Definitions

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Definitions Key terms
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• 1GS314 RISK ANALYSIS ASSESSMENT

SCHOOL OF EARTH ENVIRONMENTAL SCIENCES Part
2 Definitions Key terms
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Background

• Risk
• Hazard Vulnerability
• Relationships
• From Hazard to Risk
• Risk Uncertainty
• Risk Assessment

Risk assessment as a Decision Making Tool
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Uncertainty
The Unknown As we know, There are known
knowns. There are things we know we know. We
also know There are known unknowns. That is to
say We know there are some things We do not
know. But there are also unknown unknowns, The
ones we don't know We don't know.
Donald Rumsfeldt Feb. 12, 2002, Department of
Defense news briefing
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Terminology

• Rapidly expanding field of Risk Assessment
• Originally Financial Sectors / High Tech
  Industries such as Nuclear Power
• Grown into many other aspects of modern day
  society
• Growth produced a huge confusing literature
• Terminology intermixed
• Need for terminology definition clarification

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Hazard Risk Vocabulary

• Risk Hazard Vocabulary
• Common everyday use of terms
• Interchangeable use
• Consistent technical use of terminology
• Specialist groups with own definitions
• Glossary or Appendix of terms

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Risk

• No single agreed set of definitions of risk
• Can cover
• Potential for adverse consequences
• Loss, harm or detriment
• Chance of loss
• Human centric concept
• Things that humans value affected
• Cultural aspects
• Risk acceptance
• Risk tolerance

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Hazard Risk Vocabulary

• 'Rio Definitions'
• European Community Directive 93/97/EEC
• Deals with chemical substances in the
  environment
• But restricted in scope for other aspectsof risk
  assessment
• e.g. construction, manufacturing etc.

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Royal Society Definitions

• Royal Society 1992 Report
• "Risk Analysis, Perception and Management"
• Risk
• A combination of the probability, or frequency,
  of occurrence of a defined hazard the magnitude
  of the consequence of occurrence
• Identifies the importance of an agent in
  generating risk
• Landsliding
• Volcanic eruption
• Rainfall

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Royal Society Definitions

• Royal Society 1992 Report
• "Risk Analysis, Perception and Management"
• Hazard
• A property or situation that in particular
  circumstances could lead to harm
• Consequences
• The adverse effects or harm as a result of
  realizing a hazard which cause the qualityof
  human health or the environment to beimpaired in
  the short or longer term

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Royal Society Definitions

• BUT
• Royal Society definition makes the assumption
  that consequences of a hazard have to be
  detrimental

Suggest examples where consequences not
detrimental
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Royal Society Definitions

• Hazardous events can do result in benefits as
  well as loses

Risk is concerned with ADVERSE consequences
Risk of good health
Risk of stabilised slopes
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Risk

• Chance of a defined hazard occurring
• Combines the probability or frequency of the
  occurrence of the hazardous event with a measure
  of the consequences of that event

" Risk is an objective measure of the likelihood
of a specific undesired event and its unwanted
consequences or loss "Engineering Council 1993
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Risk Hazard
Risk
Hazard
is not concerned with the cause of the potential
outcomes, this is
Risk frequently used in the context of the
probability or likelihood of failure or the
occurrence of natural hazard events
'Increased risk of rain' 'Growing avalanche risk'
Misleading Refers to the increased likelihood
of the occurrence of the phenomena Rather
than An increase in the likelihood scale of
adverse consequences
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Benefits of Risk Analysis

• Risk Benefit Analysis
• Cost Benefit Analysis
• Project Appraisal

When the potential for adverse outcomes can be
compared with the benefits to be gained from
actions, activities, locations and events
E M Lee D K C Jones (2004) Landslide Risk
Assessment. Thomas Telford.
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Risk Definitions

• After Lee Jones (2004)
• The likelihood of specified adverse consequences
  arising from an event, circumstance or action
• The likelihood of differing levels of potential
  detriment arising from an event, circumstance or
  action
• An amalgam of the likelihood magnitude of
  potential adverse consequences arising from an
  event, circumstance or action

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Risk Definitions

• After Lee Jones (2004)
• Definitions empahsise that risk is concerned with
  yet to be realised harms loses
• Usual to link consideration of risk within
  reasonable spatial temporal limits within
  a stated period area

Risk resides in the future
Risk can be increased, decreased, transfered but
rarely removed
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Risk Avoidance

• Flood Hazard
• Development of flood control scheme Reduction
  of hazard
• Relocation of assets away from hazardous areas
  to safe location Avoidance of risk

