Natural and Man-made Disasters ICSE Class 8: Safety, Management and Case Studies

What Natural and Man-made Disasters is about

Weightage: CISCE publishes no question paper, marking scheme or chapter weightage for Class VIII Geography: your school sets and marks the exam. Natural and Man-made Disasters sits in the Natural and Man-made Disasters theme of the CISCE Curriculum for Upper Primary Classes (VI-VIII).Source: CISCE Curriculum for Upper Primary Classes (VI-VIII), RDCD 2016

Key concepts

Disasters: meaning and types

A hazard is a natural or human-made event that could cause harm, such as heavy rainfall or an earthquake. It becomes a disaster when it seriously disrupts a community, causing widespread loss of life, property, livelihoods or environment that people cannot cope with using their own resources.

Natural disasters: caused by natural processes.

• Geological: earthquakes, volcanic eruptions, tsunamis, landslides.
• Weather and climate: floods, cyclones, droughts, cloudbursts, heat waves, cold waves.
• Biological: epidemics.

Man-made disasters: caused by human activity, accident or negligence.

• Industrial accidents, such as gas leaks: the Bhopal gas tragedy of December 1984, when a poisonous gas (methyl isocyanate) leaked from a pesticide factory, killing thousands.
• Oil spills from tankers or offshore wells.
• Fires in buildings, factories and forests (when caused by people).
• Nuclear accidents, such as Chernobyl (1986).
• Building and bridge collapses; stampedes; war and terrorism.

Vulnerability: poor housing, crowding, lack of awareness and poverty make some people more likely to suffer in a disaster.

Worked example

(2 marks) Distinguish between a natural and a man-made disaster with one example each.

Try it first, then show the solutionSolution

1. Natural: caused by natural processes, e.g. an earthquake or flood - 1 mark.
2. Man-made: caused by human activity or negligence, e.g. an oil spill or the Bhopal gas leak - 1 mark.

Answer: A natural disaster is caused by natural processes, such as an earthquake; a man-made disaster is caused by human activity or negligence, such as the Bhopal gas leak of 1984 or an oil spill.

Disaster management and its importance

Disaster management is the organisation and management of resources and responsibilities for dealing with all aspects of disasters, in order to reduce their harm.
The disaster management cycle has four stages:
1. Mitigation: long-term steps to reduce risk, such as earthquake-resistant buildings, embankments, afforestation and land-use rules.
2. Preparedness: plans, early-warning systems, drills, training, stockpiling relief material, public awareness.
3. Response: immediate action during and just after the disaster: rescue, evacuation, first aid, food, water and shelter.
4. Recovery: rebuilding homes, roads and livelihoods; rehabilitation and counselling; 'building back better'.
Importance:

• Saves lives through warnings and quick rescue.
• Reduces loss of property and damage to the economy.
• Helps communities recover faster.
• Protects the environment.
• Builds resilience, so future disasters do less harm.

Worked example

(4 marks) Name the four stages of the disaster management cycle and give one example of action in each.

Try it first, then show the solutionSolution

1. Mitigation: earthquake-resistant buildings / embankments - 1 mark.
2. Preparedness: early warning, drills - 1 mark.
3. Response: rescue, evacuation, relief camps - 1 mark.
4. Recovery: rebuilding houses and livelihoods - 1 mark.

Answer: (1) Mitigation, such as constructing earthquake-resistant buildings; (2) preparedness, such as early-warning systems and drills; (3) response, such as rescue, evacuation and relief camps; and (4) recovery, such as rebuilding homes, roads and livelihoods.

Safety measures: floods, earthquakes and fire

Floods:

• Before: know safe higher ground and evacuation routes; keep an emergency kit (torch, radio, medicines, documents in a waterproof bag, dry food, drinking water); listen to official warnings.
• During: move to higher ground; switch off electricity and gas; do not walk or drive through flowing water; avoid touching electric poles and wires.
• After: drink only boiled or treated water; stay away from damaged buildings; watch for snakes and disease.

