2. Disaster Risk
Definition of concepts:
The term disaster is coined from Latin words dis & astro- , which
means away from the star or an event to be blamed on an unfortunate
astrological configuration.
In the past, disasters were seen as „Acts of God”.
Death is the just punishment for sin (Romans 6:23).
Does God use natural disasters to punish mankind today ?
Some people believe that God uses natural calamities to discipline
humankind. Others reject that notion. Still others do not know what to
believe.
He is the Creator and as such has the power and authority to control
earth‟s natural forces (Revelation 4:11) . His actions are always in
harmony with his personality, qualities, and principles.
3. These perspectives viewed disasters as a divine punishment for moral
misbehavior, rather than a consequence of human misuse of the
environment.
In other words, disasters were accepted as external inevitable events
Until 1950, disaster risk was solely seen as caused by natural hazards
• However, development in science & technology gradually started to
question these perceptions on disasters.
• From 1970, views which recognize the role played by human actions
in exacerbating hazards have emerged.
• But until 1990s most of the approach had over emphasized on
extreme events & humanitarian or emergency response, which was
the dominant strategy in reducing the impact of disasters.
• This neglected the root causes & everyday social processes that
influence vulnerability & looked to see how this could be
incorporated into long-term development approaches .
4. • Since 1990, the contemporary understandings has re-emphasized the
mutual interactions between nature & society
• Hence, in contemporary understanding disaster is:
• considered as a function of the characteristics & frequency of
hazards at a specified location,
• the nature of the elements at risk (people, infrastructure, &
economic activities),
• their inherent degree of vulnerability to the hazard &
• their capacity to manage or reduce the hazards‟ impact
• The greatest challenges of humanity at the start of the 21st century are
conflict, violence, terrorism, and war along with their terrible
consequences of poverty, disease, environmental destruction, and poor
leadership.
• Religious fanaticism, insecurity, unemployment, illiteracy, fear, depression
and unhappiness have been some of the primary causes of terrorist
activities in the world.
• These challenges are present at all levels of human life—family, school,
community, society, and globally
5. • UNISDR is the UN office dedicated to disaster risk reduction..” Acc.
to. UNISDR (2009), a disaster is a result from the combination of
hazard, vulnerability and insufficient capacity or measures to reduce
the potential chances of risk.
• A disaster happens when a hazard impacts on the vulnerable
population and causes damage, casualties and disruption.
• E.g A given hazard – flood, earthquake or cyclone which is a
triggering event along with greater vulnerability (inadequate access
to resources, sick and old people, lack of awareness etc) would lead
to disaster causing greater loss to life and property.
• a serious disruption of the functioning of society, causing
widespread human, material or environmental losses & impacts
• which exceeds the ability of the affected community to cope using
only its own resources.
6. DRM cont…
• Therefore, we need to understand the three major
components namely hazard, vulnerability and
capacity with suitable examples to have a basic
understanding of disaster management.
• Hazards are always prevalent, but the hazard becomes a
disaster only when there is greater vulnerability and less
of capacity to cope with it.
• In other words, the frequency or likelihood of a hazard
and the vulnerability of the community increases the risk
of being severely affected.
7. A disaster happen only when a hazard meets a vulnerable
situation or people.
People are vulnerable when they are unable to adequately
anticipate, withstand & recover from hazards.
Vulnerability refers to the characteristics of a person or a group &
their situation that influence their capacity to anticipate, cope with,
resist & recover from the impact of a hazard.
There are many aspects of vulnerability arising from various
physical, social, economic, & environmental factors
E.g. -poor design & construction of buildings,
-inadequate protection of assets,
-lack of public information & awareness
8. • A disaster is a function of the risk process.
• It results from the combination of hazards, conditions of vulnerability & insufficient
capacity or measures to reduce the potential negative consequences of risk.
Disaster risk (R) = Vulnerability (V) X Hazard (H)/Capacity (C) .
• What is the difference between a 'hazard' and a 'risk'?
• A hazard is something that can cause harm, e.g. electricity, chemicals, working up a
ladder, noise, a keyboard, stress, etc.
• A risk is the chance, high or low, that any hazard will actually cause somebody
harm.
• Risk is a function of the probability of particular hazardous event and the losses
each would cause.” The level of risk depends upon:-
(i) Nature of the hazard (ii) Vulnerability of the elements which are affected
(iii) Economic value of those elements
-A community/locality is said to be at ‘risk’ when it is exposed to hazards and is likely to
be adversely affected by its impact. Whenever we discuss ‘disaster management’ it is
basically ‘disaster risk management’. - Disaster risk management includes all measures
which reduce disaster related losses of life, property or assets by either reducing the
hazard or vulnerability of the elements at risk.
