Concept and Meaning
A disaster
is a consequence of a sudden disastrous event which seriously disrupts the
normal function of the society or the community to the extent that it cannot
subsist without outside help.
A
disaster is not just the occurrence of an event such as an earthquake, flood,
conflict, health epidemic or an industrial accident; a disaster occurs if that
event/process negatively impacts human populations.
Disasters combine two elements: hazard, and the
vulnerability of affected people. "A disaster occurs when a hazard exposes
the vulnerability of individuals and communities in such a way that their lives
are directly threatened or sufficient harm has been done to their community's
economic and social structure to undermine their ability to survive.
A
disaster can be defined as any tragic event stemming from events such as earthquakes,
floods, catastrophic accidents, fires, or explosions. It is a phenomenon that
disasters can cause damage to life, property and destroy the economic, social
and cultural life of people.
Disaster is the exposure of a group of people to a hazard, leading
to a serious disruption of the functioning of a society and causing human, material, economic environmental
losses which exceed the ability of the affected community or society to cope.
A disaster results from a combination of hazards and vulnerability that exceeds the capacity of
a society to reduce the potential negative consequences of risk.
Hazard is an extreme event, natural or man-made , with a destructive
potential to social, economic and human assets. These may include future threats,
and may be “natural”
(geological, hydro meteorological and biological) or “man-made” (Conflict, environmental degradation and technological hazards).
Disasters are often described as a result of the combination of: the exposure to a hazard; the conditions of vulnerability that are present; and insufficient capacity or measures to reduce or cope with the potential negative consequences. Disaster impacts may include loss of life, injury, disease and other negative effects on human physical, mental and social well-being, together with damage to property, destruction of assets, loss of services, social and economic disruption and environmental degradation.
A disaster is a calamitous, distressing, or
ruinous effect of a disastrous event which seriously affects or disrupts (or
threaten to disrupt) the critical functions of a community, society or system,
for a period long enough to significantly harm it or cause its failure. It is beyond
the capapabilty of the local community to overcome it. The stricken community needs extraordinary
efforts to cope with it, often with outside help or international aid.
It is
a situation resulting from an environmental phenomenon or armed conflict that
produce stress, personal injury, physical damage, and economic disruption of
great magnitude.
Definition
The World
Health Organisation (WHO) defines Disaster as "any occurrence that causes
damage, ecological disruption, loss of human life, deterioration of health and
health services, on a scale sufficient to warrant an extraordinary response
from outside the affected community or area."
Types
of disasters
Disasters
are broadly divided into two types:
1) Natural
2) Man made disasters.
Natural
disasters
Natural
disasters occur as the result of action
of the natural forces and tend to be accepted as unfortunate, but
inevitable. They include:
Ø Famines
Ø Droughts
Ø Tornadoes,
Ø Hurricanes,
Ø Floods / Sea Surges /
Tsunamis
Ø Volcanoes
Ø Snow storms,
Ø Earthquakes,
Famines
may be defined as a persistent failure in food supplies over a prolonged
period. It is a phenomenon in which a large percentage of the populations of a
region or country are so undernourished and that death by starvation becomes
increasingly common. A famine weakens body resistance and leads to increases in
infectious diseases, especially cholera, dysentery, malaria, and smallpox. Famine
is associated with naturally-occurring crop failure due to draught and
pestilence and artificially with war and genocide.
Drought is lack or insufficiency of rain for an extended period of
months or years when a region notes a deficiency in its water supply.
Generally, this occurs when a region receives consistently below average
precipitation. It can have a substantial impact on the ecosystem and
agriculture of the affected region.
A
flood is an overflow of water that submerges land, producing measurable
property damage or forcing evacuation of people and vital resources. Floods are
caused due to heavy rainfall and the inadequate capacity of rivers to carry the
high flood discharge. Floods develop slowly as rivers swell during an extended
period of rain. A flood occurs when water overflows or inundates land that is
normally dry. Mostly it happens when rivers or streams overflow their banks.
