Environmental Hazards and Environmental Disaster and Its Types

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Environmental Hazards and Environmental Disaster and Its Types
Disasters are as old as human history but the dramatic increase and the damage caused
by them in the recent past have become a cause of national and international concern. Over
the past decade, the number of natural and manmade disasters has climbed inexorably. From
1994 to 1998, reported disasters average was 428 per year but from 1999 to 2003, this figure
went up to an average of 707 disaster events per year showing an increase of about 60 per
cent over the previous years. The World Scenario showed the deadliest disasters of the
decade (1992 – 2001). Drought and famine (45%) have proved to be the deadliest disasters
globally, followed by flood (16%), technological disaster (14%), earthquake (12%),
windstorm(10%), extreme temperature and others(3%). Global economic loss related to
disaster events average around US $880 billion per year.
The scenario in India is no different from the global context. India is vulnerable, in
varying degrees, to a large number of natural as well as man-made disasters. 58.6 per cent of
the landmass is prone to earthquakes of moderate to very high intensity; over 40 million
hectares (12 per cent of land) is prone to floods and river erosion; of the 7,516 km long
coastline, close to 5,700 km is prone to cyclones and tsunamis; 68 per cent of the cultivable
area is vulnerable to drought and hilly areas are at risk from landslides and avalanches.
Vulnerability to disasters/ emergencies of Chemical, Biological, Radiological and Nuclear
(CBRN) origin also exists. Heightened vulnerabilities to disaster risks can be related to
expanding population, urbanization and industrialization, development within high-risk
zones, environmental degradation and climate change.
45%
16%
14%
12%
10% 3%
World Scenario (1992-2001)
Drought and Famine
Technological
disaster
Earthquake
Windstorm
Extreme
Temperature

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India due to its geo-climatic and socio-economic condition is prone to various
disasters. During the last thirty years’ time span the country has been hit by 431 major
disasters resulting into enormous loss to life and property. According to the Prevention Web
statistics, 1,43,039 people were killed and about 150crore were affected by various disasters
in the country during these three decades. The disasters caused huge loss to property and
other infrastructures costing more than US $ 4800crore.
The super cyclone of Orissa (1999), the Gujarat earthquake (2001) and the recent
Tsunami (2004) affected millions across the country leaving behind a trail of heavy loss of
life, property and livelihood.
The following is the list of some of the major disasters occurred in India.
Major disasters in India since 1970
1. Cyclone
1. 29th October 1971, Orissa Cyclone and tidal waves killed 10,000 people
2. 19th November, 1977, Cyclone and tidal waves killed 20,000 Andhra Pradesh people
3. 29th and 30th October 1999, Cyclone and tidal waves killed 9,000 and Orissa 18 million
people were affected
2. Earthquake
1. 20th October 1991 Uttarkashi An earthquake of magnitude 6.6 killed 723 people
2. 30th September 1993 Latur Approximately 8000 people died and there was a heavy loss to
infrastructure.
3. 22 May 1997 Jabalpur 39 people dead
4. 29th March 1997, Chamoli 100 people dead
5. 26th January, 2001, Bhuj, More than 10,000 dead and heavy loss to Gujarat.
6. May 12, 2015 Nepal earthquake
3. Landslide
1. July 1991, Assam 300 people killed, heavy loss to roads and infrastructure

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2. August 1993, Nagaland 500 killed and more than 200 houses destroyed and about 5kms.
Road damaged.
3. 18th August 1998, Malpa 210 people killed. Villages were washed away.
4. Flood
1. 1978 Floods in North East India 3,800 people killed and heavy loss to property.
2. 1994 Floods in Assam, More than 2000 people killed and Arunachal Pradesh, Jammu and
thousands affected Kashmir, Himachal Pradesh, Panjab, Uttar Pradesh, Goa, Kerala and
Gujarat. More than 2000 people killed and thousands were injured.
3. 13 June 2013 the flood in (Kedaranath temple) the Uttarakhand state, which has caused
death of 5700 people.
It is therefore important that we are aware of how to cope with their effects. We have
seen the huge loss to life, property and infrastructure a disaster can cause but let us
understand what is a disaster, what are the factors that lead to it and its impact.
What is a Disaster?
Almost every day, newspapers, radio and television channels carry reports on disaster
striking several parts of the world. But what is a disaster? The term disaster owes its origin to
the French word “Desastre” which is a combination of two words ‘des’ meaning bad and
‘aster’ meaning star. Thus the term refers to ‘Bad or Evil star’.
A disaster can be defined as “A serious disruption in the functioning of the
community or a society causing wide spread human, material, economic, social or
environmental losses which exceed the ability of the affected society to cope using its own
resources”.
Generally, disaster has the following effects in the concerned areas,
1. It completely disrupts the normal day to day life
2. It negatively influences the emergency systems
3. Normal needs and processes like food, shelter, health, etc. are affected and
deteriorate depending on the intensity and severity of the disaster.