9. The concept of hazards
• A potentially damaging physical event,
phenomenon or human activity, which may
cause the loss of life or injury, property
damage, social & economic disruption or
environmental degradation
• Potential cause form harm
• Some examples of hazards are
earthquakes, volcanic eruptions,
cyclones, floods, landslides, droughts,
& other such events.
10. Hazards classification
1. Natural Hazards: Natural processes or phenomena occurring in
the biosphere that may constitute a damaging event.
• Natural hazards can be classified according to their geological,
hydro-meteorological or biological origins.
• Natural hazards comprise phenomena such as earthquakes; volcanic
activity; landslides; tsunamis, tropical cyclones & other severe storms;
tornadoes & high winds; river floods & coastal flooding; wildfires &
associated haze; drought; sand/dust storms; insect infestations.
11. 2. Anthropogenic hazards: These are human induced processes or phenomena
occurring in the biosphere that may constitute a damaging event.
• These hazards are the consequences of human activities which may
cause loss of life or injury, damage to property, social & economical
disruption or environmental degradation.
• Examples of human-made hazards mostly include Technological
hazards: such as the toxicity of pesticides to fauna, accidental release of
chemicals or radiation from a nuclear plant. These arise directly as a result
of human activities.
• Disasters have always been a result of human interaction with nature,
technology & other living entities. Sometimes unpredictable & sudden,
sometimes slow & persistent, various types of disasters continually affect
the way in which we live our daily lives. Human beings as innovative
creatures have sought new ways in which to control/limit the devastating
effects of disasters.
12. 3. quasi-natural hazards …
• Another classification includes quasi-natural hazards that arise
through the interaction of natural processes & human activities.
• Environmental degradation is partly due to processes induced
by human behavior & activities in a way (sometimes combined
with natural hazards).
• ED damages the natural resource base or adversely alters
natural processes or ecosystems. E.g.. Desertification.
13. Origin PHENOMENA/ EXAMPLES
Hydro-meteorological hazards
Natural processes or phenomena
of atmospheric, hydrological or
oceanographic nature.
• Floods, debris & mudflows
• Tropical cyclones, storm surges, wind,
rain & other severe storms, blizzards, lightning
•Drought, desertification, wildfires, temperature
extremes, sand or dust storms
• Permafrost, snow avalanches
Geological hazards
Natural earth processes or
phenomena that include processes
of endogenous origin or tectonic
or exogenous origin, such as mass
movements.
• Earthquakes, tsunamis
• Volcanic activity & emissions
•Mass movements, landslides, rockslides
liquefaction, sub-marine slides
• Surface collapse, geological fault activity
Biological hazards
Processes of organic
those conveyed by biological
vectors, including exposure to
pathogenic micro-organisms,
toxins & bioactive substances.
Outbreaks of epidemic diseases, plant
origin or or animal contagion & extensive -------infestations
Classification of Natural Hazards
14. Origin Phenomena/Examples
Technological Hazards
Danger associated with technological or
industrial accidents, infrastructure failures or
certain human activities which may cause the
loss of life or injury, property damage, social &
economic disruption or environmental
degradation, sometimes referred to as
anthropogenic hazards.
•Industrial pollution, nuclear
release & radioactivity, toxic
waste, dam failure, transport,
industrial or technological
accidents (explosions, fires,
spills).
Environmental Related Hazards
Processes induced by human behavior &
activities (sometimes combined with natural
hazards) that damage the natural resource base
or adversely alter natural processes or
ecosystems. Potential effects are varied & may
contribute to an increase in vulnerability & the
frequency & intensity of natural hazards.
Examples include land
degradation, deforestation,
desertification, wild fires, loss
of biodiversity, land, water &
air pollution, climate change,
sea level rise & ozone
depletion.
Classification of Anthropogenic Hazards
15. Natural Hazards Vs. Disasters
• A disaster is the result of the impact of a natural or human
made hazard on a socio-economic system with a given
level of vulnerability, which prevents the affected society
from coping adequately with this impact.
• Natural hazards themselves do not necessarily lead to
disasters.
• It is only their interaction with people & their environment
that generates impacts, which may reach disastrous
proportions .
• Human social & economic development has further
contributed to creating vulnerability & thus weakening the
ability of humans to cope with disasters & their effects.
16. Hazards Vs. Disasters….
• Many scholars have expressed diverse views on what exactly
constitutes a disaster.
