Disaster prevention and preparedness.pdf

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1. Disaster prevention and preparedness
Cr.Hr: 1

By Lencho.K (BSc, MPH)
School of Public Health
Wollega University
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2. Course contents
1.Unit 1: introduction to disaster
2.Unit 2: General Consequences of Disaster
3.Unit 3: Health Consequences of Disaster
4.Unit 4: Prevention and control of disaster
5.Unit 5: Role of PHCU team in the events of disaster

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3. Unit one: Introduction to Disaster
Unit objective
At the end of this lesson, students will be able to:
–Definition of disaster
–Discuss epidemiology of disaster in Ethiopia
–List causes of the disaster
–Identify natural and man-made disasters
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4. Disaster
■A sudden ecological phenomenon of sufficient magnitude
to require external assistance.
■Also called “calamity” and “catastrophe”
–Is a sudden, devastating event that causes serious disruption of
the functioning of a community or a society
–with widespread human, material, economic, and/or
environmental losses that exceed the ability of the affected
community or society to cope using its own level of resources.
Source: UN/ISDR 2004 and ECHO

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5. •Disaster may occur with or without a warning.
•It is inevitable, but its impact can be minimized.
•The combination of hazards, vulnerability, and inability to
reduce the potential negative consequences of risk
results in disaster.
• (Vulnerability+ hazard ) / capacity = disaster)




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6. Definition of terms
•Emergency:
oA state in which normal procedures are suspended and extraordinary
measures are taken in order to avert the problem
•Vulnerability:
oSusceptibility to damage or harm by a hazard or
oInability to cope with the consequences of a hazard
•Hazard
oA rare or extreme event in the natural or human made environment that
adversely affects human life, property or activity to the extent of causing
a disaster
oWe cannot avoid hazards, but we can prevent them from becoming
disasters


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7. •Risk
oExpected losses (lives lost, persons injured, damages to
property and disruption of economic activity) due to a
particular hazard.
oCombines the level of hazard and degree of vulnerability
(product of hazard and vulnerability)
oRisk = hazard x vulnerability
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8. •Mitigation:
oIs permanent reduction of the risk of a disaster.
oPrimary mitigation refers to reducing the resistance of the
hazard and reducing vulnerability.
oSecondary mitigation refers to reducing the effects of the hazard
(preparedness).
oDisaster prevention refers to measures taken to eliminate
the root causes that make people vulnerable to disaster .
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9. Definition of terminologies…
Prevention planning is based on two issues:
Hazard identification - identifying the actual threats facing a
community.
Vulnerability assessment - evaluating the risk and capacity of
a community to handle the consequences of the disaster

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10. Definition of terminologies…
Disaster preparedness is the building up of capacities before a
disaster situation prevails in order to reduce impacts.
Its measures include the availability of
-Food reserve, - Warning systems,
-Emergency reserve fund, - Logistical infrastructure,
-Seed reserve, - Relief manual, and
-Health facilities, - Shelves of projects
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11. Definition of terminologies…
Response is the set of activities implemented after the impact
of a disaster in order to assess the needs, reduce the suffering,
and limit the spread and the consequences of the disaster, open
the way to rehabilitation.
Reconstruction: the full resumption of socio-economic
activities plus preventive measures.
Rehabilitation is the restoration of basic social functions.
Resilience: adaptability, capacity to recover.
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12. Definition of terminologies…
•Disaster impact is the total effect, including negative effects
(e.g., economic losses) and positive effects (e.g., economic
gains), of a hazardous event or a disaster.
•The term includes economic, human and environmental impacts,
and may include death, injuries, disease and other negative
effects on human physical, mental and social well-being.
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13. Features of a disaster
May be unpredictable
Speed
Urgency
Uncertainty
Threat

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14. Types of Disasters
Disasters are broadly divided into two types:
1)Natural disaster
2)Man-made (technological) disaster
Sometimes Hybrid type of disaster
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15. 1. Natural Disasters
•Occur as the result of the action of the natural forces.
•Result from forces of climate and geology
•The most “unexpected” and costly overall in terms of loss
of human lives and resources