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Tolerability

• Zero risk society

Thus the once fashionable aspirations to a zero
risk society are now seen as pure fantasy Lee
Jones (2004)
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Hazard Vulnerability

• Hazard another human / cultural concept
• Applied to objects, organisms, phenomena, events
  situations which emphasises

.the potential to affect adversely humans the
things that humans value
Hazard is the source of human harm or loss
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Hazard Royal Society Definition

• Royal Society 1992 Report
• "Risk Analysis, Perception and Management"
• Hazard
• A property or situation that in particular
  circumstances could lead to harm
• Consequences
• The adverse effects or harm as a result of
  realizing a hazard which cause the qualityof
  human health or the environment to beimpaired in
  the short or longer term

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Hazard BSI Definition

• British Standards Institute 1991
• Quality Vocabulary. BS 4778
• Hazard
• the potential for adverse consequences of some
  primary event, sequence of events or combinations
  of circumstances

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Hazard Perry 1981 Definition

• Perry, A.H. 1981
• Environmental hazards in the British Isles
• Hazard
• Threats to humans what they value, like well
  being, material goods environment

Heather Matre "Environmental Hazard
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Concepts Definitions

• Hazard
• Potential for adverse consequences
• Potential to cause harm
• In particular circumstances
• Hazardous Situation
• Hazardous Event
• A trigger which exposes a person to harm
• Hazard Analysis

" A condition with the potential for causing
harm.... Poisonous chemicals are an example of
hazard "Engineering Council 1993
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Hazard
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Hazard

• Complete for
• Landslide or slope instability
• Volcano

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Hazard
For a hazard to exist situations have to arise or
circumstances occur where human - valued
systems can be adversely impacted
Landslides on remote uninhabited mountains are
not hazards ???
Is this contentious?
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Vulnerability

• Another human concept
• The potential to suffer harm, loss or detriment
  from a human perspective
• Inverse of robustness or durability

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Relationships

• H ( E V ) C
• H Specified hazard event
• E Total value of all threatened items (ie.
  Elements at risk)
• V Vulnerability or the proportion of E reduced
  by the hazard event
• C Adverse consequences of hazard event

Hazard Event Vulnerability Adverse
Consequence
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Vulnerability

• Elements at risk vulnerability can vary over
  time
• Some authors thus consider that vulnerability can
  be regarded as consisting of 2 distinct aspects

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Vulnerability

• The level of potential damage, disruption or
  degree of loss experienced by a particular asset
  or activity subjected to a hazard event of a
  given intensity

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For example the different vulnerability of a
timber framed building to slow ground movement
compared with a rigid concrete structure
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Vulnerability

• The proportion of time that an asset or person is
  exposed to the hazard

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Exposure
For example consider the contrasting exposure of
a person walking underneath an overhanging rock
compared with a static beach hut
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Exposure

• Not the vulnerability that changes in the short
  term but the value of the elements at risk
• A person is equally vulnerable to a falling rock
  irrespective of whether they are actually present
  when the rock falls

Presence or absence Exposure
For example the different vulnerability of a
timber framed building to slow ground movement
compared with a rigid concrete structure
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Relationships
Exposure Elements at risk Vulnerability

• E E V
• E Exposure
• E Total value of all threatened items (ie.
  Elements at risk)
• V Vulnerability or the proportion of E reduced
  by the hazard event
• C Adverse consequences of hazard event
• C H E
• Adverse Consequences Hazard Exposure

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Relationships
Culshaw, M (2007) Communication the risks from
geohazards. 4th CLIFFS Workshop http//cliffs.lbor
o.ac.uk/
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Relationships

• Elements of risk

EXPOSURE
HAZARDS
RISK
LOCATION
VULNERABILITY
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Hazards

• Hazards
• Natural
• Human
• Technological
• Societal
• Hybrid Hazards
• Na tech
• Quasi natural
• Geohazard
• Biogeophysical
• Geophysical

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The Hazard Spectrum
Social Hazards
Technological Hazards
Natural Hazards
Based on Jones (1993) Environmental hazards in
the 1990s, Geography, 79, 339, pp 161-165
Environmental Hazards
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References

• A Guide to Risk Assessment Risk Management for
  Environmental Protection. 1995. Dept. of the
  Environment. HMSO
• www.defra.gov.uk/environment/eramguide/index.htm
• Risk Analysis, Perception and Management. 1992.
  Royal Society
• EC Directive 93/67/EEC. Official Journal of the
  European Communities, L227, 8 September, 1993.
  HMSO
• The Tolerability of Risk from Nuclear Power
  Stations. 1992. HSE, HMSO
• E M Lee D K C Jones (2004) Landslide Risk
  Assessment. Thomas Telford.