• Some link the existence of a disaster to a specific amount of losses
sustained (e.g. number of people killed & injured).
• others judge an event to be a disaster if a certain predefined threshold
is breached
• some judge disasters on their geographical extent & significance with
regard to “normal” conditions,
• while some express a disaster in terms of its monetary value in losses.
17. More hazard terminology….
1. Secondary hazards
• These are hazards that follow as a result of other hazard events.
• Examples of secondary hazards are: Building collapse; Dam failure ; Fire;
Hazardous material spill; Interruption of power/ water supply/
communication/ transportation/ waste disposal; Landslide; Tsunami
(tidal wave); Water pollution…
2. Chronic hazards
• A group of hazards that do not stem from one event but arise from continuos
conditions.
• Exemples: ., famine, Resource degradation, pollution, & large-scale toxic
contamination, which accumulate over time.
18. Distribution of common hazards in the World
• Despite the lethal reputation of earthquakes, epidemics &
famine, natural hazards, are not the greatest threat to humanity,
• a much greater proportion of the world‟s population find their lives
shortened by events that often go unnoticed: violent conflict, illnesses,
& hunger (Wisner et al., 2005)
• Wisner et al (2005) distinguish between slow onset & rapid
onset hazard types
• There is a need to connections between the risks people face
& the reasons for their vulnerability to hazards.
19. Top 10 countries by number of reported events in 2014
Source: Annual Disaster Statistical Review 2014: the numbers & trends
20. Hazard types & their contribution to deaths, 1900–1999
Avalanches: a mass of snow, ice, and rocks falling rapidly down a mountainside.
21. Deaths during disasters, listed by cause, 1900–1999
The Great Leap Forward famine in China (1958–1961), & then low estimates put
the number of deaths at 13 million & higher ones at up to 30 million or more
22. Total number of reported natural disasters between 1900 & 2015
Disaster Database-www.emdat.be
Source: Author‟ computation from EM-DAT: OFDA/CRED International
23. Total affected persons by reported natural disasters between 1960 & 2015
Disaster Database-www.emdat.be
Source: Author‟ computation from EM-DAT: OFDA/CRED International
24. Source: UNISDR 2016
February 11, 2016– UNISDR 2015/16
The human cost of the hottest year on record - climate change & Drove disasters El Nino
worldwide in 2015
– The hottest year on record, 2015, has confirmed that weather and climate-related disasters
now dominate disaster trends linked to natural hazards, according to a new analysis
presented today.
346 reported disaster
22 773 people died
98.6 million people affected
66.5 USD billion economic damage
The top five most disaster-hit countries in 2015 were China USA,
India , Philippines and Indonesia .
27. 3.4 Common Hazards in Ethiopia
Ethiopia has a long recorded history of disasters of both natural and
anthropogenic origin. The common hazards causing disasters include
drought, floods, landslides, civil war, epidemics, and mass
displacement.
Drought:
Ethiopia has faced severe drought 15 times since 1965. According to
the Food Security Risk Index for 2010, it is one of 10 countries
considered to be at extreme risk, and is ranked as having the 6th
highest risk out of 163 countries surveyed.
The pastoralist populations of the Afar and Somali Region continue to
be the most acutely food insecure in the country.
A significant proportion of the population in the northeastern
highlands is chronically food insecure.
In addition, people living along the riverbanks of major rivers of the
countries are at chronic risk of food insecurity including in the Awash
valley.
28. • Since early 2008, the Ethiopian government has embarked on a
process to award millions of hectares (ha) of land to foreign and
national agricultural investors.
• According to the Oakland Institute team (2011) research shows that
at least 3,619,509 ha of land have been transferred to investors,
although the actual number may be higher. And most of the land is
transferred for floriculture production.
• The Ethiopian government claims that these investments will allow
for much needed foreign currency to enter into the economy and will
contribute to long-term food security through the transfer of
technology to small-scale farmers.
• Despite Ethiopia‟s endemic poverty and food insecurity, there are no
mechanisms in place to ensure that these investments contribute to
improved food security. What do you say?.....
Our goal is not to alleviate hunger. I am a businessman. What I am
doing is positive, cheaper food, making employment. Can’t understand
how that can be negative.” — Foreign investor in Gambella
29. Droughts are a weather-related natural
hazard, which can affect vast regions for
months or years
- have a significant impact on a country’s
economic performance, particularly food
production.
-Contributed about 48.8 % of Nationally
reported losses of lives (1990-2014)
During the period from 1980 to 2006,
more than 99% of the total drought
fatalities globally were reported in Africa
. For example, the fatalities in Sudan &
Ethiopia in 1983 added up to 450,000.
