A recent study published in Scientific Reports has revealed that industrial zones in Telangana have experienced a significantly sharper rise in heat stress compared to non-industrial areas over the past two decades. The research, titled "Data-driven assessment of industrial influences on urban heat index dynamics across Telangana, India," analyzed the period from 2003 to 2023, utilizing multi-temporal satellite data and machine-learning models to assess the impact of industrial growth on the state's thermal environment.
Key Findings on Urban Heat Index
The study found that the mean Urban Heat Index (UHI) in industrial regions doubled from 1.35 in 2003 to 2.7 in 2023. In contrast, non-industrial areas recorded a lower increase, rising from 1 to 1.82 over the same period. Industrial zones accounted for nearly 70% of the expansion of extreme thermal hotspots across Telangana.
Industrial Clusters and Thermal Signatures
Pharmaceutical and heavy-manufacturing clusters exhibited stronger thermal signatures than light industrial estates. The Hyderabad–Medak corridor was identified 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 urbanization and industrial development.
Warangal Case Study
Warangal 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 Hotspots
Across Telangana, industrial areas recorded a steeper rise in both UHI and Land Surface Temperature (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. 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 Identified
Machine-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 characterize industrial zones. Industrial operations and energy consumption further contribute to localized heating through process-related heat emissions. Conversely, areas with higher vegetation indices demonstrated a measurable cooling effect.
Green Buffers Could Reduce Heat
The 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 prioritize 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.
