NCERT Textbook - Natural Hazards and Disasters | Geography for UPSC CSE PDF Download

 Page 1


NATURAL HAZARDS AND DISASTERS:
CAUSES, CONSEQUENCES AND MANAGEMENT
This unit deals with
• Floods and droughts
• Earthquakes and tsunami
• Cyclones
• Landslides
UNIT
IV
Reprint 2025-26
Page 2


NATURAL HAZARDS AND DISASTERS:
CAUSES, CONSEQUENCES AND MANAGEMENT
This unit deals with
• Floods and droughts
• Earthquakes and tsunami
• Cyclones
• Landslides
UNIT
IV
Reprint 2025-26
Y
ou might have read about tsunami or
seen the images of horror on
television set immediately after it
happened. You may also be aware of the severe
earthquake in Kashmir on both sides of the
Line of Control (LOC). The damage caused to
human life and properties during these
episodes has moved us all. What are these as
phenomena and how they are caused? How
can we save ourselves? These are some
questions which come to our minds. This
chapter will attempt to analyse some of these
questions.
Change is the law of nature. It is a continuous
process that goes on uninterruptedly involving
phenomena, big and small, material and non-
material that make our physical and socio-
cultural environment. It is a process present
everywhere with variations in terms of
magnitude, intensity and scale. Change can be
a gradual or slow process like the evolution of
landforms and organisms and it can be as
sudden and swift as volcanic eruptions,
tsunamis, earthquakes and lightening, etc.
Similarly, it may remain confined to a smaller
area occurring within a few seconds like
hailstorms, tornadoes and dust storms, and it
can also have global dimensions such as global
warming and depletion of the ozone layer.
Besides these, changes have different
meanings for different people. It depends upon
the perspective one takes while trying to
understand them. From the perspective of
nature, changes are value-neutral (these are
neither good nor bad). But from the human
perspective, these are value-loaded. There are
some changes that are desirable and good like
the change of seasons, ripening of fruits, while
there are others like earthquakes, floods and
wars that are considered bad and undesirable.
Observe the environment you live in and
prepare a list of changes, which take
place over a long period of time and
those, which take place within a short
period of time. Do you know why some
changes are considered good and others
bad? Prepare a list of changes, which
you notice in your daily life and give
reasons why some of these are
considered good and others bad.
In this chapter, we will read about some of
these changes, which are considered bad and
have haunted humankind for a long time.
Disasters in general and natural disasters
in particular, are some such changes that are
always disliked and feared by humankind.
What is a Disaster?
“Disaster is an undesirable occurrence
resulting from forces that are largely
outside human control, strikes quickly
with little or no warning, which causes
or threatens serious disruption of life
and property including death and injury
to a large number of people, and requires
therefore, mobilisation of efforts in excess
of that which are normally provided by
statutory emergency services”.
For a long time, geographical literature
viewed disasters as a consequence of natural
forces; and human beings were treated as
innocent and helpless victims in front of the
mighty forces of nature.  But natural forces are
NATURAL HAZARDS AND DISASTERS
CHAPTER
Reprint 2025-26
Page 3


NATURAL HAZARDS AND DISASTERS:
CAUSES, CONSEQUENCES AND MANAGEMENT
This unit deals with
• Floods and droughts
• Earthquakes and tsunami
• Cyclones
• Landslides
UNIT
IV
Reprint 2025-26
Y
ou might have read about tsunami or
seen the images of horror on
television set immediately after it
happened. You may also be aware of the severe
earthquake in Kashmir on both sides of the
Line of Control (LOC). The damage caused to
human life and properties during these
episodes has moved us all. What are these as
phenomena and how they are caused? How
can we save ourselves? These are some
questions which come to our minds. This
chapter will attempt to analyse some of these
questions.
Change is the law of nature. It is a continuous
process that goes on uninterruptedly involving
phenomena, big and small, material and non-
material that make our physical and socio-
cultural environment. It is a process present
everywhere with variations in terms of
magnitude, intensity and scale. Change can be
a gradual or slow process like the evolution of
landforms and organisms and it can be as
sudden and swift as volcanic eruptions,
tsunamis, earthquakes and lightening, etc.
