the last two decades, according to the Tamil Nadu State Land Use Research Board (TNSLURB). These losses alter surface albedo, reduce evapotranspiration, and accelerate the Urban Heat Island effect. Meanwhile, once-cultivated lands have been either built upon or left fallow, which further degrades the State's climate buffer zones. Blocks such as Sriperumbudur, Poonamallee, and Kundrathur — peri-urban zones with little built-up area in 1985 — have rapidly urbanised and now record high heat intensities. Coastal districts, already vulnerable to sea-level rise and cyclonic activity, are doubly exposed to extreme heat, making integrated adaptation planning essential. Effective strategies To effectively combat rising heat levels across Tamil Nadu, the report urgently calls for climate-sensitive planning, particularly in urban, peri-urban, and hilly regions. Integrating green infrastructure like parks, green roofs, and permeable surfaces into city planning can reduce the Urban Heat Island Effect, while updated building codes should mandate passive cooling features, green cover, and rainwater harvesting. In peri-urban and hill areas, land suitability mapping, regulated construction, and afforestation are essential to prevent ecological degradation, the report says. The study recommends enhanced heat monitoring through a real-time dashboard combining satellite and ground data, especially in rural and data-scarce areas, and embedding heat exposure indicators into planning frameworks such as Master Plans and Smart City proposals to prioritise interventions in vulnerable blocks.