Earthquakes:

• During: if indoors, Drop, Cover and Hold On: drop to the ground, take cover under a sturdy table, and hold on; stay away from windows, glass and heavy furniture; do not use lifts; do not run out while the ground is shaking. If outdoors, move to an open space away from buildings, trees and power lines.
• After: expect aftershocks; check for injuries and gas leaks; leave damaged buildings carefully.
• Long term: build earthquake-resistant structures; secure heavy furniture to walls.

Fire:

• Raise the alarm and call the fire service (101 in India, or the emergency number 112).
• Leave by stairs, not lifts; crawl low under smoke, where air is cleaner; feel doors before opening them.
• If clothes catch fire: Stop, Drop and Roll.
• Use the right fire extinguisher; never use water on electrical or oil fires.
• Prevention: do not overload sockets; keep exits clear; practise fire drills.

Worked example

(3 marks) What should you do if an earthquake strikes while you are in a classroom?

Try it first, then show the solutionSolution

1. Drop to the floor, take cover under a sturdy desk and hold on - 1 mark.
2. Keep away from windows, glass and heavy objects; do not run out while shaking - 1 mark.
3. After shaking stops, leave calmly by stairs to an open ground, expecting aftershocks - 1 mark.

Answer: Drop to the floor, take cover under a sturdy desk and hold on until the shaking stops, staying away from windows and heavy cupboards. Do not rush out while the ground is shaking. When it stops, leave calmly by the stairs to an open area away from buildings, and be ready for aftershocks.

Role of the government

In India the Disaster Management Act, 2005 set up a system at every level:

• National Disaster Management Authority (NDMA), chaired by the Prime Minister: makes policies, plans and guidelines.
• State Disaster Management Authorities (SDMA), chaired by Chief Ministers, and District Disaster Management Authorities (DDMA), headed by the District Collector or Magistrate.
• National Disaster Response Force (NDRF): specialised teams for rescue in floods, earthquakes, building collapses and chemical emergencies. States also have State Disaster Response Forces.
• Early warning: the India Meteorological Department (IMD) warns of cyclones and heavy rain; the Central Water Commission forecasts floods; tsunami warnings are issued by INCOIS.
• The armed forces help in large rescue and relief operations.

Functions of the government:
1. Prepare disaster plans and building codes; enforce them.
2. Give early warnings and organise evacuation.
3. Carry out rescue, relief camps, medical aid, food and water.
4. Provide compensation and rebuild infrastructure.
5. Spread awareness and conduct mock drills in schools and offices.
6. Cooperate with other countries in big disasters.

Worked example

(3 marks) Explain three roles of the government in disaster management in India.

Try it first, then show the solutionSolution

1. Planning and policy through the NDMA, SDMAs and DDMAs (Disaster Management Act, 2005) - 1 mark.
2. Early warning (IMD, Central Water Commission) and evacuation - 1 mark.
3. Rescue and relief by the NDRF and armed forces; rebuilding and compensation - 1 mark.

Answer: (1) Under the Disaster Management Act, 2005, the NDMA, SDMAs and DDMAs prepare plans and guidelines. (2) Agencies such as the IMD and the Central Water Commission give early warnings, and authorities organise evacuation. (3) The NDRF and armed forces carry out rescue, while the government runs relief camps and rebuilds homes and roads.

Case studies: floods in Assam and Bihar; earthquake in Nepal

Floods in Assam:

• Causes: very heavy monsoon rainfall; the Brahmaputra carries a huge load of sediment, which raises its bed; the river is wide and braided; tributaries from the hills bring flash floods; erosion of banks; deforestation in catchments; breaches in embankments.
• Effects: floods occur almost every monsoon, displacing large numbers of people; crops, houses and roads are destroyed; river-bank erosion eats away land (Majuli, a large river island, has lost much land); animals in Kaziranga National Park drown or are hit by vehicles while fleeing to higher ground.
• Environment: fertile silt is deposited, but erosion and waterlogging damage land and habitats.

Floods in Bihar:

• The Kosi is called the 'Sorrow of Bihar' because it often floods and shifts its course. In August 2008 it breached its embankment at Kusaha in Nepal and changed course, flooding large areas of north Bihar and affecting millions of people.
• Causes: heavy rain in Nepal and Bihar, high sediment load, flat land, embankment failures.
• Effects: loss of life, crops, cattle and homes; disease; people forced into relief camps.