Similarly, it may remain confined to a smaller
area occurring within a few seconds like
hailstorms, tornadoes and dust storms, and it
can also have global dimensions such as global
warming and depletion of the ozone layer.
Besides these, changes have different
meanings for different people. It depends upon
the perspective one takes while trying to
understand them. From the perspective of
nature, changes are value-neutral (these are
neither good nor bad). But from the human
perspective, these are value-loaded. There are
some changes that are desirable and good like
the change of seasons, ripening of fruits, while
there are others like earthquakes, floods and
wars that are considered bad and undesirable.
Observe the environment you live in and
prepare a list of changes, which take
place over a long period of time and
those, which take place within a short
period of time. Do you know why some
changes are considered good and others
bad? Prepare a list of changes, which
you notice in your daily life and give
reasons why some of these are
considered good and others bad.
In this chapter, we will read about some of
these changes, which are considered bad and
have haunted humankind for a long time.
Disasters in general and natural disasters
in particular, are some such changes that are
always disliked and feared by humankind.
What is a Disaster?
“Disaster is an undesirable occurrence
resulting from forces that are largely
outside human control, strikes quickly
with little or no warning, which causes
or threatens serious disruption of life
and property including death and injury
to a large number of people, and requires
therefore, mobilisation of efforts in excess
of that which are normally provided by
statutory emergency services”.
For a long time, geographical literature
viewed disasters as a consequence of natural
forces; and human beings were treated as
innocent and helpless victims in front of the
mighty forces of nature.  But natural forces are
NATURAL HAZARDS AND DISASTERS
CHAPTER
Reprint 2025-26
54 INDIA : PHYSICAL ENVIRONMENT
not the only causes of disasters. Disasters
are also caused by some human activities.
There are some activities carried by human
beings that are directly responsible for
disasters. Bhopal Gas tragedy, Chernobyl
nuclear disaster, wars, release of CFCs
(Chlorofluorocarbons) and increase of green
house gases, environmental pollutions like
noise, air , water and soil are some of the disasters
which are caused directly by human actions.
There are some other activities of human
beings that accelerate or intensify disasters
indirectly. Landslides and floods due to
deforestation, unscientific land use and
construction activities in fragile areas are some
of the disasters that are the results of indirect
human actions. Can you identify some other
human activities going on in and around your
neighbourhood and schools that can lead to
disasters in the near future? Can you suggest
some measures to prevent it? It is a common
experience that human-made disasters have
increased both in their numbers and
magnitudes over the years and concerted
efforts are on at various levels to prevent and
minimise their occurrences. Though the
success has been only nominal so far, it is
possible to prevent some of these disasters
created by human actions. As opposed to
this, very little is possible to prevent natural
disasters; therefore, the best way out is to
emphasise on natural disaster mitigation and
management. Establishment of National
Institute of Disaster Management, India,
Earth Summit at Rio de Janeiro, Brazil, 1993
and the World Conference on Disaster
Management in May 1994 at Yokohama,
Japan, etc. are some of the concrete steps
towards this direction initiated at different
levels.
Most often it is observed that scholars use
disasters and natural hazards as interchangeable.
Both are related phenomena, yet quite distinct
from each other. Hence, it is necessary to
distinguish between the two.
Natural Hazards are elements of
circumstances in the Natural environment that
have the potential to cause harm to people or
property or both. These may be swift or
permanent aspects of the respective
environmental settings like currents in the
oceans, steep slope and unstable structural
features in the Himalayas or extreme climatic
conditions in deserts or glaciated areas.
As compared to natural hazards, natural
disasters are relatively sudden and cause
large scale, widespread death, loss of
property and disturbance to social systems
and life over which people have a little or no
control. Thus, any event can be classed as
disaster when the magnitude of destruction
and damage caused by it is very high.
Generally, disasters are generalised
experiences of people the world over, and no
two disasters are similar and comparable to
each other . Every disaster is unique in terms
of the local socio-environmental factors that
control it, the social response it generates, and
the way each social group negotiates with it.