Drought fatalities were the highest
during the period from 1983 to 1985
when droughts occurred in Africa.
Drought..cont..
30. Common Hazards in Ethiopia Cont…
Flood
Flooding is usually the
result of heavy or
continuous rain that
exceeds the absorptive
capacity of the soil & the
flow capacity of rivers,
streams & coastal areas.
Types of Flood :River flood,
Flash flood, Coastal flood
31. Volcanoes
A volcano is an opening, or rupture, in the planet’s surface or
crust, which allows hot, molten rock, ash & gases to escape
from deep below the surface.
Erta Ale (or Ertale or Irta'ale) is a continuously active basaltic shield volcano
in the Afar Region of northeastern Ethiopia. It is situated in the Afar
Depression, a badland desert area spanning the border with Eritrea. Erta
Ale is the most active volcano in Ethiopia.
32. Landslide in Ethiopia
During a funeral service held at
Gebrekristos church in Addis Ababa,
Ethiopia, Mar 13, 2017
A landslide is the movement of rock, debris or earth
down a slope. They result from the failure of the
materials which make up the hill slope and are driven
by the force of gravity. Landslides are known also as
landslips, slumps or slope failure
Eg Ethiopian trash dump landslide (koeshe
34. • Definitions of risk are commonly probabilistic in
nature, relating either to:
(i) the probability of occurrence of a hazard that acts to
trigger a disaster or series of events with an undesirable
outcome, or
(ii) the probability of a disastrous outcome, combining the
probability of the hazard event with a consideration of the
likely consequences of the hazard (Smith, 1996; Stenchion, 1997;
Downing et al., 2001; Brooks, 2003;Jones & Boer, 2003).
• DR also defined as the potential disaster losses, in lives,
health status, livelihoods, assets and services, which could
occur to a particular community or a society over some
specified future time period.
Disaster risks
35. Disaster risk equation
Disaster Risk = Hazard (H) x Vulnerability (V)
Capacity (C)
OR
Disaster Risk = f(H & V / C)
• For many risks, mitigation can best be handled at the
level of the community because the exposure of the
community is greater than that of the individual, & because
protection often requires collective, sometimes large-scale
action.
• In the 20th century the scale of natural disasters (including
famine) has been much greater than that of technological
disasters (apart from wars), both in terms of the total
number of casualties & the numbers of high casualty
events.
36. The Crunch model shows that a disaster happens only if a hazard meets
a vulnerable situation.
37. A disaster is a result from the combination of hazard, vulnerability and insufficient capacity or
measures to reduce the potential chances of risk.
40. Characteristics of disasters
Flood X Poorly constructed
house
=
Life & Property
damage
Disaster
X
=
Hazard/
Disaster Risks
Drought X Crops that depend on
rainfall
= Life loss
41. Sources of disaster risks and their characteristics
Figure : Risk sources and their characteristics
42. Characteristic of risk
The Level of Risk in any project depends on the degree and
Extent of Controllable and Un controllable Risks.
Controllable Risks: Included factor of human error and
decision making:
These risks are Internal to the project and are controllable by
good management and good quality control procedures.
Can be seen and adequate provision can be made against its
occurrence.
Uncontrollable Risks:
Include factors that are outside the immediate control of the
projects.
E.g Adverse weather (Force Majeure). This can be covered
with some form at insurance
43. How is risk determined?
• There are three essential components in the determination of risk,
each of which should be separately quantified:-
a) the hazard occurrence probability: the likelihood of experiencing any natural or
technological hazard at a location or in a region.
b) the elements at risk: identifying and making an inventory of people or buildings
or other elements which would be affected by the hazard if it occurred, and
where required estimating their economic value.
c) the vulnerability of the elements at risk: how damaged the buildings or people
or other elements would be if they experienced some level of Hazard.
Evaluation of risk : how where, how much and howl long exposed for one can be
exposed fro the risk
44. Concluding remarks on current trends of disaster
The number of disasters is increasing each year…..
Overall number of people affected by disaster is rising…..
Overall, disasters are becoming less deadly, but more costly( Disasters cause major
economic impact).
Poor countries are disproportionately affected by disasters( Disasters hurt poor and
vulnerable people the most).
Evidence suggests that the impact of disasters will continue to increase.
Mainstreaming DRM in development planning can reverse the current trend of
rising disaster impact.
Development planners at national, municipal, and local levels have a major role to
play in managing and reducing disaster risk.
The international development community must support countries to manage
growing disaster risks.