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A disaster is a result from the combination of hazard, vulnerability and insufficient
capacity or measures to reduce the potential chances of risk. A disaster happens when a
hazard impacts on the vulnerable population and causes damage, casualties and disruption.
Any hazard – flood, earthquake or cyclone which is a triggering event along with greater
vulnerability (inadequate access to resources, sick and old people, lack of awareness etc)
would lead to disaster causing greater loss to life and property.
For example; an earthquake in an uninhabited desert cannot be considered a disaster,
no matter how strong the intensities produced. An earthquake is disastrous only when it
affects people, their properties and activities. Thus, disaster occurs only when hazards and
vulnerability meet. But it is also to be noted that with greater capacity of the
individual/community and environment to face these disasters, the impact of a hazard
reduces. Therefore, we need to understand the three major components namely hazard,
vulnerability and capacity with suitable examples to have a basic understanding of disaster
management.
What is a Hazard? How is it classified?
Hazard may be defined as “a dangerous condition or event, that threat or have the
potential for causing injury to life or damage to property or the environment.”
OR
Hazard is defined as “An event that pose a threat to people, structure, environmental
resources and economic assets and which will cause a disaster”.
In the order of decreasing severity, the following threats can be recognized,
1. Hazard to people: death, injury, diseases
2. Hazard to goods: property damage both to individual and state
3. Hazard to environment : loss of flora and fauna, different types of pollution
4. Hazard to development : break in the pace of development , livelihood, and economic
loss.
Hazards can be grouped into two broad categories namely natural and manmade.
1. Natural hazards/Disasters: are hazards which are caused because of natural
phenomena (hazards with meteorological, geological or even biological origin).

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OR It is an event that is caused by a natural hazard and leads to human, material,
economic and environmental losses, which exceed the ability of those affected people to
cope.
Examples of natural hazards are cyclones, tsunamis, earthquake and volcanic
eruption which are exclusively of natural origin. Landslides, floods, drought, fires are socio-
natural hazards since their causes are both natural and manmade.
Natural hazards/disasters are classified into two types,
A. Planetary hazards/disasters: the hazards/disasters which are occurring within the
planet are called as planetary hazards/disasters.
Planetary hazards are classified into two types:
a. Endogenous hazards/disasters: The hazards/disasters which are occurring within the
earth or on the surface of the earth (earth as their origin) are called as Endogenous
hazards/disasters.
Example: Earthquake , Volcanoes
b. Exogenous hazards/disasters: the hazards/disasters which are occurring due to the
external cause other than earth are called as Exogenous hazards/disasters.
Example: Drought, cyclone, heat waves and cold waves.
B. Extra Planetary hazards/disasters: The hazards/disasters which are occurring in the
outer space of the planet are called as Extra Planetary hazards/disasters.
2. Manmade hazards/Disasters: A serious disruption of normal life triggered by a
human induced hazard causing human, material, economic and environmental losses,
which exceed the ability of those affected people to cope.
Manmade hazards are associated with industries or energy generation facilities
and include explosions, accidents (roadways, railways, ship and airways), leakage of
toxic waste, pollution (all types), dam failure, wars, terrorism etc.
Classification based on Speed:
1. Slow onset hazards/Disasters: A hazard that prevails for many days, months or even
years like drought, environmental degradation, pest infection are some of examples.
2. Rapid onset hazards/Disasters: A hazard that is triggered by an instantaneous shock.
The impact of this hazard may be short term or long term. Earthquake, Cyclone,
Flood, Volcanic eruption, is some of examples.

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The list of hazards is very long. Many occur frequently while others take place
occasionally. However, on the basis of their genesis, they can be categorized as follows,
Types of Hazards/Disasters:
1. Geological Hazards/Disasters:
1. Earthquake
2. Tsunami
3. Volcanic eruption
4. Landslide
5. Dam burst
6. Mine Fire
2. Water & Climatic Hazards/Disasters:
1. Tropical Cyclone
2. Tornado and Hurricane
3. Floods
4. Drought
5. Hailstorm
6. Cloudburst
7. Landslide
8. Heat & Cold wave
9. Snow Avalanche
10.Sea erosion
3. Environmental Hazards/Disasters::
1. Environmental pollutions
2. Deforestation
3. Desertification
4. Pest Infection

