Disaster Management: Responding to Disasters — Class 9 Social Science (Samacheer Kalvi)
TN State Board (Samacheer Kalvi) Class 9 Social Science, Geography — Chapter 8. Understanding and responding to disasters.
1. About this lesson
This chapter covers disasters — their types, causes, effects, and how to prepare, respond, and recover. It also explains the disaster management cycle and the role of agencies in India.
2. What is a Disaster?
A disaster is a serious disruption causing widespread human, material, economic, or environmental losses that exceed the affected community's ability to cope.
- Hazard: A dangerous phenomenon that may cause loss (potential threat).
- Vulnerability: The conditions that increase susceptibility to hazards.
- Risk: Probability of harmful consequences from a hazard.
3. Types of Disasters
Natural Disasters
| Type | Causes | Effects | Indian Examples |
|---|---|---|---|
| Earthquake | Tectonic plate movement | Building collapse, landslides, tsunamis | Bhuj (2001), Kashmir (2005), Nepal (2015) |
| Flood | Heavy rain, dam failure, cyclones | Submergence, crop loss, displacement | Kerala (2018), Chennai (2015), Bihar (annual) |
| Cyclone | Low pressure over warm seas | Strong winds, storm surge, floods | Fani (2019), Amphan (2020), Gaja (2018) |
| Tsunami | Undersea earthquake/volcano | Massive sea waves, coastal destruction | Indian Ocean Tsunami (2004) |
| Drought | Deficient rainfall | Crop failure, water scarcity, famine | Maharashtra, Rajasthan, Bundelkhand |
| Landslide | Heavy rain, earthquakes, deforestation in hills | Burying of settlements, road blockage | Uttarakhand (2013), Kerala |
Man-made Disasters
- Industrial accidents: Bhopal Gas Tragedy (1984).
- Nuclear accidents: Chernobyl (1986), Fukushima (2011).
- Fires: Urban fires, forest fires.
- Oil spills: Marine pollution, ecological damage.
4. Disaster Management Cycle
| Phase | Activities |
|---|---|
| Preparedness | Early warning systems, evacuation plans, training, mock drills, stockpiling supplies |
| Response | Search and rescue, medical aid, food and shelter, relief distribution |
| Recovery | Rehabilitation, reconstruction, restoration of services, counselling |
| Mitigation | Long-term measures to reduce risk — building codes, embankments, afforestation, zoning laws |
5. Disaster Management in India
Key Agencies
| Agency | Role |
|---|---|
| NDMA (National Disaster Management Authority) | Apex body; chaired by the Prime Minister; formulates policies and guidelines |
| NDRF (National Disaster Response Force) | Specialized force for search, rescue, and relief operations |
| SDMA (State Disaster Management Authority) | State-level body; chaired by the Chief Minister |
| IMD (India Meteorological Department) | Weather forecasting and cyclone warnings |
| NIDM (National Institute of Disaster Management) | Training, research, and capacity building |
Key Legislation
- Disaster Management Act, 2005: Established NDMA and framework for disaster management in India.
6. Do's and Don'ts During Common Disasters
Earthquake
- DO: Drop, Cover, Hold; stay away from windows; if outdoors, move to open space.
- DON'T: Use elevators; stand near buildings, trees, or power lines.
Flood
- DO: Move to higher ground; store drinking water; listen to radio for updates.
- DON'T: Walk/drive through floodwater; touch electrical equipment with wet hands.
Fire
- DO: Crawl low under smoke; use stairs (not lifts); call 101 (fire service).
- DON'T: Panic; re-enter a burning building.
7. Worked examples
Example 1. What is the difference between a hazard and a disaster? Hazard = potential threat. Disaster = when a hazard causes widespread loss beyond coping capacity.
Example 2. Name India's apex disaster management body. NDMA — National Disaster Management Authority (chaired by PM).
Example 3. What does "Drop, Cover, Hold" apply to? Earthquake safety drill.
Example 4. What number do you call for fire in India? 112 (national emergency number).
8. Book-back questions (Samacheer Kalvi)
I. Choose the best answer
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One among the following is NOT the first responder in case of a disaster — (a) Police officers / (b) Firefighters / (c) Insurance agents / (d) Emergency medical technicians. Ans: (c) Insurance agents.
