Natural disasters are - geo.lu.lv
Transcript of Natural disasters are - geo.lu.lv
Natural disasters are extreme geophysical events, biological processes and widespread
technological accidents
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Danger may affect:
People Properties Environment
Major natural disasters and anthropogenic accidents are:
Car accidents
Accidents with chemical compounds
Hunger
Cyclones, hurricanes,
Epidemics
Insect invasions
Extreme cold or heat periods
Avalanches and landslides
Flooding
Public unrest
Drought
FiresVolcanic eruptions
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Cyclones, hurricanes, typhoons, storms
Tsunami
Avalanches and landslides
Displacement or movement of people
Volcanic eruptionsEarthquakes
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According to the probability of death cases
Damage by natural disasters Damage by natural disasters (1980 (1980 -- 2008)2008)
Number of disasters
Number of dead
Number of victims
Economic losses, billions EUR
Drought 410 558 565 1 551 455 112 54, 745
Storms 1 211 402 911 496 639 560 379,460
Earthquakes 706 385 630 136 333 515 249, 771
Tsunami 18 229 551 2 481 879 7,441
Floods 2 887 195 843 2 809 481 489 282,779
Epidemics 1 039 183 278 19 411 394 ?
Heat waves 126 89 889 4 614 411 22,261
Vulcano eruptions 140 25 197 4 080 791 2,042
Landslides 366 20 008 7 031 523 0,004
Tornado 182 4 780 12 710 204 22, 417
Avalanches 73 3 532 69 637 0,626
Fires 294 1 666 5 766 092 30, 453
Invasions of insects 75 0 2 200 0,164
Top 10 countries by number of reported events
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Natural disaster impacts by disaster sub-group: 2012 versus 2002-2011annual average
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Percent share of reported economic damages by disaster sub-group and continent in 2012
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The number of reported disasters in Europe (65) was above the annual average disaster occurrence from 2002 to 2011(56). This is largely due
to cold waves and extreme winter conditions which affected most European countries in the beginning of the year. The number of such
climatological disasters (45) is almost three times superior to its annual average for years 2002-2011 (17).
Inversely, 2012 shows a strong decrease in the number of hydrological disasters (16), compared to an annual average of 23. Such decrease is
still more pronounced for meteorological disasters: only one was reported in 2012 –the lowest number ever reported since years 1990 -
compared to an annual average of 14 in years 2002-2011.Therefore, compared to the previous decade, 2012 appears, in Europe, as an
atypical year, with disasters occurring in proportions distinctly different from those of previous years.
In 2012, the decrease in the number of victims (0.58 million) compared to their 2002-2011 annual average (0.66 million) is largely explained
by the decrease of their number in meteorological disasters (-99.7% in 2012 compared to the 2002-2011 annual average) and in hydrological
disasters (-62.2%). In contrast, compared to annual average of the years 2002-2011, the number of victims of geophysical disasters increased
of 76.6% and of climatological disasters of 68.2%. Two earthquakes in Emilia-Romagna and in the Ferrare region made 14,367 and 11,057
victims, respectively. Extreme winter conditions made 230,005 victims in Albania and 18,243 in Serbia. Cold waves made 87,612 victims in
Ukraine, 70,010 in Serbia and 10,351 in Bosnia-Hercegovenia. These five climatological disasters account for 71.7% of the total of victims of
disasters in Europe.
Europe, 2012
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Whereas per year on average from 2002to 2011,hydrological disasters took the largest share of total disaster victims in Europe (41.5%),
followed by climatological (40.3%), meteorological (16.0%) and geophysical (2.2%) disasters, in 2012the picture is different. Climatological
disasters took the largest share (77.6%) and hydrological disasters took a share of 18.0%, only followed by geophysical disasters with 4.4%
and meteorolological disasters with 0.1%.
Damages from natural disasters in Europe in 2012 (US$ 24.2 billion) were the highest of the decade, more than two times the annual average
damages for 2002-2011 (US$ 11.7billion), largely explained by the cost associated with the Ferrare region earthquake in Italia (US$ 15.8
billion)which is the highest cost ever reported in Europe for a geophysical disaster since the year 1990 and is thirty times higher than the
2002-2011 annual damages average for such disasters.
