ICSE CLASS 8 GEOGRAPHY OF VOYAGE SOLUTION Chapter NATURAL AND MAN MADE DISASTER
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.
Explanation: 1. A drought is defined as a period of abnormally
dry weather sufficiently prolonged for the lack of water to cause serious
hydrologic imbalance in the affected area. Droughts are major
natural disasters for many parts of the world. Dry areas, where the precipitation
pattern is markedly seasonal, or is otherwise highly variable, are the most
susceptible
2. Natural disasters are catastrophic events with
atmospheric, geological, and hydrological origins (e.g., droughts, earthquakes,
floods, hurricanes, landslides) that can cause fatalities, property damage and
social environmental disruption. Natural disasters have
a significant impact on the public health and well-being of populations
affected.
3. A cyclone is a region of low atmospheric
pressure. It occurs as a swirling atmospheric disturbance, accompanied by
powerful cyclonic winds blowing in a clockwise direction in the Northern
Hemisphere and in an anti-clock wise direction in the Southern hemisphere.
4. One of the dangerous and major natural disasters
that take place is the Earthquake. Due to earthquakes every year huge damage to
property and life is caused all around the world. it is the shaking of
the surface of the earth resulting from a sudden release of energy in the
Earth’s lithosphere which creates seismic waves.
Causes of earthquake are
a.
Tectonic movements: Earthquakes are caused by sudden tectonic
movements in the Earth’s crust when tectonic plates, one rides over the
other, causing orogeny collide (mountain building), earthquakes.
b.
Folding and Faulting: due to large fault, when
two the plates moves against each other, the chances of earthquakes occurring
are more. San Andreas Fault of California is one such example.
c.
Volcanoes: when two plates move far away each other, the chances
of volcanoes occurring are more there, most volcanic eruptions are accompanied
by earthquakes. However, many active volcanoes are located far away from the
plate margins.
d.
Isostatic Disturbances: Isostatic disturbances may disturb the equilibrium
of the earth’s crust. Due to deposition carried by river, glaciers, on the
ocean floor, there is highly chances of isostatic disturbances.
5. Bhopal Gas Tragedy
The Bhopal disaster, also referred to as the
Bhopal gas tragedy, was a gas leak incident in India, considered the world's
worst industrial disaster. It occurred on the night of 2–3 December 1984 at the
Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh.
Over 500,000 people were exposed to methyl isocyanate (MIC) gas and other
chemicals. The gas spread within the radius of eight kilometers. The gas caused
coughing, breathlessness, stomach pain, burning in the respiratory tract.
B. Match the following columns
Answer:
Explanation:
1.
Drought: A drought is defined as a period of abnormally dry
weather sufficiently prolonged for the lack of water to cause serious
hydrologic imbalance in the affected area. Droughts are major natural disasters
for many parts of the world. Dry areas, where the precipitation pattern is
markedly seasonal, or is otherwise highly variable, are the most susceptible
2.
Hiroshima bombing: On 6th August 1945, an atomic bomb was
dropped on Hiroshima by US air forces. This was the first time a nuclear weapon
had ever been used; the fireball created by the bomb destroyed 13 square
kilometers of the city, and those dead as a result numbered up to 180,000.it
was a man-made disaster,
3.
Tsunami: A tsunami is a very large and powerful wave. A tsunami
is a series of waves caused by earthquakes or undersea volcanic eruptions. It
is caused by earthquakes under the sea. The deadly tsunami hit Thailand, India
and the Andaman Islands on 26 December, 2004.
4.
Chemical disaster: chemical disaster is defined as The
accidental release of large amounts of toxins into the environment. The effects
suffered by people in the area are determined by the toxicity of the chemical,
its speed in spreading, its composition (liquid, solid, or gaseous), and the
spill site. A chemical disaster may occur due to both, natural or human-made
sources. Chemical disasters are occurrence of emission, fire or explosion
involving one or more hazardous chemicals in the course of industrial activity
(handling), storage or transportation.
