Department of Geological Sciences, Faculty of Sciences
Masaryk University/Brno
& Czech Geological Society
September 12-14, 2011
Short Course on Geological HazardsShort Course on Geological Hazards
Topic 1Topic 1: Introduction and Basic: Introduction and Basic
PrinciplesPrinciples:
Hazard & Risk Assessment /
Management
Klaus H. JacobKlaus H. Jacob
Lamont-Doherty Earth Observatory
of Columbia University, NY
jacob@ldeo.columbia.edu
Introduction:
Principles of
• Hazard Assessment,
• Risk Assessment
and
• Risk Management.
The Historian - Philosopher
Will Durant (1885-1981) wrote:
"Civilization exists by
geological consent,
subject to change
without notice.”
“.... without notice.”
??
“Natural” Disasters occur
at the Intersection
of VulnerableVulnerable Societies with
ExtremeExtreme Events that are an Integral
Part of NaturalNatural Processes
We need to understand the workings of
both, Society and Nature,Society and Nature, to create
sustainable and disaster-resilient
communities.
Natural Disasters:Natural Disasters:
NaturalNatural DisastersDisasters (misnomer): when extreme natural
events occur whose frequency-magnitude
distributions are statistically predictable, and which
are an integral part of natural processes, then
a)a) if there is no human society - there are noif there is no human society - there are no
disasters, just natural eventsdisasters, just natural events
b)b) if natural hazards hitif natural hazards hit resilient societiesresilient societies - there are- there are
acceptable losses, but not disastersacceptable losses, but not disasters
c)c) if natural hazards hitif natural hazards hit vulnerable societiesvulnerable societies --
disasters are inevitabledisasters are inevitable
Lesson:Lesson: The Problem is Societal Vulnerability, not
Nature! Nature is. Societies Evolve.
Issue: How can societies (re-)adapt to extreme
natural events.
Example: North Coast of Venezuela, Province of Vargas, near Caracas,
Mudslide Disaster, December 1999
Dec 1999 Flashfloods killed >30,000 in VenezuelaDec 1999 Flashfloods killed >30,000 in Venezuela
So: Why do Societies Take Risks, and Expose Lives and
Assets to Hazards, Often Quite Unmitigated?
•• DisconnectDisconnect of Modern Societies from Nature.
Geological vs. human time horizons. Ignorance
of Real Hazards and Vulnerabilities, and hence of
Risks, results often in a false Sense of Security.
•• Many PeopleMany People have no Choice (Poverty, Equity &
Equality, Political Issues) . But some People and
Communities have Choices: Risk-Taking is Misplaced
Hubris/Arrogance.
•• The Up-front CostsThe Up-front Costs of Hazard Mitigation are often
Perceived to Outweigh the Long-Term Benefits.
(Turns out not to be true, in most cases)
Rising Global Losses from Natural Disasters through 2008 (Munich Re)
http://www.munichre.com/publications/302-06026_en.pdf
Number of Global Natural Disasters through 2008 (Munich Re)
http://www.munichre.com/publications/302-05703_en.pdf
Note: No Drought Fatalities are shown !Note: No Drought Fatalities are shown !
Related Famines are often not considered of Natural Origin.Related Famines are often not considered of Natural Origin.
What is Risk ?What is Risk ?
P= Probability (in the Future, => Uncertain)
P (Loss) = P (Hazard) x P (Consequence)P (Loss) = P (Hazard) x P (Consequence)
Risk (the expected future Loss) is the Product of
3 Factors, summed up over a given region:
RiskRisk = SUM (Hazard x Assets x FragilityFragility)
Risk can be evaluated probabilistically (annual exceedance
probability) or deterministically for given scenario events
(what if ….. ?).
Region
1
9
87
6
5
4
3
2
Estimated ANNUALIZED Earthquake Losses in the US
Two Types of Risk and Vulnerability: PhysicalPhysical vs. SocialSocial
RiskRisk == ∑∑ ((HazardHazard xx AssetsAssets xx VulnerabilityVulnerability))
Region
We differentiate between Physical Risks and Social/Economic Risks.
