Transcript Earthquake Loss Estimation Session 3 Mr. James Daniell Risk Analysis

Earthquake Loss Estimation
Session 3
Mr. James Daniell
Risk Analysis
Earthquake Risk Analysis
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Learning Objectives
 Learn how to undertake an earthquake loss estimation
 Know how to convolve the hazard, exposure and
vulnerability using damage loss conversion and
uncertainties
 Know what socio-economic loss components are needed
in an earthquake loss estimation
 Know where earthquake risk analysis fits into
earthquake risk management.
 Know what global software tools are available to
undertake an earthquake loss estimation
 Understand that there are many uncertainties that can
only be quantified by earthquake loss estimation
engineers.
Risk Analysis
Earthquake Risk Analysis
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Why do we undertake Earthquake Loss
Estimation?
Total Economic Losses
Earthquake
andbut
Secondary
Effect
The number of earthquakes
areforthe
same
exposure
is increasing,
Events from Jan. 1900 - Mar. 2010 CATDAT Damaging Earthquakes Catalogue
therefore losses
are increasing
184.2m
129.1m
100000
Total Economic losses for earthquake and secondary
effect events from Jan 1900 – Marc 2010, CAT DAT
Damaging Earthquake Catalogue
80000
 Developing Country Losses
70000
 Developed Country Losses
Developed Losses
Developing Losses
60000
50000
40000
30000
20000
10000
2010
2000
1990
1980
1970
1960
1950
1940
1930
1920
1910
0
1900
$ USD Billion (2010 inflation adjusted)
90000
Year
Risk Analysis
Earthquake Risk Analysis
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Earthquake Loss Estimation - towards mitigation
 Earthquake loss estimation is the combination of three
main factors – hazard, vulnerability and asset value.
 Losses are the decrease in asset value resulting from
damage.
 Losses are typically given in terms of the number of
damaged assets, or as a cost – such as the cost to replace
or repair the damaged assets.
 “Acceptable Risk” and Cost-Benefit Analysis
 Loss estimation studies are very useful tool for developing
emergency preparedness plans and for promoting seismic
risk mitigation.
Seismic Risk, loss, mitigation, acceptable risk, cost-benefit.
Risk Analysis
Earthquake Risk Analysis
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Earthquake Loss Estimation
Adapted from RiskScape, 2009
Risk Analysis
Earthquake Risk Analysis
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What influences damage-loss conversion?
Magnitude, depth &
duration of EQ source
Time of Day
Population Density
Site Hazard, Exposure
& Topography
Distance from
quake source
Vulnerability & Cost
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Earthquake Risk Analysis
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Damage-Loss Conversion
 After the vulnerability assessment, the infrastructure damage is
expressed as the no. of infrastructure per geocell, in a damage state
(none to collapse) or as a damage ratio with variability.
OR
Age
Pre1970
Pre1970
Post1970
Post1970
Type
URM
Timber
URM
Timber
Geocell B
0.269
0.151
0.077
0.055
Geocell E
0.811
0.603
0.396
0.269
 A relationship of economic and social loss estimates for each of
these damage states is needed!
 If the scenario is changed, building damage needs to be recalculated.
Risk Analysis
Earthquake Risk Analysis
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Direct vs. Indirect Impact
Earthquake
Impacts
direct
indirect
calculated via
empirical historical EQ
ratios of losses, or
analytical numerical
models
a consequence of the
direct physical damage
associated with the
earthquake
Risk Analysis
Earthquake Risk Analysis
Social
Economic
Social
Economic
deaths, injuries,
homeless,
evacuated and
affected population
repair and
reconstruction
costs associated
with infrastructure
damage
Psycho-social
trauma, weakening
of institutions,
Business
interruption,
diminished
production and
services
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Direct Economic Loss Conversion
 The replacement cost is usually calculated multiplying the floor
area, construction cost per unit area, number of buildings and
number of storeys.
 Empirical repair ratios can be derived for each of these damage
levels vs. the entire replacement cost.
 Repair/Replacement = Mean Damage Ratio (MDR)
 Local construction and cost data, production
material, demolition and debris removal, lifeline,
government law and social data are needed!
Risk Analysis
Earthquake Risk Analysis
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Direct Social Loss Conversion
 This includes both empirical and analytical social death, injury and
homeless, evacuated, affected population ratios for conversion from
building damage estimates.
 Much uncertainty – development level!
 Given the damage levels, occupancy data is required per building
given a certain time of day.
 It is also important to identify large social loss areas, like
marketplaces, schools and stadiums.
Risk Analysis
Earthquake Risk Analysis
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Direct Social Loss Conversion
 KOERI (2002) give deaths as the
number of severely damaged (D4)
and collapsed (D5) buildings.
 An expert opinion system gave
serious injuries as 4x deaths.
 There are many empirical casualty
rate models.
 Region-specific usually.
Jaiswal et al., 2009
Risk Analysis
Earthquake Risk Analysis
Spence, 2007
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Indirect Socio-Economic Loss Conversion
 Modelling indirect effects is difficult due to lack of data and
complexity of relationships between indirect and direct effects!
 Two types – hazard dependent and hazard independent.
Hazard Dependent
Hazard Independent
Systems approach computing
output by modelling between
and within system elements.
Calculating an impact factor using
socio-economic indicators that
aggravate the physical risk values.
Business Interruption
Social vulnerability (fragility)
Flow-on lifeline problems
Coping Capacity (resilience)
Bottlenecks (Economy)
Economic vulnerability (fragility)
Risk Analysis
Earthquake Risk Analysis
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Earthquake Loss Consequences
Outputs of earthquake loss estimation
Adapted from SYNER—G, 2009
Risk Analysis
Earthquake Risk Analysis
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Earthquake Loss Assessment for mediation and
mitigation
COST
BENEFIT
COST
PRE-EVENT
Earthquake
Occurrence
Risk Analysis
Earthquake Risk Analysis
POST-EVENT
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Using the earthquake cycle to protect against
Earthquakes and Secondary Hazards
Risk Analysis
Earthquake Risk Analysis
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Earthquake Loss Estimation Tools
 Many tools that can be used depending on the desired model, use and
data availability:




open source or proprietary
for real-time monitoring
complex or simple
empirical or analytical
 Some example of non-proprietary tools
 HAZUS-MH (North America) – scenario risk analysis for hurricane,
earthquake and floods.
 CAPRA (Central America) – probabilistic risk analysis to the analysis of
hurricane, earthquake, volcano, flood, tsunami and landslide hazards.
 RADIUS – excel-based tool for preliminary estimation of damage in
developing countries
 GEM – currently being developed as the first global earthquake model
Risk Analysis
Earthquake Risk Analysis
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