5.
Deep water horizon: Deepwater Horizon oil spill, also called
Gulf of Mexico oil spill, largest marine oil spill in history, caused by an
April 20, 2010, explosion on the Deepwater Horizon oil rig—located in the Gulf
of Mexico, approximately 41 miles (66 km) off the coast of Louisiana—and its
subsequent sinking on April 22.
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
explanation: Drought is one of the natural disasters that can be
reverted by nature itself. Drought is a temporary situation in which
there is the rainfall is below normal that leads to water shortage.
causes of drought
a.
Land and water temperatures cause drought.
b.
Air circulation and weather patterns also cause drought.
c.
Soil moisture levels also contribute to drought.
d.
Drought can also be a supply and demand of water issue
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
Explanation: Chernobyl disaster, accident in 1986 at the
Chernobyl nuclear power station in the Soviet Union, the worst disaster in the
history of nuclear power generation. The Chernobyl power station was situated
at the settlement of Pryp’yat, 10 miles (16 km) northwest of the city of
Chernobyl (Ukrainian: Chornobyl) and 65 miles (104 km) north of Kyiv, Ukraine.
The station consisted of four reactors, each capable of producing 1,000
megawatts of electric power. The accident destroyed the Chernobyl 4
reactor, killing 30 operators and firemen within three months and several
further deaths later
3. Chemical disasters are caused by _______.
1.
gases
2. germs
3. pollen
4. virus
explanation: A chemical disaster is the unintentional release of
one or more hazardous substances which could harm human health and the
environment.
Causes of chemical disaster
1.
Equipment failure: mal function of equipment may cause the
chemical disaster.
2.
inadequate safety review/analysis: many workplaces is the total
lack or absence of a solid chemical safety risk assessment process.
3.
Improper training: sometimes people are not trained properly or
adequately, industrial accidents are more likely to occur. Workers should be
taught how to operate the equipment
4.
Warnings ignored: Many large scale chemical
accidents come as a result of ignoring warning signs
4. Biological disasters occur when______,
which are grown in laboratories, get released in the air.
1. chemical
2.
germs
3. pollen
4. blossoms
explanation: Biological disasters are natural scenarios
involving disease, disability or death on a large scale among humans, animals
and plants due to micro-organisms like bacteria, or virus or toxins.
5. Chemicals from ______ kill marine life and coral reefs and
also affect birds and mammals.
1. cyclones
2. drought
3. earthquakes
4.
oil spills
Explanation: An oil spill is the release of any
hydro-carbons into the environment, especially in marine environments usually
due to human activity and is considered a form of pollution. Oil spills
occur when petroleum oil is released into the ocean following accidents, such
as vessels crashing or damage and problems with oil platforms and drilling.
They can have devastating effects on the environment, affecting marine and
coastal ecologies. The ocean tide, currents and weather affect the movement of
oil spills, making them unpredictable.
D.
State whether the following are true or false
1.
Earthquakes also trigger landslides, avalanches, and tsunamis.
Answer.
True
Explanation:
Earthquakes also trigger landslides, avalanches, and tsunamis. One of the dangerous and major
natural disasters that take place is the Earthquake. Due to earthquakes every
year huge damage to property and life is caused all around the world. it is the
shaking of the surface of the earth resulting from a sudden release of energy
in the Earth’s lithosphere which creates seismic waves.
Causes
of earthquake are
a. Tectonic movements: Earthquakes are
caused by sudden tectonic movements in the Earth’s crust when tectonic plates,
one rides over the other, causing orogeny collide (mountain building),
earthquakes.
b. Folding and Faulting: due to large fault,
when two the plates moves against each other, the chances of earthquakes
occurring are more. San Andreas Fault of California is one such example.
c. Volcanoes: when two plates move far away
each other, the chances of volcanoes occurring are more there, most volcanic
eruptions are accompanied by earthquakes. However, many active volcanoes are
located far away from the plate margins.
d. Isostatic Disturbances: Isostatic disturbances
may disturb the equilibrium of the earth’s crust. Due to deposition carried by
river, glaciers, on the ocean floor, there is highly chances of isostatic
disturbances.
