The document discusses various natural disasters including earthquakes, tsunamis, floods, droughts, and cyclones. It defines each disaster and describes their causes and effects. For each disaster, it provides examples of past events that caused significant damage and loss of life in India. It also lists precautionary measures that can be taken to reduce risks and prepare for disasters. Key points covered include the definition of an earthquake and tsunami, cyclones developing due to low pressure systems, floods occurring when rivers overflow, drought prone areas of India, and the devastating impact of past events like the 2001 Gujarat earthquake and 1990 Andhra Pradesh cyclone.

2. What is a disaster?
Ans. Any natural hazard which causes loss of life
and property is called a disaster.
 How can a hazard cannot become a disaster?
Ans. If we can take some precautionary
measures, the loss of life and property reduces.
Thus the hazard cannot become a disaster.
 Why is nature one of the biggest source of
destruction?
Ans. It is due to natural hazards like
earthquakes, tsunamis, floods, droughts, cyclone
s.


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Sudden movements under the earth’s crust is called
an earth quake.
An earthquake is caused by sudden movements which
cause vibrations called seismic waves. The study of
earthquakes are called are called seismology. The
scientists who study it are called seismologists.
The place of origin of an earthquake is called focus.
The place which is directly above the focus on the
surface of the earth is called epicentre.
The occurrence of an earthquake is detected by an
instrument called seismograph.
The intensity of an earthquake is measured with the
help of an instrument known as the Richter Scale.

4.  Violent
earthquakes are often very
destructive. They cause serious damage to
life and property. More than 20,000 people
died, over 15 lakh were injured, and about 8
lakh houses were destroyed in a powerful
earthquake in Gujarat on 26 January 2001.
 The Himalayan region in the northern part of
India is earthquake prone.

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Leave your home or school building and move to
an open area.
Learn the basic first aid functions.
Do not stay near
windows, bookcases, mirrors, hanging pots and
fans during or immediately after an earthquake.
If trapped in a building remain close to an
interior wall and protect your head with your
arms. Avoid using a lift.
If outdoors, keep away from
trees, signboards, buildings, poles and electric
wires.
Do not sit inside a car or a bus.
If you are inside a theatre hall, stadium or
auditorium, do not panic. Stay inside.

7.  The
circulatory winds which rotates inward
in the lower parts of an atmosphere is called
a cyclone.
 A cyclone develops when a low pressure area
is surrounded by high pressure.
 The tropical cyclones which originate in the
Bay of Bengal can reach inland. The areas
which are prone to cyclones in India are West
Bengal, Orissa, Andhra Pradesh, Tamil
Nadu, and coastal areas of Gujarat and
Maharashtra.

8. The winds blows towards the centre at a very
high speed and are destructive in nature. These
winds are accompanied by heavy rains and are
often disastrous.
 The coastal areas in Andhra Pradesh were hit by
a cyclone storm in May 1990. the speed of the
winds was about 250 km per hour. The cyclone
affected about 6,000 villages in the coastal
areas. It killed about 1,000 persons and about
25,000 cattle. About 12 lakh houses were fully or
partially destroyed. The total loss was estimated
to be worth several hundred crore rupees. This
included the destruction of crops.


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Listen regularly to weather bulletins on
television and radio.
Keep an emergency kit ready at home.
Secure your home or move to a safer place
before the cyclone hits your area.
Store enough non-perishable food articles in
waterproof bags.
Do not venture into the sea.
Keep phone numbers of hospitals, police, help
agencies, relatives and friends handy.
After the cyclone, check gas leaks and dry the
electrical appliances.
Avoid floodwater and be careful about snake
bites.

11.  Overflowing
of large amount of water beyond
its normal course is called a flood.
 The most common type of flood
occurs, when a river overflows its banks and
water spreads on the surrounding land. It can
be also caused due to : Blocking of river channel due to landslides.
 Strong tides and storms in the sea.
 Cyclones and tsunamis.
 Faulty design of embankments, canals or
dams.
 Deforestation

12.  India
has experienced more floods than any
other part of the world. The main season for
the occurrence of floods is the rainy season
between June and September. Floods are
more frequent in northern India than in
southern India. About one-eighth of the total
area of our country is estimated to be floodprone. Most of it is in the plains of northern
India.
 Floods can cause damage to life, property
and crops.

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Know the routes and locations of safe shelters.
Listen to the radio or watch television for warning and advice.
Keep the first-aid kit ready, especially for diarrhoea and snake
bites.
Keep strong ropes for tying things.
Keep a radio, torch, matchbox, candles and spare batteries.
Keep adequate stock of freshwater, food articles and kerosene.
Keep waterproof bags for packing food articles and clothes.
Keep bamboo sticks to ward off snakes.
Do not enter the flooded area of unknown depth.
Switch off power and electrical appliances.
Drink only boiled water and eat only fresh cooked food.
Take help from disaster management teams and other agencies.

15.  Extreme
shortage of water in a region is
called drought.
 The drought-prone areas of India are
Rajasthan, Gujarat, western
Orissa, Rayalaseema and Telengana in Andhra
Pradesh, Chhattisgarh, Jharkhand, central
Maharashtra, interior Karnataka, West
Bengal, Tamil Nadu, Punjab, Haryana, Bihar
and Uttar Pradesh.

16. It affects human beings, animals, and
agricultural production. The drought-prone areas
are those that experience low and variable
rainfall.
 More than 70 per cent of the total cultivable
land in India is drought-prone. These areas
receive low and highly unreliable rainfall and
have inadequate irrigate facilities.
 Drought still occur at frequent intervals.
However, its capacity to kill large number of
people and animals has now been reduced due to
better drought management, and development
of irrigation and transport facilities.
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17. Learn to harvest and conserve water at
home.
 Develop rainwater harvesting systems.
 Promote drip irrigation.
 Increase forest cover through plantations.
 Encourage crop insurance schemes.
 Plant drought resistant crops.
 The best way to fight the menace of drought
on the agricultural front is to provide proper
irrigational facilities.
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19. The displacement of large mass of water is
called tsunami.
 This can be caused by an undersea earthquake or
a volcanic eruption. When an undersea
earthquake occurs it causes large areas of the
seafloor to rise or subside. This leads to the
occurrence of huge waves.
 Tsunami travels at a high speed of about 500 to
1,000 km per hour. However, its speed reduces
when it enters shallow coastal waters and its
height increases. When the tsunami reaches the
coast, it appears as a wall of water.


20.  With
its tremendous energy, the fast moving
wave can crush houses and other structures
in the coastal areas. Large objects such as
ships can be pushed several kilometres
inland.
 Tsunami causes great loss of life and
property. Most of the deaths caused by a
tsunami are due to drowning. Although
tsunamis are not frequent, they can occur at
any time of the year.

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If you experience an earthquake that lasts for about 20 seconds
or longer when you happen to be in a coastal area, move to
higher ground immediately after the shaking stops.
In some cases, the sea water may recede upto 800m from the
coast. Do not enter this temporary dry area, as the sea water
may come back soon.
Know the height of your street above sea level and distance from
the coast. The areas of great risk are less than 10m above sea
level and within 2km from the coast.
Prepare a plan of the evacuation route from your house, school
or workshop and find an area about 30m above sea level. You
should be able to reach a safe location in 15 minutes.
The tsunami warning systems should be installed in high-risk
zones.
If you are visiting a place in high risk zone, check with the hotel
or tour operators about tsunami evacuation information, and how
you would be warned about it.
Discuss tsunami with your family as this will help reduce the fear
and anxiety associated with it.

23. Done
By
A.Basheer