2021-01-18 GC - Item 3 - Attachment 1 - Coastal Hazards Adaptation Plan for Community Consultation

                                             Reference Box #2

                                    Understanding ‘hazard’ and ‘risk’

 The risk from a natural hazard is determined by the combined understanding of the nature of the hazard,
 how likely it is to occur, and what the consequences if it did occur might be.

 A hazard is a natural or man-made event that has the potential to cause impacts to people, buildings,
 infrastructure, agriculture, environmental assets and communities. Hazard modelling helps us
 understand a hazard's intensity (or magnitude), frequency and source. It is typically underpinned by
 mathematical models that describe the propagation of the hazard across the landscape. We use
 historical data and other information in a mathematical model to estimate the probability of the hazard
 event occurring.

 Understanding the impacts of the event relies on determining the ‘exposure’ – that is what things will
 the hazard interact with (e.g. people, buildings, infrastructure, habitat etc.); and how the level of
 ‘vulnerability’ of each – that is, how will it cope when it is exposed to that hazard? For the purposes of
 the CHAP, five difference criteria were used to determine the possible consequences in line with
 Council’s risk management guidelines. These were:

     •     Community – Social
     •     Community – Economic
     •     Environmental
     •     Council – Financial
     •     Council – Other

 The ‘risk’ to an asset/value is worked out by combining the likelihood of the event occurring (in this case,
 a coastal hazard event), combined with the expected consequence (impacts) of the event on that
 particular asset/value (e.g. infrastructure asset, recreational facility, etc). Table 1 shows an example of
 how risk is calculated using likelihood and consequence.

  LIKELIHOOD               CONSEQUENCE

                           Insignificant    Minor            Moderate        Major           Catastrophic

  Almost Certain           Low              Medium           High            Very High       Very High

  Likely                   Low              Medium           High            High            Very High

  Possible                 Low              Medium           Medium          High            Very High

  Unlikely                 Low              Low              Medium          High            Very High

  Rare                     Low              Low              Low             Medium          High

                                            Table 1: calculating risk

 Estimating risk is has always been an uncertain science as it involves forecasting events for which the
 exact time and location might be largely unknown, but is still critical for making sure decisions are
 appropriately informed by best available information.

Noosa Council – Coastal Hazards Adaptation Plan 2020 - 2030 (community consultation version)           Page 20