Industrial areas drive 70% of Telangana’s thermal hotspot expansion: Study

Hyderabad: Telangana’s industrial zones have experienced a significantly sharper rise in heat stress than non-industrial areas over the past two decades, according to a study published in Scientific Reports in May.The study, “Data-driven assessment of industrial influences on urban heat index dynamics across Telangana, India,” found that industrial expansion, urbanisation, and land-use changes have contributed to increasing Land Surface Temperature (LST) and Urban Heat Index (UHI) across the state between 2003 and 2023. Using multi-temporal satellite data and machine-learning models, researchers assessed the impact of industrial growth on Telangana’s thermal environment.The findings show that the mean UHI in industrial regions doubled from 1.35 in 2003 to 2.7 in 2023. Non-industrial areas also recorded an increase, but at a lower rate, rising from 1 to 1.82 over the same period. Industrial zones accounted for nearly 70% of the expansion of extreme thermal hotspots across the state.According to the study, pharmaceutical and heavy-manufacturing clusters exhibited stronger thermal signatures than light industrial estates. The study highlighted the Hyderabad–Medak corridor as the state’s primary industrial hotspot, while the Rangareddy–Sangareddy belt emerged as another major cluster where dense built-up areas and impervious surfaces have altered the local surface energy balance.Secondary cities, including Karimnagar, Nizamabad, and Khammam, also recorded increasing thermal stress linked to rapid urbanisation and industrial development.Warangal Case StudyWarangal was selected for a detailed city-level assessment as a representative secondary industrial city. The study found that Warangal’s mean UHI doubled from 1.2 in 2003 to 2.4 in 2023, while statistically significant thermal hotspot areas expanded by about 62%.Spatial analysis showed that industrial corridor expansion in Warangal is occurring predominantly toward the city’s north-eastern sector.Rising Temperatures and Expanding HotspotsAcross Telangana, industrial areas recorded a steeper rise in both UHI and LST compared to non-industrial regions. Mean LST in industrial zones increased from 33.8°C in 2003 to 39.8°C in 2023, while in non-industrial areas, it rose from 31.4°C to 35.9°C.Thermal hotspot areas within industrial zones expanded from 420 ± 35 sq km in 2003 to 1,120 ± 90 sq km in 2023. In contrast, hotspot extent in non-industrial areas grew from 680 ± 50 sq km to 980 ± 75 sq km. Statewide, total thermal hotspot coverage increased from 1,100 sq km to 2,100 sq km during the two-decade period.According to the study, industrial regions contributed nearly 70% of this expansion, adding roughly 35 sq km of hotspot area annually. Their share of Telangana’s total thermal hotspots increased from 38.2% in 2003 to 53.3% in 2023.Key Drivers IdentifiedMachine-learning models, including random forest and gradient boosting, identified industrial land use, built-up density, and near-surface air temperature as the strongest drivers of heat variability.The study noted that extensive impervious surfaces, heat-retaining building structures, and limited vegetation cover characterise industrial zones. Industrial operations and energy consumption further contribute to localised heating through process-related heat emissions.Conversely, areas with higher vegetation indices demonstrated a measurable cooling effect.Green Buffers Could Reduce HeatThe researchers suggested several mitigation measures to reduce heat stress in industrial regions. Increasing green buffer coverage around industrial areas by 10% could lower the mean UHI by approximately 0.15 units, the study found.Other recommendations include adopting reflective or “cool” roofing materials on industrial buildings, integrating heat-index considerations into industrial zoning and spatial planning, and using hotspot detection systems to prioritise heat-reduction interventions.The study was authored by Bhogayya Naidu of the Singapore Institute of Technology and Vignanan Bharathi Institute of Technology, Hyderabad; Tan Kuan Tak and Sivaneasan Bala Krishnan of the Singapore Institute of Technology; Vinay Kumar Gaddam of the Singapore Institute of Technology and Siddhartha Academy of Higher Education, Vijayawada; and Shankar Karuppannan of Adama Science and Technology University, Ethiopia, and Saveetha University, Chennai.