When assessing the Physical Risks & Associated Financial Costs then
the Physical VulnerabilityPhysical Vulnerability (also known as ““FragilityFragility””, F, F) of the assets
needs to be known (it is the fraction, ranging between 0 and 1, of the
Replacement Value of an asset that is damaged or lost during an
hazardous event of a given size ( F=0, no damage; F=1, total destruction
and hence total loss). The physical vulnerability F increases as the
hazard severity increases.
The Social VulnerabilitySocial Vulnerability is a more complex construct. Its prime indicator
is PovertyPoverty. And when hazardous events strike poverty-stricken societies,
then both people’s Lives and Livelihoods are at high risk.
But also the political stability of an entire country can be at risk after a major
disaster (e.g. Nicaragua Earthquake, Dec 1972, 20,000 deaths in Managua, lead
to the eventual fall of the conservative and autocratic Somoza Gov., and
replacement by the more democratic socialist Sandinista in 1979).
Some Key Issues:Some Key Issues:
•• HazardsHazards (Natural Environment,(Natural Environment, ≈≈ const., except Climate)const., except Climate)
•• AssetsAssets (Demographic & Economic Trends, Urbanization)(Demographic & Economic Trends, Urbanization)
•• FragilityFragility (Quality of Built Environment)(Quality of Built Environment)
•• RisksRisks (Assets, Hazard, Fragility)(Assets, Hazard, Fragility)
•• VulnerabilityVulnerability (Social / Institutional Environment.)(Social / Institutional Environment.)
•• Risk ManagementRisk Management (Risk Reduction;(Risk Reduction;
Vulnerability Reduction; Risk Distribution / Risk Sharing).Vulnerability Reduction; Risk Distribution / Risk Sharing).
Source: Munich Re
We will return to this & similar hazard maps in more detail
GSHAP earthquake shaking hazard map
Shown is the level of ground shaking that is expected to be reached
or exceeded with a probability of 10% in 50 years (or 90% probability
not to be exceeded in 50 years), corresponding to an average recurrence
period of ~ 500 years
““ASSETSASSETS””: ~7 Billion (7x10: ~7 Billion (7x1099) People in 2011, and growing) People in 2011, and growing
Risk and Vulnerability (continued):
RiskRisk == ∑∑ ((HazardHazard xx AssetsAssets xx VulnerabilityVulnerability))
Region
.
For the same severity of hazardous events, FinancialFinancial Losses in
““More DevelopedMore Developed”” CountriesCountries ((MDCsMDCs)) are often higher (high
assets) than in ““Less DevelopedLess Developed”” CountriesCountries ((LDCsLDCs);); the reverse is
true for Loss of Lives (MDCs = low vulnerability; LDCs = High
vulnerability). And in MDCs the livelihood of families and
communities is more likely to stay largely intact because of
access to contingency resources, including insurance.
In LDCsLDCs hazardous events tend to kill a much larger fraction of
the population, and while the fiscal losses may be in absolute
terms smaller than in MDCsMDCs, they usually destroy more severely
the livelihoods of communities, and recovery is hindered by lack
of access to contingency resources or insurance. Help from the
outside can be vital, but can bring with it new social stresses as
well.
Risk and Vulnerability
Vulnerability has been defined1 as:
“The conditions determined by physical,
social, economic, and environmental
factors or processes, which increase
the susceptibility of a community to the
impact of Hazards”.
1 UN/ISDR. Geneva 2004.
Social VulnerabilitySocial Vulnerability (in the context of disasters)
is the lack of personal, institutional or societal resilience
to cope with the incurred losses and related social
impacts of disasters (loss of shelter, sustenance, health
& livelihood, disruption of social networks and support
systems, trauma, crime, personal safety).
What are key factors that contribute to Vulnerability?
