Silent Killers: Droughts, Heatwaves and Wildfires

1. Drought: The "Creeping" Disaster

Drought is a unique disaster because it lacks a sudden onset. It is a prolonged period of water deficiency that leads to environmental and socio-economic distress. Unlike a flood which lasts days, a drought can persist for years.

India's Vulnerability: Almost 68% of India's net sown area is prone to drought in varying degrees. The regions of Marathwada, Vidarbha, and Rayalaseema are chronically affected.

2. The Four Stages of Drought

UPSC requires a clear distinction between the types of drought:

1. Meteorological Drought: Defined by actual rainfall being significantly less than the long-term average (>25% deficit).
2. Hydrological Drought: Occurs when surface and groundwater levels (rivers, lakes, aquifers) fall below normal despite some rain.
3. Agricultural Drought: When soil moisture is insufficient to sustain crops, leading to "wilting" and yield loss.
4. Socio-economic Drought: When the water shortage begins to affect the economy, causing migration, loss of livelihoods, and food insecurity.

3. Mitigation and Management of Drought

A. Short-term: Providing immediate fodder for cattle, emergency water supply (Water Trains), and crop insurance (PMFBY). B. Long-term:

• Watershed Management: Recharging groundwater through check dams and ponds.
• Crop Diversification: Shifting from water-intensive crops (like Sugarcane/Paddy) to Millets and Pulses in dry zones.
• Micro-irrigation: Scaling up Drip and Sprinkler systems (Per Drop More Crop).

4. Heatwaves: The New Urban Lethality

A heatwave is a period of abnormally high temperatures. With climate change, heatwaves in India are starting earlier (March instead of May) and staying longer.

IMD Criteria:

• Plains: Daily max temperature reaches 40°C.
• Coastal: Daily max reaches 37°C.
• Hills: Daily max reaches 30°C.
• Severe Heatwave: When the departure from normal is > 6.4°C.

5. Physics and Biology of Heat Stress

Heatwaves affect humans through "Wet-bulb temperature"—a combination of heat and humidity. If the wet-bulb temperature exceeds 35°C, the human body can no longer cool itself through perspiration, leading to heatstroke and organ failure.

Urban Heat Island (UHI): Cities are 3-5°C hotter than surrounding rural areas due to concrete, lack of vegetation, and waste heat from ACs and cars.

6. Heat Action Plans (HAP) - The Ahmedabad Model

Ahmedabad was the first South Asian city to implement a Heat Action Plan (2013).

• Key Features: Color-coded alerts to hospitals, "Cool Roofs" program (painting roofs white), public cooling centers, and adjusting outdoor work hours for laborers. This model is now being scaled nationally by the NDMA.

7. Forest Fires: An Ecological Emergency

Forest fires in India are mostly (95%) anthropogenic (man-made).

• Natural Causes: Lightning and high temperatures during extreme drought.
• Man-made Causes: Shifting cultivation (Jhum), collection of Non-Timber Forest Produce (like Mahua flowers) where dry leaves are burnt, and negligence (cigarettes).
• Vulnerable Regions: Central India (Odisha, Chhattisgarh) and the Himalayan pine forests (Uttarakhand).

8. Impact of Forest Fires

• Loss of Biodiversity: Destruction of young saplings and ground-nesting birds.
• Carbon Cycle: Massive release of CO2 into the atmosphere, turning "carbon sinks" into "carbon sources."
• Soil Erosion: Intense heat kills soil microorganisms and destroys the organic "litter" layer that prevents erosion during rains.

9. Technological Interventions

• FSI Fire Alerts: The Forest Survey of India (FSI) uses MODIS and VIIRS satellite data to send real-time SMS alerts to forest guards within 2 hours of detecting a "hot spot."
• Aerial Support: The Indian Air Force uses "Bambi Buckets" to douse fires in inaccessible Himalayan terrains.

10. Summary: Integrating Climate Adaptation

Drought, Heat, and Fire are interconnected. For UPSC, argue that we need "Nature-based Solutions." Restoring traditional water bodies (Johads) helps with drought, while massive urban afforestation (Miyawaki forests) reduces UHI. We must treat Heatwaves as a "National Disaster" to unlock SDRF funding.