Natural hazard
A natural hazard is a threat of a naturally
occurring event that will have a negative effect on people or the environment.
Many natural hazards are interrelated, e.g. earthquakes
can cause tsunamis
and drought
can lead directly to famine or population displacement. It is possible that some
natural hazards are intertemporally correlated, as well. 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 living on a fault line is a hazard.
Geophysical hazards
Earthquake
An earthquake
is a phenomenon
that results from a sudden release of stored energy that radiates seismic waves.
At the Earth's
surface, earthquakes may manifest themselves by a shaking or displacement of
the ground and sometimes tsunamis. Most of the world's earthquakes (90%, and 81% of the
largest) take place in the 40,000-km-long, horseshoe-shaped zone called the
circum-Pacific seismic belt, also known as the Pacific Ring of Fire, which for
the most part bounds the Pacific Plate. Many earthquakes happen each
day, few of which are large enough to cause significant damage.
Sink holes
A Sink hole
is localized depression in the surface topography, usually caused by the
collapse of a subterranean structure, such as a cave. Although rare, large
sink holes that develop suddenly in populated areas can lead to the collapse of
buildings and other structures.
Volcanic eruption
Hydro Meteorological hazards
Drought
Scientists warn
that global warming and climate
change may result in more extensive droughts
in coming years.
Hailstorm
A hailstorm is a natural
hazard where a thunderstorm produces numerous hailstones
which damage the location in which they fall. Hailstorms can be especially
devastating to farm
fields, ruining crops and damaging equipment.
Heat wave
A heat wave
is a hazard characterized by heat which is considered extreme and unusual in the area in
which it occurs. Heat waves are rare and require specific combinations of weather
events to take place, and may include temperature inversions, katabatic
winds, or other phenomena. There is potential for longer term events
causing global warming, including stadial
events (the opposite to glacial 'ice age' events), or through human induced
climatic warming.
Maelstrom
A maelstrom
is a very powerful whirlpool. It is a large, swirling body of water with
considerable downdraft. There are virtually no documented accounts of large
ships being sucked into a maelstrom, although smaller craft and swimmers are in
danger. Tsunami generated maelstroms may even threaten larger crafts.
Cyclonic storms
Hurricane,
tropical cyclone, and typhoon
are different names for the same phenomenon: a cyclonic storm system that forms
over the oceans. It is caused by evaporated water that comes off of
the ocean
and becomes a storm.
The Coriolis Effect causes the storms to spin, and
a hurricane is declared when this spinning mass of storms attains a wind speed
greater than 74 mph (119 km/h). Hurricane is used for these
phenomena in the Atlantic and eastern Pacific
Oceans, tropical cyclone in the Indian,
typhoon in the western Pacific.
Ice storm
An ice storm
is a particular weather
event in which precipitation falls as ice, due to atmosphere conditions.
Tornado
A tornado
is a natural disaster resulting from a thunderstorm.
Tornadoes are violent, rotating columns of air which can blow at speeds between
50 mph (80 km/h) and 300 mph (480 km/h), and possibly
higher. Tornadoes can occur one at a time, or can occur in large tornado
outbreaks associated with supercells
or in other large areas of thunderstorm development. Waterspouts
are tornadoes occurring over tropical waters in light rain conditions.
Climate change
Climate
change is a long-term hazard which can increase or decrease the risk
of other weather hazards, and also directly endangers property due to sea level
rise and biological organisms due to habitat
destruction.
Geomagnetic storm
Geomagnetic
storms can disrupt or damage technological infrastructure, and
disorient species with magnetoception.
Disease
Disease
is a natural hazard that can be enhanced by human factors such as urbanization
or poor sanitation.
Disease affecting multiple people can be termed an outbreak
or epidemic.
In some cases,
a hazard exists in that a human-made defense against disease could fail, for
example through antibiotic resistance.
International campaigns
In 2000, the United
Nations launched the International Early Warning Programme
to address the underlying causes of vulnerability and to build
disaster-resilient communities by promoting increased awareness of the
importance of Disaster Risk Reduction as an integral
component of sustainable development, with the goal of
reducing human, economic and environmental losses due to hazards of all kinds
(UN/ISDR, 2000). The 2006-2007 United Nations International Disaster Reduction
Day theme is “Disaster reduction education begins in school”. The Foundation of
Public Safety Professionals has launched an international campaign giving
everybody a chance to have their say, thought their international open essay or
documentary competition “Disaster Risk Reduction Education Begins at School”.