Some Examples of Vulnerability Factors:
• Poverty & Income Inequality
• Lack of Access to Coping-Resources incl. Knowledge
• Unavailability of Land Titles
(perpetuates fragile Squatter & Shanty Towns)
• Inadequate participation of large sectors of civil
society in the ‘democratic’ process (government).
• Governments lack the institutional infrastructure to
provide risk management, emergency services,
mitigation plans, and produce / enforce regulations.
• Means of Risk Distribution (Insurance) and for Providing
Emergency Relief are often poorly developed or absent
in vulnerable countries and communities.
Example of How to Measure Vulnerability:
Human Development Index (HDIHDI) of the United Nations Development Program,
as determined for countries at the end of the 1990s1990s
The HDI is calculated based on a combination of three factors:
1) Live Expectancy,
2) Educational Level (Literacy and Knowledge)
3) Income Level (Adjusted for Purchasing Power)
Disaster Risk Management (DRM):Disaster Risk Management (DRM):
• Mitigation by Reduction of Risk Exposure
• Adaptation to Risk (Preparedness, Build Resilience & Coping Capacity)
• Distribution of the Remaining Risk (Mutual Aid, Insurance)
There are various elements and stages of Disaster Risk Management:
– Constitutional / Legal / Institutional Framework, i.e. DRM
requires clear organizational structures, e.g. Emergency Management
Administrations at all Government Levels (I,N,R,L,F)
– Quantitative Hazard & Risk Identification & Assessment
– Risk Minimization (Long-term Mitigation, Cost-Benefit Analyses)
– Pre-Disaster Preparedness (Capacity Building, Education)
– Disaster Response (First Responders executing a Disaster Response
Plan - Command and Control Issues, Incident Command System [ICS]
provides Coordination, Information, Communication, Logistics, and
Resource Allocation)
– Post-Disaster Relief (temporary), and then Recovery (final*)
– Risk Distribution (Mutual Aid Agreements, Insurance)
* Includes Mitigation against Future Events
Some Basic Principles and Tools of Disaster RiskSome Basic Principles and Tools of Disaster Risk
Management:Management:
• Nothing can be well managed that cannot be measured.
• Hence, the need for Risk AssessmentRisk Assessment as aas a Starting PointStarting Point..
• How is Risk assessed?
– By quantifying the different Hazards,Hazards, in terms of their spatial distributions of
severity and frequency of occurrence.
– By evaluating the AssetsAssets (their monetary value and livelihood importance)
that are exposed to the different hazards.
– By evaluating the VulnerabilityVulnerability (Fragility) of the Assets to different Hazard
Types and Hazard Severity.
– By computing the risk via the risk equation (aided by computerized GIS
tools, where available). Estimate the loss magnitudes vs. their frequency of
occurrence. Add up all likely losses (small and big) over time, over space
and analyze their economic and social impacts on the nation(s), regions,
communities, and by sectors of the national and local economies.
Risk Management Tools (continued):Risk Management Tools (continued):
• One Objective of Risk Management is Minimizing the Risk
via Risk Mitigation Measures (Let’s use the Risk Equation !) :
RiskRisk = Sum (Hazard x Assets x Vulnerability)
|_________|
Land Use Planning & Zoning,
Considerate Placements of new Assets,
Relocation of Essential Assets. Equity Issues.
or, alternatively by
RiskRisk = Sum (Hazard x Assets x Vulnerability)
|__________|
Good Engineering, Construction Quality-Control,
Codes and Code Enforcement, Retrofitting
• Multiple Risk Computations may be needed to explore the Optimal
Mitigation Measures by Cost-Benefit Analysis for various Levels of
Performance: Life Safety, Sustainable Livelihood, Acceptable Economic
Losses. Essential vs. Ordinary Facilities.