However, the opinion mentioned above is
indicative of three important things. Firstly, the
magnitude, intensity, frequency and damages
caused by natural disasters have increased
over the years. Secondly, there is a growing
concern among people the world over to deal
with the menace created by these so that the
loss of human life and property can be
minimised. And finally, significant changes
have taken place in the pattern of natural
disasters over the years.
There has also been a change in the
perception of natural disasters and hazards.
Previously, hazards and disasters were seen
as two closely associated and interrelated
phenomena, i.e. areas prone to natural
hazards, were more vulnerable to disasters.
Hence, people avoided tampering with the
delicate balance that existed in a given
ecosystem. People avoided intensification of
their activities in such areas and that is how
disasters were less damaging. Technological
power has given large capacity to human
intervention in nature. Consequently, now,
human beings tend to intensify their activities
into disaster prone areas increasing their
vulnerability to disasters.   Colonisation
of flood plains of most of the rivers and
development of large cities and port-towns like
– Mumbai and Chennai along the coast, and
touching the shore due to high land values,
make them vulnerable to the occurrence of
cyclones, hurricanes and tsunamis.
Natural disasters have caused
widespread loss of life and property.
Reprint 2025-26
Page 4


NATURAL HAZARDS AND DISASTERS:
CAUSES, CONSEQUENCES AND MANAGEMENT
This unit deals with
• Floods and droughts
• Earthquakes and tsunami
• Cyclones
• Landslides
UNIT
IV
Reprint 2025-26
Y
ou might have read about tsunami or
seen the images of horror on
television set immediately after it
happened. You may also be aware of the severe
earthquake in Kashmir on both sides of the
Line of Control (LOC). The damage caused to
human life and properties during these
episodes has moved us all. What are these as
phenomena and how they are caused? How
can we save ourselves? These are some
questions which come to our minds. This
chapter will attempt to analyse some of these
questions.
Change is the law of nature. It is a continuous
process that goes on uninterruptedly involving
phenomena, big and small, material and non-
material that make our physical and socio-
cultural environment. It is a process present
everywhere with variations in terms of
magnitude, intensity and scale. Change can be
a gradual or slow process like the evolution of
landforms and organisms and it can be as
sudden and swift as volcanic eruptions,
tsunamis, earthquakes and lightening, etc.
Similarly, it may remain confined to a smaller
area occurring within a few seconds like
hailstorms, tornadoes and dust storms, and it
can also have global dimensions such as global
warming and depletion of the ozone layer.
Besides these, changes have different
meanings for different people. It depends upon
the perspective one takes while trying to
understand them. From the perspective of
nature, changes are value-neutral (these are
neither good nor bad). But from the human
perspective, these are value-loaded. There are
some changes that are desirable and good like
the change of seasons, ripening of fruits, while
there are others like earthquakes, floods and
wars that are considered bad and undesirable.
Observe the environment you live in and
prepare a list of changes, which take
place over a long period of time and
those, which take place within a short
period of time. Do you know why some
changes are considered good and others
bad? Prepare a list of changes, which
you notice in your daily life and give
reasons why some of these are
considered good and others bad.
In this chapter, we will read about some of
these changes, which are considered bad and
have haunted humankind for a long time.
Disasters in general and natural disasters
in particular, are some such changes that are
always disliked and feared by humankind.
What is a Disaster?
“Disaster is an undesirable occurrence
resulting from forces that are largely
outside human control, strikes quickly
with little or no warning, which causes
or threatens serious disruption of life
and property including death and injury
to a large number of people, and requires
therefore, mobilisation of efforts in excess
of that which are normally provided by
statutory emergency services”.
For a long time, geographical literature
viewed disasters as a consequence of natural
forces; and human beings were treated as
innocent and helpless victims in front of the
mighty forces of nature.  But natural forces are
NATURAL HAZARDS AND DISASTERS
CHAPTER
Reprint 2025-26
54 INDIA : PHYSICAL ENVIRONMENT
not the only causes of disasters. Disasters
are also caused by some human activities.