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4. Biological Hazards/Disasters:
1. Human / Animal Epidemics
2. Pest attacks
3. Food poisoning
4. Weapons of Mass Destruction
5. Chemical, Industrial and Nuclear Accidents/Disasters::
1. Chemical disasters
2. Industrial disasters
3. Oil spills/Fires
4. Nuclear
5. Terrorism
6. Accident related Disasters::
1. Boat / Road / Train accidents / air crash / Urban fires /serial bomb blast
2. Forest Fire
3. Building collapse
4. Electric Accidents
5. Festival related
6. Mine flooding
When does a hazard lead to a disaster?
A disaster occurs when the impact of a hazard on a section of society is such that the
people are unable to cope with the event, causing death, injury, loss of property and
economic loss.
If an earthquake strikes a desert uninhabited by human beings, it would not cause
direct and immediate damage to the society and thus, would not be termed as a disaster. On
the other hand, the earthquake that struck to bhuj in Gujarat in 2001 and killed more than
10000 people became a disaster owing to its immediate impact on the society.

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What is vulnerability?
Vulnerability may be defined as “The extent to which a community, structure,
services or geographic area is likely to be damaged or disrupted by the impact of particular
hazard, on account of their nature, construction and proximity to hazardous terrains or a
disaster prone area.”
Physical Vulnerability: It includes notions of who and what may be damaged or
destroyed by natural hazard such as earthquakes or floods. It is based on the physical
condition of people and elements at risk, such as buildings, infrastructure etc; and their
proximity, location and nature of the hazard. It also relates to the technical capability of
building and structures to resist the forces acting upon them during a hazard event.
Fig.1. Unchecked growth of settlements in unsafe areas exposes the people to the
hazard. In case of an earthquake or landslide the ground may fail and the houses on the top
may topple or slide and affect the settlements at the lower level even if they are designed well
for earthquake forces.
1. Socio-economic Vulnerability: The degree to which a population is affected by a
hazard will not merely lie in the physical components of vulnerability but also on the
socioeconomic conditions. The socio-economic condition of the people also
determines the intensity of the impact. For example, people who are poor and living in
the sea coast don’t have the money to construct strong concrete houses. They are
generally at risk and lose their shelters, whenever there is strong wind or cyclone.
Because of their poverty they too are not able to rebuild their houses.
River Unstable Slope
Fig. 1 Site after pressures from population growth and urbanization

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Who is more vulnerable?
During the Gujarat earthquake the people living in the old city of bhuj, with the
narrow roads, newly constructed unsafe high rise buildings and high density of population
faced more injuries and loss of life during the earthquake, than those living in the sub-urban.
Whereas the people living in sub-urban had broader roads, single/double storied
buildings and lower density of population, which helped quick exit from falling buildings
during the earthquake. Thus, we can say that people living in old city of bhuj were more
vulnerable than those living in urban areas.
In the context of human vulnerability to disasters, the economically and socially
weaker segments of the population are the ones that are most seriously affected. For example,
people living in low lying areas are vulnerable to floods which thereby damage their houses
and affect their livelihood. In terms of vulnerability children’s, elder people, physically
challenged are the ones who are likely to be affected more.
What is capacity?
Capacity can be defined as “resources, means and strengths which exist in households
and communities and which enable them to cope with, withstand, prepare for, prevent,
mitigate or quickly recover from a disaster”. People’s capacity can also be taken into account.
Capacities could be,
1. Physical Capacity: People whose houses have been destroyed by the cyclone or
crops have been destroyed by the flood can salvage things from their homes and from
their farms. Some family members have skills, which enable them to find employment
if they migrate, either temporarily or permanently.
2. Socio-economic Capacity: In most of the disasters, people suffer their greatest losses
in the physical and material both. Rich people have the capacity to recover soon
because of their wealth. In fact, they are seldom hit by disasters because they live in
safe areas and their houses are built with stronger materials. However, even when
everything is destroyed they have the capacity to cope up with it.
Hazards are always prevalent, but the hazard becomes a disaster only when there is
greater vulnerability and less of capacity to cope with it. In other words the frequency or

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likelihood of a hazard and the vulnerability of the community increases the risk of being
severely affected.
What is risk?
Risk is a “measure of the expected loss due to a hazard event occurring in a given area
over a specific time period. Risk is a function of the probability of particular hazardous event
and the losses each would cause.”
OR Risk is the anticipated losses from the impact of a given hazard. It is the
combination of the probability of an event and its negative consequences.
The level of risk depends upon:
1. Nature of the hazard
2. Vulnerability of the elements which are affected
3. Economic value of those elements
A community/locality is said to be at ‘risk’ when it is exposed to hazards and is likely to
be adversely affected by its impact. Whenever we discuss ‘disaster management’ it is
basically ‘disaster risk management’. Disaster risk management includes all measures which
reduce disaster related losses of life, property or assets by either reducing the hazard or
vulnerability of the elements at risk.
The figure on the top illustrates essentially the four factors essentially hazards, location,
exposure, and vulnerability which contribute to risk. They are:
 Hazards (physical effects generated in the naturally occurring event
 Location of the hazards relative to the community at risk,

