Disaster management (or emergency management) is the discipline
of dealing with and avoiding both natural and manmade disasters. It
involves preparedness, response and recovery in order to lessen the
impact of disasters. It may also involve preparedness training by
private citizens, as by FEMA in the United States. All aspects of disaster
management deal with the processes used to protect populations or
organizations from the consequences of disasters, wars and acts of
terrorism. Disaster management does not necessarily avert or
eliminate the threats themselves, although the study and prediction of
the threats is an important part of the field. The basic level of
emergency management are the various kinds of search and rescue
1986 Chernobyl disaster in Ukraine and 2011 earthquake and tsunami
in Japan were the most large-scale and cost-intense single instances
of emergency management in history.
A natural disaster is a major adverse event resulting from natural processes of the Earth;
examples include floods, volcanic eruptions, earthquakes, tsunamis, and other geologic
processes. A natural disaster can cause loss of life or property damage, and typically
leaves some economic damage in its wake, the severity of which depends on the
affected population's resilience, or ability to recover. An adverse event will not rise to the
level of a disaster if it occurs in an area without vulnerable population. In a vulnerable
area, however, such as San Francisco, an earthquake can have disastrous
consequences and leave lasting damage, requiring years to repair.
In 2012, there were 905 natural catastrophes worldwide, 93% of which were weather-
related disasters. Overall costs were US$170 billion and insured losses $70 billion. 2012
was a moderate year. 45% were meteorological (storms), 36% were hydrological
(floods),12% were climatological (heat waves, cold waves, droughts, wildfires) and 7 %
were geophysical events (earthquakes and volcanic eruptions). Between 1980 and 2011
geophysical events accounted for 14% of all natural catastrophes
Personal mitigation is a key to national preparedness. Individuals and families train to avoid
unnecessary risks. This includes an assessment of possible risks to personal/family health and to
personal property. For instance, in a flood plain, home owners might not be aware of a property
being exposed to a hazard until trouble strikes. Specialists can be hired to conduct risk
identification and assessment surveys. Professionals in risk management typically recommend
that residents hold insurance to protect them against consequences of hazards.
In earthquake prone areas, people might also make structural changes such as the installation
of an Earthquake Valve to instantly shut off the natural gas supply, seismic retrofits of property,
and the securing of items inside a building to enhance household seismic safety. The latter may
include the mounting of furniture, refrigerators, water heaters and breakables to the walls, and
the addition of cabinet latches.
In flood prone areas, houses can be built on poles/stilts. In areas prone to prolonged
electricity black-outs installation of a generator would be an example of an optimal structural
mitigation measure. The construction of storm cellars and fallout shelters are further examples of
personal mitigate actions.
Mitigation involves Structural and Non-structural measures taken to limit the impact of disasters.
Structural mitigation are actions that change the characteristics of a building or its surrounding,
examples include shelters, window shutters, clearing forest around the house. Non-structural
mitigation on personal level mainly takes the form of insurance or simply moving house to a safer
An earthquake (also known as a quake, tremor or temblor) is the result of a
sudden release of energy in the Earth's crust that creates seismic waves. The
seismicity, seismism or seismic activity of an area refers to the frequency, type and
size of earthquakes experienced over a period of time.
Earthquakes are measured using observations from seismometers. The moment
magnitude is the most common scale on which earthquakes larger than
approximately 5 are reported for the entire globe. The more numerous
earthquakes smaller than magnitude 5 reported by national seismological
observatories are measured mostly on the local magnitude scale, also referred to
as the Richter scale. These two scales are numerically similar over their range of
validity. Magnitude 3 or lower earthquakes are mostly almost imperceptible or
weak and magnitude 7 and over potentially cause serious damage over larger
areas, depending on their depth. The largest earthquakes in historic times have
been of magnitude slightly over 9, although there is no limit to the possible
magnitude. The most recent large earthquake of magnitude 9.0 or larger was a
9.0 magnitude earthquake in Japan in 2011 (as of October 2012), and it was the
largest Japanese earthquake since records began. Intensity of shaking is
measured on the modified Marcella scale. The shallower an earthquake, the
more damage to structures it causes, all else being equal.
Earthquakes are usually caused when rock
underground suddenly breaks along a fault.
This sudden release of energy causes the
seismic waves that make the ground shake.
When two blocks of rock or two plates are
rubbing against each other, they stick a little.
They don't just slide smoothly; the rocks catch
on each other. The rocks are still pushing
against each other, but not moving. After a
while, the rocks break because of all the
pressure that's built up. When the rocks break,
the earthquake occurs. During the earthquake
and afterward, the plates or blocks of rock
start moving, and they continue to move until
they get stuck again. The spot underground
where the rock breaks is called the focus of the
earthquake. The place right above the focus
(on top of the ground) is called the epicenter
of the earthquake.
DAMAGE TO HUMAN STRUCTURES -Earthquakes cause great damage to human structures such as
buildings, roads, rails, factories, dams, bridges etc , and thus cause heavy damage to human
LANDSLIDES-The shocks produced by earthquakes particularly in hilly areas and mountains which
are tectonically sensitive causes landslides and debris fall on human settlements and transport
system on the lower slope segments, inflicting damage to them.
FIRES- The strong vibrations caused by severe earthquakes strongly shake the buildings and thus
causing severe fires in houses, mines and factories because of overturning of cooking gas,
contact of live electric wires, churning of blast furnaces, displacement of other fire related and
FLASH FLOODS- Strong seismic waves cause damage to dams thereby causing severe flash
floods. Severe floods are also caused because of blocking of water flow of rivers due to rock
blocks and debris produced by severe tremors in the hill slopes facing the river valleys. Sometimes
the blockage is so severe that rivers change their main course.