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16. Natural disaster…
They can be divided into four specific groups:
A.Hydro-meteorological disasters- Avalanches and Floods, wave
surges, storms, and Cyclones.
B.Climatological (e.g. Extreme Temperatures, Drought, and
Wildfires)
C.Geophysical disasters:- includes earthquakes, landslides,
Tsunamis, and volcanic eruptions
D.Biological disasters:- includes epidemics and insect/animal
plagues
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17. Natural disasters can also be categorized as “acute” or “slow”
in their onset
Natural disasters with acute onsets
-Earthquake
-Flood
-Hurricane
-Cyclone or
typhoon
-Tornado
-Fire
-Tsunami or
storm surge
-Avalanche
-Volcanic
eruption
-Extreme cold or
blizzard
-Heat wave

Natural hazards with slow or
gradual onset
-Drought
-Famine
-Desertification
-Deforestation
-Pest infestation
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18. Floods
•Occurs when water covers dry areas
•The most frequent type of natural disaster associated with sudden
migration of large populations and food shortage
•The frequency of floods is increasing faster than any type of disaster
•Much of flood incidence can be can be attributed to
–Uncontrolled urbanization
–Deforestation
–Effect of El Niño (more recently)
•It may also accompany other natural disasters, such as sea surges
during hurricanes and tsunamis following earthquake.



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19. Cont’d…
•Flood is one of the major natural hazards in Ethiopia which
causes significant damages to lives and livelihoods in parts of
the country.
•In most cases floods occur in the country as a result of
prolonged heavy rainfall causing rivers to overflow and inundate
areas along the river banks in lowland plains.
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20. Cont’d…
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21. Cont’d…
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22. Impact of floods
•Mass homelessness
•Disruption of communications and health care systems
•Heavy loss of business, livestock, crops, and grain, particularly
in densely populated, low lying areas like that of the Awash
Valley.
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23. Cont’d…
•Acute effect:
–Death through drowning(sinking) and accidents such as falls,
electrocution and the effect of landslides
–People lose their homes and often also lose their source of
food and water
–Sanitation is a major problem in all flooded areas
–Increased risk(favor the spread) of diarrheal disease
including cholera


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24. Cont’d…
•Long term effect:
–Provide an ideal breeding ground for mosquitoes - an
increased risk of diseases such as malaria, dengue, and Rift
Valley Fever.
–Displace rodent populations - may cause human outbreaks
of leptospirosis and Hantavirus infection.
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25. Earthquake
•Sudden slippages or movements in a portion of the earth's
crust accompanied by a series of vibrations
•It strikes all of a sudden at any time of day or night and quite
violently
•If it happens in a populated area, the earthquake can cause
great loss to human life and property
•No prior warning
•It can occur at any time of the year
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26. Cont’d…
•Is generally considered to be the most destructive and
frightening of all forces of nature.
•The Richter scale, used as an indication of the force of an
earthquake, measures the magnitude and intensity or energy
released by the quake.
–But it does not address the possible damaging effects of the
earthquake.
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27. Impact of earthquake
Injuries and deaths - more in undeveloped
countries
–It can vary according to:-
-Type of housing available
-Time of day of occurrence
-Population density
More financial losses
Morbidity and mortality
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28. Drought and famine
Drought
•Is lack or insufficiency of rain for an extended period that
severely disturbs the hydrologic cycle in an area.
•Any lack of water for the normal needs of agriculture,
livestock, industry, or human population
•Involve water shortages, crop damage, stream flow
reduction, and depletion of groundwater and soil moisture.
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29. Cont’d…
•Human activities also contribute to the creating of
drought conditions.
–Overgrazing
–Poor cropping methods
–Improper soil conservation techniques
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30. Impact of Droughts on Built and Natural
Environments
•Primary (Immediate) Effects
-Water supplies are overtaxed and finally dry up
-Loss of crops
-Loss of livestock and other animals
-Loss of water for hygienic use and drinking
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31. Cont’d…
•Secondary (Resulting) Effects of Drought
-Migration in search of better grazing lands
-Famine
-Permanent changes of settlement, social, and living
patterns
-Major ecological changes (scrub growth, flash flooding and
increased wind erosion of soils)
-Desertification.
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32. 32