There are some activities carried by human
beings that are directly responsible for
disasters. Bhopal Gas tragedy, Chernobyl
nuclear disaster, wars, release of CFCs
(Chlorofluorocarbons) and increase of green
house gases, environmental pollutions like
noise, air , water and soil are some of the disasters
which are caused directly by human actions.
There are some other activities of human
beings that accelerate or intensify disasters
indirectly. Landslides and floods due to
deforestation, unscientific land use and
construction activities in fragile areas are some
of the disasters that are the results of indirect
human actions. Can you identify some other
human activities going on in and around your
neighbourhood and schools that can lead to
disasters in the near future? Can you suggest
some measures to prevent it? It is a common
experience that human-made disasters have
increased both in their numbers and
magnitudes over the years and concerted
efforts are on at various levels to prevent and
minimise their occurrences. Though the
success has been only nominal so far, it is
possible to prevent some of these disasters
created by human actions. As opposed to
this, very little is possible to prevent natural
disasters; therefore, the best way out is to
emphasise on natural disaster mitigation and
management. Establishment of National
Institute of Disaster Management, India,
Earth Summit at Rio de Janeiro, Brazil, 1993
and the World Conference on Disaster
Management in May 1994 at Yokohama,
Japan, etc. are some of the concrete steps
towards this direction initiated at different
levels.
Most often it is observed that scholars use
disasters and natural hazards as interchangeable.
Both are related phenomena, yet quite distinct
from each other. Hence, it is necessary to
distinguish between the two.
Natural Hazards are elements of
circumstances in the Natural environment that
have the potential to cause harm to people or
property or both. These may be swift or
permanent aspects of the respective
environmental settings like currents in the
oceans, steep slope and unstable structural
features in the Himalayas or extreme climatic
conditions in deserts or glaciated areas.
As compared to natural hazards, natural
disasters are relatively sudden and cause
large scale, widespread death, loss of
property and disturbance to social systems
and life over which people have a little or no
control. Thus, any event can be classed as
disaster when the magnitude of destruction
and damage caused by it is very high.
Generally, disasters are generalised
experiences of people the world over, and no
two disasters are similar and comparable to
each other . Every disaster is unique in terms
of the local socio-environmental factors that
control it, the social response it generates, and
the way each social group negotiates with it.
However, the opinion mentioned above is
indicative of three important things. Firstly, the
magnitude, intensity, frequency and damages
caused by natural disasters have increased
over the years. Secondly, there is a growing
concern among people the world over to deal
with the menace created by these so that the
loss of human life and property can be
minimised. And finally, significant changes
have taken place in the pattern of natural
disasters over the years.
There has also been a change in the
perception of natural disasters and hazards.
Previously, hazards and disasters were seen
as two closely associated and interrelated
phenomena, i.e. areas prone to natural
hazards, were more vulnerable to disasters.
Hence, people avoided tampering with the
delicate balance that existed in a given
ecosystem. People avoided intensification of
their activities in such areas and that is how
disasters were less damaging. Technological
power has given large capacity to human
intervention in nature. Consequently, now,
human beings tend to intensify their activities
into disaster prone areas increasing their
vulnerability to disasters.   Colonisation
of flood plains of most of the rivers and
development of large cities and port-towns like
– Mumbai and Chennai along the coast, and
touching the shore due to high land values,
make them vulnerable to the occurrence of
cyclones, hurricanes and tsunamis.
Natural disasters have caused
widespread loss of life and property.
Reprint 2025-26
55 NATURAL HAZARDS AND DISASTERS
Concerted efforts are on at various levels to
take appropriate measures to deal with the
situation. It is also being felt that the
damages caused by natural disasters have
global repercussions that are beyond the
means and capabilities of individual nation-
states to cope up with. Hence, this issue
was raised at the U.N. General Assembly in
1989 and it was finally formalised at the
World Conference on Disaster Management
in May 1994 at Yokohama, Japan.  This
was subsequently called the Yokohama
Strategy and Plan of Action for a Safer World.
