Assignment on –
“Natural Disaster, its causes & effects.”
Introduction of Natural Disaster:
A natural disaster is a disaster caused by nature, such as floods, volcanic eruptions,
earthquakes, tsunamis, avalanches, lahars (volcanic mudslides), landslides,
sinkholes, blizzards, drought, hailstorms, heat waves, hurricanes, tropical storms,
typhoons, Ice Ages, tornadoes, and wildfires. Epidemics caused by bacteria or
viruses are sometimes considered natural disasters, but sometimes put into a
different category. A biological threat such as locusts or toxic fungi could also be
considered a natural disaster.
Some disasters are on the edge of natural and non-natural. Famines, the chronic
lack of food, may be caused by a combination of natural and human factors. Two
space-originating categories of natural disaster, both of which rarely effect humans
on the surface, include asteroid impacts and solar flares. Although the risk of
asteroid impact in the short term may be low, some scientists argue that in the long
term, the likelihood of death by asteroid is similar to that of death by traditional
natural disasters such as disease.
The deadliest natural disasters are famines, which claimed 70 million people
during the 20th century alone, with 30 million dying during the famine of 1958–61
in China. In the Soviet Union there were several man-made famines that killed
millions, blamed on the collectivist policies of Stalin, the leader of the country at
the time. Famines have a history of bringing out the worst in people, including
atrocities and cannibalism.
Another of the deadliest natural disasters is epidemics, most notably the Spanish
flu of 1918-1919, which killed 50 million — more than World War I, which had
occurred just before. Rather than killing infants or the aged, the Spanish flu struck
down people in the prime of life. Having a good immune system was no protection
against this virus — in fact, it was a liability. The virus is believed to have killed
its victims primarily through over activating the immune system in a process called
a cytokine storm.
Historically, volcanoes may have been the biggest type of natural disaster. Some
scientists believe that the eruption of Mt. Toba in Indonesia over 73,000 years ago
may have killed off most of the human species, leaving behind only 1,000 - 10,000
breeding pairs. This phenomenon, called a population bottleneck, has been
confirmed through genetic analysis.
Definition of Natural Disaster:
A natural disaster is the effect of earth’s natural hazards, for example flood,
tornado, hurricane, volcanic eruption, earthquake, heat wave, or landslide. They
can lead 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. If these disasters continue it would be a great danger for the earth. 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
Natural disasters are cataclysmic events that can have a direct or indirect impact on
the public's health and well-being, according to the United States Department of
Health and Human Services. Natural disasters can include weather phenomena as
well as landslides and avalanches, which occur as a result of erosion or severe
Natural disaster of a different kind: Cold Spell in Bangladesh:
Being a Bangladeshi, it is never a pleasant experience to talk about the periodic
natural disasters, mainly floods and cyclones that ravage the country every now
and then. To increase the sufferings of the poor disaster vulnerable people of the
country, recently there has been a new addition to the list of regular natural
disasters of Bangladesh named Cold Spell, thanks to the global climate change.
The impact of Cold Spell is as notorious as other regular natural calamities of
Bangladesh as far as the death toll is in concern. The recent Cold Spell that
appeared on the 7th January in Bangladesh has already taken sixteen lives, out of
which are 9 children and made most of the population of the northern Bangladesh
to suffer with pneumonia, cold diarrhea, cough, fever, asthma and other cold-
During a Cold Spell, gusty extreme cold wind coupled with heavy fog covers the
whole area of Bangladesh. Historically the average winter temperature in
Bangladesh is within 15 to 20 degree Celsius. However, in recent Cold Spells this
average temperature has dropped to as low as 4 degree Celsius, a new record for
the country. The most affected area during this calamity is the northern part of the
Bangladesh which is closer to the Himalayas. Northern Bangladesh is the most
poverty stricken area of the country where people have year round income poverty
and seasonal food poverty during the time of agricultural lean seasons. The recent
catastrophe of Cold Spell has magnified their sufferings to a severe extent,
shortage of warm clothing and shelter has caused them even their lives.
The sufferings of poor people of northern Bangladesh reached to an untold terrible
stage especially for those who live in the remote island areas of river Tista, which
is locally known as Char. Some places in the northern part had not seen the sun for
the last 3 to 4 days due to the extreme fog and clouds. Most places of the char areas
in the river basins remained covered with fog, reducing the visibility till noon
almost every day. In such situations, poor cannot join their regular work because of
the unfavorable weather condition as well as due to sickness. As a result, they lose
a significant share of their regular income which further reduces their ability to
take proper action against the shock.
Also the daily transportation of food items from all parts of the country has been
dangerously interrupted. Basic road and water transportation has been delayed for
an indefinite time, causing major physical communication to an almost complete
halt. Needless to say, such physical communication chaos has triggered the price of
common household commodities to a seasonal extreme, causing the sufferings of
the poor even more severe. People who took desperate attempt to hit the road
ignoring such bad driving conditions have already paid the price with road
accidents if not heavy traffic congestions in the highways.