Cyclones
are strong winds that are formed over the oceans. The term "cyclone"
refers to all classes of storms with low atmospheric pressure at the centre,
are formed when an organized system of revolving winds, clockwise in the
Southern Hemisphere, anti-clockwise in the Northern Hemisphere, develops over
tropical waters.
A
hurricane is a huge storm. It is a powerful, spiraling storm that begins over a
warm sea, near the equator and accompanied by fierce winds, flash floods,
mudslides and huge waves.It is a low pressure, large scale weather system which
derives its energy from the latent heat of condensation of water vapor over
warm tropical seas.
An
earthquake is a sudden motion or trembling of the ground crust caused by the collision of tectonic plates resulting in the abrupt
displacement of rock masses. Earthquakes result from the movement of one rock
mass past another in response to tectonic forces underneath the earth’s surface.
Volcanoes
result when magma rises, pushes through a weakness in the Earth’s crust, and
spills out onto the surface, devastating anything in its path. The superheated
rock is not the only danger, however. Far below the earth’s surface, volcanic
gasses are dissolved in the magma. As the magma rises, it begins to cool down,
and gas bubbles begin to form. This makes the magma less dense than the
surroundings, causing it to rise faster.
A third threat is a pyroclastic flow. This high speed ejection of hot gasses and debris can travel in excess of 80 kilometers per hour and usually averages between 200 and 700 degrees Celsius. Not only does the pyroclastic flow travel too fast to be outran, but it will incinerate everything in its path. pyroclastic
Man
made disasters
Ø explosions,
Ø fires,
Ø release of toxic
chemicals or radioactive materials(industrial accidents),
Ø dam failures
Ø nuclear reactor accidents
Ø wars
Disaster risk/threats
The
potential disaster losses, in lives, health status, livelihoods, assets and
services, which could occur to a particular community or a society over some
specified future time period. Traditional disaster threats:
Most
of the old disaster threats still exist like earthquakes, cyclones, volcanic
eruptions, tsunamis, wildfires, floods, landslides, and drought so do the
man-made ones like fire, explosions and other major accidents which cause heavy
human casualties, economic and social losses. These same traditional threats
have increased as increase in population has force people to settle in disaster
prone areas which increase the impact of disasters.
Modern
disaster threats:
These
consist of manmade events like hijacking, terrorism, civil unrest, terrorism
and conflict with conventional arms as well as chemical, biological, nuclear,
or radiological weapons. Increased social violence has drastically affected
many nations and communities.
Hazard
A
dangerous phenomenon, substance, human activity or condition that may cause
loss of life, injury or other health impacts, property damage, loss of
livelihoods and services, social and economic disruption, or environmental
damage.
Hazards
are conditions that have the potential to harm to a community or environment
Geological Hazards
Geological
process or phenomenon that may cause loss of life, injury or other health
impacts, property damage, loss of livelihoods and services, social and economic
disruption, or environmental damage.
These
disasters include landmass related disasters like earthquakes, mudslides,
volcanoes etc,
Water
and climatic Hazards (Hydro
meteorological hazards)
These
include storms, cyclones, floods etc
Chemical Hazards
By their nature, the manufacture, storage, and transport of chemicals are accidents waiting to happen. Chemicals can be corrosive, toxic, and they may react, often explosively. The impacts of chemical accidents can be deadly, for both human beings and the environment.
Industrial/ Technological hazards
A hazard originating from technological or
industrial conditions, including accidents, dangerous procedures,
infrastructure failures or specific human activities, that may cause loss of
life, injury, illness or other health impacts, property damage, loss of
livelihoods and services, social and economic disruption, or environmental
damage.
These include industrial pollution, nuclear radiation, toxic wastes, dam failures, transport accidents, factory explosions, fires, and chemical spills.
Biological hazards, also known as biohazards, refer to biological substances that pose a
threat to the health of living organisms, primarily that of humans. This can
include medical waste or samples of a microorganism, virus or toxin (from a biological
source) that can affect human health. It can also include substances harmful to
animals. Examples: anthrax, smallpox, plague, tularemia, brucellosis and
botulinism toxin, bird flu.
