4. Catastrophe Modelling Flashcards
What are the 7 targets of the UNISDR Sendai Framework for DRR?
1) Substantially reduce global disaster mortality by 2030
2) Substantially reduce the number of people affected globally by 2030
3) Reduce direct disaster economic loss in relation to global GDP by 2030
4) Substantially reduce disaster damage to critical infrastructure and disruption of basic services (namely health and education facilities), through developing their resilience by 2030
5) Substantially increase the number of countries with national and local disaster risk reduction strategies by 2020
6) Substantially enhance international cooperation to developing countries through adequate and sustainable support to complement their national actions for implementation of this framework by 2030
7) Substantially increase availability of and access to multi-hazard early warning systems and disaster risk information and assessments to people by 2030
What are the UNISDR 4 priorities for action?
Priority 1: Understanding disaster risk
Priority 2: Strengthening DR governance to manage disaster risk
Priority 3: Investing in DRR for resilience
Priority 4: Enhancing disaster preparedness for effective response and to ‘Build Back Better’ in recovery, rehabilitation and reconstruction
What is the definition of risk? (equation plus wordy)
RISK = f(hazard * exposure * vulnerability)
‘An uncertain situation involving exposure to danger
Engineers often qualify risks as…
Losses: financial, casualties, downtime
What is a catastrophe?
When losses exceed a given amount.
Natural - EQ, FL, LS
Man-made - Cyber attacks, terrorism, war
Which 4 categories of events/catastrophes cause the greatest overall losses and give examples of each?
Meteorological (58%) - tropical cyclone, convective storms, local storms
Climatological (20%) - Extreme temperature, drought, forest fire
Hydrological (14%) - Flood, mass movement
Geophysical (8%) - EQ, LS, tsunami, volcanic activity
In 2018, overall losses were $160bn
What do engineers do?
Plan, design, build, maintain and decommission infrastructures and structures
A design deals with the ____, whereas assessment deals with the ______
New
Existing
What are the disadvantages of models (risk modelling) (4)
- Models are no precise
- Data are not sufficient
- Natural variability
- Experience is subjective
The framework for CAT modelling
(HAZARD) Event generation and Intensity calculation + (EXPOSURE) Asset identification
—>
(VULNERABILITY) damage estimation and policy conditions
—>
Loss calculation
The _____ _______within the framework of ______ ______, provides the bases for _______ _______ _______ in the case of uncertain and/or incomplete information
Risk assessment
Decision analysis
Rational Decision Making
In the asset identification section of the CAT framework, how do we classify properties by their main characteristics (3)?
Geographical resolution
Public or private asset
Age of the asset
e.g. for exposure identification of buildings, buildings are grouped according to their main structural characteristics (construction material, resisting mechanism and height)
Damage estimation - intensity measures should:
What does the mean damage ratio vs intensity measure graph look like
Reflect relevant hazard characteristics
Reflect buildings response
The ‘Typical damage function’ is a roughly s shaped curve
What does mean damage ratio represent?
The ratio of repair cost to replacement value
How are damage functions derived?
Level 1: Simplified dynamic analysis
Level 2: Claims data
Level 3: Complex dynamic analysis
Level 4: Experimental testing
Losses are expressed in terms of…
Expected Annual Loss (EAL) aka average annual loss
Losses can be building-by-building or total
The model for the loss assessment needs validation, validation is event based
DR financing, traditional insurance
What is the payout basis?
What are the advantages and disadvantages?
Pay-out basis: Claims i.e. actual losses
Advantages: Pay-out = loss sustained
Disadvantages: Very slow processes - pay-out only pays insured assets
Describe an alternative risk transfer instrument - CAT bonds
EQ risks are transferred to FINANCIAL MARKETS - much greater risk bearing capacity than insurance/reinsurance companies.
Investors purchase bonds from a third party, single purpose reinsure (principal) and receive relatively high return from the bonds
If a specified trigger event occurs (i.e. parametric trigger), the principal is released to the sponsor i.e. local gov
In cases no such EQ occurs before the bonds mature, the principal together with profit is returned to the investors
Pay-out basis, advantages and disadvantages of CAT bonds?
POB - trigger mechanism (conventional CAT bond triggering mechanism is defined in terms of scenarios e.g. location and magnitude - scenario-based approach)
Adv - immediate pay-out, flexible bounds
Disadv - payout basis risk (Basis risk = difference between actual losses incurred by the sponsor and payment received by the sponsor
Who are the three main end users of seismic CAT modelling?
DRR policy-makers in funding organisations e.g. WB/UN
Governments
DR financers e.g. insurers and re-insurance industries (CCRIF etc.)
What is a decision variable? And what are 2 effective decision variables for urban FL risk management?
A decision variable is a measurable quantity supporting managers and stakeholders in decision making
Life cycle cost and return on investment
What do LCC and ROI do?
Allow evaluating the economic and financial feasibility of different alternatives (e.g. different flood mitigation strategies).
LCC and ROI analyses can be performed at urban level considering as exposed asset a portfolio of flood-prone buildings
Specifically the reduced FL damage to the exposed asset can be seen as avoided costs or as returns
