ICLR Friday Forum: Conflagrations! (June 15, 2018)

Conflagrations
C. Scawthorn 2015, 2018 ICLR Friday Forum, 15 June 2018 1
Conflagrations
An ICLR Friday Forum webinar
15 June 2018
Prof. Charles Scawthorn, S.E.
SPA Risk LLC and University of California, Berkeley

Conflagrations
Outline
• Self-introduction
• Conflagrations – what are they?
• Wildland Urban Interface (WUI) Fires
• Background / size of the problem
• Modeling of WUI fires
• WUI code
• Benefits of the WUI code
• Relevance for Canada
• Urban conflagrations
 Fire Following Earthquake
• Background…
• Modeling…
• Codes (there are none)
• Relevance for Canada
• Closing remarks
• Q&A

Conflagrations

Conflagrations
Charles Scawthorn
• Education
• B.E. (The Cooper Union, New York City)
• MSCE (Lehigh University, Penn.)
• D.Eng. (Kyoto University, Urban Seismic Risk: Analysis and Mitigation)
• Consulting Engineer (San Francisco, London, Tokyo) 1970s-2003
• Dames & Moore
• EQE: Senior Vice President  $80 million / year global consulting firm, 10 countries
• Founded / ran Tokyo office 1995-1998
• co-founder EQECAT
• Projects all over the world
• Professor, Kyoto University (2003 - 2008)
• Earthquake Risk Reduction
• Infrastructure Risk Management
• 2008 
• Visiting Professor (Stanford, UC Berkeley, Waseda [Tokyo], Beijing Normal University)
• Research (NSF, USGS, SSC, WRN…)
• Consultant:
• government agencies (World Bank, FEMA, State of California…)
• Real estate and insurance entities
4

Conflagrations
Conflagrations – what are they?

Conflagrations
Wildland Urban Interface / Intermix (WUI) Fires
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Conflagrations
The Mine Fire, San Diego County, California burned through the wildland urban interface in 2003. (USFWS)

Conflagrations
• 220 million acres of WUI
• 46 million single family homes
• several hundred thousand businesses
• > 120 million people (38% of the nation)
• 14% of the available WUI lands in WUS have been developed,
• 86% remains available for development
• Nationally, 30% developed / 70% remain to be developed
• Over 38,000 homes have been lost since 2000 (not including 2017)
• Financial loss of WUI fires in 2009 ~ $14 billion
• Costs for firefighting (not losses) exceed $4.7 billion per year
• Many other loss costs not generally accounted for
- ICC (2013) WUI Fact Sheet
WUI fire problem is a large and growing hazard in the US.

Conflagrations
X

Conflagrations

Conflagrations
• Mark Finney, Research Scientist
USFS RMRS Missoula Fire Sciences Laboratory
• Kim Zagaris, Chief, CA OES Fire and Rescue
• Jack Cohen, Research Scientist (ret.)
USFS RMRS Missoula Fire Sciences Laboratory
• Rob Plonski, Sr. Fire Protection Engineer, DOE
WUI Fire Oversight Committee

Conflagrations
Analytical Approach
WUI Fire
Damage / Loss
Vulnerability / Risk Calcs
Exposure
Hazard

Conflagrations
Hazard
“heavy lifting” been done by US Forest Service
Northern Research Station. Newtown Square, PA
Rocky Mountain Research Station.
Missoula, MT

Conflagrations
WUI mapping (USFS, Northern Research Stn)

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WUI mapping

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Hazard and Vulnerability (USFS, Rocky Mtn. Research Stn.)

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“Burn probabilities” (USFS, Rocky Mtn. Research Stn.)

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Mitigation – Comply with IWUIC

Conflagrations

Conflagrations
Methodology
• benefit-cost ratios (BCR) given WUI fire mitigation
• For selected counties (4)
• For an “index” building (single family wood frame dwelling)
• Determine “as-is” WUI fire loss, assuming:
A. No mitigation or compliance with WUI code
B. Compliance with ICC WUI code
• Benefit = AAL [avoided losses] (property…PTSD)
PV (all future B-A losses)
• Cost = cost of complying with ICC WUI code
• BCR= B / C

Conflagrations
County Population (millions)
Los Angeles CA 10.12
Alameda CA 1.61
Ada ID 0.43
Atlantic NJ 0.28

Conflagrations
Mitigation:
The specific mitigation measure to be examined for this study is compliance with the WUI
Code,

