India, a land of diverse climates, is no stranger to extreme weather phenomena. Among these, heatwaves have emerged as a recurring and deadly threat to human life. According to a Health Ministry statement in the Lok Sabha, Kerala, Gujarat, and Telangana have witnessed alarming numbers of heatwave-related deaths.
What is a Heat Wave?
A heatwave is an extended period of excessively high temperatures that surpass the normal maximum temperature of a region. These periods can last for several days or even weeks and are characterized by scorching temperatures that make them potentially hazardous to human health. The rise in temperatures can be attributed to various factors, including climate change and urbanization, exacerbating their impact on human life.
Criteria for Declaring Heatwaves
The India Meteorological Department (IMD) has established specific criteria for declaring heatwaves based on the actual temperature or its departure from normal. The primary criteria are as follows:
Heat Wave Thresholds:
For Plains: The maximum temperature of a station reaches at least 40°C or more.
For Hilly Regions: The maximum temperature of a station reaches at least 30°C or more.
Departure from Normal:
Heat Wave: Departure from normal is 4.50°C to 6.40°C.
Severe Heat Wave: Departure from normal is greater than 6.40°C.
Actual Maximum Temperature:
Heat Wave: When the actual maximum temperature is 45°C or higher.
Severe Heat Wave: When the actual maximum temperature is 47°C or higher.
A heatwave occurrence is declared if these criteria are met in at least two stations within a Meteorological sub-division for two consecutive days, with the declaration being made on the second day.
Understanding the Impact
Heatwaves can have severe consequences on human health, with vulnerable populations at higher risk. The extreme heat puts a strain on the human body, leading to heat-related illnesses such as heatstroke, heat exhaustion, and dehydration. Elderly individuals, children, and those with pre-existing medical conditions are especially susceptible to the dangers of heatwaves.
The rising temperatures can also cause disruptions in daily life and affect agricultural practices, leading to crop failures and economic losses. Additionally, heatwaves can worsen air quality and contribute to the formation of ground-level ozone, which is harmful to respiratory health.
Coping Strategies and Mitigation
To combat the adverse effects of heatwaves, it is essential to implement effective coping strategies and mitigation measures. Some of the key approaches include:
- Early Warning Systems: Developing and implementing early warning systems can help alert communities about impending heatwaves. Timely communication can enable people to take necessary precautions and protect themselves from extreme heat.
- Cooling Centers: Establishing cooling centers in urban areas can provide respite to those without access to air-conditioning during heatwaves. These centers can be equipped with cooling facilities and medical aid to cater to individuals at risk.
- Public Awareness and Education: Conducting public awareness campaigns can educate people about the dangers of heatwaves and the importance of staying hydrated and cool during extreme heat events.
- Urban Planning: Implementing heat-reducing measures in urban planning, such as green spaces, reflective surfaces, and proper ventilation, can mitigate the heat island effect and help regulate temperatures in urban areas.
- Water Conservation: Encouraging water conservation practices can ensure an adequate supply of water during heatwaves, preventing water scarcity during critical times.