Understanding Disaster Notes 6th Social Science
6th Social Science Lesson 21 Notes in English
21. Understanding Disaster
1. What is a Disaster?
A disaster is a serious disruption of the functioning of a society involving human and material loss.
2. How are Disaster Classified?
Disaster is broadly classified into natural and manmade disasters.
3. What is an Earthquake?
The sudden shaking of the earth at a place for a short spell of time is called an earthquake. The duration of the earthquake may be a few seconds to some minutes.
4. What is Focus?
The point where an earthquake originates is called its ‘focus’.
5. What is Epicentre?
The vertical point at the surface from the focus is called ‘Epicentre’.
6. Define Volcanoes:
Volcanoes are openings or vents where lava, small rocks and steam erupt onto the earth’s surface.
7. Define Tsunami:
Tsunami are waves generated by earthquake, volcanic eruptions and underwater landslides.
8. What are Cyclones?
A low pressure area which is encircled by high-pressure wind is called a cyclone.
9. What is a Floods?
An overflow of a large amount of water, beyond its normal limits, especially on the rain fed areas is called a flood.
10. What is a Landslide?
The movement of a mass of rocks, debris, Soil etc., down slope is called a landslide.
11. Define Avalanche:
A large amount of ice, snow and rock falling quickly down the side of a mountain is called an Avalanche.
12. How does Thunder and lightning occur?
Thunder is a series of sudden electrical discharge resulting from atmospheric conditions. This discharge results in sudden flashes of light and trembling sound waves which are commonly known as thunder and lightning.
13. How Forest Fire occur?
Massive forest fires may start in hot and dry weather as a result of lightning, and human carelessness or from other causal factors.
14. How Destruction of buildings are caused?
Demolition of buildings by human Activites.
15. What are the Accidents in industries?
Chemical, biological accidents that occur due to human error. (e.g.) Bhopal gas tragedy
16. What are the Accidents in Transport?
Violation of road rules, carelessness cause accidents.
17. What is Terrorism?
The social unrest or differences in principles leads to terrorism.
18. Define Stampede:
The term stampede is a sudden rush of a crowd of people, usually resulting in injuries and death from suffocation and trampling.
19. Describe the Massive Tsunami in 2004:
A killer Tsunami hit the south east Asian countries on the 26th of December, 2004.
20. What was the Magnitude of Tsunami in 2004?
A massive earthquake with a magnitude of 9.1 -9.3 in the Richter scale Epicentre in the Indonesian island of Sumatra. It triggered one of the biggest Tsunamis the world had ever witnessed.
21. Estimate the Death Sentence of Tsunami in 2004:
The massive waves measuring up to 30 metres that killed more than 2,00,000 people of Asia. In India, over 10,000 people were killed by this disaster. Tamil Nadu alone accounted for 1,705 deaths.
22. Mention the Bad Effects of 2004 Tsunami:
All the coastal districts were affected, Nagapattinam was the worst hit in the state of Tamil Nadu. Fishermen, tourists, morning walkers, children playing in beach and people living on the coast were unprepared for the waves. So they lost their life and the most of the loss of lives and damage to property was within 500 metres of the shore.
23. When was INCOIS Started?
The Indian government set up a Tsunami Early Warning System at Indian National Centre for Ocean Information Services (INCOIS), Hyderabad in 2007.
24. What are the measures should be taken while Tsunami?
- You should find out if your home, school etc., are in vulnerable areas along sea shore.
- Know the height of your street above sea level.
- Plan evacuation routes and practice your evacuation routes.
- Discuss tsunamis with your family.
- Review safety and preparedness measures with your family.
- If you see the sea water receding, you must immediately leave the beach and go to higher ground far away from the beach.
- Be aware facts about tsunami.
25. What should not be done while Tsunami?
- Don’t go to the coast to watch the Tsunami.
- Dont try to surf the tsunami waves.
26. How Floods occur?
Floods are high stream flows, which overlap natural or artificial banks of a river or a stream and are markedly higher than the usual flow as well as inundation of low land.
27. What are Flash floods?
Flash floods that occur within six hours during heavy rainfall.
28. What are River floods?
River floods are caused by Precipitation over large catchment areas or by melting of snow or sometimes both.
29. What are Coastal floods?
Sometimes floods are associated with cyclone high tides and tsunami.
30. What are the Causes of floods?
- Torrential Rainfall.
- Encroachment of rivers bank.
- Excessive rainfall in catchment.
- Inefficient engineering design in the construction of embankments, dams and canals.
31. What are the Effects of floods?
- Destruction of drainage system
- Water pollution
- Soil erosion
- Stagnation of water
- Loss of agricultural land and cattle
- Loss of life and spread of contagious diseases.
32. What are Measures should be taken while Floods?
- To find out if the settlement area is to be affected by flood or not.
- Keeping radio, torch and additional batteries, storing drinking water, dry foods items, salt and sugar.
- Safeguarding materials like kerosene, candle, match box, clothes and valuable things.
- Keeping umbrella and bamboo poles.
- Keeping first aid box and strong ropes to bind things.
- To dig canals from the farm land, to drain the excessive water keeping sand bags etc.,
33. What should not be done while Flood?
- Try to connect electricity once it is cut.
- Operate vehicles
- Swim against floods
- Avoid going on excursions.
- Neglect flood warning messages
34. What are Quick action should be taken during floods?
- Cut off gas connection and electricity.
- Keep sand bags on drainage holes and bathroom holes.
- Leave immediately through the known passage or prescribed passage
- Drink hot water.
- Use bleaching powder to keep your environment hygienic.
- Before using match sticks and candles, ensure that there is no gas leakage.
- Don’t eat more food when you are affected by diarrhea.
- Don’t try to take anything that floats in flood.
35. What is Disaster Risk Reduction?
The practice of reducing disaster risks through systematic efforts to analyze and manage the causal factors of disasters. There are four key approaches to public awareness for disaster risk reduction. Campaigns, participatory learning, informal education, and formal school based interventions.
36. Explain in detail about Chennai cyclone:
Chennai is one of the largest metropolitan cities in India, which lies on the south eastern coast. The north east monsoon along with tropical cyclone hits Chennai every year and gives heavy cyclonic rainfall.
37. When was the cyclone Occurred in Chennai?
In 2015, November and December due to heavy rain, the devastating floods that hit Chennai and other parts of Tamil Nadu claimed more than 400 lives and caused enormous economic damage.
38. Various Forecasting Places:
Weather forecasting, Tsunami early warning system, cyclonic forecasting and warning provide necessary information which help in reducing risks during disasters. School Disaster Management Committee, Village Disaster Management Committee, State and Central government institutions take mitigation measures together during disaster.
39. How Quick Mitigation should be Done?
Newspaper, Radio, Television and social media bring updated information and give alerts on the vulnerable area, risk, preparatory measures and relief measures including medicine.