New Delhi: The Centre for Science and Environment (CSE) analyzed heat stress in six major Indian cities: Bengaluru, Chennai, Delhi, Hyderabad, Kolkata, and Mumbai during an unprecedented heat wave.
Key findings include:
Increasing Humidity: Across all climate zones, rising relative humidity has worsened the heat index, intensifying heat stress.
Nighttime Temperatures: Cities are not cooling down at night, exacerbating heat-related health risks.
Urban Heat Island Effect: Significant increases in built-up areas contribute to this effect.
Key Recommendations
Urgent Action Plans: Develop heat management strategies to expand green areas, reduce thermal load on buildings, and protect public health during heat waves.
Findings on Heat Stress Components
Heat Index: A combination of air temperature, land surface temperature, and relative humidity significantly impacts thermal discomfort and health.
Diurnal Trends: Reduced nighttime cooling and rising humidity levels are increasing heat stress.
City-Specific Highlights
Delhi
Cooler temperatures but higher humidity.
Urban core cooling slower than peri-urban areas.
Increased green cover impacts daytime but not nighttime temperatures.
Mumbai
Rising temperatures and humidity.
Significant urban heat island effect at night.
Reduced green cover and increased built-up area.
Kolkata
Stable temperatures but higher humidity.
Consistent night cooling rates.
High urban heat island effect due to increased built-up area.
Hyderabad
Decline in temperatures but rise in humidity.
Strong urban heat island effect at night.
Increased green cover but significant urban expansion.
Bengaluru
Rising temperatures, stable humidity.
Significant nighttime heat retention.
Increased green cover yet high urban heat island effect at night.
Chennai
Increased temperatures and humidity.
High number of days with dangerous heat index levels.
Significant increase in built-up area and reduced green cover.
Trends and Future Projections
Climate Change Impact: Increased frequency and intensity of heat extremes expected.
Urbanization: Amplifies local air temperature increases, enhancing urban heat island effects.
Recommended Actions
City-Specific Heat Management Plans: Address both immediate heat events and long-term heat-proofing strategies.
Target Heat Generators: Manage concrete surfaces, vehicles, industries, and cooling devices.
Modify Land Use: Expand green areas and waterbodies.
Tracking Mechanism: Monitor temperature and humidity trends.
Emergency Action Plans: Protect public health during heat waves.
Complete story is found at https://www.cseindia.org/decoding-the-urban-heat-stress-among-indian-cities-12191