Landslides: Landslides are caused by
disturbances in the natural stability of a slope. They can accompany heavy
rains or follow droughts, earthquakes, or volcanic eruptions.
Avalanches:
Avalanches are caused by four factors: a steep slope, snow cover, a weak layer
in the snow cover and a trigger.
Tsunami:
A tsunami is a very large and powerful wave. A tsunami is a series of waves
caused by earthquakes or undersea volcanic eruptions. It is caused by
earthquakes under the sea.
2.
Floods wash away the top layer of the soil, which is the most infertile.
Answer.
False.
Explanation:
Floods wash away the top layer of the soil, which is the most fertile.
Flood: A flood is an overflow of water onto land. Many different situations can cause
a flood. Here are just a few:
·
Heavy
rainfall
·
Ocean
waves coming on shore, such as a storm surge
·
Melting
snow and ice, as well as ice jams
·
Dams
or levees breaking
3.
West Bengal is most vulnerable to floods.
Answer.False.
Explanation:
Bihar is most vulnerable to floods. Bihar is India's most flood-prone
state, with 76% population in the North Bihar living under the recurring threat
of flood devastation. Bihar makes up 16.5% of India's flood affected area and
22.1% of India's flood affected population. Bihar is the most flood-prone state
among all north Indian states because many of the rivers flowing through Bihar
such as the Kosi Bagmati and Gandaki flow through the high mountainous region
of Nepal before crossing very small distances and rapidly reaching the plains
of Bihar making them far more forceful
4.
Oil spills harm marine life.
Answer.
True.
Explanation:
Oil spills are harmful to marine birds and mammals as well as fish and
shellfish.
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: One of the dangerous and major natural
disasters that take place is the Earthquake. Due to earthquakes every year huge
damage to property and life is caused all around the world. it is the shaking
of the surface of the earth resulting from a sudden release of energy in the Earth’s
lithosphere which creates seismic waves.
Causes of earthquake are
a. Tectonic
movements: Earthquakes are caused by sudden tectonic movements in the Earth’s
crust when tectonic plates, one rides over the other, causing orogeny collide
(mountain building), earthquakes.
b. Folding and
Faulting: due to large fault, when two the plates moves against each other, the
chances of earthquakes occurring are more. San Andreas Fault of California is
one such example.
c. Volcanoes: when
two plates move far away each other, the chances of volcanoes occurring are
more there, most volcanic eruptions are accompanied by earthquakes. However,
many active volcanoes are located far away from the plate margins.
d. Isostatic
Disturbances: Isostatic disturbances may disturb the equilibrium of the earth’s
crust. Due to deposition carried by river, glaciers, on the ocean floor, there
is highly chances of isostatic disturbances.
e. stress: When the
stress on the edge overcomes the friction, there is an earthquake that releases
energy in waves that travel through the earth's crust and cause the shaking
that we feel.
f. human activities:
Induced earth quakes are caused by human activity, like tunnel construction,
filling reservoirs and implementing geothermal or fracking projects.
Question 2.
What causes floods ? What kind of environmental damage does a
flood cause ?
Answer: Flood is a term used to denote an influx
amount of water. When there is an outflow of water in a place, it is said to be
flooded.
Causes of Floods
Flood is usually a result of natural causes. It may also be
caused by man-made factors. It causes huge damage to life and property.
a.
Massive Rainfall: due to heavy rainfall, flood can occur
b.
Overflowing of the Rivers: overflow of rivers have a risk of people
living in bank of rivers
c.
Collapsed Dams: due to
massive rainfall, the dams built begin to collapse.
d.