More Risk Management Tools (continued):More Risk Management Tools (continued):
• Pre-Disaster Preparedness
– Planning, Capacity Building, Institutions, Rehearsing, Education
• Disaster Response
– Command and Control (ICS) including international coordination
– Communication and Information
– Logistics
– Field Execution
– Accounting and Checking
• Post-Disaster Relief and Ultimate Recovery
– Who is in charge, what resources are available, strict accounting and
avoidance of corruption, humanitarian & equality issues. Long-term
Mitigation vs. Short-term Recovery Needs. Preplanning (Master Plan) prior
to Disasters!
• Risk Distribution :
– Aid Agreements and Insurance.
Summary:Summary:
• A disaster is not the time to start DRM planning. “PEPPER”:
Pre-Event Preparedness, Post-Event Recovery
• Extreme Events become Disasters only when they strike Vulnerable Communities.
• DRM includes 3 options: Mitigate Risk (Landuse, Zoning, Codes, Engineering)
Adapt to Risk (Preparedness, Coping Capacity)
Distribute Risk (Insurance etc.).
• Long-term Essence of DRM: Reduce Physical & Social Vulnerability to
Disasters (Reduce Poverty !! Feedback !!).
• DRM is intrinsically interwoven with the Sustainable Development of Countries.
• Bottom-up involvement of Communities in DRM tends to be more
effective than top-down DRM.
• Long-term Mitigation is Cost-Effective (in US: about ~ 4 : 1 benefit/cost-ratio).
• Global Climate Change increases some Risk Exposure for all Nations,
but more so for a few (e.g. small islands and Pacific atoll nations).
Questions?
1a
Department of Geological Sciences, Faculty of Sciences
Masaryk University/Brno & Czech Geological Society
September 12-14, 2011
Short Course on Geological HazardsShort Course on Geological Hazards
Topic 1b :Topic 1b :
Natural (mostlyNatural (mostly EquEqu.) Hazards & Risks:.) Hazards & Risks:
Basic Concepts (Continued)Basic Concepts (Continued)
Klaus H. JacobKlaus H. Jacob
Lamont-Doherty Earth Observatory
of Columbia University, NY
jacob@ldeo.columbia.edu
What is Risk ?What is Risk ?
P (Loss) = P (Hazard) x P (Consequence)P (Loss) = P (Hazard) x P (Consequence)
Risk (the expected future Loss) is the Product of 3
Factors, summed up over a given Region:
RiskRisk = SUM ( Hazard x Assets x FragilityFragility )
Risk can be evaluated probabilistically (annual exceedance
probability) or deterministically (P=1) for given scenario events
(what if ….. ?).
[[ProbProb of $/T]of $/T] RegionRegion [ Prob. of H[ Prob. of H≥≥h/Timeh/Time T]T] A [ $]A [ $] [0[0≥≥F(h,A)F(h,A)≥≥1]1]
Some Basic Principles and Tools of Disaster Risk ManagementSome Basic Principles and Tools of Disaster Risk Management
(Repeat from Lecture 1a !):(Repeat from Lecture 1a !):
• Nothing can be well managed that cannot be measured.
• Hence, the need for Risk AssessmentRisk Assessment as aas a Starting PointStarting Point..
• How is Risk assessed?
– By quantifying the different Hazards,Hazards, in terms of their spatial distributions of
severity and frequency of occurrence.
– By evaluating the AssetsAssets (their monetary value and economic & livelihood
importance), that are exposed to the different hazards.
– By evaluating the VulnerabilityVulnerability (Fragility) of the Assets to different Hazard
Types and Hazard Severity.
– By computing the risk via the risk equationrisk equation (aided by computerized GIS
tools, where available). Estimate the loss magnitudes vs. their frequency of
occurrence. Add up all likely losses (small and big) over time, over space
and analyze their economic and social impacts on the nation(s), regions,
communities, and by sectors of the national and local economies, security,
and political stability.
