Trichy City Grapples with Severe Heat Wave Vulnerability, Study Warns
A comprehensive study led by the Tamil Nadu government has uncovered alarming findings regarding heat wave risks in Trichy city. The research, titled ‘Urban Heat Island (UHI) Assessment and Strategic Guidelines for Urban Cooling,’ indicates that more than half of Trichy is highly or very highly vulnerable to heat waves, posing significant threats to public health and the environment.
Study Details and Methodology
Conducted by the Tamil Nadu Green Climate Company (TNGCC) and the International Council for Local Environment Initiatives (ICLEI), South Asia, the study focused on four major cities: Chennai, Coimbatore, Trichy, and Tirunelveli. In Trichy, a ward-level heat risk index was compiled using key parameters such as land surface temperature (LST), urban heat island (UHI) intensity, and built-up area coverage.
The analysis categorised 16 wards as ‘very high-risk’ and an additional 20 as ‘high-risk,’ highlighting areas most prone to heat stress. This classification underscores the urgent need for targeted interventions to mitigate the escalating heat challenges.
Alarming Green Cover Depletion
Trichy was selected for the study due to its interior location and rapid urbanisation, which has come at the expense of green spaces. According to Land Use Land Cover (LULC) analysis, the city’s green cover or vegetation area stands at a mere 3% of the total area as of 2024. In stark contrast, built-up areas account for 59%, exacerbating heat retention.
A normalized difference vegetation index (NDVI) study revealed that only three wards—Srirangam (ward 1), Ananda Avenue (ward 18), and Kamaraj Nagar (ward 37)—boast substantial green gardens. Wards like Rockfort (ward 14) and Big Bazaar Street (ward 19) suffer from low green cover coupled with high built-up densities, while areas such as Ariyamangalam, Palpannai Junction, and Central Bus Stand exhibit elevated land surface temperatures.
Expert Insights and Public Concerns
Local experts have voiced concerns over the diminishing green spaces. S Vijayakumar, a senior architect based in Trichy, remarked, "Both residents and authorities are not encouraging open green spaces. Vacant areas are often sealed with paver blocks or concrete, inevitably increasing heat risks."
Urban heat islands, characterized by significantly warmer temperatures compared to surrounding rural zones, have expanded in locations like Panjapur, Trichy airport, and the Karumandapam vicinity. The study assessed heat hazards, exposure factors like population density, and vulnerabilities such as limited green space, identifying 17 wards as low or very low risk, 12 as medium risk, and 36 as high to very high risk.
Proposed Cooling Interventions
To combat these risks, the study recommends several ward-level urban cooling strategies, including:
- Cooling roofs designed to reflect sunlight
- Development of community parks
- Improved thermal ventilation in slum areas
- Restoration of public tanks
V Anand Gideon, Dean of Extension Activities at Bishop Heber College, emphasized, "Even existing green covers are largely confined to educational institutions. The public must take initiative to enhance greenery on their own properties."
Future Initiatives and Government Response
A senior corporation official disclosed plans to increase green cover using the Miyawaki method on identified vacant properties within the city. "We have pinpointed suitable sites, and work will commence post-elections to boost the green cover," the official stated.
This study serves as a critical wake-up call for Trichy, urging immediate action to address heat wave vulnerabilities through sustainable urban planning and community engagement.