Snowmelt: At the time of the high melting of snow due to heavy precipitation
and other factors, the situation of flooding arises.
e.
Deforestation: deforestation is major cause of man made
flooding. Recklessly cutting down the trees are unable to prevent soil erosion.
f.
Emission of Greenhouse Gases: The burning of fossil fuels, the
industrial influences, the pollution all is depleting the level of the ozone
layer and increasing the level of greenhouse gases, becoming a major cause of
man-made flooding.
Question 3.
What is a drought ? What are the effects of a drought ?
Answer: A drought is defined as a period of abnormally
dry weather sufficiently prolonged for the lack of water to cause serious
hydrologic imbalance in the affected area
The effects of a drought are:
a.
Droughts damage agriculture and the food supplies.
b.
Droughts create floods and wildfires.
c.
Drought worsened the Great Depression.
Question 4.
What should people do in the event of a nuclear disaster ?
Answer:
In the event of a nuclear disaster,
A. Stay away from any
obvious plume or dust cloud.
B. closed doors and
windows as quickly as possible
C. listen for information
from emergency responders and authorities.
Question 5.
How do chemical disasters occur ?
Answer:
A chemical disaster is the unintentional release of one or more
hazardous substances which could harm human health and the environment.
Causes of chemical disaster
1.
Equipment failure: mal function of equipment may cause the
chemical disaster.
2.
inadequate safety review/analysis: many workplaces is the total
lack or absence of a solid chemical safety risk assessment process.
3.
Improper training: sometimes people are not trained properly or
adequately, industrial accidents are more likely to occur. Workers should be
taught how to operate the equipment
4.
Warnings ignored: Many large scale
chemical accidents come as a result of ignoring warning signs
Question 6.
How do biological disasters occur?
Answer: A biological disaster is a disaster caused by
the rapid spread of disease among humans, animals, and plants, caused by
microorganisms like bacteria, toxins, or viruses. It is explained as the
devastating effects produced by a vast spread of a certain kind of living
organism – that may spread disease, virus, or infestations of plant, insect, or
animal life on an epidemic or pandemic level.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: Travel related disaster has been defined as
the practice of visiting locations at which an environmental disaster, either
natural or man-made.
Some examples of travel-related disasters are
Aeroplane clashes, derailed of trains, collapsed of roads etc.
F. Answer the following questions in one or two paragraphs
Question 1.
Write a short note on the earthquake zones of India.
Answer:
The Himalayan belt is on the boundary between the Eurasian and
the Indian plates. The Indian subcontinent has a history of
devastating earthquakes. The major reason for the high frequency and intensity
of the earthquakes is that the Indian plate is driving into Eurasia plate at a
rate of approximately 47 mm/year. Geographical statistics of India show that
almost 54% of the land is vulnerable to earthquakes and is, therefore, prone to
earthquakes. There are 4 seismic zones namely Zone-II, Zone-III, Zone-IV and
Zone-V in India.
Himalaya falls under the very high risk zone (Seismic Zone V).
Because of frequent seismic activity, it causes severe damage to life and
settlements in the area. Not only Himalayan regions but also The regions of
Kashmir, the Western and Central Himalayas, North and Middle Bihar, the
North-East Indian region, the Rann of Kutch and the Andaman and Nicobar group
of islands fall in this zone.
Jammu and Kashmir, Ladakh, Himachal Pradesh, Uttarakhand,
Sikkim, parts of the Indo-Gangetic plains (North Punjab, Chandigarh, Western
Uttar Pradesh, Terai, a major portion of Bihar, North Bengal, the Sundarbans)
and the capital of the country Delhi fall in Zone 4.(Seismic Zone IV).
