A natural disaster occurs when a natural hazard affects a vulnerable population, leading to losses. The effects depend on a population's resilience to resist the hazard. Disasters only occur when hazards interact with vulnerability. While hazards exist naturally, it is human involvement that transforms them into disasters. For example, the 1906 San Francisco earthquake was a disaster due to its effects on the city, while unpopulated areas experience only hazards. Natural disasters disrupt communities and economies through damage and health impacts. Common natural disasters include earthquakes, floods, landslides, volcanic eruptions, wildfires and storms.

4. A natural disaster is the effect of a natural hazard . It leads to financial,
environmental or human losses. The resulting loss depends on the
vulnerability of the affected population to resist the hazard, also called
their resilience. This understanding is concentrated in the formulation:
"disasters occur when hazards meet vulnerability." Thus a natural
hazard will not result in a natural disaster in areas without vulnerability,
e.g. strong earthquakes in uninhabited areas. The term natural has
consequently been disputed because the events simply are not hazards or
disasters without human involvement. A concrete example of the division
between a natural hazard and a natural disaster is that the 1906 San
Francisco earthquake was a disaster, whereas earthquakes are a hazard.
This article gives an introduction to notable natural disasters, refer to
the list of natural disasters for a comprehensive listing.

5. Types of Natural Disasters
Earthquakes
Landslide
Floods
Drought
Cyclone
Tsunamis

6. An avalanche is a sudden rapid flow of snow down a slope, occurring when
either natural triggers, such as loading from new snow or rain, or artificial
triggers, such as explosives or backcountry skiers, punctuate the equilibrium of
the snowpack . Typically occurring in mountainous terrain, an avalanche can
mix air and water with the descending snow. Powerful avalanches have the
capability to entrain ice, rocks, trees, and other material on the slope.
Avalanches are primarily composed of flowing snow, and are distinct from
mudslides, rock slides, and collapses on an icefall. In contrast to other natural
events which can cause disasters, avalanches are not rare or random events
and are endemic to any mountain range that accumulates a standing
snowpack. In mountainous terrain avalanches are among the most serious
objective hazards to life and property.

7. An earthquake is the result of a sudden release of
energy in the Earth's crust that creates seismic waves.
At the Earth's surface, earthquakes manifest
themselves by vibration, shaking and sometimes
displacement of the ground. The vibrations may vary in
magnitude. Earthquakes are caused mostly by
slippage within geological faults, but also by other
events such as volcanic activity, landslides, mine
blasts, and nuclear tests. The underground point of
origin of the earthquake is called the focus. The point
directly above the focus on the surface is called the
epicenter. Earthquakes by themselves rarely kill
people or wildlife. It is usually the secondary events
that they trigger, such as building collapse, fires,
tsunamis (seismic sea waves) and volcanoes, that are
actually the human disaster. Many of these could
possibly be avoided by better construction, safety
systems, early warning and evacuation planning.

8. Effects of Earthquake
Earthquake brings physical damage to the place
including destruction of building in
telecommunication
Water and electric supply.
Due to loss of houses and distruption of daily
routine, health and hygiene of living being are
also adversely affected.

9. Causes of Earthquakes
 Geologically the earth is made up of 7 long plates. These plates
are called tectonic plates. These plates move ranging from faint
motion to a violent shifting. When there is faint very slow
movement of these plates it goes unnoticed.
 Earthquake are caused when the tension is released from inside the
crust. This happens because plates do not move smoothly
sometimes they get stuck. When this happen a great deal of
pressure build up. Eventually this pressure is released and an
earthquake tends to be occur.

10. Volcanoes can cause widespread destruction and consequent disaster
through several ways. The effects include the volcanic eruption itself that
may cause harm following the explosion of the volcano or the fall of rock.
Second, lava may be produced during the eruption of a volcano. As it
leaves the volcano, the lava destroys many buildings and plants it
encounters. Third, volcanic ash generally meaning the cooled ash - may
form a cloud, and settle thickly in nearby locations. When mixed with
water this forms a concrete-like material. In sufficient quantity ash may
cause roofs to collapse under its weight but even small quantities will
harm humans if inhaled.

11. A tsunami (plural: tsunamis or tsunami; from Japanese: , lit.
"harbor wave"; is a series of water waves caused by the
displacement of a large volume of a body of water, typically an
ocean or a large lake. Earthquakes, volcanic eruptions and other
underwater explosions (including detonations of underwater
nuclear devices), landslides, glacier calving, meteorite impacts
and other disturbances above or below water all have the potential
to generate a tsunami.

12. Effect of Tsunami
Loss of life:- Tsunami leads to violent backward
flow of water on the coasts. When the wave recede.
In this back wash many lives are lost especially
people living in coastal areas.
Aquatic animal:- Animals living in sea are also
badly affected.

13. Effect of Tsunami
Physical damage:- Thousand
of village get damaged by
the effect of Tsunami wave.
Telecommunication lines,
water electric wires poles,
sea resorts, hotels, port
facilities are destrupted.
Plants:- May also get
uprooted due to Tsunami
wave.