DEFORMATION OF GROUND SURFACE- severe tremors and resultant vibrations caused by
earthquakes result in the deformation of ground surface because of rise and subsidence of
ground surface and faulting activity( formation of faults).
TSUNAMIS-The seismic waves caused by earthquake( measuring more than 7 on richter scale)
travelling through sea water generate high sea waves and cause great loss of life and property.
Emergency management is greatly helpful especially at bad time.
The generic purpose of mitigation strategies is to take preemptive
measures, and activity base costing and on spot management
skills. However, there are three levels of mitigation strategies such
as preemptive measures, response and reaction. On other hand,
mitigation strategies are the suitable in offering the ideal solution to
balancing the needs of maintaining the integrity , economic
development. Mitigation strategies are as such mandate
conservation and efficiency. In earthquake case, the generic roles
of mitigation strategies are to practice Mitigation of Earthquake.
The main and first condition of earthquake is to be calm.
Keep yourself away from doors, windows, cupboard, mirror etc. made of glass.
Stay under table or bed so that you can remain safe from falling heavy things on you.
If possible then go to an open place as soon you can.
If you are outside then stay away from high-rise buildings.
Do not run on the road, hoarding or lamp-post could, hit you.
If the earthquake hits a little, then keep yourself prepared for a bigger one. Because
sometimes a little one carries the sign of a big one.
Do not make crowd on the way of door or stairs, it could be jammed or broken.
Do not make crowd around damaged area or building.
If you find anyone injured, try to provide first-aid. Do not be restless to take him/her in the
Do not try to move a person who is seriously injured.
Do not spread rumor during earthquake. It could raise up the fear and worse down the
A tsunami is a series of water waves caused by the displacement of a large volume of a body of
water, generally an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater
explosions (including detonations of underwater nuclear devices), landslides, glacier calving's,
meteorite impacts and other disturbances above or below water all have the potential to
generate a tsunami.
Tsunami waves do not resemble normal sea waves, because their wavelength is far longer.
Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising
tide, and for this reason they are often referred to as tidal waves. Tsunamis generally consist of a
series of waves with periods ranging from minutes to hours, arriving in a so-called "wave train". Wave
heights of tens of metres can be generated by large events
Tsunamis, also called seismic sea waves or, incorrectly, tidal waves,
generally are caused by earthquakes, less commonly by submarine landslides,
infrequently by submarine volcanic eruptions and very rarely by a large meteorite
impact in the ocean. Submarine volcanic eruptions have the potential to
produce truly awesome tsunami waves. The Great Krakatau Volcanic Eruption of
1883 generated giant waves reaching heights of 125 feet above sea-level, killing
thousands of people and wiping out numerous coastal villages.
The 1992 Nicaragua tsunami may have been the result of a "slow"
earthquake comprised of very long-period movement occurring beneath the sea
floor. This earthquake generated a devastating tsunami with localized damage
to coastal communities in Nicaragua.
Not all earthquakes generate tsunamis. To generate tsunamis,
earthquakes must occur underneath or near the ocean, be large and create
movements in the sea floor. All oceanic regions of the world can experience
tsunamis, but in the Pacific Ocean there is a much more frequent occurrence of
large, destructive tsunamis because of the many large earthquakes along the
margins of the Pacific Ocean.
Tsunamis are some of the most devastating natural disasters
known to man. Think of a flood with its source being an ocean and you can
grasp a little of how much devastation tsunamis can create. For most people
who live in land the greatest threat is from overflowing rivers and creeks. Normally
extraordinarily heavy rainfall causes rivers and and other waterways to overflow.
The excess water creates deadly currents and sweep away people, causing
them to drown. It also does a lot of damage in the initial surge and then with
standing water. A tsunami has all of these detrimental effects plus the added
destructive power crashing waves.
As you many know a tsunami is caused by a strong earthquake
on the ocean bed. The vibrations travel through the water traveling sometimes
thousands of kilometers. If you were on the water or deep sea diving in SCUBA
gear you would not notice much probably just rough waves or a momentarily
strong downward pull if you were underwater. However, a tsunami gains its true
destructive power as it approaches land. The water level becomes shallower
causing the waves caused by the earthquake to compress and combine. This is
what creates the massive and destructive waves that cause so much destruction.
WHAT TO DO BEFORE AND DURING A TSUNAMI :
The Following Are Guidelines For What You Should Do If A Tsunami Is Likely In Your Area:
Turn on your radio to learn if there is a tsunami warning if an earthquake occurs and you are
in a coastal area.
Be alert for Early Warnings
Learn to understand and notice the sea. If there is noticeable recession in water away from
the shoreline become cautious and move away immediately.
Move inland to higher ground immediately and stay there.
Stay away from the beach.
Never go down to the beach to watch a tsunami come in. If you can see the wave you are
too close to escape it.
WHAT TO DO AFTER A TSUNAMI :
The Following Are Guidelines For The Period Following A Tsunami:
Stay away from flooded and damaged areas until officials say it is safe to return.
Stay away from debris in the water; it may pose a safety hazard to boats and people.
Save yourself - not your possessions
In some tsunami-prone countries earthquake
engineering measures have been taken to reduce the damage
Japan, where tsunami science and response
measures first began following a disaster in 1896, has produced ever-
more elaborate countermeasures and response plans. That country
has built many tsunami walls of up to 12 metres (39 ft) high to protect
populated coastal areas. Other localities have built floodgates of up
to 15.5 metres (51 ft) high and channels to redirect the water from