Kerala, Goa, Lakshadweep islands, remaining parts of Uttar
Pradesh, Gujarat and West Bengal, parts of Punjab, Rajasthan, Madhya Pradesh,
Bihar, Jharkhand, Chhattisgarh, Maharashtra, Odisha, Andhra Pradesh, Tamil Nadu
and Karnataka. lie in this zone.(Seismic Zone III)
It is the zone with low chances of having earthquakes. ex-
cities of Bulandshahr , Moradabad, Gorakhpur, Chandigarh (Seismic Zone II)
Question 2.
How is a cyclone caused ? Which coastal region of India is
cyclone-prone ?
Answer: A cyclone is a system of wind that moves
rapidly inward with a low-pressure area in the middle, A cyclone is formed
when warm, moist air near the ocean’s surface rises upward. When air rises away
from the ocean’s surface, it generates a low-pressure zone beneath it. It
causes air from higher-pressure places to travel towards the low-pressure area,
warming the air and causing it to climb above.
India is prone to natural calamities like earthquakes, floods,
droughts, cyclones and landslides. According to the Meteorological Department,
there are 13 coastal states and Union Territories of India prone to cyclones.
The four states at risk are West Bengal, Andhra Pradesh, Odisha, Tamil Nadu,
and one union territory on the east coast, Pondicherry, and one on the west
coast, Gujarat.
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,The conditions people face during a drought
1.
Crop failure: In drought conditions, the soil does not have
sufficient moisture to grow crops well.
2.
Shortage of water: there is no life
without water, people die of thirst
3.
unhygienic conditions : Drought creates unhygienic conditions
due to lack of water and there arise danger if epidemic diseases.
4.
shortage of fodder : The vegetation such as grass and fodder
does not grow well and leads to shortage of fodder for domestic animals.
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.
Question 5.
Why is nuclear disaster so harmful?
Answer:
Nuclear weapons are weapons of mass destruction (WMD) and leads
to mass destruction of life and property. The adverse effects of nuclear
radiation through the use of these weapons leaves thousands of people crippled
for life. Several thousands suffer throughout life due to exposure to
radiation. A nuclear
explosion is so bright that it can make people blind if they see
it with naked eyes. The explosion is followed by a heat wave and a huge cloud
formation at the blast site. In such a disaster, radioactivity is the silent
killer whose effects continue for a very long time after the incident. The
energy released in the form of particles from the radioactive elements such as
uranium, plutonium, etc. is called radioactivity. It spreads in the area and
causes nausea, dizziness, vomiting and disorientation. It is very harmful to
human health and causes serious illnesses like cancer. The worst type of
man-made disaster, it can cause the collapse of social, political and economic
establishments across the globe. Crises of this kind could occur intentionally
as well as unintentionally.
Question 6.
Which man-made nuclear disaster shook the world during World War
II ? Give details.
Atomic bombings of Hiroshima and Nagasaki, during World War II,
American bombing raids on the Japanese cities of Hiroshima (August 6, 1945) and
Nagasaki (August 9, 1945) that marked the first use of atomic weapons in war.
Tens of thousands were killed in the initial explosions and many more would
later succumb to radiation poisoning. On August 10, one day after the bombing
of Nagasaki, the Japanese government issued a statement agreeing to accept the
Allied surrender terms that had been dictated in the Potsdam Declaration.
Question 7.
Write a short note terror attacks with examples.
Answer:
This kind of disaster occurs in the event of a terror strike,
either through the use of explosives, guns, or chemical and biological weapons.
Most of these disasters are brought about by misdirected elements who think
that social, political, or religious goals can be achieved by killing people.
Terrorists also hijack planes and destroy public infrastructure, such as
railway tracks and bridges, to cause massive devastation. The attack on the
World Trade Center in the US on 11 September 2001, when terrorists hijacked
planes to spread terror, resulted in nearly 3,000 deaths. The most destructive
terror attacks in India include the attack on Parliament on 13 December 2001,
and the Mumbai attacks on 26 November 2008.
Question 8.
Write a short note on the Nepal earthquake of 2015.
