Selina Textbook Solutions: Natural and Man-made Disasters with Case Studies | Geography Class 8 ICSE PDF Download

 Page 1


Natural and Man-made Disasters with Case Studies 
Exercises 
A. Fill in the blanks 
1. Some disasters like droughts may begin slowly and later increase in extent and 
intensity. 
2. Earthquake is an example of a major natural disaster. 
3. Cyclones are low-pressure areas that occur over warm ocean waters of 
temperate and tropical regions. 
4. The collision of the earth’s plates caused the earthquake in Nepal in April 2015. 
5. The Bhopal gas tragedy was caused by the accidental leakage of a highly toxic 
gas called methyl isocyanate from the Union Carbide factory. 
B. Match the following columns 
 
Answer: 
 
Page 2


Natural and Man-made Disasters with Case Studies 
Exercises 
A. Fill in the blanks 
1. Some disasters like droughts may begin slowly and later increase in extent and 
intensity. 
2. Earthquake is an example of a major natural disaster. 
3. Cyclones are low-pressure areas that occur over warm ocean waters of 
temperate and tropical regions. 
4. The collision of the earth’s plates caused the earthquake in Nepal in April 2015. 
5. The Bhopal gas tragedy was caused by the accidental leakage of a highly toxic 
gas called methyl isocyanate from the Union Carbide factory. 
B. Match the following columns 
 
Answer: 
 
C. Choose the correct answer  
1. Droughts are caused by insufficient _______ over a long period of time. 
1. flood 
2. storm 
3. rainfall 
4. sunlight 
2. In 1986, an accidental explosion at a nuclear plant at ________ in the former USSR 
caused radiation to spread across Ukraine and other regions, killing over 12,000 people. 
1. Kiev 
2. Chernobyl 
3. Astana 
4. St Petersburg 
3. Chemical disasters are caused by _______. 
1. gases 
2. germs 
3. pollen 
4. virus 
4. Biological disasters occur when______, which are grown in laboratories, get released 
in the air. 
1. chemical 
2. germs 
3. pollen 
4. blossoms 
5. Chemicals from ______ kill marine life and coral reefs and also affect birds and 
mammals. 
1. cyclones 
2. drought 
3. earthquakes 
4. oil spills 
 
 
Page 3


Natural and Man-made Disasters with Case Studies 
Exercises 
A. Fill in the blanks 
1. Some disasters like droughts may begin slowly and later increase in extent and 
intensity. 
2. Earthquake is an example of a major natural disaster. 
3. Cyclones are low-pressure areas that occur over warm ocean waters of 
temperate and tropical regions. 
4. The collision of the earth’s plates caused the earthquake in Nepal in April 2015. 
5. The Bhopal gas tragedy was caused by the accidental leakage of a highly toxic 
gas called methyl isocyanate from the Union Carbide factory. 
B. Match the following columns 
 
Answer: 
 
C. Choose the correct answer  
1. Droughts are caused by insufficient _______ over a long period of time. 
1. flood 
2. storm 
3. rainfall 
4. sunlight 
2. In 1986, an accidental explosion at a nuclear plant at ________ in the former USSR 
caused radiation to spread across Ukraine and other regions, killing over 12,000 people. 
1. Kiev 
2. Chernobyl 
3. Astana 
4. St Petersburg 
3. Chemical disasters are caused by _______. 
1. gases 
2. germs 
3. pollen 
4. virus 
4. Biological disasters occur when______, which are grown in laboratories, get released 
in the air. 
1. chemical 
2. germs 
3. pollen 
4. blossoms 
5. Chemicals from ______ kill marine life and coral reefs and also affect birds and 
mammals. 
1. cyclones 
2. drought 
3. earthquakes 
4. oil spills 
 