The main reason for such calamity is the constant and consistent blow of chilly
wind from the northwest blowing at a speed of 10-15 kms per hour which made the
weather further cooler during the typical winter season. As there is no rain, pollen
count in the air is relatively high in this season making the air full of dust and
causing respiratory problem and allergic infections along with asthma, pneumonia,
chronic bronchitis, respiratory problem, chronic obstructive pulmonary disease.
Hospitals, especially those in the northern part of the country, are experiencing
massive admission of patients suffering from cold related illnesses for the last few
days. Reports received from different sources mentioned seriously sufferings of
thousands and millions people living in the sandy char areas in Kurigram,
Lalmonirhat, Gaibandha, Rangpur, Nilphamari, Bogra and Sirajganj districts on the
Effects of Natural Disasters:
Natural disasters have become so commonplace that they hardly receive passing
notice on the news unless there have been a large number of casualties. Volcanoes,
mudslides, tsunamis and floods are just a few of the ways nature strikes on a daily
basis, leaving behind destruction and heartache. Humans have learned to prepare
for the possibility of tornadoes, earthquakes, hurricanes and wildfires, but no
amount of preparation can lessen the impact that natural disasters have on every
aspect of society.
The biggest visible effect of natural
disasters is the physical ruin they
leave behind. Homes, vehicles and
personal possessions are often destroyed within a short period of time, leaving
families homeless and shutting some businesses down permanently. Tornadoes
destroy structures at whim, earthquakes can
cause structural damage that might not be
apparent at first glance, and tsunamis and
floods sweep homes off their foundations.
Possessions are not hard to replace, as many
people keep insurance on their property and
tangible goods. The emotional toll of natural
disasters is much more devastating. The death of a loved one may be the worst-
case scenario but it's not the only lasting emotional effect victims experience.
Whole communities may be displaced, separating friends and neighbors; victims
face anxiety and depression as they wonder if it could happen again. In extreme
cases, they may experience post traumatic stress disorder (PTSD).
According to the National Hurricane Center, Hurricane Katrina cost the U.S. $75
billion when it slammed into New Orleans in August 2005. That doesn't include
the damage caused in the Florida counties of Miami-Dade and Broward by the
same storm. While destruction of this magnitude is not commonplace, even a
minor storm can cause considerable damage. At the very least, the local economy
must be able to absorb the cost of cleanup and repairs.
While the visible effects of natural disasters are
immediate and strongly felt, communities that
surround ground zero can be indirectly affected by
them as well. Natural disasters almost always lead to
a disruption in utility services around the area
impacted. This can mean life or death for those who rely on dialysis or oxygen to
live. Medical assistance is also often slowed, as emergency crews must focus on
the victims of the disaster. Banks and other businesses might be closed, affecting a
family's ability to withdraw money to pay bills and buy groceries.
Geography plays a large role in how natural disasters affect an area. In rural or
isolated communities, natural disasters can thrust families into a situation where
they must do without modern conveniences like electric and running water. They
may not be able to get to town to buy necessities and have to rely on what they
have stocked up. Densely populated areas face their own unique problems from
natural disasters. Hygiene becomes a concern, as people crowd into temporary
relief centers and competes for limited resources.
Humans aren't the only living things affected by natural disasters. As is the case
with humans, animals can be displaced from their homes. Sometimes they have no
alternative but to leave the area and try to fit into a new habitat. Volcanoes,
earthquakes, floods, wildfires and mudslides often permanently alter an area's
Landscape, leading in some cases to the destruction of a local species
Disruption of Utilities
Communities that surround areas affected by natural disasters are seriously
affected by the disruption caused to utility services. Generally, power is the first
thing to go when there's a natural disaster. This can literally mean life or death to
the people who are on life support systems such as oxygen and dialysis. Medical
assistance becomes hard to get since the crews are busy helping the victims of the
disaster. Banks can be shut down, causing a shortage of cash circulation that
prevents people from accessing funds for much needed provisions for babies and
When a natural disaster strikes, the emotional toll on the people affected is quite
devastating. While possessions can be replaced eventually through insurance, the
emotional damage can take a long while to heal. People lose loved ones in natural
disasters; deaths of people and precious pets, serious injury and people missing all
add up to severe emotional trauma. Communities get displaced meaning separation
from family and friends. Victims face stress, trauma, anxiety and depression as a
result of natural disasters.
The social consequences of natural disasters in the short and long term are wide
ranging. The disasters affect housing; people are left homeless and rebuilding a
home takes a long time and a lot of money. Health care infrastructure is affected;
the impacts are worse in developing countries that already have poor facilities to
begin with. Disease starts spreading and, without proper medical attention, makes a
bad situation worse. Education is a big loser when a natural disaster happens,
schools are often closed, teachers are unable to come in to work and children are
displaced and unable to attend school. Transportation capacity is reduced hindering
relief efforts and disrupting normal life.
What Are the Different Types of Natural Disasters?
