Disaster 101 - Defining & Dividing
A disaster is a serious disruption of community functioning, causing widespread losses (human, material, economic, environmental) that exceed its ability to cope using its own resources.
- Key Criteria: Overwhelms local capacity. Often >10 deaths, >100 affected.
⭐ A disaster is an event that overwhelms local capacity to respond without external assistance. (WHO)
- Primary Classification:
- Natural: Geophysical (earthquake, tsunami), Hydrological (flood), Biological (epidemic).
- Man-made (Anthropogenic): Technological (industrial spill), Intentional (conflict, terror).
Nature's Wrath - Cataloguing Calamities
📌 Mnemonic for Natural Disaster Categories: Good Heavens, My Cat Bit! (Geophysical, Hydrological, Meteorological, Climatological, Biological)
| Category | Sub-type | Key Examples/Characteristics |
|---|---|---|
| Geophysical | Earthquakes | Richter (magnitude), Mercalli (intensity); ground shaking |
| Tsunamis | Giant sea waves from underwater seismic activity | |
| Volcanic Eruptions | Molten rock (lava), ash, gas expulsion | |
| Landslides | Downslope movement of soil, rock, debris | |
| Hydrological | Floods | Inundation: flash, riverine, coastal |
| Avalanches | Rapid flow of snow, ice, or debris down a slope | |
| Storm Surges | Abnormal sea level rise with storms | |
| Limnic Eruptions | Sudden CO2 gas release from deep lakes | |
| Meteorological | Cyclones/Hurricanes/Typhoons | Intense tropical storms; Saffir-Simpson (Cat 1-5) |
| Tornadoes | Violent rotating air columns (land); Fujita (F0-F5) | |
| Heat Waves/Cold Waves | Prolonged extreme hot/cold temperatures | |
| Blizzards/Hailstorms | Severe snowstorms / Solid ice precipitation | |
| Climatological | Droughts | Extended lack of rainfall, water shortage |
| Wildfires | Uncontrolled fires in forests/wildlands (forest fires) | |
| GLOFs | Sudden water release: Glacial Lake Outburst Floods | |
| Biological | Epidemics/Pandemics | Widespread disease (e.g., Cholera, COVID-19) |
| Pest Infestations | Destructive insects/animals (e.g., locust swarms) |
⭐ India is one of the most flood-prone countries in the world, with riverine floods being particularly common during monsoon season.
Human Errors - Unveiling Man-Made Crises
Man-made disasters arise from human actions: intent, negligence, or technological failure. Key types:
| Category | Sub-type | Key Examples/Characteristics |
|---|---|---|
| Technological | Industrial accidents | Chemical spills (Bhopal - MIC), gas leaks, explosions, fires. |
| Nuclear accidents | Meltdowns, radiation release (Chernobyl, Fukushima). | |
| Radiological emergencies | Lost sources, improper disposal, contamination. | |
| Transport accidents | Major road, rail, air, sea incidents; mass casualties. | |
| Structural collapses | Buildings, bridges, dams, tunnels; design flaws. | |
| Others | Mine disasters, large oil spills, major power outages. | |
| Intentional/Sociological | Terrorism | Politically motivated violence; CBRN-T. 📌 CBRN: Can Be Really Nasty! |
| War & Civil Strife | Armed conflicts, insurgencies, displacement. | |
| Riots & Civil Unrest | Mass public disturbances, looting. | |
| Stampedes | Crowd surges at mass gatherings (religious, sports). | |
| Others | Deliberate arson, sabotage. | |
| Complex Emergencies | Combination | Natural + man-made factors (e.g., drought + conflict → famine). |
⭐ The Bhopal Gas Tragedy in 1984, involving the release of Methyl Isocyanate (MIC) gas, is a stark example of a catastrophic industrial disaster.
Pace & Punch - Onset, Severity & India Focus
- Onset Speed:
- Rapid/Sudden: Earthquake, Cyclone, Flash Flood. 📌 Every Child Falls.
- Slow/Creeping: Drought, Famine, Climate Change.
- Severity: Minor, Moderate, Major/Catastrophic (impact on life, property, environment; overwhelms local capacity).
- India Focus:
- NDMA leads. High vulnerability: hydro-meteorological (floods, cyclones), seismic zones.
⭐ Drought is a slow-onset disaster that affects more people in India than any other single disaster type.
High‑Yield Points - ⚡ Biggest Takeaways
- Key types: Natural (earthquakes, floods) and Man-made (industrial accidents, CBRN events).
- Onset: Rapid (cyclones, tsunamis) versus Slow (droughts, environmental degradation).
- Biological disasters: Include epidemics (e.g., cholera) and pandemics (e.g., COVID-19).
- Complex emergencies: Often involve conflict, large-scale displacement, and food insecurity.
- Severity is assessed by human casualties, economic losses, and geographical scope.
- India's Disaster Management Act, 2005 provides the crucial legal framework for management activities.
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