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'Drop, Cover, Hold' is a mock drill for — (a) Fire / (b) Earthquake / (c) Tsunami / (d) Riot. Ans: (b) Earthquake.
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When you happen to see a fire break out, you will make a call to — (a) 114 / (b) 112 / (c) 115 / (d) 118. Ans: (b) 112.
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Which of the following statements is UNTRUE? — (a) 'Stop, Drop, Roll' is for fire / (b) 'Drop, Cover, Hold' is for earthquake / (c) 'If sea water recedes, run to higher places' is for flood / (d) 'If gunshots are heard, drop to ground, cover head' is for riot. Ans: (c). (Sea water receding is a tsunami warning sign, not flood.)
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Which statement belongs to responding to earthquake? — (a) Avoid places where police action is in progress / (b) Know your street height above sea level / (c) Stay away from glass, windows, outside doors and walls / (d) Before opening a door, feel it with the back of your hand. Ans: (c). (a = riot; b = tsunami; d = fire.)
II. Answer in brief
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Who are the community's first responders to disaster? — Police officers, firefighters, and emergency medical technicians (EMTs). They respond daily during fire, flood, or acts of terrorism.
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What are the four phases of the Disaster Management Cycle? — Mitigation (prevention/reduction), Preparedness (planning/training), Response (immediate action), Recovery (rebuilding/restoration).
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Japan has the densest seismic network; Indonesia has more earthquakes. Why? — Japan is in a very active seismic zone with the densest seismic network. Indonesia is in an active seismic zone too, but larger → more earthquakes.
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How many males and females die per day due to fire in India? — ~25,000 persons die annually. Females account for ~66% of fire deaths. Estimated ~42 females and ~21 males die every day.
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What should you do after a Tsunami?
- Use radio/Coast Guard frequency for updated emergency information.
- Check for injuries; get first aid before helping others.
- Call professionals for rescue.
- Help special-needs persons (infants, elderly, disabled).
- Stay out of buildings with water around them.
- Check for gas leaks — if you smell gas, open windows, evacuate.
III. Answer in a paragraph
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Write a short note on Tsunami.
- Series of enormous ocean waves caused by earthquakes, underwater landslides, volcanic eruptions or asteroids.
- Travels 700–800 km/h; waves 10–30 meters high.
- Causes flooding; disrupts transport, power, communications, water supply.
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What do you do if you are indoors during an earthquake?
- DROP to the ground; COVER under sturdy table/furniture; HOLD ON until shaking stops.
- No table → cover face/head with arms, crouch in inside corner.
- Stay under lintel of inner door, corner of room, under table/bed.
- Stay away from glass, windows, outside doors/walls, falling objects.
- Stay inside until shaking stops and it's safe to go out.
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How do you respond to Tsunami?
- Know if your home/school/workplace is in a tsunami hazard zone.
- Plan evacuation routes.
- Use weather radio/local station for watches and warnings.
- Discuss tsunamis with family — awareness reduces fear, saves time.
- Review flood safety measures.
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Write about what to do during a fire.
- Evacuate calmly and quickly when alarm sounds.
- Stop, Drop, and Roll if clothes catch fire.
- Before opening a door, feel it with back of hand. If hot, don't open.
- Crawl low under smoke.
- Call 112.
9. Common mistakes
- Mistake: Mitigation = response. Fix: Mitigation = long-term prevention/reduction (building codes). Response = immediate action during/after a disaster.
- Mistake: Tsunami = tidal wave caused by wind. Fix: Tsunami is caused by undersea earthquakes/volcanic eruptions, not wind.
- Mistake: NDMA is chaired by the Home Minister. Fix: NDMA is chaired by the Prime Minister.
9. Quick revision
- Geography Ch 8 · Disaster Management.
- Disaster types: Natural (earthquake, flood, cyclone, tsunami, drought, landslide) and Man-made (industrial, nuclear, fire, oil spill).
- Management cycle: Preparedness → Response → Recovery → Mitigation.
- Indian agencies: NDMA (PM-chaired), NDRF (rescue force), SDMA (state level), IMD (weather), NIDM (training).
- Disaster Management Act, 2005.
- Earthquake: Drop, Cover, Hold. Flood: move to higher ground. Fire: crawl low, use stairs.