The costs associated with the other Italian earthquake are, actually, not reported. Damages from climatological disasters (US$ 4.2 billion) are
1.5 higher than the 2002-2011 annual damages average for these disasters and are explained by damages from three droughts in Ukraine
(US$ 1.7 billion), Italia (US$ 1.2 billion) and Russia (US$ 1.1 billion). Damages from hydrological disasters (US$ 4.2 billion) are close to their
2002-2011 annual average (US$ 4.7 billion) and are largely explained by four floods in the United Kingdom which cost a total of US$ 2.9
billion or 69% of all damages caused by hydrological disasters.
The damage arising from the only meteorological disaster reported in Europe in 2012 is directly attributable to a tornado which occurred
in Poland and cost US$ 0.006 billion.
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Natural disasters, the annual average economic loss due to natural disasters, from 1980
In subsequent decades, the increase of the global temperature will cause significant climate changes that
will be bigger and stronger than ever in the past 10 000 years
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The hardest will suffer those countries which existence is highly dependent on intensive us e of natural resources
World population in 2011 exceeded 7 billion people, mainly due to the population growth in developing countries
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Urbanization - migration of population from rural to urban areas, caused by depletion of agricultural conditions and due to global economic forces, resulted with excessive growth
of urban population
Dead
Injuries
Homeless
Disrupted Region
Place of disaster
Country
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Media aware
Disrupted
Tax payers
Inconvenienced
Aid donors
Region
World
Impact of natural disasters affect a wide range of persons not only direct victims in the disaster area
Environmental risk studies become more complex, but also narrower and more
detailed in some subsectors
Natural scientists are focused more on the natural Social sciences are looking for
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more on the natural processes , the nature of
developments in the mechanism and frequency
Social sciences are looking for answers exploring public reaction and behaviours in
critical circumstances
But decision-makers need realrecommendations for solving a
problem rather than just a theoretical discussion
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Even if a considerable damage is caused to property or the environment, direct danger to people lives is
perceived as the most dangerous effect
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People's vulnerability and sensitivity is often caused by a lack of emergency management
Natural and anthropogenic accidents may be classified by the inducing factors :
� Atmospheric factors
� Hydrologic factors
� Geological factors
� Biological factors
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� Biological factors
� Technological factors
� Social violence
� Complicated danger factors
Direct effects are effects that appear immediately after
the disaster
Indirect effects appear later and sometimes can be difficult to identify
and link up with a disaster
Natural disasters can cause direct and indirect effects:
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Tangible effects are those for which it is possible to estimate losses in monetary terms, such as the damaged property to restore the necessary resources
Undetectable effects – actual effects, but impossible to determine in monetary expression:
loss of life can be detectable medically and legally, but economical or financial loss value calculation is very complex
Natural disasters recurrence time is the average time between two following natural disasters
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Most natural hazards can be measured by some physica l parameters within a specific scale
The most dangerous places are around the tectonicfractures - usually in high mountains or on coastal areas
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About the half of the world's population is living in 60 km coastal area near the river deltas or at the seaside
About 25% of the world population are exposed to na tural disasters , the majority of them live in developing countries
Sensitivity is a critical factor , that can be increased by people poverty, age, health and
human physical abilities
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Well equipped societies and families with access to resources can more easily survive if natural disasters occur
Access to the information and social communication networks also is very important
Earthquakes and volcanic eruptions occur mainly around the borders of the
lithosphere plates
Lithosphere plates are from 6 km to 200 km thick, solid Earth's outer shell that consists of different sized boards, which are:
� In some places moving away from each other – divergence
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� In some places moving away from each other – divergence� Other moving towards one another – convergence� Or slipping one beneath the other or one moving along the second
Convergence Divergence
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San Andreas fault in CaliforniaSan Andreas fault in California
Earthquake strength can be measured using the Richt er scale : earthquakes, power is expressed in terms of the size of the output
energy, which can be measured by seismograph amplitude ratio scale
Minor: up to magnitude 4
Little: magnitude 4-5
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For earthquake intensity determination Mercalli scale is used, with the scores from I to XII determine the impact the earthquake has had on
people, buildings and the environment
Harmful: magnitude 5-6
Destructive: magnitude 6-7
ballesStrong: magnitude 7-8
Disruptive: more as
magnitude 8
Earthquakes primary effects are associated with the earth shake, and
vertical or horizontal
This leads to a strong impact on people and
structures
Secondary effects of earthquakes are
associated with rock mass movement,
such as rock falls and
Earthquakes are characterized by primary and secondary effects:
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vertical or horizontal ground movements
such as rock falls and landslides
TsunamiTsunami
On December 26, 2004 India ocean earthquake (9.1 magnitude) with epicentre atSumatra, Indonesia aroused huge tsunami wave, which killed approximately 230 000persons in 11 countries, mainly in Indonesia, Sri Lanka, India and Thailand.
