Alarming temperature rise in Hyderabad and Bengaluru

Hyderabad: The urban heat island (UHI) intensity for the past two decades in Hyderabad was determined to be 2.44º Celsius, and increasing at the rate of 0.033°C per year. It was found to be increasing annually at a rate of 0.040°C per year.

The average land surface temperature (LST) had increased by 0.99°C due to the conversion of the natural land surfaces (vegetation cover, water bodies, and bare soil), to built-up areas, a study carried out by the National Institute of Technology (NIT), Tiruchirappalli, said.

The UHI intensity is the difference in temperature between built-up urban areas and the suburban areas that have fewer constructions. LST is a measure of how hot the surface of the Earth, particularly the ground and built-up areas like roads and buildings, is due to the energy from the sun.

For the study, ’Geospatial and statistical analysis of urban heat islands and thermally vulnerable zones,’ NIT-T’s Aneesh Mathew and Arunab K.S. used remotely sensed satellite data from the National Aeronautics and Space Administration (Nasa) of the US.

“Changes in the UHI effect can have wide-ranging impacts on the people. From health risks to economic burden and changes in lifestyle, understanding and addressing UHI is crucial for creating more liveable and sustainable urban environments,” the researchers told Deccan Chronicle.

The UHI effect is caused by a combination of factors associated with urbanisation, increased human activity, and change in land use. These factors collectively lead to elevated LST within urban areas, creating local temperature disparities between cities and their surrounding rural regions.

People living in urban environments experience hotter and more uncomfortable weather, especially during summer. High temperatures can lead to discomfort, dehydration, heat-related illnesses, and even heatstroke.

UHI can worsen air quality, like increase in the formation of ground-level ozone, a major component of smog, and exacerbate the presence of particulate matter in the air.  Poor air quality has negative impacts on respiratory health and can lead to conditions like asthma and other respiratory diseases.

UHI can also have economic implications in the form of increased energy demand for cooling. Businesses and industries might also face higher energy costs due to increased air conditioning use.

Moreover, the health impacts of UHI can lead to increased healthcare costs for individuals and governments. UHI can decrease the overall quality of life in urban areas and have an impact on local ecosystems and wildlife as well. It can also influence water management.