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 Exposure (the value and importance of the various types of structures and lifeline
systems such as water supply, communication network, transportation network
etc in the community serving the population, and
 Vulnerability of the exposed structures and systems to the hazards expected to
affect them during their useful life.
Distribution of people affected by Natural Disasters
78.40%
12.10%
11.30%
Disaster Events (1900-2009)
Hydro-Meterological
Gelological
Biological

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Vulnerability of Profile of India:
India has been vulnerable, in varying degrees, to a large number of natural, as well as,
human-made disasters on account of its unique geo-climatic and socio-economic conditions.
It is highly vulnerable to floods, droughts, cyclones, earthquakes, landslides, avalanches and
forest fires. Out of 36 states and union territories in the country, 27 of them are disaster
prone. Almost 58.6 per cent of the landmass is prone to earthquakes of moderate to very high
intensity; over 40 million hectares (12 per cent of land) are prone to floods and river erosion;
of the 7,516 km long coastline, close to 5,700 km is prone to cyclones and tsunamis; 68 per
cent of the cultivable area is vulnerable to drought and hilly areas are at risk from landslides
and avalanches. During the last two decades of the 19th century (1982-2001), natural
disasters in India had claimed a total death toll of around 1, 07,813 people (on an average
more than 5,390 death toll every year). A multi-hazard map of India may be seen in Figure 2.
Hazard Profile of India
1. India is one of the ten worst disaster prone countries of the world. The country is
vulnerable to disasters due to number of factors; both natural and human induced,
including adverse geo climatic conditions, topographic features, environmental
degradation, population growth, urbanization, industrialization, non scientific
development practices etc. The factors either in original or by accelerating the
intensity and frequency of disasters are responsible for heavy toll of human lives and
disrupting the life supporting system in the country.
The basic reason for the high vulnerability of the country to natural disasters is its
unique geographical and geological situations. As far as the vulnerability to disaster is
concerned, the five distinctive regions of the country i.e. Himalayan region, the alluvial
47.94%
41.06%
11%
Disaster Deaths (1900-2009)
Hydro-Meterological
Geological
Biological

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plains, the hilly part of the peninsula, and the coastal zone have their own specific
problems. While on one hand the Himalayan region is prone to disasters like earthquakes
and landslides, the plain is affected by floods almost every year. The desert part of the
country is affected by droughts and famine while the coastal zone susceptible to cyclones
and storms.
2. The natural geological setting of the country is the primary basic reason for its increased
vulnerability. The geo-tectonic features of the Himalayan region and adjacent alluvial plains
make the region susceptible to earthquakes, landslides, water erosion etc. Though peninsular
India is considered to be the most stable portions, but occasional earthquakes in the region
shows that geo- tectonic movements are still going on within its depth.
3. The tectonic features, characteristics of the Hiamalya are prevalent in the alluvial plains
of Indus, Ganga and Brahmputra too, as the rocks lying below the alluvial pains are just
extension of the Himalayan ranges only. Thus this region is also quite prone to seismic
activities. As a result of various major river systems flowing from Himalaya and huge
quantity of sediment brought by them, the area is also suffering from river channel siltation,
resulting into frequent floods, especially in the plains of Uttar Pardesh and Bihar.
4. The western part of the country, including Rajasthan, Gujarat and some parts of
Maharashtra are hit very frequently by drought situation. If Monsoon worsens the situation
spreads in other parts of the country too. The disturbance in the pressure conditions over
oceans, results into cyclones in coastal regions. The geo tectonic movements going on in the
ocean floor make the coastal region prone to tsunami disaster too.
5. The extreme weather conditions, huge quantity of ice and snow stored in the glaciers etc.
are other natural factors which make the country prone to various forms of disasters.
6. Various human induced activities like increasing demographic pressure, deteriorating
environmental conditions, deforestation, unscientific development, faulty agricultural
practices and grazing, unplanned urbanisation, construction of large dams on river channels
etc. are also responsible for accelerated impact and increase in frequency of disasters in the
country.