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Conflagrations
HAZARD: Burn Probabilities (USFS)

Conflagrations

Conflagrations
Flame Intensity
Level (1-6)

Conflagrations

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Exposure
WUI exposure has been mapped for the conterminous US at the census block level
(Martinuzzi et al. 2015a; Martinuzzi et al. 2015b). This dataset provides information on
housing units (HUs) and population in each census block and is the basis for analysis of
assets at risk. A sample, for the state of California, is shown in Figure 8.
For analysis purposes, all HUs in the WUI are assumed to be single family dwellings, a
prototype of which is shown in Figure 1. Only this prototype is considered this analysis.
The costs of construction and mitigation for this prototype are shown in Table 5.

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Vulnerability

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Loss Calculation

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LOS ANGELES COUNTY, CA

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Frequency of BCR per HU:
Observation: about 10% (5000/47870) of
census blocks examined (purely urban CBs
excluded) have BCR > 2.1

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41
Compliance with 2015 International WUI Code: BCR = 4:1

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42
Post-Fire Debris-Flow Hazards

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43

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44

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Part 1: WUI Fire / Mitigation
Summary
• Modeling WUI fire risk for the entire US
• Calculation of Benefit-cost ratio for 4 case studies
• Extrapolation to entire US
• 0 < BCR < 12 with avg BCR (>1) = 4
• Post-WUI fire debris modeling

Conflagrations
Relevance for Canada
In general, results of this investigation
showed that a few FireSmart solutions
have been widely adopted by
homeowners, others in part, and some
very little or not at all. The degree of
adoption for known risk mitigations
varied between geographic areas,
between different categories of
wildfire hazards, within categories of
related hazard factors, and spatially
within the home ignition zone. Equally
important, the study revealed
similarities among levels of adoption
for some risk mitigations. Differences
between urban centres and more rural
settings were minor. Overall, twice as
many wildfire hazard factors received a
poor adoption grade, than those that
attained an “excellent” rating.

Conflagrations
Fire Following Earthquake
- the M7.05 HayWired Scenario
Charles Scawthorn, S.E.

Conflagrations
ShakeOut: San Andreas fault (southern
California) earthquake scenario (2008)
ARkStorm: winter storm scenario
impacting U.S. West Coast (2010)
Tsunami Scenario: tsunami generated by
an Alaskan earthquake and impacting the
U.S. West Coast (2013)
HayWired: Hayward fault (northern
California) earthquake scenario (in
progress; April 18, 2018 - release date)
ARkStorm Retrospective: 2017 ARs,
disaster declarations, beach loss, extreme
storms, snow pack & melt runoff
The SAFRR Scenarios…The SAFRR Scenarios…

Conflagrations
The Hayward Fault
is arguably the
most urbanized
active fault in the
United States.
It offers an
informative case
study of the effects
of a large urban
earthquake on a
modern U.S.
metropolis.

Conflagrations
HayWired: Physics-Based ScenarioHayWired: Physics-Based Scenario
Hayward Mw 7.0 median Same earthquake, bilateral
rupture, physics-based model

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HayWired: Mainshock Ground MotionsHayWired: Mainshock Ground Motions
M7.0 earthquake occurring on April
18, 2018, at 4:18 p.m, wind
Is mild, no rain, temperature avg.
Rupture starts under Oakland,
north into San Pablo Bay and south
to the city of Fremont (53 miles)
The HayWired scenario describes a
M 7.0 earthquake, 83-km (51 mile)
rupture, with up to 2 meters (6.5
feet) of fault offset either in the
form of coseismic slip or afterslip

Conflagrations
HayWired shaking animation

Conflagrations
C. Scawthorn 2015, 2018 ICLR Friday Forum, 15 June 2018 542016 M 7.8 Kaikoura,NZ earthquake
HayWired: Fault Slip, Afterslip and AftershocksHayWired: Fault Slip, Afterslip and Aftershocks
1.7m
Coseismic surface slip variability in meters
0.9m
2.1m

Conflagrations
HayWired: Hazus aftershock analysisHayWired: Hazus aftershock analysis
• Aftershocks contribute 20% of
loss
– 12% from 3 aftershocks Mw
6.0 to 6.4
– 8% to 13 aftershocks Mw 5.0
to 5.9
• Some areas more damaged by
aftershocks
• Repeat liquefaction is a concern
• 1st Hazus-MH analysis of entire
earthquake sequence in a
scenario