33. Cont’d…
Famine
•A phenomenon in which a large percentage of the
populations of a region or country are so undernourished
and that death by starvation becomes increasingly
common.
•Associated with naturally-occurring crop failure and
pestilence, and artificially with war and genocide.
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34. Tsunamis
•Is a series of enormous waves
generated by an under sea
disturbance such as submarine
earthquake, volcano, landslide or
strong winds.
•Also known as seismic sea waves
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35. Storms
•An atmospheric disturbance
manifested in strong winds
accompanied by rain, snow and
often by thunder and lightning

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36. Cyclones, Hurricane or Typhoon
•Cyclones develop when a warm ocean gives rise to hot air,
which in turn creates convectional air currents and these
convectional air currents are being displaced.
•During a cyclone trees can be uprooted, buildings can be
destroyed and cars can be overturned.

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37. 2. Man-Made Disasters
•Result from some human activities, such as
oExplosion, Fires
oWar/conflict
oRelease of toxic chemicals or radioactive materials,
Nuclear reactor accidents
oBridge or building collapse, crashes
oDam or levee failure
oBreaks in water, gas, or sewer lines
oDeforestation, etc.
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38. Cont’d…
•Caused by humans intentionally or unintentionally or due to negligence or
lack of concentration, as well as variability of interest or feeling of distress
•Tend to involve many more casualties than natural disasters of the same
magnitude of energy release
•Unpredictable
•Can spread across geographical areas
•May be non-preventable
•May have limited physical damage but long-term effect
•Much more difficult for the community to deal with and for victims to accept
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39. Explosions
•It can inflict multi-system life-threatening injuries to many persons
simultaneously.
•Contributing factors include:-
Composition and amount of the materials
Method of delivery, such as a bomb
Distance between the victim and the blast
Absence/presence of protective barriers or environmental hazards in the
area of the blast


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40. Fires
•There are two types of fire disasters.
–Domestic and wild fires
•They can be triggered or exacerbated by
–Lightning - most significant natural contributor
–High winds
–Earthquakes
–Volcanoes
–Floods
–Deliberate setting of fire by human beings
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41. Cont’d…
•Wild land fires are classified into three categories:
a.A surface fire: is the common type and burns
along the floor of a forest, moving slowly and
killing or damaging the trees;
b.A ground fire: is usually started by lightning and
burns on or below the forest floor;
c.A crown fire: spreads rapidly by winds and moves
quickly by jumping along the top of trees.
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42. Cont’d…
•Wildfire that broke out at Nech Sar National Park in Arba Minch city (Jan 25,
2019)
–Destroyed some 1, 000 hectar forest
–No human & wild life causalities
–Caused by suspected illegal activities
•Wildfire has burn 340 hectares of forest in Ethiopia’s Simien National Park,
which is found in Amhara Region (March 31, 2019)
–It is not yet clear how the fire has started according to the report
–Rumour - it might be caused by some people in the area who have been
complaining about not benefiting from the Park
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43. 3. Hybrid Disasters
•Disasters that result from both human error and natural forces.
e.g. the extensive clearing of dense forest causing soil erosion, and
subsequently heavy rain causing landslides.
Landslides
•Downward movement of masses of rock and soil
•The factors affecting landslides can be geophysical or human-made

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44. Landslide… •Geophysical:-
–Rains
–Floods
–Earthquakes
•Human-made:-
–Grading
–Terrain cutting
–Filling
–Excessive
development
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Landslide in Koshe, Addis Ababa March, 2017

45. Another classification of disasters
I.Sudden-onset disasters: include floods, earthquakes,
tsunamis, tidal waves, tropical storms, volcanic eruptions, and
landslides.
•As their name implies, sudden-onset disasters occur swiftly
and often without any warning.
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46. Another classification of disasters
II. Slow-onset disasters include droughts, famine,
environmental degradation, deforestation (loss of trees and
vegetation), pest infestation, and desertification (conversion
of arable lands to deserts).
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