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Environmental Stress:
Our environment plays a vital role in determining our well-being. We live in an
environment and the quality of our life depends on the quality of the surrounding
environment.
Environmental stress can be defined as undesirable interactions between the human
activities and the environment. The demands made by environmental factors on us constitute
the sources of environmental stress. The environment has both constructive as well as
destructive effects on human life. The various aspects of environmental stress which are also
known as stressors. We can categorize the various types of pollution as air pollution, water
pollution and noise pollution.
Pollution is an undesirable change in the physical, chemical or biological
characteristics of air, land and water that may harmfully affect life. It is an unfavourable
alteration of the environment largely as a result of human activities. It is caused by various
pollutants which are substances foreign to the medium such as air or water in which they are
present. It causes problems to the animal and human world. The various types of pollutions
are as follows:
1. Air pollution
2. Water pollution
3. Noise pollution
4. Crowding
5. Green house effect
1. Air pollution: Air pollution is defined as an imbalance in the quality of air so as to
cause adverse effects on the living organisms. It is caused by the excessive presence
of certain gases and suspended material particulates (SPM). The air is the carrier of
oxygen for all life forms. Gases like carbon di-oxide (CO2), Nitrous Oxide (NO2),
Sulphur dioxide (SO2) and suspended particulates including lead are the major
pollutants. These not only cause irritation but also result in diseases like respiratory
problems, cardio-vascular problems, hypertension, asthama, eye-related and
neurological problems and result in early deaths too. The major sources of air
pollution are increase in power consumption, industrialization, vehicular traffic and
burning of refuse, garbage, smoking and cutting trees for building construction.
Nobody can ever forget Bhopal Gas tragedy when thousands of innocent people died

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due to inhaling of methyl isocynate gas which got mixed in the air - the essential
component of life. Till today its ill effects are felt as new born babies and adults suffer
from asthma, cough and defective eyesight.
2. Water Pollution: Pollution of water refers to addition of excess undesirable
substance to water that makes it harmful to human, animal and aquatic life. It has
been found that all surface water and a lot of ground water in India is unfit for direct
consumption by human beings. The poor quality of water causes various diseases like
diarrhoea, intestinal worms and hepatitis. It has also been found that ten percent of all
diseases and twenty percent of the communicable diseases in India are water-related.
how does the water quality gets affected. It is largely due to following factors :
(i) domestic and human waste water,
(ii) industrial waste water, and
(iii) Agricultural run off.
The domestic and human waste water is often times used without proper treatment as
irrigation water. If these vegetables are eaten by the people then they may face
different types of water born diseases. the industrial waste water are dumped into the
rivers which contaminate the river water too. The chemically treated water of the
industries pollutes the river water in such a way that it becomes polluted beyond
treatment and it will affect the whole aquatic environment. This further affects the
quality of our ground and surface water. The decreasing life of our rivers can be seen
in the case of Yamuna in Delhi and Ganga in Kanpur. Water is a basic necessity for
life. If water pollution is not checked, then that day is not very far when we will have
to buy water even for taking bath and cooking.
3. Noise pollution: Have you ever listened to music which has been so loud that you
have to raise your voice to talk? Have you ever stood beside a railway track and talk
in your normal voice as the express train passes by at a high speed? Have you ever
tried to work while workmen dug up the road just outside your room? Do all these
things allow you to function in your normal self? Your answer will be definitely
negative. Why? It is because high sound causes noise pollution.
Noise pollution can be defined as the intensity, loudness, timbre or pitch of sound
which causes us physical discomfort or it may be unwanted because of the situation.

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There are various ill effects of noise pollution, they are as follows:
Health hazards: It has been observed that traffic noise is related to certain symptoms
such as nervousness, sleeplessness, undue irritability, depression and asthma. Some
studies have also revealed that noise pollution triggers aggressive behaviour and
reduces helping behavior. It has also been observed that noise disrupts the harmony
of interpersonal relations.
Problems in Communication: One of the easily observed effects of high level of
noise is the disruption of communication. Another effect of noise appears to be
reduction in performance and low job satisfaction. This has also been inferred that
noisy classroom reduces student’s clarity regarding tasks, attention, motivation and
reduces academic performance.
4. Green house effect: Human beings have been indulging in anti-environmental
behaviors on a large scale. Because of this abuse of the environment, like producing
waste, burning of fossil fuel (petrol, diesel etc.) deforestation, burning of coal, forest
fires, the use of chlorofluorocarbons (CFC) for refrigeration, etc. global warming is
taking place. The gradual increase in temperature of earth’s atmosphere and oceans is
being brought about partly as a result of various human activities. It has far reaching
consequences on the ecology and environment. These include increase in storms and
other weather extremes, melting of ice caps at the North and South Poles that has
resulted in raising the sea levels. These effects have been observed in several parts of
the world. The oceans are rising about one inch every five years.
The change in climate (global warming) is closely related to ‘greenhouse effect’. The
effect is called ‘green house effect’ because in cold regions of the world where sunlight is
needed for developing plants, a glass house is made which they call - Greenhouse. The
Greenhouse has a glass roof that lets in warming sunlight but prevents escape of warm
air. In the same manner the four gases released into the atmosphere (carbon dioxide,
methane, and CFC) trap the sun’s heat, that turns the earth into a vast “green house” i.e.
not letting the heat to be released. This increases the temperature of the atmosphere. The
increase in the levels of the three gases began about the middle of the 18th century. If this
trend continues, it is estimated that it will result in an average warming of the earth’s
surface air temperature by about 3.5 degrees Fahrenheit by the year 2100. Even an
average increase of l or 2 degrees can change regional climates and disrupt agriculture