A tornado occurs on the surface of the earth's land as a result of humidity in the
lower atmosphere combining with wind shears. The spinning comes by way of
downdrafts and updrafts, but the violent speed is usually due to rapid changes in
the air (such as dry air suddenly becoming very cool). When air mass is unstable
and storms come through an area, a tornado often results. The reason most
tornadoes occur in the Midwest of the United States is because tropical winds from
the south Gulf move up to meet the cool winds of Canada's north. When they
collide in the middle, it's usually somewhere around Kansas or Nebraska (though
tornadoes can occur anywhere if the conditions are right, they're usually not as
severe in other regions).
Violent tremors of the earth's surface are the result of earthquakes, which are
caused by the shifting of the earth's tectonic plates and fault lines below the
surface. When the earth's temperature changes, this causes movement of rock and
plates in the earth's mantle. This happens all over the globe, but some stresses are
more severe in some areas. Parts of the world that experience more earthquakes
usually do so because the plates below them are more brittle and weak. In the
Pacific Ocean, there is the Ring of Fire that stretches up and down the coasts of
North America and South America and continues across to Japan and down to east
of Australia. Volcanic eruption occurs for similar reasons, in that activity occurs
below the surface of the earth causing stress and sudden release of molten rock.
Also known as a tropical cyclone or typhoon, hurricanes are violent storms that
occur off of ocean shores. High winds are produced by water that has evaporated
from an ocean surface in a low pressure area. This also causes a spiraling effect,
which gains momentum the more condensation it collects. Minimal hurricanes
have winds of about 75 mph (Category 1), but the most catastrophic storms will
blow more than 155 mph (Category 5). Once a hurricane hits land, it begins to cool
and slow, but this is the point at which a hurricane does its most damage.
Destruction of trees, cars and buildings is likely in the event of a hurricane.
Causes of Natural Disasters:
According to the U.S. Environmental Protection Agency (EPA), barring fire,
floods are the most common natural disaster affecting Americans. Floods are a
factor in 90 percent of natural disasters. Flood events have both natural and man-
made causes. Storm events can create flood waters that exceed the capacity of the
environment or man-made structures. Levees and dams provide a false sense of
security as became evident during the Great Flood of 1993 in the Upper
Mississippi River valley. A painful lesson was learned. Wetlands destruction
removed a natural means to absorb floodwaters.
Fires are nature's environmental managers. They create and maintain ecosystems
such as prairies and pine forests. In fact, prairies evolved with the presence of fire.
The health of the ecosystem is dependent on this disturbance. Fires remove a
buildup of litter on the soil surface, allowing nutrients to be released into the
environment. It also creates favorable conditions for seed germination. Suppression
of fire allows litter to accumulate, setting the stage for catastrophic fires. Plants and
trees have adapted to the presence of fire. However, the higher temperatures of
crown fires can kill plants entirely. These fires are more difficult to control.
Suppression of fires is expensive, upward of $1 billion annually, according to the
U.S. Forest Service.
Drought has had more widespread effects than any other natural disaster. Each
year, drought costs the United States more than $6 billion. It's safe to say that
droughts have greater impacts in modern times. More people are affected by loss
of land and food crops as well as environmental damage. The immediate effects
are overshadowed by secondary issues. Compacted, dry soils are vulnerable to
topsoil loss and erosion. Dry conditions make fires more common. Evidence
suggests global warming may be the cause for an increase in drought frequency
and changes in the global climate.
Like drought, an increase in severe weather events has been recorded in the last
100 years by the National Climatic Data Center. While notification systems are in
place, vulnerabilities still exist for property damage and crop loss. Development
has also complicated the effects of such events. An increase in development leads
to a decrease in wetlands and an increase in impervious surfaces such as roads and
driveways. This creates a scenario for floods and flash flooding. As with drought,
scientists believe a link between global warming and climate changes exists.
Not all natural disasters can be prevented. Each natural disaster has its own factors
and complications. Understanding the basic principles of ecology can provide keys
to lessening their effects. Nature evolved with natural disasters and disturbance.
The best prevention is looking at the strategies found in nature.
What Is Natural Disaster Management?
Effective natural disaster management saves lives. Procedures set in place before a
catastrophe occurs ensure a speedier and more effective response. A preventative
measure, such as strengthening the infrastructure of buildings in earthquake
regions, minimizes the risk of injuries and helps people to resume normal life more
Governments and some large corporations in developed countries designate aid
money for natural disasters before they happen. They also liaise with the
governments of affected regions and aid workers on the ground when a disaster
occurs to determine the extent of medical aid and supplies needed. Aid workers are
trained to assess the scale of the disaster. Non-government overseas aid workers
may already be based in the region and have a good understanding of the local
culture, which can be invaluable in advising how to administer help effectively,
according to the Global Education website.
Governments and aid organizations, such as the Red Cross, and representatives of
the affected region usually work together to save lives and restore order after a
disaster occurs. Natural disaster management continues long after the initial crisis
has passed. Funds, for example, may be allocated to rebuild homes destroyed by a