Appendix B - Geotechnical Investigation Report

 Risk Terminology             Description
 Probability                  (ii) Subjective probability (degree of belief) – Quantified measure of belief, judgment, or confidence
 (continued)                       in the likelihood of an outcome, obtained by considering all available information honestly, fairly,
                                   and with a minimum of bias. Subjective probability is affected by the state of understanding of a
                                   process,                judgment               regarding               an              evaluation,
                                   or the quality and quantity of information. It may change over time as the state of knowledge
                                   changes.
 Qualitative Risk             An analysis which uses word form, descriptive or numeric rating scales to describe the magnitude of
 Analysis                     potential consequences and the likelihood that those consequences will occur.
 Quantitative Risk            An analysis based on numerical values of the probability, vulnerability and consequences and resulting
 Analysis                     in a numerical value of the risk.
 Risk                         A measure of the probability and severity of an adverse effect to health, property or the environment.
                              Risk is often estimated by the product of probability x consequences. However, a more general
                              interpretation of risk involves a comparison of the probability and consequences in a non-product form.
 Risk Analysis                The use of available information to estimate the risk to individual, population, property, or the
                              environment, from hazards. Risk analyses generally contain the following steps: scope definition,
                              hazard identification and risk estimation.
 Risk Assessment              The process of risk analysis and risk evaluation.
 Risk Control or Risk         The process of decision-making for managing risk and the implementation or enforcement of risk
 Treatment                    mitigation measures and the re-evaluation of its effectiveness from time to time, using the results of
                              risk assessment as one input.
 Risk Estimation              The process used to produce a measure of the level of health, property or environmental risks being
                              analysed. Risk estimation contains the following steps: frequency analysis, consequence analysis and
                              their integration.
 Risk Evaluation              The stage at which values and judgments enter the decision process, explicitly or implicitly, by including
                              consideration of the importance of the estimated risks and the associated social, environmental and
                              economic consequences, in order to identify a range of alternatives for managing the risks.
 Risk Management              The complete process of risk assessment and risk control (or risk treatment).
 Societal Risk                The risk of multiple fatalities or injuries in society as a whole: one where society would have to carry
                              the burden of a landslide causing a number of deaths, injuries, financial, environmental and other
                              losses.
 Susceptibility               See ‘Landslide Susceptibility’.
 Temporal Spatial             The probability that the element at risk is in the area affected by the landsliding, at the time of the
 Probability                  landslide.
 Tolerable Risk               A risk within a range that society can live with so as to secure certain net benefits. It is a range of risk
                              regarded as non-negligible and needing to be kept under review and reduced further if possible.
 Vulnerability                The degree of loss to a given element or set of elements within the area affected by the landslide
                              hazard. It is expressed on a scale of 0 (no loss) to 1 (total loss). For property, the loss will be the value
                              of the damage relative to the value of the property; for persons, it will be the probability that a
                              particular life (the element at risk) will be lost, given the person(s) is affected by the landslide.
NOTE:           Reference should be made to Figure A1 which shows the inter-relationship of many of these terms and the
                relevant portion of Landslide Risk Management.

                Reference should also be made to the paper referenced below for Landslide Terminology and more detailed
                discussion of the above terminology.

This appendix is an extract from PRACTICE NOTE GUIDELINES FOR LANDSLIDE RISK MANAGEMENT as presented in Australian
Geomechanics, Vol 42, No 1, March 2007, which discusses the matter more fully.



February 2019