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worldwide. This trend will cause extensive melting of polar ice caps, resulting in raised
ocean levels and flooding of huge low lying coastal areas in many countries. The global
warming can be reversed, if human behavior that brought about this problem is changed.
For example, the carbon dioxide emissions are reduced, planting more trees and ban on
the use of CFC for refrigeration. The ban on CFC use by fifty nations has brought some
change in the ozone layer. However, the extent of damage to the ozone layer has been so
much that it should return to its normal thickness in fifty to one hundred years.
Sustainable Development:
According to World Commission on Environment and Development, sustainable
development is defined as “development which meets the needs of the present without
compromising the ability of future generations to meet their own needs”. Sustainable
development means preservation of the stocks of resources including environmental
resources and exhaustible resources. The major cause of worry about the sustainability of
development is supposed to be the wasteful consumption style. The present production
technology is making large use of the non-renewable natural resources such as coal, gas,
petroleum which are also called fossil fuels. These sources of energy are the result of natural
storage which is of million years old. Even the renewable natural resources like forest
animals, water etc. are being used by the human being in such a way that very soon there will
be shortage of these resources. The nature has assimilating capacity but if the pollution levels
remain very high then nature may not be able to assimilate it. This may result in lack of clean
water and clean air. If these non-renewable natural resources deplete rapidly then our future
generations may not find anything for their use. Therefore, a little restraint needs to be
practiced. The environment is not restricted to natural boundaries which means that if people
in any part of the world follow unhealthy practices it may result in harming the entire
humanity. Hence sustainable development is a path of development in which options of
future generations are not compromised by the acts of present generation.
Ecosystem Approach:
An ecosystem is a dynamic complex of living communities, including micro-organisms,
plants, animals and humans, and their nonliving environment interacting as a functional unit
in a given area. Ecosystems are thus viewed as integrated human-ecological systems that
work together to provide the range of goods and other benefits necessary to support life,
livelihoods and human well-being. On the other hand, the term environment is often applied

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in a more generic sense, which can include ecosystems but also refer to the physical and
external conditions, including both natural and human-built elements, which surround and
affect the life, development and survival of organisms or communities.
People derive indispensable benefits from nature, also referred to as ecosystem services.
These include provisioning services, such as food, fuel and water; regulating services such as
natural hazard mitigation, erosion control and water purification; supporting services such as
soil formation and nutrient cycling; and cultural services such as recreational and other
nonmaterial benefits. “Sustainable ecosystems” or “healthy ecosystems” imply that
ecosystems are largely intact and functioning, and that human demand for ecosystem services
does not impinge upon the capacity of ecosystems to maintain future generations.
Unfortunately, approximately 60 percent of all ecosystem services and up to 70 percent of
regulating services are being degraded or used unsustainably.
It is suggested that the regulating services of ecosystems may form the largest portion of the
total economic value of ecosystem services, although they are also, along with cultural
services, the most difficult to measure in economic terms. Some examples of the value of
natural hazard mitigation are presented in Table 1.1, although it is important to note that
ecosystem service values are often very context specific. For example, the role of a coastal
vegetation to protect against extreme weather events can be vital or marginal, depending on
the location of the community. In consequence, the value of a service measured in one
location can only be extrapolated to similar sites and contexts if suitable adjustments are
made In addition, it is often difficult to assess the full economic value of a given ecosystem,
especially non-use values, but even approximate estimates can be useful to guide resource
management decisions. The Economics of Ecosystems and Biodiversity (TEEB) report is an
important attempt to address economic valuation of ecosystem services.
Table 1.1. Estimated economic value of ecosystem services for natural hazard mitigation
Ecosystem Hazard Hazard mitigation value (US$)
Coral reefs (global) coastal 189,000 per hectare/year
Coral reefs (Caribbean) coastal 700,000– 2.2 billion per year (total value)
Coastal wetlands (U.S) hurricane 8,240 per hectare/year
Coastal wetlands (U.S) storms 23.2 billion per year (total value).