Earthquake in Nepal (25 April 2015):

• Cause: Nepal lies where the Indian plate pushes under the Eurasian plate, building the Himalaya; stress released suddenly. The epicentre was in the Gorkha district; the magnitude was about 7.8. A strong aftershock struck on 12 May 2015.
• Effects: nearly 9,000 people died and many more were injured; hundreds of thousands of houses were destroyed; historic monuments in Kathmandu valley, including the Dharahara tower, collapsed; an avalanche struck Everest base camp; landslides blocked roads.
• India launched relief operations (Operation Maitri) and many countries sent help.

Worked example

(4 marks) Explain two causes and two effects of floods in Assam.

Try it first, then show the solutionSolution

1. Cause: very heavy monsoon rainfall in the Brahmaputra basin - 1 mark.
2. Cause: heavy silt raises the river bed; breaches in embankments / deforestation - 1 mark.
3. Effect: people displaced; crops, houses and roads destroyed - 1 mark.
4. Effect: bank erosion (Majuli) and wildlife losses in Kaziranga - 1 mark.

Answer: Causes: (1) very heavy monsoon rain over the Brahmaputra basin; (2) the river's huge silt load raises its bed, and embankments breach. Effects: (1) large numbers of people are displaced and crops, homes and roads are destroyed; (2) river-bank erosion eats away land, as on Majuli, and animals in Kaziranga National Park drown or are killed while fleeing.

Case study: oil spills in the coastal areas of the United States

An oil spill is the release of crude oil or petroleum products into the sea or coastal waters, usually from tankers, pipelines or offshore drilling platforms.

Deepwater Horizon (Gulf of Mexico, 2010):

• Cause: on 20 April 2010 an explosion on the Deepwater Horizon offshore drilling rig, operated for the company BP, killed 11 workers. The damaged well on the sea floor leaked oil for 87 days before it was capped in July 2010. It is one of the largest marine oil spills in history.
• Effects: oil spread over large areas of the Gulf and reached the coasts of Louisiana, Mississippi, Alabama and Florida.

Exxon Valdez (Alaska, 1989):

• Cause: on 24 March 1989 the oil tanker Exxon Valdez ran aground in Prince William Sound, Alaska, spilling a large quantity of crude oil.
• Effects: oil polluted a long stretch of remote coastline.

Impacts on life and environment:
1. Marine life: oil coats birds' feathers so they cannot fly or stay warm; it poisons fish, shellfish, dolphins and turtles; coral and marshes are damaged.
2. Coastal ecosystems: wetlands and beaches are polluted for years.
3. Livelihoods: fishing and tourism suffer heavy losses.
4. Health: clean-up workers and coastal residents may be exposed to toxic chemicals.
Clean-up methods: floating booms to contain oil, skimmers, controlled burning, chemical dispersants (themselves controversial), and washing beaches. Prevention: double-hulled tankers, stricter safety rules for drilling.

Worked example

(3 marks) State the cause of the Deepwater Horizon oil spill and two of its impacts.

Try it first, then show the solutionSolution

1. Cause: explosion on an offshore drilling rig in the Gulf of Mexico (April 2010); the well leaked for 87 days - 1 mark.
2. Impact: birds, fish, dolphins and turtles were killed or harmed; marshes polluted - 1 mark.
3. Impact: fishing and tourism along the Gulf coast suffered heavy losses - 1 mark.

Answer: The spill was caused by an explosion on the Deepwater Horizon drilling rig in the Gulf of Mexico in April 2010, after which the damaged well leaked oil for 87 days. It killed or harmed birds, fish, dolphins and turtles and polluted coastal marshes, and it caused heavy losses to fishing and tourism along the Gulf coast.

Natural and Man-made Disasters in real life

Each concept, met in an everyday situation. Read the situation, answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Topics in this chapter

• Case Studies: Assam-Bihar Floods, Nepal Earthquake and US Oil Spills
• Disaster Management: Cycle, Safety Measures and the Role of Government

Natural and Man-made Disasters: key facts

Disaster management cycle

$Mitigation->Preparedness->Response->Recovery$

Repeats; recovery should 'build back better'.