CLASSIFICATION OF NATURAL DISASTERS
Human beings the world over have
experienced disasters and have faced and lived
with them. Now people are becoming aware
and various steps have been initiated at
different levels for mitigating the effects of
disasters. Identification and classification of
disasters is being considered as an effective and
scientific step to deal promptly and efficiently
with the disasters. Broadly, natural
disasters can be classified under four
categories (See Table 6.1).
India is one of those countries which has
experienced most of the natural disasters
mentioned in Table 6.1. Every year it loses
thousands of lives and property worth millions
of rupees due to these natural calamities. In
the following section, some of the highly
devastating natural disasters have been
discussed, particularly in the context of India.
NATURAL DISASTERS AND HAZARDS IN INDIA
It was discussed in one of the previous
chapters that India is vast and diverse in terms
of its physical and socio-cultural attributes.
It is largely due to its vast geographical area,
environmental diversities and cultural
pluralities that scholars often described it
using two meaningful adjectives like the
‘Indian-subcontinent’ and the ‘land of unity
in diversity’. Its vastness in terms of natural
attributes combined with its prolonged colonial
past, continuing various forms of social
discriminations and also equally large
population have enhanced its vulnerability to
natural disasters. These observations can also
be illustrated by focussing on some of the
major natural disasters in India.
Earthquakes
Earthquakes are by far the most unpredictable
and highly destructive of all the natural
disasters. Y ou have already learnt the causes
of earthquakes in your book Fundamentals
of Physical Geography (NCERT, 2006).
Earthquakes that are of tectonic origin have
proved to be the most devastating and their
area of influence is also quite large.  These
earthquakes result from a series of earth
movements brought about by a sudden
release of energy during the tectonic activities
in the earth’s crust. As compared to these,
the earthquakes associated with volcanic
eruption, rock fall, landslides, subsidence,
particularly in the mining areas, impounding
of dams and reservoirs, etc. have limited  area
of influence and the scale of damage.
It was mentioned in Chapter 2 of the book
that the Indian plate is moving at a speed of
one centimetre per year towards the north
and northeastern direction and this
movement of plates is being constantly
obstructed by the Eurasian plate from the
north. As a result of this, both the plates are
Figure 6.1 : A Damaged Building
Due to an Earthquake
Table 6.1 : Classification of Natural Disasters
Blizzards
Thunderstorms
Lightening
Tornadoes
Tropical Cyclone
Drought
Hailstorm
Frost, Heat
Wave or Loo,
Cold Wave etc
Atmospheric        Terrestrial          Aquatc        Biological
Earthquakes
Volcanic Eruptions
Landslides
Avalanches
Subsidence
Soil Erosion
Floods
Tidal Waves
Storm Surge
Tsunami
Plants and
Animals as
colonisers
(Locusts etc),
Insect’s
infestation –
fungal, bacterial
and viral
diseases such
as bird flu,
dengue etc.
Reprint 2025-26
Page 5


NATURAL HAZARDS AND DISASTERS:
CAUSES, CONSEQUENCES AND MANAGEMENT
This unit deals with
• Floods and droughts
• Earthquakes and tsunami
• Cyclones
• Landslides
UNIT
IV
Reprint 2025-26
Y
ou might have read about tsunami or
seen the images of horror on
television set immediately after it
happened. You may also be aware of the severe
earthquake in Kashmir on both sides of the
Line of Control (LOC). The damage caused to
human life and properties during these
episodes has moved us all. What are these as
phenomena and how they are caused? How
can we save ourselves? These are some
questions which come to our minds. This
chapter will attempt to analyse some of these
questions.
Change is the law of nature. It is a continuous
process that goes on uninterruptedly involving
phenomena, big and small, material and non-
material that make our physical and socio-
cultural environment. It is a process present
everywhere with variations in terms of
magnitude, intensity and scale. Change can be
a gradual or slow process like the evolution of
landforms and organisms and it can be as
sudden and swift as volcanic eruptions,
tsunamis, earthquakes and lightening, etc.