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Luznce floodplain (Czech Republic) floods 11,788 per hectare/year
Muthurajawela marsh (SriLanka) floods 5 million per year (total value);
1,750 per hectare/year
Coastal ecosystems (Catalonia, Spain) storms 77,420 per hectare/year
Mountain forests (Switzerland) avalanche up to 170,000 per hectare/year in
High value built up areas
Understanding linkages between environment, disasters and development
That the environment, development and disasters are linked is now widely accepted. What is
less understood is the multi-dimensional role of the environment in the context of disasters,
and how environment-disaster linkages in turn are affected by and can also shape
development processes and outcomes.
Disasters can have adverse consequences on the environment and on ecosystems in
particular, which could have immediate to long-term effects on the populations whose life,
health, livelihoods and well-being depend on a given environment or ecosystem.
Environmental impacts may include:
(i) direct damage to natural resources and infrastructure, affecting ecosystem
functions,
(ii) acute emergencies from the uncontrolled, unplanned or accidental release of
hazardous substances especially from industries, and
(iii) indirect damage as a result of post-disaster relief and recovery operations that fail
to take ecosystems and ecosystems services into account.
As a result, pre-existing vulnerabilities may be exacerbated, or worse, new vulnerabilities and
risk patterns may emerge especially in circumstances where there are cumulative impacts due
to recurring natural hazards.
On the other hand, environmental conditions themselves can be a major driver of disaster
risk. Degraded ecosystems can aggravate the impact of natural hazards, for instance by
altering physical processes that affect the magnitude, frequency and timing of these hazards.

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This has been evidenced in areas like Haiti, where very high rates of deforestation have led to
increased susceptibility to floods and landslides during hurricanes and heavy rainfall events.
Why do ecosystems matter in disaster risk reduction?
It is argued that ecosystems contribute to reducing disaster risk in two important ways.
Ecosystems, such as wetlands, forests and coastal systems, can reduce physical exposure to
natural hazards by serving as natural protective barriers or buffers and thus mitigating hazard
impacts. Well-managed ecosystems can provide natural protection against common natural
hazards, such as landslides, flooding, avalanches, storm surges, wildfires and drought. For
example, in the European Alps, mountain forests have a long history of being managed for
protection against avalanches and rockfall.
Ecosystem Hazard mitigation
Mountain forests and other
1. vegetation on hillsides Vegetation cover and root structures protect against erosion
and increase slope stability by binding soil together, preventing landslides.
2. Forests protect against rockfall and stabilise snow reducing the risk of avalanches.
3. Catchment forests, especially primary forests, reduce risk of floods by increasing
infiltration of rainfall, and delaying peak floodwater flows, except when soils are fully
saturated.
4. Forests on watersheds are important for water recharge and purification, drought
mitigation and safeguarding drinking water supply for some of the world’s major
cities.
Wetlands and floodplains
1. Wetlands and floodplains control floods in coastal areas, inland river basins, and
mountain areas subject to glacial melt.
2. Peatlands, wet grasslands and other wetlands store water and release it slowly,
reducing the speed and volume of runoff after heavy rainfall or snowmelt in
springtime.
3. Coastal wetlands, tidal flats, deltas and estuaries reduce the height and speed of storm
surges and tidal waves.

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4. Marshes, lakes and floodplains release wet season flows slowly during drought
periods.
Coastal ecosystems, such as mangroves, saltmarshes, coral reefs, barrier islands and
sand dunes
1. Coastal ecosystems function as a continuum of natural buffer systems protecting
against hurricanes, storm surges, flooding and other coastal hazards – a combined
protection from coral reefs, seagrass beds, and sand dunes/coastal wetlands/coastal
forests is particularly effective. Research has highlighted several cases where coastal
areas protected by healthy ecosystems have suffered less from extreme weather events
than more exposed communities.
2. Coral reefs and coastal wetlands such as mangroves and saltmarshes absorb (low-
magnitude) wave energy, reduce wave heights and reduce erosion from storms and
high tides.
3. Coastal wetlands buffer against saltwater intrusion and adapt to (slow) sea-level rise
by trapping sediment and organic matter.
4. Non-porous natural barriers such as sand dunes (withassociated plant communities)
and barrier islands dissipate wave energy and act as barriers against waves, currents,
storm surges and tsunami.
Integrating ecosystem management and disaster risk management
Four previously separate institutional spheres need to converge to establish new working
arrangements that facilitate integrated disaster risk management (Figure 2.2). Ecosystem
management provides the unifying base for promoting DRR and climate change adaptation,
with the overall goals of achieving sustainable development, human well-being and
livelihood security. While there has been improved dialogue and coordination between these
various spheres, more effort is needed to achieve greater convergence. Ecosystem
management initiatives could be enhanced by including disaster risk and climate change
considerations, while DRR, climate change adaptation and development planning need to
recognize the potential of harnessing ecosystem services and also address vulnerability linked
to ecosystem degradation.