14. Cyclone, tropical cyclone, hurricane,
and typhoon are different names for
the same phenomenon a cyclonic
storm system that forms over the
oceans. The deadliest hurricane ever
was the 1970 Bhola cyclone; the
deadliest Atlantic hurricane was the
Great Hurricane of 1780 which
devastated Martinique, St. Eustatius
and Barbados. Another notable
hurricane is Hurricane Katrina which
devastated the Gulf Coast of the United
States in 2005.

15. CAUSES OF CYCLONE
Cause :- When moisture evaporates from ocean in hot
wheather it goes up condenses and
From clouds. Air rushes inwards to air
There it forms a swirt circular motion
Around a center.

16. Effect of cyclone
 Crops:- Sometimes cyclone are followed by terrific
wind and rains then it become more hazards.
Cyclone damage standing crops and flood grains.
 Health:- Cyclone may bring disease causing
carriers with them which affect human health
negatively.

17. Drought occurs when rainfall is insufficient
to maintain river flow and ground-water
levels fall to such an extent that water
becomes unavailable or almost unavailable
to support life. The formal definition of
drought varies from area to area.

18. Drought do not
Effect of Drought
cause any structural
damage but it affect
production of crop,
fishery production
unemployment, loss
of biodiversity ,
ground water.

19. A tornado is a violent, dangerous, rotating column of air that is in
contact with both the surface of the earth and a cumulonimbus cloud
or, in rare cases, the base of a cumulus cloud. They are often referred
to as a twister or a cyclone,[ although the word cyclone is used in
meteorology in a wider sense, to name any closed low pressure
circulation. Tornadoes come in many shapes and sizes, but are
typically in the form of a visible condensation funnel, whose narrow
end touches the earth and is often encircled by a cloud of debris and
dust.

20. A limnic eruption occurs when a gas, usually
CO2, suddenly erupts from deep lake water,
posing the threat of suffocating wildlife,
livestock and humans. Such an eruption may
also cause tsunamis in the lake as the rising
gas displaces water. Scientists believe
landslides, volcanic activity, or explosions
can trigger such an eruption. To date, only
two limnic eruptions have been observed and
recorded:
In 1984, in Cameroon, a limnic eruption in
Lake Monoun caused the deaths of 37 nearby
residents.
At nearby Lake Nyos in 1986 a much larger
eruption killed between 1,700 and 1,800
people by asphyxiation.

21. An epidemic is an outbreak of a contractible
disease that spreads at a rapid rate through a
human population. A pandemic is an epidemic
whose spread is global. There have been many
epidemics throughout history, such as Black
Death. In epidemiology, an epidemic meaning
"people"), occurs when new cases of a certain
disease, in a given human population, and
during a given period, substantially exceed
what is expected based on recent experience.
Epidemiologists often consider the term
outbreak to be synonymous to epidemic, but
the general public typically perceives
outbreaks to be more local and less serious
than epidemics.

22. Blizzards are severe winter storms
characterized by low temperature, strong
winds, and heavy snow. The difference
between a blizzard and a snow storm is the
strength of the wind. To be a considered a
blizzard, the storm must have winds in
excess of 35 miles per hour, it should
reduce the visibility to 1/4 miles, and must
last for a prolonged period of 3 hours or
more. Ground blizzards require high winds
to stir up snow that has already fallen,
rather than fresh snowfall. Blizzards have a
negative impact on local economics and
can terminate the visibility in regions where
snowfall is rare.

23. Landslide
Landslide is sliding
or movement of rock
down slope due to
its own weight.
Sliding may occur
gradually or
suddenly without
warning

24. Effect of Landslide
Destruction of
houses
Loss of human
life
Flood
Injuries
Distruption of
traffic

25. Shipping:- Tropical cyclone may to
ships, fairies, boats which are anchored. It
may cause an accident also.
Landslide:- Usually landslide occur due to high
velocity of wind which again brings loss of houses,
property and human lives.

26. A flood is an overflow of an expanse of water that submerges land. The
EU Floods directive defines a flood as a temporary covering by water of
land not normally covered by water. In the sense of "flowing water", the
word may also be applied to the inflow of the tide. Flooding may result
from the volume of water within a body of water, such as a river or lake,
which overflows or breaks levees, with the result that some of the water
escapes its usual boundaries. While the size of a lake or other body of
water will vary with seasonal changes in precipitation and snow melt, it is
not a significant flood unless such escapes of water endanger land areas
used by man like a village, city or other inhabited area.

27. Effect of Flood
Disease:- Usually floodwater mixes up with
waste. So it cause many types of disease.
Soil erosion:- Many plant are uprooted due
to speed and pressure of floodwater. It
result in soil erosion.
Loss of lives:- In flood many people and
cattle put their life in danger. Sometimes
they meet with some injuries also.

28. Effect of Flood
Disease:- Usually floodwater mixes up with
waste. So it cause many types of disease.
Soil erosion:- Many plant are uprooted due
to speed and pressure of floodwater. It
result in soil erosion.
Loss of lives:- In flood many people and
cattle put their life in danger. Sometimes
they meet with some injuries also.

29. Conclusion
Though developing countries in region vulnerable to
disaster receives many development initiates and
investment the increase and frequency and magnitude of
natural catastrophes associated with economic loss
and human suffering have consider only hindered those
initiates. It can be seen in the chapter that human
development and income level of a country are crucial
determinates for deciding upon how to effectively
implement risk management approaches and post
disaster management initiates.