Similarly, it may remain confined to a smaller
area occurring within a few seconds like
hailstorms, tornadoes and dust storms, and it
can also have global dimensions such as global
warming and depletion of the ozone layer.
Besides these, changes have different
meanings for different people. It depends upon
the perspective one takes while trying to
understand them. From the perspective of
nature, changes are value-neutral (these are
neither good nor bad). But from the human
perspective, these are value-loaded. There are
some changes that are desirable and good like
the change of seasons, ripening of fruits, while
there are others like earthquakes, floods and
wars that are considered bad and undesirable.
Observe the environment you live in and
prepare a list of changes, which take
place over a long period of time and
those, which take place within a short
period of time. Do you know why some
changes are considered good and others
bad? Prepare a list of changes, which
you notice in your daily life and give
reasons why some of these are
considered good and others bad.
In this chapter, we will read about some of
these changes, which are considered bad and
have haunted humankind for a long time.
Disasters in general and natural disasters
in particular, are some such changes that are
always disliked and feared by humankind.
What is a Disaster?
“Disaster is an undesirable occurrence
resulting from forces that are largely
outside human control, strikes quickly
with little or no warning, which causes
or threatens serious disruption of life
and property including death and injury
to a large number of people, and requires
therefore, mobilisation of efforts in excess
of that which are normally provided by
statutory emergency services”.
For a long time, geographical literature
viewed disasters as a consequence of natural
forces; and human beings were treated as
innocent and helpless victims in front of the
mighty forces of nature.  But natural forces are
NATURAL HAZARDS AND DISASTERS
CHAPTER
Reprint 2025-26
54 INDIA : PHYSICAL ENVIRONMENT
not the only causes of disasters. Disasters
are also caused by some human activities.
There are some activities carried by human
beings that are directly responsible for
disasters. Bhopal Gas tragedy, Chernobyl
nuclear disaster, wars, release of CFCs
(Chlorofluorocarbons) and increase of green
house gases, environmental pollutions like
noise, air , water and soil are some of the disasters
which are caused directly by human actions.
There are some other activities of human
beings that accelerate or intensify disasters
indirectly. Landslides and floods due to
deforestation, unscientific land use and
construction activities in fragile areas are some
of the disasters that are the results of indirect
human actions. Can you identify some other
human activities going on in and around your
neighbourhood and schools that can lead to
disasters in the near future? Can you suggest
some measures to prevent it? It is a common
experience that human-made disasters have
increased both in their numbers and
magnitudes over the years and concerted
efforts are on at various levels to prevent and
minimise their occurrences. Though the
success has been only nominal so far, it is
possible to prevent some of these disasters
created by human actions. As opposed to
this, very little is possible to prevent natural
disasters; therefore, the best way out is to
emphasise on natural disaster mitigation and
management. Establishment of National
Institute of Disaster Management, India,
Earth Summit at Rio de Janeiro, Brazil, 1993
and the World Conference on Disaster
Management in May 1994 at Yokohama,
Japan, etc. are some of the concrete steps
towards this direction initiated at different
levels.
Most often it is observed that scholars use
disasters and natural hazards as interchangeable.
Both are related phenomena, yet quite distinct
from each other. Hence, it is necessary to
distinguish between the two.
Natural Hazards are elements of
circumstances in the Natural environment that
have the potential to cause harm to people or
property or both. These may be swift or
permanent aspects of the respective
environmental settings like currents in the
oceans, steep slope and unstable structural
features in the Himalayas or extreme climatic
conditions in deserts or glaciated areas.
As compared to natural hazards, natural
disasters are relatively sudden and cause
large scale, widespread death, loss of
property and disturbance to social systems
and life over which people have a little or no
control. Thus, any event can be classed as
disaster when the magnitude of destruction
and damage caused by it is very high.
Generally, disasters are generalised
experiences of people the world over, and no
two disasters are similar and comparable to
each other . Every disaster is unique in terms
of the local socio-environmental factors that
control it, the social response it generates, and
the way each social group negotiates with it.