Answer: Earthquakes are caused by the release of built-up
pressure at plate boundaries. The Nepal earthquake was a devastating earthquake
that struck near Kathmandu, the capital of Nepal on April 25, 2015. They can
destroy buildings and infrastructure. The earthquake
occurred on a convergent collision plate boundary between the Indian and
Eurasian plates. The focus was only eight kilometers deep and the epicenter was
just 60 kilometers north-west from the capital Kathmandu. Nearly 9000 people were killed and several
thousands more injured. The earthquake destroyed over 600,000 small and large
buildings and structures in Kathmandu. The magnitude on Richter scale was 7.8
with two large aftershocks of magnitudes 6.6 and 6.7 within an hour of the main
quake. The collision of earth’s plates caused the earthquake in Nepal. Nepal
lies on the fault called thrust fault.
Question 9.
What makes Bihar the most flood-prone state among all north
Indian states?
Answer:
Bihar is most vulnerable to floods. Bihar is India's most
flood-prone state, with 76% population in the North Bihar living under the
recurring threat of flood devastation. Bihar makes up 16.5% of India's flood
affected area and 22.1% of India's flood affected population. Bihar is the most
flood-prone state among all north Indian states because many of the rivers
flowing through Bihar such as the Kosi Bagmati and Gandaki flow through the
high mountainous region of Nepal before crossing very small distances and
rapidly reaching the plains of Bihar making them far more forceful.
G Picture study.
Question 1.
Identify the type of disaster as shown in the picture.
Answer:
It is droughts condition. . A drought is
defined as a period of abnormally dry weather sufficiently prolonged for the
lack of water to cause serious hydrologic imbalance in the affected area.
Question 2.
Is it man-made or natural?
Answer:
Its man made as well as natural as droughts are caused by shortage of rainfall
and also due to deforestation, misuse of ground water, unscientific
agricultural practices, etc.
Question 3.
What are the causes of this kind of disaster?
Answer:
causes of drought
a. Land and water
temperatures cause drought.
b. Air circulation
and weather patterns also cause drought.
c. Soil moisture
levels also contribute to drought.
d. Drought can also
be a supply and demand of water issue
H. Map work
On an outline map of India mark the following :
1. Earthquake zones with
moderate damage risk and high damage risk.
2. Any two flood-prone
areas
3. Any two cyclone zones
4. Any two drought-prone
areas
Answer:
1. (a) Earthquake zones
with moderate damage risk are : Jabalpur, Ratnagiri.
(b) Earthquake zones with high damage risk are : Chamoli, Sikkim.
(c) Earthquake zones with very high damage risk are: Kangra, Bhuj.
2. Two floods prone areas
are : Rivers of Punjab, River Krishna.
3. Two cyclones zone are
: Andhra Pradesh and Tamil Nadu.
4. Two drought prone
areas are : Gujarat and Rajasthan.
Extra Questions
Question 1.
What do you mean by disasters ? How are they classified?
Answer:
Disasters are serious disruptions to the functioning of a community that exceed
its capacity to cope using its own resources. Disasters can be caused by
natural, man-made and technological hazards.
Disasters can be broadly categorised into :
1. Natural disasters — Natural
disasters are catastrophic events with atmospheric, geological, and
hydrological origins (e.g., droughts, earthquakes, floods, hurricanes,
landslides) that can cause fatalities, property damage and social environmental
disruption. Natural disasters have a significant impact on the public health
and well-being of populations affected.
2. Man-made disasters
— The man-made disasters
are triggered by human beings. Some of the man-made disasters are: bomb
explosions, terrorism, war or civil war, leakage of poisonous chemicals, breach
in dams, air or water pollution, industrial accidents and epidemics.
Question 2.
Which countries are more adversely affected by disasters? Why?
Answer:
Disasters affect people living in underdeveloped countries more adversely than
those in developed countries because underdeveloped countries do not have
proper disaster management systems in place.