 
D. State whether the following are true or false 
1. Earthquakes also trigger landslides, avalanches, and tsunamis. 
Answer. True 
2. Floods wash away the top layer of the soil, which is the most infertile. 
Answer. False. 
Floods wash away the top layer of the soil, which is the most fertile. 
3. West Bengal is most vulnerable to floods. 
Answer.False. 
Bihar is most vulnerable to floods. 
4. Oil spills harm marine life. 
Answer. True. 
5. The attacks carried out on Hiroshima and Nagasaki by the United States during 
World War II were an example of unintentional nuclear disaster. 
Answer. False. 
The attacks carried out on Hiroshima and Nagasaki by the United States during World 
War II were an example of intentional nuclear disaster. 
E. Answer the following questions in brief 
Question 1. 
How are earthquakes caused ? 
Answer: 
The surface of the earth is made up of interlocking plates of 
rock that float on a semi-liquid layer called the mantle. When two floating plates collide, 
the vibrations pass through the , earth’s surface or the crust. This makes the crust and 
everything on it shake uncontrollably and causes earthquake. 
Question 2. 
What causes floods ? What kind of environmental damage does a flood cause ? 
Answer: 
A flood occurs when a sudden influx of water submerges land, posing a danger to life 
and property. They are mostly caused due to overflowing of rivers in the monsoon. It 
occurs almost every year. Floods wash away the top layer of the soil which is the most 
fertile and hence causes soil erosion. 
 
Page 4


Natural and Man-made Disasters with Case Studies 
Exercises 
A. Fill in the blanks 
1. Some disasters like droughts may begin slowly and later increase in extent and 
intensity. 
2. Earthquake is an example of a major natural disaster. 
3. Cyclones are low-pressure areas that occur over warm ocean waters of 
temperate and tropical regions. 
4. The collision of the earth’s plates caused the earthquake in Nepal in April 2015. 
5. The Bhopal gas tragedy was caused by the accidental leakage of a highly toxic 
gas called methyl isocyanate from the Union Carbide factory. 
B. Match the following columns 
 
Answer: 
 
C. Choose the correct answer  
1. Droughts are caused by insufficient _______ over a long period of time. 
1. flood 
2. storm 
3. rainfall 
4. sunlight 
2. In 1986, an accidental explosion at a nuclear plant at ________ in the former USSR 
caused radiation to spread across Ukraine and other regions, killing over 12,000 people. 
1. Kiev 
2. Chernobyl 
3. Astana 
4. St Petersburg 
3. Chemical disasters are caused by _______. 
1. gases 
2. germs 
3. pollen 
4. virus 
4. Biological disasters occur when______, which are grown in laboratories, get released 
in the air. 
1. chemical 
2. germs 
3. pollen 
4. blossoms 
5. Chemicals from ______ kill marine life and coral reefs and also affect birds and 
mammals. 
1. cyclones 
2. drought 
3. earthquakes 
4. oil spills 
 
 
D. State whether the following are true or false 
1. Earthquakes also trigger landslides, avalanches, and tsunamis. 
Answer. True 
2. Floods wash away the top layer of the soil, which is the most infertile. 
Answer. False. 
Floods wash away the top layer of the soil, which is the most fertile. 
3. West Bengal is most vulnerable to floods. 
Answer.False. 
Bihar is most vulnerable to floods. 
4. Oil spills harm marine life. 
Answer. True. 
5. The attacks carried out on Hiroshima and Nagasaki by the United States during 
World War II were an example of unintentional nuclear disaster. 
Answer. False. 
The attacks carried out on Hiroshima and Nagasaki by the United States during World 
War II were an example of intentional nuclear disaster. 
E. Answer the following questions in brief 
Question 1. 
How are earthquakes caused ? 
Answer: 
The surface of the earth is made up of interlocking plates of 
rock that float on a semi-liquid layer called the mantle. When two floating plates collide, 
the vibrations pass through the , earth’s surface or the crust. This makes the crust and 
everything on it shake uncontrollably and causes earthquake. 
Question 2. 
What causes floods ? What kind of environmental damage does a flood cause ? 
Answer: 
A flood occurs when a sudden influx of water submerges land, posing a danger to life 
and property. They are mostly caused due to overflowing of rivers in the monsoon. It 
occurs almost every year. Floods wash away the top layer of the soil which is the most 
fertile and hence causes soil erosion. 
 
