Earthquake Loss Estimation Session 3 Mr. James Daniell Risk Analysis Earthquake Risk Analysis 1

Earthquake Loss Estimation

Session 3

Mr. James Daniell

Risk AnalysisEarthquake Risk Analysis 1

Risk AnalysisEarthquake Risk Analysis

2

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.


3

Why do we undertake Earthquake Loss Estimation?

Total Economic Losses for Earthquake and Secondary Effect Events from Jan. 1900 - Mar. 2010 CATDAT Damaging Earthquakes Catalogue

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

10000019

00

1910

1920

1930

1940

1950

1960

1970

1980

1990

2000

2010

Year

$ U

SD B

illi

on (

2010

infl

atio

n ad

just

ed)

Developed Losses

Developing Losses

184.2m 129.1m

Total Economic Losses for Earthquake and Secondary Effect Events from Jan. 1900 - Mar. 2010 CATDAT Damaging Earthquakes Catalogue

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

10000019

00

1910

1920

1930

1940

1950

1960

1970

1980

1990

2000

2010

Year

$ U

SD B

illi

on (

2010

infl

atio

n ad

just

ed)

Developed Losses

Developing Losses

184.2m 129.1m

The number of earthquakes are the same but exposure is increasing, therefore losses are increasing

Total Economic losses for earthquake and secondary effect events from Jan 1900 – Marc 2010, CAT DAT Damaging Earthquake Catalogue

Developing Country Losses Developed Country Losses


4

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.


5

Earthquake Loss Estimation

Adapted from RiskScape, 2009


Population Density

6

What influences damage-loss conversion?

Distance from quake

sourceVulnerability &

Cost

Site Hazard, Exposure & Topography

Time of Day

Magnitude, depth & duration

of EQ source


7

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.

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.

AgePre-1970

Pre-1970

Post-

1970Post-1970

Type URMTimb

er URMTimb

er

Geocell B

0.269 0.151 0.077 0.055

Geocell E

0.811 0.603 0.396 0.269

OR


Earthquake

Impacts

Earthquake

Impacts

indirect

indirect

directdirect

calculated via empirical historical EQ ratios of losses,

or analytical numerical models

repair and reconstruction costs associated with infrastructure damage

deaths, injuries, homeless, evacuated and affected population

a consequence of the direct physical damage associated with the earthquake

Social

Economic

8

Business interruption, diminished

production and services

Psycho-social trauma,

weakening of institutions,

Social

Economic

Direct vs. Indirect Impact


9

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!


10

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.


11

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.

Spence, 2007Jaiswal et al., 2009


12

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

Systems approach computing output by

modelling between and within system elements.

Hazard Independent

Calculating an impact factor using socio-economic indicators that aggravate the physical risk

values.

Business Interruption

Flow-on lifeline problems

Bottlenecks (Economy)

Social vulnerability (fragility)

Coping Capacity (resilience)

Economic vulnerability (fragility)


13

Earthquake Loss Consequences

Outputs of earthquake loss estimation

Adapted from SYNER—G, 2009


14

Earthquake Loss Assessment for mediation and mitigation

POST-EVENT

COST

Earthquake

Occurrence

COSTBENEFIT

PRE-EVENT


15

Using the earthquake cycle to protect against Earthquakes and Secondary Hazards


16

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

Documents

Earthquake Loss Estimation Session 3 Mr. James Daniell Risk Analysis Earthquake Risk Analysis 1