HEAT WAVES AND HEAT INDEX
HEAT WAVES AND HEAT INDEX
Why in News?
India has witnessed a significant decline in heat-related deaths in recent years, reflecting the country's efforts to combat the adverse effects of heatwaves.
The India Meteorological Department (IMD) plays a vital role in this endeavor, issuing timely forecasts and warnings to mitigate the impact of severe weather events, including heatwaves.
Recently, IMD introduced the Heat Index, a valuable tool that considers humidity's influence on temperatures.
- Heat waves are prolonged periods of excessively hot weather that can cause adverse impacts on human health, the environment, and the economy.
- India, being a tropical country, is particularly vulnerable to heat waves, which have become more frequent and intense in recent years.
- IMD Criteria for Declaring Heat Wave in India:
- Heat wave is considered if the maximum temperature of a station reaches at least 40°C or more for Plains and at least 30°C or more for Hilly regions.
Based on Departure from Normal:
Heat Wave: Departure from normal is 4.5°C to 6.4°C.
Severe Heat Wave: Departure from normal is >6.4°C.
Based on Actual Maximum Temperature:
Heat Wave: When actual maximum temperature ≥ 45°C.
Severe Heat Wave: When actual maximum temperature ≥47°C.
IMD's Initiatives and Tools to Combat Heat Waves:
- Timely issuance of heat wave forecasts to keep the public informed.
- Warnings provided to disaster management authorities for necessary preparedness.
- IMD offers Seasonal outlook and extended range forecast offering additional insights into temperature trends.
- Daily forecasts for the next five days with real-time updates.
- Color-coded warnings for severe weather events, including heat waves.
- Cooperation with National Disaster Management Authority (NDMA) and local health departments for heat action plans.
- Implementation of plans in vulnerable regions to minimize heat-related risks.
- The Heat Index is a parameter that considers both temperature and humidity to calculate the apparent temperature or "feel like" temperature for human beings.
- It helps in understanding the impact of humidity on high temperatures and how it contributes to human discomfort during hot weather.
- The Heat Index has been launched on an experimental basis by the India Meteorological Department (IMD).
- It aims to provide general guidance for regions experiencing higher apparent temperatures causing discomfort to people.
Indication of Heat Stress:
High Heat Index values indicate a greater risk of heat-related stress and health issues.
It serves as a warning for potential heat-related illnesses and dangers.
Categorization of Heat Levels:
The Heat Index categorizes the apparent temperature into different levels using color codes:
- Green: Experimental heat Index less than 35°C.
- Yellow: Experimental heat Index in the range 36-45°C.
- Orange: Experimental heat Index in the range 46-55°C.
- Red: Experimental heat Index greater than 55°C.
Useful Tool for Public Health:
- By understanding the Heat Index, individuals and communities can take proactive steps to protect public health during heatwaves.
- It assists in making informed decisions and formulating heat action plans to ensure the well-being of the population.