Question 3.
What do you understand by natural disasters ?
Answer:
Natural disasters are catastrophic events with atmospheric, geological, and
hydrological origins (e.g., droughts, earthquakes, floods, hurricanes,
landslides) that can cause fatalities, property damage and social environmental
disruption. Natural disasters have a significant impact on the public health
and well-being of populations affected.
Question 4.
What is the difference between a hazard and a disaster ?
Answer:
Difference Between Hazard and Disaster
·
Definition: Hazard is a dangerous situation that poses a threat
to human life while disaster is an event that completely causes damage to human
life and property.
·
Degree: Disaster has more critical consequences when compared to
the threats to the humans from a hazard. Therefore, disaster is more
catastrophic in nature than a hazard.
·
Occurrence: Disaster happens most often in a short time, thus
making more severe while hazard will take its full shape after a series of
events, which might have led it to happen. Therefore, necessary precautions can
be taken to avoid the negative consequences of a hazard.
Question 5.
What is an earthquake ? What are its effects ?
Answer:
An earthquake is a sudden, violent movement of a portion of the earth’s crust
caused by a disturbance under the earth’s surface. At times, earthquakes take a
heavy toll on life and property. Extensive damage is caused to houses, large
buildings, bridges, dams, rail lines and power lines, communication networks
etc. An earthquake can also act as a hazard by triggering landslides,
avalanches and tsunamis.
Question 6.
Name the states worst affected by water scarcity in India.
Answer:
Rajasthan, Gujarat, Chhatisgarh, Madhya Pradesh, Maharashtra, Karnataka and
Odisha.
Question 7.
What do you mean by man-made disasters ?
Answer:
Crises caused by a human act, intentionally or unintentionally are man-made
disasters. The leakage of a hazardous gas from a chemical factory or fire in a
restaurant can be classified under the unintentional man-made disaster whereas
the effects of a planned nuclear explosion or a terrorist attack can be
classified under the intentional man-made disaster.
Question 8.
What causes fire ? Give one example.
Answer:
Fire usually occur due to poor wiring and faulty electrical equipment, leakage
of cooking gas or a carelessly thrown matchstick. One such incident was the
Uphaar cinema hall tragedy in New Delhi on 13 July 1997.
Question 9.
Give an example of the intentional nuclear disaster and unintentional nuclear
disaster.
Answer:
An example of intentional nuclear disaster is the attacks carried out on
Hiroshima and Nagasaki cities in Japan by the United States during World War
II. An example of unintentional nuclear disaster is an accidental explosion at
a nuclear plant in Chernobyl in the former USSR in 1986 which caused radiation
to spread across Ukraine and other regions. As many as 12,000 Ukrainians died
in the chernobyl disaster.
Question 10.
Give an example of a chemical disaster.
Answer:
The Bhopal Gas Tragedy in Madhya Pradesh in 1984 is considered the world’s
worst industrial disaster. It was caused by the accidental leakage of a highly
toxic gas called methyl isocyanate from the Union Carbide factory. It left
2,500 people dead and its effects continue to harm the future generations.
Question 11.
What are biological disasters ?
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 system through a cut or wound, they can infect
him. Example — Even a few drops of the smallpox or plague virus could start an
epidemic, killing thousands of people.
Question 12.
How and why are terror attacks carried out ? Give examples.
Answer:
Terror attacks occur in the form of a terror strike through the use of
explosives, guns or chemical and biological weapons. Terrorists also hijack
planes and destroy public infrastructure such as railway track and bridges to
cause massive devastation. Most of the attacks are brought about by misdirected
elements who think that social, political or religious goals can be achieved by
killing people.
For example :
1. The attack on the
World Trade Center in the US on 11 September 2001, when terrorists hijacked
planes to spread terror, resulting in nearly 3000 deaths.
2. The terror attack on
Parliament in India on 13 December 2001.
3. The Mumbai attacks on
26 November 2008.
Question 13.