Question 3. 
What is a drought ? What are the effects of a drought ? 
Answer: 
Droughts are caused when a region receives insufficient rainfall for a long period of 
time. Shortage of water in drought- prone areas leads to a fall in the water table, crop 
failure, shortage of food, fodder and employment. As people begin to starve, they 
migrate to other places and become homeless. It occurs almost every year bringing with 
them epidemics and causing human suffering. 
Question 4. 
What should people do in the event of a nuclear disaster ? 
Answer: 
In the event of a nuclear disaster, one should close all the doors and windows of their 
houses and remain indoors as radiation does not penetrate solid structures. People 
should not go out until the government makes arrangements for their rescue. 
Question 5. 
How do chemical disasters occur ? 
Answer: 
Chemical disasters occur by the accidental release of toxic chemicals or gases into the 
environment from factories or other establishments. The hazardous substances 
released into the environment travel very fast and cause large-scale devastation. 
Question 6. 
How do biological disasters occur? 
Answer: 
Biological disasters are caused by germs developed in laboratories and released in the 
air to kill a large number of people. When these microbes are inhaled by a person, or 
get absorbed in his/her system through a cut or wound, they can infect him/her . Even a 
few drops of the smallpox or plague virus could start an epidemic, killing thousands of 
people. 
Question 7. 
Give some examples of travel-related disaster. 
Answer: 
Some examples of travel-related disasters are air crashes, train collisions and 
derailments, capsizing of boats and ships, etc. All these travel related disasters 
adversely impact a large number of people. 
 
 
 
Page 5


Natural and Man-made Disasters with Case Studies 
Exercises 
A. Fill in the blanks 
1. Some disasters like droughts may begin slowly and later increase in extent and 
intensity. 
2. Earthquake is an example of a major natural disaster. 
3. Cyclones are low-pressure areas that occur over warm ocean waters of 
temperate and tropical regions. 
4. The collision of the earth’s plates caused the earthquake in Nepal in April 2015. 
5. The Bhopal gas tragedy was caused by the accidental leakage of a highly toxic 
gas called methyl isocyanate from the Union Carbide factory. 
B. Match the following columns 
 
Answer: 
 
C. Choose the correct answer  
1. Droughts are caused by insufficient _______ over a long period of time. 
1. flood 
2. storm 
3. rainfall 
4. sunlight 
2. In 1986, an accidental explosion at a nuclear plant at ________ in the former USSR 
caused radiation to spread across Ukraine and other regions, killing over 12,000 people. 
1. Kiev 
2. Chernobyl 
3. Astana 
4. St Petersburg 
3. Chemical disasters are caused by _______. 
1. gases 
2. germs 
3. pollen 
4. virus 
4. Biological disasters occur when______, which are grown in laboratories, get released 
in the air. 
1. chemical 
2. germs 
3. pollen 
4. blossoms 
5. Chemicals from ______ kill marine life and coral reefs and also affect birds and 
mammals. 
1. cyclones 
2. drought 
3. earthquakes 
4. oil spills 
 
 
D. State whether the following are true or false 
1. Earthquakes also trigger landslides, avalanches, and tsunamis. 
Answer. True 
2. Floods wash away the top layer of the soil, which is the most infertile. 
Answer. False. 
Floods wash away the top layer of the soil, which is the most fertile. 
3. West Bengal is most vulnerable to floods. 
Answer.False. 
Bihar is most vulnerable to floods. 
4. Oil spills harm marine life. 
Answer. True. 
5. The attacks carried out on Hiroshima and Nagasaki by the United States during 
World War II were an example of unintentional nuclear disaster. 
Answer. False. 
The attacks carried out on Hiroshima and Nagasaki by the United States during World 
War II were an example of intentional nuclear disaster. 
E. Answer the following questions in brief 
Question 1. 
How are earthquakes caused ? 
Answer: 
The surface of the earth is made up of interlocking plates of 
rock that float on a semi-liquid layer called the mantle. When two floating plates collide, 
the vibrations pass through the , earth’s surface or the crust. This makes the crust and 
everything on it shake uncontrollably and causes earthquake. 
Question 2. 
What causes floods ? What kind of environmental damage does a flood cause ? 
Answer: 
A flood occurs when a sudden influx of water submerges land, posing a danger to life 
and property. They are mostly caused due to overflowing of rivers in the monsoon. It 
occurs almost every year. Floods wash away the top layer of the soil which is the most 
fertile and hence causes soil erosion. 
 