Earthquake magnitude

Each whole-number step: about 10 times the ground shaking and about 32 times the energy

Two steps: about 1,000 times the energy.

Rainfall volume

$Volume(m3)=rainfalldepth(m)xarea(m2)$

300 mm on 1 sq km = 0.3 x 10,00,000 = 3,00,000 m3.

Key dates

1984	Bhopal gas tragedy
1989	Exxon Valdez
2005	Disaster Management Act
2008	Kosi breach
2010	Deepwater Horizon
2015	(25 April) Nepal earthquake

Emergency numbers (India)

112: all emergencies; 101: fire

Natural and Man-made Disasters: map work

The places on the official CISCE map list for this chapter. Find each one on an outline map of India and practise marking it.

How the school exam asks Natural and Man-made Disasters

The question patterns to expect, and the method that works for each.

Tricks to remember Natural and Man-made Disasters

Short memory aids. Say each one aloud once, then use it on a question the same day.

• Management cycle: M-P-R-R

  'My Plan Rescues Recovery': Mitigation, Preparedness, Response, Recovery.

  Use it when: Stages of disaster management.

• Earthquake drill

  Drop, Cover, Hold On.

  Use it when: Safety during an earthquake.

• Clothes on fire

  Stop, Drop and Roll.

  Use it when: Fire safety.

Natural and Man-made Disasters: exam-level solved questions

Ordered from exam level to HOTS. Cover the solution, write your own, then compare step by step.

Case-study practice (Section B style)

Read the situation, then answer every part. In a school exam set on the board pattern this is a 7-mark question split into 2 + 3 + 2 marks.

Where the marks are

How a typical answer is split into step marks. Show every step: a right final answer alone rarely earns full marks.

Where students lose marks in Natural and Man-made Disasters

The slips examiners see most often, and what to write instead.

• ✗Mistake: Telling people to run outside during earthquake shaking

  A common instinct.

  ✓Do this: Drop, Cover and Hold On while shaking; go out only after it stops.

  Usually costs: 1 mark.

• ✗Mistake: Writing case-study answers without places or dates

  Vague answers.

  ✓Do this: Name the river, state, epicentre, year: Brahmaputra/Assam, Kosi 2008, Gorkha 2015, Gulf of Mexico 2010.

  Usually costs: 1-2 marks.

• ✗Mistake: Listing only causes when 'impacts on life and environment' are asked

  Not reading the question.

  ✓Do this: Give effects on people (lives, homes, livelihoods) and environment (wildlife, land, water).

  Usually costs: 1-2 marks.

• ✗Mistake: Calling all disasters 'natural'

  Forgetting the human role.

  ✓Do this: Show how human actions increase damage (building on floodplains, deforestation, weak buildings).

  Usually costs: 1 mark in HOTS questions.

Practice questions on Natural and Man-made Disasters

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

1. Q1 · 1 mark · MCQExam level

   Which of these is a man-made disaster?
   (a) Tsunami
   (b) Cyclone
   (c) Oil spill
   (d) Landslide caused by heavy rain

   Hint

   Caused by human activity.

   Answer

   (c) Oil spill.

2. Q2 · 1 mark · MCQHarder exam level

   The National Disaster Management Authority of India is chaired by:
   (a) the President
   (b) the Prime Minister
   (c) the Home Minister
   (d) the Chief Justice

   Hint

   Disaster Management Act, 2005.

   Answer

   (b) the Prime Minister.

3. Q3 · 1 mark · Very short answerExam level

   In which year and where did the Deepwater Horizon oil spill occur?

   Hint

   South of the USA.

   Answer

   2010, in the Gulf of Mexico.

4. Q4 · 2 marks · Very short answerHarder exam level

   What is the difference between a hazard and a disaster?

   Hint

   Potential versus actual.

   Answer

   A hazard is an event that could cause harm, such as heavy rain or an earthquake; it becomes a disaster when it actually causes widespread loss that the community cannot cope with using its own resources.

5. Q5 · 2 marks · Very short answerExam level

   Why should you not walk through flowing flood water?