Tsunami, India ocean, 26.12.2004.Tsunami, India ocean, 26.12.2004.
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Flooding is irregular water level rise at any time and place , which occurs in floodplain and other areas
Due to the origin of nature there can be separated floods and flooding:
� Flood is a river water treatment � Flooding can be characterized by
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� Flood is a river water treatment phase characterized by the seasonal largest watering that occurs yearly or seasonally, and usually at the floodplain areas
� Flooding can be characterized by intermittent (at any time and place) and a sharp but temporary rise of water level, which occurs during floodplain or other areas
Flooding or flood is usually associated with rivers , and less with lakes or other water bodies
North Sea October 11. - 12.,
1634.
Flood risk can also be a result of
human economic activities
Extreme flood situations is often associated with heavy rain , which causes storms, or rapid melting of
snow
In some cases flooding occur when natural or man -made
Earthquakes in the ocean can cause catastrophic
Threat of
flooding:
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when natural or man -made dams are broken
ocean can cause catastrophic floods, by releasing of massive
tsunami waves
Flooding in urban areas present more difficulties because of natural ground surface is built with a water-
tight materials
� Flooding primary physical effects
� Secondary effects result in decrease of water quality
Flooding effects can be primary and secondary :
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However, flooding may also give beneficial effects on river ecosystems –by groundwater recharge and increase of soil fertility
by bringing fertile mud into soils
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In Europe flooding occurs mostly in central and southern
part and is caused mostly by rainfalls and may affects about
1.5% of the population
However, 70% of the world flooding occurs in Asia
Floods in BangladeshFloods in Bangladesh
In flooding risk areas risk assessment is very important therefore the flooding frequency should be detected over
a specified period
Flooding hazard mitigation can be implemented in various ways:
Betterments, creating of
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Betterments, creating of channels , straightening of
river beds etc.
Creating of wetlands , which work as water sponges during
floodingFlooding prevention barriers
helps to keep and store a certain volume of flooding waters to
dissipate later steadily
Building of permanent or temporary embankments
along the river banks certain in places
Territory of Latvia is divided into four river basin management areas - Venta, Lielupe, Daugava and Gauja
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Daugava River flood is seasonal, mainly formed in the spring, when snow melts, rivers are rising water levels and ice jams.
Strong wind affects the water flow from the Gulf of Riga - water can be blown into the Daugava River, raising the water level and threatening the
city of Riga.
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Biological factors or agents , which can lead to disasters:Bacteria Viruses Fungi Protozoan
Algae Plants Insects Animals
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� Different nature of the diseases and epidemics or pandemics
� Undesirable, harmful or noxious plant and animal invasions
� Insect invasion with its consequences on people,
environment and agriculture
� Predatory animal attacks
� Fish, crustaceans and molluscs pollution
� Forest fires
Biological agents can cause:
Epidemic expandswhen in the
population appears more and more new
cases of certain
If an epidemic is covering very large areas, it is called a pandemic
Simple diseases that are a little
variable but rather in a small scale, can be called as
endemic
Infectious diseases are characterized by several specific terms:
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disease in a short period of time
endemic
Nowadays, the world is concerned about the wide spread of such
diseases as malaria, tuberculosis, influenza strains
MalariaMalaria
Anopheles albimanus mosquitofeeding on a human arm
An estimated 655,000 people died from malaria in 2010, a decrease from the 781,000 who died in 2009,according to the World Health organisation’s 2011
World Malaria Report, accounting for 2.23% of deaths worldwide.
