What’s making Telangana hotter? A two-decade look at industry’s role in rising temperatures
HYDERABAD: Telangana’s industrial regions have witnessed a significantly faster increase in heat stress than non-industrial areas over the past two decades, according to a study published in Scientific Reports in May.
The study, titled “Data-driven assessment of industrial influences on urban heat index dynamics across Telangana, India”, found that industrial growth, urbanisation and land-use changes have driven a steady rise in Land Surface Temperature (LST) and Urban Heat Index (UHI) across the state between 2003 and 2023, as reported by TOI.
Using multi-temporal satellite imagery and machine-learning models, researchers examined how industrial expansion has influenced Telangana’s thermal environment.
The study found that the mean UHI in industrial areas doubled from 1.35 in 2003 to 2.7 in 2023. In comparison, non-industrial regions recorded a slower increase, rising from 1 to 1.82 during the same period.
Industrial zones accounted for nearly 70% of the state’s expansion in extreme thermal hotspots. The researchers noted that pharmaceutical and heavy manufacturing clusters generated stronger thermal signatures than light industrial estates.
Hyderabad-Medak corridor leads hotspot growth
The Hyderabad-Medak corridor emerged as Telangana’s primary industrial heat hotspot. The Rangareddy-Sangareddy belt was identified as another major cluster where dense construction activity and impervious surfaces have altered the local surface energy balance.
The study also recorded rising thermal stress in secondary cities such as Karimnagar, Nizamabad and Khammam, linking the trend to rapid urbanisation and industrial development.
Warangal heat stress doubles in two decades
Researchers selected Warangal for a detailed city-level assessment as a representative secondary industrial city.
The study found that Warangal’s mean UHI increased from 1.2 in 2003 to 2.4 in 2023. Statistically significant thermal hotspot areas expanded by about 62% during the period.
Spatial analysis showed that industrial corridor expansion in Warangal is occurring mainly towards the north-eastern part of the city.
Industrial zones warming faster
Across Telangana, industrial areas recorded a steeper rise in both UHI and LST compared with non-industrial regions.
Mean LST in industrial zones increased from 33.8°C in 2003 to 39.8°C in 2023. In non-industrial areas, the average rose from 31.4°C to 35.9°C.
Thermal hotspot coverage within industrial regions expanded from 420 ± 35 sq km in 2003 to 1,120 ± 90 sq km in 2023. In non-industrial areas, hotspot extent increased from 680 ± 50 sq km to 980 ± 75 sq km.
Overall, Telangana’s thermal hotspot area grew from 1,100 sq km to 2,100 sq km over the two-decade period.
Industrial regions contributed nearly 70% of the increase, adding about 35 sq km of hotspot area annually. Their share of the state’s total thermal hotspots rose from 38.2% in 2003 to 53.3% in 2023.
Land use and built-up density key factors
Machine-learning models, including random forest and gradient boosting algorithms, identified industrial land use, built-up density and near-surface air temperature as the strongest factors influencing heat variability.
The researchers said industrial zones are characterised by extensive impervious surfaces, heat-retaining structures and limited vegetation cover. Industrial operations and energy consumption further increase local temperatures through process-related heat emissions.
Areas with higher vegetation cover showed a measurable cooling effect.
Green buffers among recommended solutions
The study suggested several measures to reduce heat stress in industrial regions.
According to the researchers, increasing green buffer coverage around industrial zones by 10% could reduce mean UHI by around 0.15 units.
Other recommendations include the adoption of reflective or cool roofing materials on industrial buildings, incorporation of heat-index considerations into industrial zoning and spatial planning, and deployment of hotspot detection systems to prioritise heat-mitigation measures.
The study was authored by Bhogayya Naidu of the Singapore Institute of Technology and Vignana 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.