Statistical Predictability:Statistical Predictability:
• Magnitude (Size) Distributions of Natural Events,
Their Frequency of Occurrence, and
Probability of Losses and Fatalities as a Function
of Event Size (Power Law Distributions, Fractal Dimensions)
• Statistical Predictability (“on average ...”, “but with
given dispersion or variance from the average”)
• A single event does not make a statistics, but each
single event contributes to it.
Example 1: Earthquake Frequency vs. Magnitude
Example 2: Natural Disaster Loss Distribution
Example 3: Earthquake Fatality Distribution
4 5 6 7 8
N=1
10
100
1000
10 000
Log N = A - bM
N= 10(A - bM) = No/10bM
Schematic Example 1: Gutenberg-Richter Magnitude / Frequency Relation
CumulativeCumulative Number NN of Earthquakes per 100 yr in the Contiguous US
vs. Magnitude MM (and larger).
Example: A=8, and b=+1 (Slope is -1); “Cumulative Power Law”
Magnitude M
Example 2: Annual US Nat. Disaster Losses (US $)
US
log N = log No + D log L
N = No LD
D is called theD is called the ““Fractal DimensionFractal Dimension””
1 - 2 events
per century
with 1 Million
fatalities
10
Example 3:Example 3:
There are different Types of Natural
Hazards (Perils)
• Geologic HazardsGeologic Hazards
EarthquakesEarthquakes
LandslidesLandslides
Volcanoes
Land Subsidence/Uplift
……………..
• Atmospheric, Hydrological
& Climate Change Hazards
• Extraterrestrial Hazards
- Slow- and Fast-Onset Hazards
- Local, Regional, Global
Source: Munich Re
Tectonics Severe Rain &
Lightning
Storms: Regional, Monsoon ,
Hail, Tornadoes
Climate Change: Rising Temp., El
Nino - Southern Oscillation - ENSO,
Draught, SLR .....
Earthquakes
Volcanoes
Tsunamis
Tropical Storms
High Seas (Waves)
Icebergs
Pack Ice
Source: Munich Re
Types of Natural Hazards
• Geologic Hazards
Earthquakes & Seismic HazardsEarthquakes & Seismic Hazards
OverviewOverview (later lectures more quantitative)(later lectures more quantitative)
Land Subsidence/Uplift
Landslides
Volcanoes
……………..
• Atmospheric, Hydrological
& Climate Change Hazards
• Extraterrestrial Hazards
- Slow- and Fast-Onset Hazards
- Local, Regional, Global
The indicated peak ground accelerations (in “g”) have a 10%probability
to be exceeded in 50 years (Average recurrence period of ≈500 years)
( grn=2-8grn=2-8%g;%g; ylw=8-16ylw=8-16%g;%g; rd=16-48%grd=16-48%g;; brwnbrwn≥≥48%g48%g )
(TIME-INDEPENDENT)
GSHAP: Probabilistic earthquake shaking hazard map
GSHAP: Probabilistic earthquake shakingGSHAP: Probabilistic earthquake shaking hazardhazard mapmap
Shown is the level of
ground shaking (peakpeak
accelerationacceleration, in units of, in units of
EarthEarth’’s gravitationals gravitational
acceleration gacceleration g) that is
expected to be reached
or exceeded with a
probability of 10% in 50probability of 10% in 50
yearsyears (or 90%
probability not to be
exceeded in 50 years),
corresponding to an
average recurrence
period of ~ 500 (actually
475) years
XX
TTRR = 2475 yr ~ 2500 yr= 2475 yr ~ 2500 yr
Site Response ….. is the local modification of ground motions due to near- & subsurface
soil and rock conditions. Microzonation Example: Ground Shaking
Amplification Map of the L.A. Basin and vicinity (Field et. al., 2000)
Site Response / Microzonation
Earthquake-Related Hazard Effects:
• Shaking & Related Collapse Hazards
• Soil Amplification, Liquefaction & Collapse
• Surface Faulting
• Land Deformation (Subsidence, Emergence)
• Land Slides & Rockfalls
• Tsunamis & Seiches
• Associated Hazards: Fires, Inundation
• Epidemiology of Earthquakes
Shaking :
Earthquakes
don’t kill,
Buildings do !!