Conflagrations
Fire Station “Voronoi areas”
HayWired Mw 7.05
shaking intensity
Exposure:
Portions of 9 SFBA counties considered
• 6.97 million persons (2010 census)
• 5.77 billion Total Bldg sq ft. floor area
• $1.15 trillion total bldg value (@ $200 psf)

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HayWired: Water dominates EQ risk to societyHayWired: Water dominates EQ risk to society
Preliminary information subject to revision. Do not cite.
Shake-
damaged
buildings
$35
Shake-
damaged
contents
$11
Fire-
damaged
buildings
$40
Fire-
damaged
contents
$25
Highway $0.4 Pipelines
(water, sewer,
gas) $1
ShakeOut property loss: $113 B
Gas $1
Ports $1
Buildings
$11
Fire
$22
Transportation $1
Power
$7
Water
$24
ShakeOut business interruption: $67 B
• Water causes economic
losses far out of proportion
to the utility’s repair cost
• Some Bay Area agencies
have >50% brittle pipe
• Aggressive pipe
replacement: 1% per year
• Equals decades until
resilient water supply
What happens in HayWired?

Conflagrations
Water Supply Factor (0 ≤ WSF ≤ 1)
WSF accounts for water (or lack) at hydrants, proximity to alternative sources (Bay, lakes…)
Water
supply

Conflagrations
The Analysis and Mitigation of Fire Following
Earthquakes involves several major aspects
 Earthquake Damage
 Multiple Simultaneous Ignitions
 Fire Spread
 Water Supply and Response Problems
 Communication Breakdowns
 Competing Demands for Fire Service
Resources (medical, SAR, hazmat…)
59
Fire Department Operations TimelineEarthquake OccursEarthquake Occurs
Phase Ignition Discovery Report FD Arrival Fireground
Operations
1
2
4
5
3
6
7
8
3
D
D
D
D
D
D
D
D
R
R
R
R
R
R
R
R
?
?
?
?
Time
Legend 7
Ignition
Fire Growth Suppression
D
Fire Discovery
R
Fire Report
Fire Response Fire Growth
(1~3 Engine fire)

Conflagrations
FFE modeling
• Stochastic process
• Ignition occurrence and fire spread
| performance of gas and power systems
• Water supply | damage to distribution system
• Fire reporting | saturation of POTS, cellular
and 911 systems
• FD decision-making | radio chatter, self-
dispatching companies, overwhelmed EOC
• Other demands: USAR, hazmat…
• ….

Conflagrations
Ignition Models

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Ignitions

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 WDs and FDs see earthquake as a very
important issue, but infrequently
communicate
 Fire agencies assume water will not be
available at hydrants (but don’ ask)
 Water agencies know it will not be
available, but don’t tell fire depts. (and
see provision of potable water as higher
priority than firefighting.
 Inescapable conclusion: Little/no water after an EQ
 The very difficult task of moving water from sources to the fire is
in many cases not well planned, adequately equipped nor
regularly drilled (SF, Oakland, Berkeley are exceptions)

Conflagrations
Pacific EarthquakeEngineering
Research Center,
UC Berkeley
2014 Workshop

Conflagrations
Findings
Entire Bay Area
• Hundreds of large fires
• Damage to buried water pipes = dry hydrants
• Losses: hundreds of lives, tens of thousands of buildings lost due to fire
• $16 billion Coverage A losses (fully insured)
Opportunities for mitigation
• Post-earthquake supply of water for firefighting
• State-wide Emergency Water Supply System is needed
• Mandated gas shut-off valves, or seismic shut-off meters, in densely
built areas
• Aggressive seismic retrofitting (e.g., on sale of house)
• Continued development of CERTs

Conflagrations

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• EQ exposure in East (Quebec) and West (BC)

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• 2001 ICLR study for Lower Mainland
• Much has changed:
• Better understanding of the hazard
• Greater exposure
• Better data on exposures
• Better insurance data
• Changes in the fire service
• Better data water mains
• Construction of Vancouver’s DFPS
• Improved FFE modeling

Conflagrations
Thank You
Q&A
cscawthorn@sparisk.com

Conflagrations

ICLR Friday Forum: Conflagrations! (June 15, 2018)

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ICLR Friday Forum: Conflagrations! (June 15, 2018)