However, the opinion mentioned above is
indicative of three important things. Firstly, the
magnitude, intensity, frequency and damages
caused by natural disasters have increased
over the years. Secondly, there is a growing
concern among people the world over to deal
with the menace created by these so that the
loss of human life and property can be
minimised. And finally, significant changes
have taken place in the pattern of natural
disasters over the years.
There has also been a change in the
perception of natural disasters and hazards.
Previously, hazards and disasters were seen
as two closely associated and interrelated
phenomena, i.e. areas prone to natural
hazards, were more vulnerable to disasters.
Hence, people avoided tampering with the
delicate balance that existed in a given
ecosystem. People avoided intensification of
their activities in such areas and that is how
disasters were less damaging. Technological
power has given large capacity to human
intervention in nature. Consequently, now,
human beings tend to intensify their activities
into disaster prone areas increasing their
vulnerability to disasters.   Colonisation
of flood plains of most of the rivers and
development of large cities and port-towns like
– Mumbai and Chennai along the coast, and
touching the shore due to high land values,
make them vulnerable to the occurrence of
cyclones, hurricanes and tsunamis.
Natural disasters have caused
widespread loss of life and property.
Reprint 2025-26
55 NATURAL HAZARDS AND DISASTERS
Concerted efforts are on at various levels to
take appropriate measures to deal with the
situation. It is also being felt that the
damages caused by natural disasters have
global repercussions that are beyond the
means and capabilities of individual nation-
states to cope up with. Hence, this issue
was raised at the U.N. General Assembly in
1989 and it was finally formalised at the
World Conference on Disaster Management
in May 1994 at Yokohama, Japan.  This
was subsequently called the Yokohama
Strategy and Plan of Action for a Safer World.
CLASSIFICATION OF NATURAL DISASTERS
Human beings the world over have
experienced disasters and have faced and lived
with them. Now people are becoming aware
and various steps have been initiated at
different levels for mitigating the effects of
disasters. Identification and classification of
disasters is being considered as an effective and
scientific step to deal promptly and efficiently
with the disasters. Broadly, natural
disasters can be classified under four
categories (See Table 6.1).
India is one of those countries which has
experienced most of the natural disasters
mentioned in Table 6.1. Every year it loses
thousands of lives and property worth millions
of rupees due to these natural calamities. In
the following section, some of the highly
devastating natural disasters have been
discussed, particularly in the context of India.
NATURAL DISASTERS AND HAZARDS IN INDIA
It was discussed in one of the previous
chapters that India is vast and diverse in terms
of its physical and socio-cultural attributes.
It is largely due to its vast geographical area,
environmental diversities and cultural
pluralities that scholars often described it
using two meaningful adjectives like the
‘Indian-subcontinent’ and the ‘land of unity
in diversity’. Its vastness in terms of natural
attributes combined with its prolonged colonial
past, continuing various forms of social
discriminations and also equally large
population have enhanced its vulnerability to
natural disasters. These observations can also
be illustrated by focussing on some of the
major natural disasters in India.
Earthquakes
Earthquakes are by far the most unpredictable
and highly destructive of all the natural
disasters. Y ou have already learnt the causes
of earthquakes in your book Fundamentals
of Physical Geography (NCERT, 2006).
Earthquakes that are of tectonic origin have
proved to be the most devastating and their
area of influence is also quite large.  These
earthquakes result from a series of earth
movements brought about by a sudden
release of energy during the tectonic activities
in the earth’s crust. As compared to these,
the earthquakes associated with volcanic
eruption, rock fall, landslides, subsidence,
particularly in the mining areas, impounding
of dams and reservoirs, etc. have limited  area
of influence and the scale of damage.
It was mentioned in Chapter 2 of the book
that the Indian plate is moving at a speed of
one centimetre per year towards the north
and northeastern direction and this
movement of plates is being constantly
obstructed by the Eurasian plate from the
north. As a result of this, both the plates are
Figure 6.1 : A Damaged Building
Due to an Earthquake
Table 6.1 : Classification of Natural Disasters
Blizzards
Thunderstorms
Lightening
Tornadoes
Tropical Cyclone
Drought
Hailstorm
Frost, Heat
Wave or Loo,
Cold Wave etc
Atmospheric        Terrestrial          Aquatc        Biological
Earthquakes
Volcanic Eruptions
Landslides
Avalanches
Subsidence
Soil Erosion
Floods
Tidal Waves
Storm Surge
Tsunami
Plants and
Animals as
colonisers
(Locusts etc),
Insect’s
infestation –
fungal, bacterial
and viral
diseases such
as bird flu,
dengue etc.