Name the world’s worst industrial disaster.
Answer:
The Bhopal Gas Tragedy.
Question 14.
What causes travel-related disasters ?
Answer:
Accidents during train, road and flight journeys are common. It becomes a
disaster when a large number of people die. Most of such incidents occur due to
equipment failure, loss of radar transmission in planes, or failure of brakes
in buses, human error. Example : driver falling asleep while driving or missing
a railway signal, fuel leakage or natural phenomenon like earthquake, storms or
landslide.
Question 15.
How do oil spills occur ? What are its effect ?
Answer:
Oil spills occur when large quantities of oil are discharged into oceans or
seas during drilling operations, cleaning of tankers and leaks from pipelines
and storage tanks, an accident or explosion on a tanker or an offshore drilling
rig. Most cases of oil spills are almost always a severe case of man-made
disaster as they cause long term damage to the ocean and its marine life.
Effects — Some of the chemicals from the oil kill many forms of marine life and
coral reefs. Other chemicals leave a residue black layer on the feathers of
birds and the fur of mammals, causing them to die or drown. If an oil reaches
the coast, it destroys fishing and tourism.
Question 16.
Which disaster is considered to be one of the worst spills to have happened in
recent times ? Elaborate.
Answer:
The offshore Macondo oil rig called Deepwater Horizon had an explosion and
tragically killed 11 workers besides injuring 16 more. Also known as the BP oil
spill (since it was owned by British Petroleum), it is considered the largest
spill in the history of the petroleum industry. An estimated 4.9 million
barrels of oil was discharged into the water. The spill resulted in severe
environmental, health and economic consequences. There was extensive damage to
marine wildlife, fishing and tourism industries were adversely affected. The
long term effects could be felt till 2013 and dolphins and other marine life
continued to die in record numbers.
Question 17.
Name two state of India where floods cause massive damages every year.
Answer:
Assam and Bihar.
Question 18.
Name two wildlife sanctuaries of Assam.
Answer:
The Kaziranga National Park and the Pobitora Wildlife Sanctuary.
Question 19.
Define —
1. Avalanche
2. Tsunami
3. Epidemic
4. Storm surge
5. Water table
Answer:
1. Avalanche — It is a fall or
slide of a large mass as of snow or rock, down a mountain side.
2. Tsunami — It is a long,
high sea wave caused by an undersea earthquake or other disturbance.
3. Epidemic — It is an outbreak of a
contagious disease that spreads rapidly and widely.
4. Storm surge — It is an
abnormal rise in the level of the sea along a coast caused by the onshore winds
of a severe cyclone.
5. Water table — It is the level below
which the ground is saturated with water.
20. Fill in the blanks
1. Disasters are incidents
that cause significant damage or destruction to life and property.
2. While most disasters
happen suddenly like earthquake, nuclear explosion, others like droughts may
have a slow beginning and later increase in extent and intensity.
3. Disasters affect
people living in underdeveloped countries more adversely.
4. Earthquakes usually
occur without warning.
5. An earthquake is
a sudden violent movement of a portion of the earth’s crust.
6. Floods are mostly
caused due to the overflowing of rivers in the monsoon.
7. About 30 per
cent of the land area in India is drought-prone.
8. Droughts lead to acute
shortage of water and crop failure.
9. Unintentional nuclear
disasters mostly occur due to accidents in nuclear power reactors.
10. The Bhopal Gas tragedy
is an incident of chemical disaster.
11. The terror attack on
Parliament of India took place on 13 December 2001.
12. Nepal lies on the
fault called Thrust Fault.
13. Deep water horizon explosion is the
largest oil spill in the history of petroleum industry.
14. Heavy rainfall in
Assam causes the Brahmaputra river and its tributaries to
overflow.
15. Bihar is the most
flood-prone region amongst the great northern plains of India with almost 73 per
cent of the state affected by floods.
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