Anchorage, Alaska, 1964
Mw=9.2
Shaking: Whittier Earthquake, CA, ca. 1986
Unreinforced Masonry is Brittle & Fails Easily
SOIL LIQUEFACTION: Niigata Earthquake, Japan: When Soils Liquefied
and Lost their Bearing Strength, Houses Sank &Tilted Slowly
TsunamiTsunami during Alaska 1964 earthquake, M=9.2, causesduring Alaska 1964 earthquake, M=9.2, causes
damage to tank farm.damage to tank farm. Note: V = (Note: V = (gHgH))1/21/2
; A ~ 1/H; g; A ~ 1/H; g ≈≈ 10m/sec10m/sec22
10 hrs
Indian OceanIndian Ocean
Tsunami afterTsunami after
Sumatra M9.2Sumatra M9.2
Quake,Quake,
Dec 2004.Dec 2004.
Travel
Times
of
First
Tsunami
Wave
(hours):
2+hrs
to Thailand
and India,
6+ hours
to Africa
Note: V = (Note: V = (gHgH))1/21/2
; A ~ 1/H; g; A ~ 1/H; g ≈≈ 10m/sec10m/sec22
Coast of Thailand 2 hours after the quake
Note: V = (Note: V = (gHgH))1/21/2
; A ~ 1/H; g; A ~ 1/H; g ≈≈ 10m/sec10m/sec22
ca. 8 m high
A minute - or so - later, the first wave crushes ashore
Indian ocean
Tsunami after
Sumatra Quake
Dec 2004.
Without warning
unsuspecting
coastal populations
are overwhelmed.
With warning and
evacuation plans
many lives could
have been saved.
Image shows City in
Thailand 2 hours
after the quake.
CURRENTCURRENT AND PROPOSED TSUANMI WARNING SYSTEMSAND PROPOSED TSUANMI WARNING SYSTEMS
Upper Left: Existing (yellow) and Proposed (red) NOOA-Operated Pacific/Atlantic/Caribbean
Tsunami alert Network using deep-ocean pressure sensors with acoustic Communications to buoys,
and GOES satellite Communication to the Pacific Tsunami Warning Center in Hawaii
Upper Right: Proposed World-wide Tsunami warning system. Other proposals exist. Open Data
Exchange between Countries still not agreed on, hindering effective implementation.
Science & Policy Lessons from 2004 Tsunami:Science & Policy Lessons from 2004 Tsunami:
•• Need rapid and reliable seismological methods to determine
the magnitude of giant (M~9) earthquakes
and of their tsunami potential. International Issue.
•• Need global tsunami detection and warning
dissemination system(s). Full International Cooperation is
Essential, despite National Concerns.
•• Need full integration of & communication between scientific
establishments and the emergency agencies at
international, national, regional and local levels.
•• Coastal Demographic Trends and Landuse are
unsustainable. More circumspect coastal rezoning is needed.
Equity Issues.
Secondary Effects of Earthquakes:Secondary Effects of Earthquakes: e.g. Fire.e.g. Fire. The San Francisco Earthquake of 1906
generated a Fire Storm that caused a larger damage than the earthquake shaking itself.
About 30,000 people had to be evacuated by boat to escape from the inferno.
Other Examples: Tokyo 1923, Kobe 1995, ......
Medical Epidemiology of Earthquakes:Medical Epidemiology of Earthquakes:
Injuries due to Collapse of Buildings:
Crushing,
Loss of Limbs
Suffocation from Dust / Fires
Crush Syndrome: Kidney Collapse
(after rescue it requires immediate access
to Dialysis Machines / Artificial Kidneys)
Other Health Effects:
Severe Trauma
Risk of
Diarrhea, Typhoid, Cholera
Malaria, Dengue Fever, ….
Questions?
1b