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56 INDIA : PHYSICAL ENVIRONMENT
Yokohama Strategy and International Decade for Natural Disaster Reduction (IDNDR)
Yokohama Strategy and Plan of Action for a Safer World
All the member states of the United Nations and other states met at the World Conference
on Natural Disaster Reduction in the city of Yokohama from May 23rd-27th 1994. It
acknowledged that the impact of natural disasters in terms of human and economic losses
has risen in recent years, and society, in general, has become vulnerable to natural disasters.
It also accepted that these disasters affected the poor and disadvantageous groups the
worst, particularly in the developing countries, which are ill-equipped to cope with them.
Hence, the conference adopted the Yokohama strategy as a guide to rest of the decade and
beyond, to mitigate the losses due to these disasters.
The resolution of the World Conference on Natural Disasters Reduction is as mentioned below:
(i) It will note that each country has the sovereign responsibility to protect its citizens from
natural disasters;
(ii) It  will give priority attention to the developing countries, particularly the least developed,
land-locked countries and small-island developing states;
(iii) It will develop and strengthen national capacities and capabilities and, where appropriate,
national legislation for natural and other disaster prevention, mitigation and preparedness,
including the mobilisation of non-governmental organisations and participation of local
communities;
(iv) It will promote and strengthen sub-regional, regional and international cooperation in activities
to prevent, reduce and mitigate natural and other disasters, with particular emphasis on:
(a) human and institutional capacity-building and strengthening;
(b) technology sharing: the collection, the dissemination and utilisation of information; and
(c) mobilisation of resources.
It also declared the decade 1990-2000 as the International Decade for Natural Disaster
Reduction (IDNDR).
said to be locked with each other resulting in
accumulation of energy at different points of
time.  Excessive accumulation of energy results
in building up of stress, which ultimately leads
to the breaking up of the lock and the sudden
release of energy causes earthquakes along the
Himalayan arch. Some of the most vulnerable
union territories/states are Jammu and
Kashmir, Ladakh, Himachal Pradesh,
Uttarakhand, Sikkim, and the Darjeeling
subdivision of West Bengal, and all the seven
states of the northeast.
Apart from these regions, the central-western
parts of India, particularly Gujarat (in 1819,
1956 and 2001) and Maharashtra (in 1967 and
1993) have also experienced some severe
earthquakes. Earth scientists have found it
difficult to explain the occurrence of earthquakes
in one of the oldest, most stable and mature
landmass of Peninsular block for a long time.
Recently , some earth scientists have come up
with a theory of emergence of a fault line and
energy build-up along the fault line represented
by the river Bhima (Krishna) near Latur and
Osmanabad (Maharashtra) and the possible
breaking down of the Indian plate (Figure 6.2).
National Geophysical Laboratory, Geological
Survey of India, Department of Meteorology,
Government of India, along with the recently
formed National Institute of Disaster
Management, have made an intensive analysis
of more than 1,200 earthquakes that have
occurred in India in different years in the past,
and based on these, they divided India into the
following five earthquake zones:
(i) V ery high damage risk zone
(ii) High damage risk zone
(iii) Moderate damage risk zone
(iv) Low damage risk zone
(v) Very low damage risk zone.
Out of these, the first two zones had
experienced some of the most devastating
earthquakes in India. As shown in the Figure
6.2, areas vulnerable to these earthquakes
are the North-east states, areas to the north
of Darbhanga and  Araria along the Indo-
Nepal border in Bihar, Uttarakhand, Western
Himachal Pradesh (around Dharamshala)
and Kashmir Valley in the Himalayan region
and the Kuchchh (Gujarat). These are
included in the Very High Damage
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