Question 3. 
What is a drought ? What are the effects of a drought ? 
Answer: 
Droughts are caused when a region receives insufficient rainfall for a long period of 
time. Shortage of water in drought- prone areas leads to a fall in the water table, crop 
failure, shortage of food, fodder and employment. As people begin to starve, they 
migrate to other places and become homeless. It occurs almost every year bringing with 
them epidemics and causing human suffering. 
Question 4. 
What should people do in the event of a nuclear disaster ? 
Answer: 
In the event of a nuclear disaster, one should close all the doors and windows of their 
houses and remain indoors as radiation does not penetrate solid structures. People 
should not go out until the government makes arrangements for their rescue. 
Question 5. 
How do chemical disasters occur ? 
Answer: 
Chemical disasters occur by the accidental release of toxic chemicals or gases into the 
environment from factories or other establishments. The hazardous substances 
released into the environment travel very fast and cause large-scale devastation. 
Question 6. 
How do biological disasters occur? 
Answer: 
Biological disasters are caused by germs developed in laboratories and released in the 
air to kill a large number of people. When these microbes are inhaled by a person, or 
get absorbed in his/her system through a cut or wound, they can infect him/her . Even a 
few drops of the smallpox or plague virus could start an epidemic, killing thousands of 
people. 
Question 7. 
Give some examples of travel-related disaster. 
Answer: 
Some examples of travel-related disasters are air crashes, train collisions and 
derailments, capsizing of boats and ships, etc. All these travel related disasters 
adversely impact a large number of people. 
 
 
 
F. Answer the following questions in one or two paragraphs 
Question 1. 
Write a short note on the earthquake zones of India. 
Answer: 
The entire Himalayan belt is on the boundary between the Eurasian and the Indian 
plates and is, therefore, prone to earthquakes. It falls under the very high risk zone 
(Seismic Zone V). Because of frequent seismic activity, it cause severe damage to life 
and settlements in the area. Kachchh in Gujarat and the Ganga-Brahmaputra basin are 
in the high risk zone (Seismic Zone IV). 
Question 2. 
How is a cyclone caused ? Which coastal region of India is cyclone-prone ? 
Answer: 
Cyclones are low-pressure areas that occur over warm ocean waters of temperate and 
tropical regions. Seen as swirling atmospheric disturbances they are accompanied by 
heavy rain, huge waves and powerful winds blowing at a velocity of 300 km per hour. 
Storm surges during the high tide, called storm tides, cause enormous damage to 
coastal regions. Cyclone-prone areas of India are West Bengal, Odisha, Andhra 
Pradesh and Tamil Nadu. 
Question 3. 
What are the conditions people face during a drought ? 
Answer: 
Droughts are caused when a region receives insufficient rainfall for a long period of 
time. Shortage of water in drought- prone areas leads to a fall in the water table, crop 
failure, shortage of food, fodder and employment. As people begin to starve, they 
migrate to other places and become homeless. It occurs almost every year bringing with 
them epidemics and causing human suffering. 
Question 4. 
Briefly explain the various causes of fire. 
Answer: 
Fires usually occur due to poor wiring and faulty electrical equipment, leakage of 
cooking gas or a carelessly thrown matchstick. The most common cause of a fire in a 
building is poor electrical wiring and faulty equipment. Electrical wiring must be regularly 
checked. If the wiring is worn-out, it must be replaced immediately by standard quality 
wires and electrical fittings to avoid any short-circuit. Fire can also be caused due to gas 
leakage. Gas pipes, regulators and stoves should be regularly checked to ensure there 
is no leakage. Regular maintenance checks in gas pipelines should also be mandatory. 
Fire is also commonly caused by carelessly thrown matches and cigarettes. It is also 
one of the common causes of forest fires. There is also fire-related disasters in areas 
where wood is used in construction activities. The loss of life is more if a fire breaks out 
in crowded areas.