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Figure 1.2. Ecosystem-based disaster risk reduction, a more sustainable approach to
DRR and climate change adaptation (CCA).
Environmental instruments and approaches for DRR
This section provides an overview of the full range of environmental tools and
instruments available that could be used to integrate environmental concerns and
ecosystems-based approaches as part of disaster risk reduction. These tools include the
following:
1. Environmental assessments;
2. Integrated risk and vulnerability assessments;
3. Protected area management;
4. Integrated ecosystems management (such as integrated water resource management,
integrated coastal zone management, integrated fire management, sustainable land
management); and
5. Community-based sustainable natural resource management.

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Community-Based Disaster Management
Community connections are the relationships necessary to develop, implement, and
maintain an effective end-to-end early warning system. A multi-hazard warning center can
only be successful if the warnings it produces reach individuals at risk and are easy to
understand, resulting in appropriate responses. To assure warnings are most effective, the
staff at a center must establish trusted partnerships among international organizations,
governmental agencies, community leaders and organizations, businesses, and local citizens
prior to issuing a warning.
The Persuasive Communication Continuum Model
Effective education and outreach must be based in a thorough understanding of the
process that individuals go through when they make decisions about modifying their personal
behavior. Warning specialists must understand human behavior in order to design and
implement better warnings. Fig1. Shows the key stages in the continuum of persuasive
communication that leads to behavior change. The success of a warning rests in the
public’s/individual’s awareness, understanding, and acceptance of their risk.
Fig.1 Persuasive communication
For example, in order to motivate residents to heed evacuation warnings, the residents
must first be aware of their risk. Second, they must understand the impacts an event may have
on their family and community. Third, they must accept the idea that not following a warning
message can result in injury or death. Finally, they must take action and heed the warning to
evacuate. If the intent is behavior change or ACTION, then public outreach must focus on
moving the public through the initial stages of awareness, understanding, and acceptance.
Community Preparedness Programs
Community preparedness can be thought of as the advance capacity of a community
to respond to the consequences of an adverse event by having plans in place so that people
know what to do and where to go if a warning is issued or a hazard is observed.

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This type of program can increase resilience to flash flood and other hazardous
events, reduce economic losses, and shorten recovery periods. Outreach and communication
with the public is crucial to their understanding of the nature of the hazards, the risks to
personal safety and property, and the steps to reduce those risks. Key components of a
community preparedness program include:
1. Raising public awareness and effecting behavioral change in the areas of mitigation
and preparedness
2. Deployment of stable, reliable, and effective warning systems
3. Development of effective messaging for inducing favorable community response to
mitigation, preparedness, and warning communications
Based Disaster Resilience Programs
Effective community preparedness programs also include hazard and vulnerability
assessments—sustained actions taken to reduce or eliminate the long-term risk to human life
and property based on risk assessments. This includes planning and zoning to manage
development in areas particularly at risk for various natural hazards, embracing severe-
weather-resistant construction, and protecting critical facilities and infrastructure. The U.S.
Coastal Community Resilience (CCR) program is an example of this type of mitigation
program.
Elements of community resilience
A resilient community is one that can carry out recovery activities in ways that minimize
social disruption and mitigate the effects of future events and impacts. Hazard readiness is an
active collaboration among national, provincial, and local emergency management agencies
and the local communities. The main goals are to improve public safety during emergencies
and to build resilience against recurring events. To achieve these goals, the following
objectives need to be met:
1. Create minimum standard guidelines for a community to follow to become “resilient”
2. Encourage consistency in educational materials and response among communities
and national emergency systems
3. Publicly recognize communities that have adopted community resilience guidelines
4. Increase public awareness and understanding of severe weather and other hazards
5. Improve community planning for disaster impact

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Community resilience requires the following processes:
1. Communications and Coordination – A key to effective hazards management is
effective communication. This is especially true for hazards like tsunamis and flash
floods, since inundation arrival times may be measured in just minutes. Such a “short-
fused” event requires an immediate, careful, systematic and appropriate response.
2. Warning Reception – Warning points and community Emergency Operations Cen-
ters (EOC) each need multiple and redundant pathways to receive warnings and to
respond quickly.
3. Warning Dissemination – Upon receipt of warnings or other reliable information
suggesting a hazard is imminent, local emergency officials should communicate the
threat to as much of the population as possible.
4. Community Preparedness – Public education is vital in preparing communities to
respond properly to threats. An educated person is more likely to take steps to receive
warnings, recognize potentially threatening events, and respond appropriately to those
events.
5. Administration – No program can be successful without formal planning, proactive
administration, and proper protocols.
Benefits of Community Resilience Programs
Benefits of following community resilience processes include:
1. Being more prepared to save lives
2. Increased contacts with emergency managers and researchers
3. A well informed public
4. Improved positioning to receive national and provincial funds
5. Enhanced core infrastructure to support other community concerns
6. Demonstrated benefits to the public showing how their tax money is being spent in
hazard programs.

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