2021-11-15 GC Agenda - Item 7 - Attachment 2 - Coastal Hazards Adaptation Plan with tracked changes

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

 A hazard is a natural or man-made event that has the potential to cause impacts to human and ecological
 systems. This can include people, buildings, values, 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 modelsformulas that describe the propagation of the
 hazard across the landscape. We useIn most cases, historical data and other information are also
 combined in athe 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 will interact with (e.g. people, buildings, infrastructure, habitat etc.); and howas well as 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 outdetermined 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 sciencerequires consideration of uncertainty as it involves
 forecasting events for which the exact time and location might not be largely unknownknown, but is still
 critical for making sureensuring decisions are appropriately informed by the best available information
 available at the time.


Determining tolerability to risks


Noosa Council – Coastal Hazards Adaptation Plan                                                       Page 31