L2: Foundations for hazard and risk assessment

Question 1

What are the 3 components of risk assessment?

Answer 1

1. risk identification
2. risk analysis
3. risk evaluation

Question 2

What factors determine the modelling approach?

Answer 2

• hazard type
• purpose of assessment
• scale of analysis
• data and model availability

Question 3

What are the main components of hazard analysis?

Answer 3

• frequency/magnitude relationship
• initiation process
• travel or transmission of hazard

Question 4

What is another name for a statistical hazard model?

Answer 4

Empirical or black box

Question 5

What method is used by statistical hazard models?

Answer 5

derive statistical relationship between observed hazard drivers and resulting hazard event. Hazard can be modelled by using statistical relationship to transform inputs to outputs

Question 6

What data do statistical hazard models use?

Answer 6

observed hazard events with associated triggers and system properties

Question 7

What assumptions do statistical hazard models make?

Answer 7

repeatability and stationarity of system (past is key to the future). only applicable in similar settings

Question 8

What is another name for a physically-based hazard model?

Answer 8

deterministic, grey or white box

Question 9

What is the method used by physically-based models

Answer 9

hazard processes explicitly represented by physics-based equations solved using numerical modelling (FE)

Question 10

What data do physically-based hazard models use?

Answer 10

measured physical parameters of the system

Question 11

What assumptions do physically based models make?

Answer 11

model and input data describe the physical system

Question 12

What is the reality of physically based models?

Answer 12

environmental systems can never be fully defined. many models use mix of measured and empirical inputs GREY BOX

Question 13

What is a qualitative model?

Answer 13

info evaluated and analysed verbally: based on judgement and logic

Question 14

What is a quantitative model?

Answer 14

info recorded, analysed and evaluated using numerical scales

Question 15

What is a heuristic model?

Answer 15

use subjective expert knowledge to describe hazard system. often encode it in form of semi-quantitative decision rules to be applied in computational models

Question 16

What are stochastic and probabilistic models?

Answer 16

input parameter values sampled from their probability distributions, and the model is run multiple times with these different input values to represent the full parameter space and account for the effects of uncertainty

Question 17

What are spatially distributed (map-based) models?

Answer 17

implemented in Geographical Information Systems (GIS)

Question 18

What is aleatory uncertainty?

Answer 18

uncertainty with stationary statistical characteristics. may be structured (bias, autocorrelation, long-term persistence) but can be reduced to a stationary random distribution

Question 19

What is epistemic uncertainty?

Answer 19

uncertainty arising from lack of knowledge of system and a lack of data

Question 20

What are the 3 types of epistemic uncertainty?

Answer 20

1. System dynamics - L.O.K. of model structure and parameters
2. Forcing and response data - L.O.K. how to interpret data
3. Disinformation - Data known to be wrong

Question 21

What is semantic/linguistic uncertainty?

Answer 21

uncertainty about what statements or quantities actually mean

Question 22

What is ontological uncertainty?

Answer 22

uncertainty associated with different belief systems e.g. assumptions

Question 23

Name 4 physics-based landslide hazard assessment models

Answer 23

Analytical
Dynamic LEM
Analysis of Continua
Discrete Element Models

Question 24

Name 4 risk modelling frameworks

Answer 24

Quantitative Risk Analysis (QRA)
Event tree analysis
Risk matricies (or Consequence-Frequency Matricies, CFM)
Indicator-based approaches

Question 25

What is the human capital method for estimating value of human life

Answer 25

based on individual’s lost future earning capacity in event of accident or death. children have highest value, zero for people who are unable to work

Question 26

What is the willingness to pay approach to estimating value of human life?

Answer 26

how much people would pay to avoid a certain reduction in their chance of accident or premature death. assessed by questionnaires

Question 27

What is the aim or risk management?

Answer 27

lower risk levels to be societally and economically acceptable. CBA used to prioritise risk reduction resources. As Low As Reasonably Practicable (ALARP)