However, a 2012 meta-study from the University of Washington and University of Queensland
estimates that malaria deaths are significantly higher - the study estimates that 1,238,000 people
died from malaria in 2010.
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Fire is the uncontrolled spread of fire which may occur in populated areas or in natural areas
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Characteristic parameters of fires are:� Distribution speed
� Quantity of material burning
� Topography
� Geographic location
� Cause of the outbreak
� Weather conditions
Fires cause considerable damage to people as well as for property and material
assets
Fires can be characterized by both, negative and positive effects:
Fires sometimes give the benefits , especially for some species in areas where the conditions for growth and
proliferation can only occur due to fires
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Adapting occur after fires including the appearance of
plant physical protection from heat and increased growth
after the fires
Natural causes of fires are:
� Lightning
� Volcanic eruptions
� Sparks rock spark
� Spontaneous ignition
� Smoldering of underground coal or peat layers
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Large fires can affect both, climate and weather , they create a regional and even global pollution, fires also
release greenhouse gas emissions
However, many fires occur from human inattention (dropped cigarette, spark from engine) or from
deliberate abuse
� Smoldering of underground coal or peat layers
An important element is the rapid forest fire detection that can be realized by observation, as follows:
Forest observations from towers equipped with surveillance equipment
and communication systems
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Satellite and aeral monitoring allows to obtain information, as well as provide insight into the events of a very broad and even low-
risk areas
and communication systems
Observations from space
Heat periods are long periods of hot weather which expression is dependent on site-specific climatic conditions
Strong heat periods which are very rare and can lead to:
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Power supply disruption from the increased air
conditioning use
Catastrophic damage to agricultural
crops
Death of thousands of people from hyperthermia or
overheating
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In summer of 2003, over the western Europe was spread a stable anticyclone and temperature contributed to the
increase of 20-30% above average
Drought can cause the following effects:
� Massive people migration
� Famine, poverty and diseases
� Decline in electricity production,
� Drastically reduce crop yields and livestock survival
� Sand and dust storms, causing desertification, soil erosion
� Damage to both terrestrial and aquatic ecosystems and species
� Social unrest and even lead to
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and livestock survival� Social unrest and even lead to war for natural resources, food and water
1973 19971987
Lake Chad in Africa from
1965 has been reduced
482001
1965 has been reduced
for 95%
Storms occur when rapidly rising or falling atmosph eric pressure areas are crossed by large cyclone or torn ado , as
well during a local or frontal a lightning storms
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Storm is a very strong wind for which the cumulative speed over 10 minutes is at least 24 m/s and gusts can
reach up to 100 m/s (360 km/h)
Tornado is a devastating and rapidly tapered atmosp heric vortex with the rain and the storm , which usually occurs when a cool, dry air mass meet the warm, moist air mass,
forcing the warm air to rise to the top suddenly
Hurricane reminds huge gyratory plate
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with a diameter can reach up to 500 km, but in rare cases up to 1000 km
Hurricanes never ! occur over land, just over the sea or ocean in tropical zone , where
temperatures in the upper layers is at least +27 °C
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TORNADOTORNADO
HurricaneHurricane “Katrina” in 2005, USA“Katrina” in 2005, USA
* Character Wind speed; km/h * Character Wind speed; km/h
Tropical depression 0–62 3. category 178–209
Tropiskā vētra 63–117 4. category 210–249
1. category 119–153 5. category ≥250
2. category 154–177Have not information
Saffir–Simpson hurricane scale
During the storms, strong air mass collisions cause raindrops and hail grain collisions in the clouds, creating an electrical
charge, resulting in huge fires spark – lightning
Most typical type of lightning - lines that spark discharges in the branches,
whose length is usually 2-3 km
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From the enormous heat that is released as a result of lightning,
nearby air rapidly expands causing thunder
whose length is usually 2-3 km