   Hint

   Current and hidden dangers.

   Answer

   Even shallow flowing water can knock a person down and sweep them away, and it may hide open drains, debris or live electric wires.

6. Q6 · 2 marks · Very short answerHarder exam level

   State two methods used to clean up oil spills.

   Hint

   Contain and remove.

   Answer

   Floating booms to contain the oil and skimmers to remove it from the surface (also controlled burning and washing beaches).

7. Q7 · 2 marks · Very short answerHarder exam level

   Why is Majuli in danger?

   Hint

   Brahmaputra.

   Answer

   Majuli, a large river island in the Brahmaputra in Assam, is losing land to severe river-bank erosion during floods.

8. Q8 · 3 marks · Short answerHarder exam level

   How does earthquake-resistant construction reduce loss of life?

   Hint

   Most deaths come from collapsing buildings.

   Answer

   Most deaths in earthquakes are caused by collapsing buildings. Earthquake-resistant designs, with reinforced frames, proper foundations and flexible joints, help buildings sway without falling, so people inside are far more likely to survive.

9. Q9 · 3 marks · Short answerExam level

   Explain why the Kosi floods are so destructive.

   Hint

   Silt and shifting course.

   Answer

   The Kosi brings heavy rain-fed floods from Nepal and carries a huge load of silt, which raises its bed. On the flat plains of north Bihar it overflows and shifts its course, and embankment breaches, as in 2008, flood vast areas suddenly, destroying crops, homes and lives.

10. Q10 · 4 marks · Long answerHOTS / competency

    Suppose a chemical factory is to be built next to a crowded town. Suggest three precautions to prevent a man-made disaster like Bhopal.

    Hint

    Location, safety, warning.

    Answer

    (1) Locate the factory at a safe distance from homes, with a buffer zone. (2) Enforce strict safety standards: regular inspection of tanks and pipes, trained staff, automatic shut-off and gas detectors. (3) Prepare an emergency plan with sirens, evacuation routes and medical readiness, and inform residents about what to do in a leak.

11. Q11 · 2 marks · Very short answerHOTS / competency

    Give two reasons why the poor suffer most in disasters.

    Hint

    Housing and savings.

    Answer

    They often live in weak houses in risky places such as floodplains or steep slopes, and they have little savings or insurance to recover their losses.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1. 1.When was the Disaster Management Act passed in India?Show answer

   2005.

2. 2.What does NDRF stand for?Show answer

   National Disaster Response Force.

3. 3.Which district was the epicentre of the 2015 Nepal earthquake?Show answer

   Gorkha.

4. 4.Which tanker spilled oil in Alaska in 1989?Show answer

   The Exxon Valdez.

5. 5.What is India's single emergency number?Show answer

   112.

6. 6.How much more energy does a magnitude 7 earthquake release than a magnitude 6?Show answer

   About 32 times.

Quick revision checklist

The night before the exam: can you do each of these without looking?

• ☐Disaster: event causing widespread loss beyond a community's coping capacity. Natural: floods, earthquakes, cyclones. Man-made: Bhopal 1984, oil spills, fires, Chernobyl 1986.
• ☐Management cycle: mitigation, preparedness, response, recovery; saves lives and property.
• ☐Floods: move to high ground, switch off power, avoid flowing water, drink safe water. Earthquake: Drop, Cover, Hold On; open space outdoors. Fire: 101/112, stairs not lifts, crawl low, Stop-Drop-Roll.
• ☐Government: Disaster Management Act 2005; NDMA (PM), SDMA, DDMA; NDRF; IMD, CWC, INCOIS warnings; armed forces.
• ☐Assam: Brahmaputra, heavy rain, silt, breaches; displacement, erosion of Majuli, Kaziranga animals. Bihar: Kosi 'Sorrow of Bihar', 2008 breach at Kusaha.
• ☐Nepal 25 April 2015: Gorkha, magnitude about 7.8, nearly 9,000 dead, Dharahara collapsed. USA oil spills: Deepwater Horizon 2010 (11 killed, 87 days), Exxon Valdez 1989; harm to birds, fish, marshes, fishing, tourism.

Natural and Man-made Disasters: frequently asked questions