disasters

1. NATURAL DISASTERS

2.  A natural disaster is
the effect of a natural
hazard- (e.g. flood,
tornado, hurricane,
volcanic eruption,
earthquake, or
landslide) that affects
the environment, and
leads to financial,
environmental and/or
human losses.

3. The World is always changing.
Natural disasters are changes which are
so great they may cause damage to the
shape of the land or to the lives of people
and other living things.
Great changes happen deep inside the
Earth and on its surface. The changes on
the outer part of the Earth happen
because of different kinds of weather.

4.  Volcanic eruption
 Earthquake
 Cyclone or Hurricane
 Monsoons
 Avalanche
 Flood
 Drought
 Forest fire or Bushfire
 Tsunami
 Electrical storms

5. A volcanic eruption is the spurting out of gases and
hot lava from an opening in the Earth’s crust.
Pressure from deep inside the Earth forces ash, gas
and molten rock to the surface.

6.  A volcano is a mountain or hill formed by the
accumulation of magma or molten rock
 Volcanoes are hazardous to wildlife and humans
alike

7.  It causes
1. Volcanic Gases
2. Landslides
3. Lahars
4. Ash Fall

8.  Volcanic Gases
 an incredible surge of sulfur dioxide gas
into the stratosphere where it combined
with water to form sulfuric acid. The
new aerosol deteriorated the Earth's
ozone layer by altering the chlorine and
nitrogen compounds.
 But even when a volcano isn't erupting, it
emits gases from fumaroles, cracks or
openings from the ground. Most of these
gases is water vapor which combines with
carbon dioxide, sulfur dioxide, hydrogen
sulfide, hydrogen, and fluorine to
produce harmful gases such as acid rain.
The extra carbon dioxide in the air will
result in animal and human deaths

9.  Lahars
However, of all the effects of volcanoes,
mudflows or lahars are the deadliest. Debris
flows of mud, rock, and water travel down
the flank and into valleys and streams at
velocities of 20 mph to 40 mph. Some of the
most extreme cases have lahars with a
consistency of wet concrete flowing up to 50
miles.

10.  Landslides
 Landslides are also very common with volcanoes. The terrible
shaking of an eruption causes the loose debris on the side of the
mountain to rapidly fall down its steep flank. However, debris
avalanches may also be caused by earthquakes or heavy rainfall.
 Mount St. Helens eruption caused the largest volcano landslide in
recorded history, while Mount Rainier have had at least five
large avalanches within the past 6,00 years. Suchmassive
landslides result in a complete burial of surrounding cities and
the obliteration of wildlife and such.

13. An earthquake is a violent shaking of the ground.
Sometimes it is so strong that the ground splits
apart.
When parts of the earth, called plates, move
against each other giant shock waves move upwards
towards the surface causing the earthquake.

14.  Earthquakes release an incredible amount of
energy and are able to destroy bridges,
buildings, and even entire cities in just a few
minutes.
 Below are some pictures of some of the most
destructive earthquakes in recent history.

15.  A Cyclone is a fierce storm with storm
winds that spin around it in a giant
circle. During a cyclone trees can be
uprooted, buildings can be destroyed
and cars can be overturned.
 a cyclone is a large air mass that
rotates around a strong center of low
atmospheric pressure,
counterclockwise in the Northern
Hemisphere and clockwise in the
Southern Hemisphere as viewed from
above. Cyclones are characterized by
inward-spiraling winds that rotate
about a zone of low pressure.

16. It can disrupt transportation, power, and
communication services.
It can cause flooding and landslides.
It can lead to water contamination and
increase the spread of disease.
It can cause displacement of people.
 It can impact livelihoods and disrupt
supply chaos.
 It can have a significant impact on the
national economy.

17.  The monsoon is a wind current in Southern
Asia, blowing northeast during the summer
and southwest during the winter.
During the summer, the monsoon brings
heavy rains to southern Asia and Africa,
while in the winter it causes the drier
seasons.


18. 
The effects of the winter monsoons are very
different from the summer monsoons.
During winter monsoons, the wind blows from the
land to ocean, while in the summer it is the
opposite.

 This can cause major climate changes throughout
the entire world depending
on the location.

