Growing land-use changes, industrial expansion and rapid urbanisation are creating an alarming network of thermal hotspots across Odisha, posing an emerging threat to public health and the state’s long-term economic growth, according to a study by researchers at the Indian Institute of Technology (IIT) Bhubaneswar.

 

The study warns that unless region-specific climate adaptation measures are integrated into urban planning and industrial development, rising land surface temperatures could significantly increase energy demand, reduce labour productivity, strain healthcare systems and undermine the sustainability of one of India’s fastest-growing industrial states.

 

Unlike conventional studies that examine average temperatures, the IIT researchers identified localised areas consistently experiencing extreme land surface temperatures and tracked how these hotspots evolved between 2017 and 2023.

 
 

The study found that districts witnessing rapid population growth, urbanisation, industrialisation and infrastructure expansion recorded the sharpest increase in thermal hotspots, with built-up urban areas experiencing hotspot growth of as much as 9 per cent annually.

 

Published in the Environmental Science: Advances journal of the Royal Society of Chemistry, the study by Dikshika Mahapatra and Debadatta Swain analysed two decades of satellite observations and mapped the evolution of thermal hotspots across all 30 districts of Odisha.

 

“Coastal districts undergoing rapid urban transformation and industrialisation saw hotspot coverage expand between 2 per cent and 9 per cent in just seven years. The results show that built-up areas exhibit significantly higher hotspot intensities than non-built-up regions,” said Swain, associate professor at the School of Earth, Ocean and Climate Sciences.

 

The study identified Khordha, Ganjam, Sundargarh, Sambalpur, Angul, Jharsuguda and Cuttack among the districts where urbanisation and industrial activities are driving significant heat accumulation. Extensive concrete structures, asphalt roads, industrial facilities and shrinking vegetation have altered the land surface, enabling these areas to absorb and retain substantially more solar radiation than natural landscapes.

 

While urban centres emerged as major heat islands, the researchers found that Odisha’s western and interior districts present an equally concerning but different challenge. Districts such as Kalahandi, Nuapada, Bargarh and Balangir recorded large thermal hotspots across non-built-up areas because of increasing barren land, degraded forests, fallow agricultural fields and declining vegetation cover.

 

One of the study’s most striking findings is the emergence of persistent thermal hotspots in districts that remain chronically hotter than surrounding regions year after year. Rayagada recorded the highest persistent hotspot coverage, with 92.09 per cent of its geographical area affected, followed by Gajapati (86.16 per cent), Nayagarh (76.05 per cent), Balangir (75.02 per cent), Nuapada (66.14 per cent), Kandhamal (62.56 per cent) and Kalahandi (60.87 per cent).

 

“In contrast, coastal districts such as Balasore and Bhadrak reported relatively low persistent hotspot coverage because of the moderating influence of the Bay of Bengal and moisture-rich landscapes,” said Mahapatra, a research scholar.

 

According to the researchers, these persistent hotspots are particularly alarming because they represent structurally stable heat reservoirs that continuously expose communities to extreme temperatures.

 

“These hotspots represent chronic, structurally unchanging heat reservoirs and could subject local communities to prolonged heat stress,” Swain said, adding that degraded forests, exposed rocky terrain, shifting cultivation and lack of vegetation prevent natural evaporative cooling, allowing these landscapes to remain exceptionally hot year after year.

 

Beyond environmental implications, the study warned of substantial economic consequences if thermal hotspots continue to expand. Higher surface temperatures increase electricity consumption as households, commercial establishments and industries rely more heavily on cooling systems. Previous international studies cited in the paper showed that urban heat islands can increase annual building cooling energy demand by 15-20 per cent, suggesting similar pressures could emerge in rapidly industrialising states such as Odisha.

 

The researchers also cautioned that rising thermal stress could directly affect labour-intensive sectors that underpin Odisha’s economy. Outdoor workers engaged in mining, construction, manufacturing, transport and agriculture are likely to experience reduced productivity, shorter safe working hours and greater health risks during prolonged heat events.

 

With Odisha positioning itself as a major destination for investments in steel, aluminium, mining, petrochemicals, renewable energy and logistics, unchecked heat stress could increase operational costs and reduce industrial efficiency. The state has received investment proposals worth more than Rs 22 trillion over the past two years, with most projects proposed in these thermal hotspot regions.

 

The study also highlighted that increasing land surface temperatures worsen air quality by accelerating the formation of ground-level ozone while increasing the risks of heat exhaustion, heatstroke, and cardiovascular and respiratory illnesses. Children, the elderly and people with existing health conditions are expected to face the greatest risks.

 

Population exposure analysis revealed that Ganjam, Sundargarh, Khordha and Cuttack consistently recorded the highest numbers of people exposed to thermal hotspots because they combine dense populations with expanding urban and industrial infrastructure. Districts such as Rayagada and Nayagarh exhibited persistently high proportions of their populations exposed to extreme heat throughout the study period.

 

The researchers observed that population exposure to thermal hotspots declined sharply during 2020, attributing the reduction largely to Covid-19 lockdowns that temporarily reduced industrial operations, vehicular traffic and other anthropogenic heat sources. The finding suggests that managing urban activities during peak heat periods could help reduce thermal stress.

 

The study recommends district-specific mitigation strategies instead of a uniform statewide approach. For rapidly urbanising industrial districts such as Khordha, Jagatsinghpur, Jajpur and Sundargarh, the researchers advocated cool roofs, reflective construction materials, permeable pavements, vertical gardens, expanded urban forests and green corridors to reduce heat absorption.

 

“Coastal districts should strengthen mangrove conservation to improve natural cooling, while western and southern districts require forest restoration, watershed management and sustainable land-use practices to restore soil moisture and vegetation cover,” Mahapatra said.

 

The researchers added that increasing urban greenery, implementing heat-resilient infrastructure and promoting sustainable land-use policies that balance development with environmental conservation would help reduce surface heating, minimise health risks and support long-term climate resilience.