19. An Avalanche is a movement of snow, ice and rock down a
mountainside. Avalanches happen very suddenly and can move as
fast as a racing car up to 124mph.
Avalanches can be caused by
 snow melting quick
 snow freezing, melting then freezing again someone
skiing
 a loud noise or an earth tremor

20. A flood is caused by an overflow of water which covers
the land that is usually dry.
Floods are caused by heavy rain or by snow
melting and the rivers burst their banks and
overflow.
Costal floods are caused by high tides, a rise in sea
level, storm waves or tsunami (earthquakes under the
sea).
FLOOD

21.  Floods make an enormous impact on the
environment and society.
 Floods destroy drainage systems in cities,
causing raw sewage to spill out into bodies of
water.
 This can lead to catastrophic effects on the
environment
 Floods cause significant amounts of erosion to
coasts, leading to more frequent flooding if not
repaired.

22.  Floods make an enormous impact on the
environment and society. Floods destroy
drainage systems in cities, causing raw sewage
to spill out into bodies of water. Also, in cases
of severe floods, buildings can be significantly
damaged and even destroyed. This can lead to
catastrophic effects on the environment as
many toxic materials such as paint, pesticide
and gasoline can be released into the rivers,
lakes, bays, and ocean, killing maritime life.

23. A drought is a period of drier-than-normal
conditions that results in water-related
problems. The amount of precipitation at a
particular location varies from year to year,
but over a period of years the average
amount is fairly constant.
Drought often has large impacts on the
ecosystems and agriculture of affected
regions, and causes harm to the local
economy.

24. Effects
•Drought can weaken an
ecosystem by stressing plant
and animal resources.
•Flora and fauna not able to
find adequate resources are
more vulnerable to predation
and disease
•Dry conditions can increase
not just the number but the
severity of fires
•Drought, of itself, is a
devastating event, leading to
crop loss and possible topsoil
loss

25.  Drought, of itself, is a devastating event, leading
to crop loss and possible topsoil loss. It also
carries another equally serious impact.
 Dry, compacted soils provide little
opportunity for rainwater to penetrate
during storms. Drought- affected areas then
become vulnerable to floods.
 Stream banks are easily eroded without the
soil-anchoring vegetation lost during a
drought. A buildup of forest litter also
increases the risk of wildfires.
The effects of drought can be felt in every
aspect of society, the economy and the
environment. While the immediate effects are
devastating, long term effects can persist,
compounding damage and loss.


26. Fires can burn out of control in areas of forest or
bush land. Fires are caused by lightning, sparks
of electricity or careless people. Wind may blow a
bushfire to areas where people live.

27. Fire effects are the
physical, chemical, and
biological impacts of
fire on ecosystem
resources and the
environment. abiotic
effects of fire include
its role in changing
air quality,
water quality,
soil properties, and
nutrient cycling.
Biotic effects include
altering vegetation and
related impacts on
wildlife.

28.  A tsunami is a series of
tremendous waves generated
by a massive underwater
disturbance.
 Tsunamis can move at speeds
as high as 500 miles per hour.

29.  Tsunamis are
capable of causing a
substantial amount
of damage.
 One tsunami can
destroy an entire
coastal village and
remove all the sand
from a beach and
sand that took
hundreds of years to
accumulate.

30.  Electrical storms are
composed of lightning and
thunder, typically
accompanied by heavy
precipitation.
Each storm forms in large
cumulonimbus clouds
(thunderheads) stretching
one to five miles in
diameter with a height of
25,000 feet.

Electrical storms

31.  Electrical storms are an amazing phenomenon.
 it is not considered a very dangerous natural
disaster.
 It is a very isolated event as each lightning
strike only affects a minimal area and rarely
kills or injures humans and animals.
 Lightning does contain a significant amount of
power, reaching temperatures hotter than the
surface of the sun, and creating shockwaves
that we hear as thunder

32. A tree split in half by lightning
A forest fire caused by an electrical storm
Lightning over a city at night Lightning striking a tall tree

33.  Natural Disaster Effects | eHow.com
http://www.ehow.com/about_5552385_natural-
disaster-effects.html#ixzz1cjJfQDzt
Read more: How do Droughts Effect the Ecosystem? |
eHow.com http://www.ehow.com/how-
does_5448138_do-droughts-effect-
ecosystem.html#ixzz1cjl7obAV

 library.thinkquest.org/03oct/00758/en/disaster/.../ef
fects.html
human-impact-owww.earthquake.tvn-the-natural-
environment
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