Victorian Coastal Cliff Assessment - Risk Score - Short Term - Now to 2040

dataset: cliff_riskscore_shortterm_to_2040
The Coastal Cliff Risk Score datasets evaluate the likelihood and consequence of cliff instability to support risk management in areas with coastal cliffs. This includes the classification of risk across the determined timeframes and climate change scenarios. The dataset provides a second-pass, regional assessment providing a top-down coastal compartment view of risk which. The outputs of second-pass risk assessments can be used to support discussion among stakeholders regarding coastal erosion and instability risks, broader climate change risks and the development of adaptation pathways within Victoria’s coastal compartments. However, it should be noted that this assessment has been undertaken at a high level (regional/state-wide scale) and is not appropriate for local scale planning. The data from this assessment may be superseded by local scale and site-specific assessments undertaken by a suitably qualified and experienced practitioner. The assessment is based on available data, tools and understanding of coastal processes. The product is recommended for use at the statewide / regional scale along the Victorian coastline. Application of the data should be guided by the accompanying Victorian Coastal Cliff Assessment, Stage 2a technical report (Tonkin & Taylor 2025) read in conjunction with the Stage 1 technical report, combined with appropriate expert advice. The product is not suitable for individual property scale assessments. Further information is contained in the study report "Victorian Coastal Cliff Assessment, Stage 2a technical report", Tonkin & Taylor 2025.
 
Citation proposal Citation proposal

(2026)

Victorian Coastal Cliff Assessment - Risk Score - Short Term - Now to 2040

Department of Energy, Environment and Climate Action

Description

Title
Victorian Coastal Cliff Assessment - Risk Score - Short Term - Now to 2040 
Alternate title
cliff_riskscore_shortterm_to_2040 
Purpose
Regional / state-wide scale 
 
 

Maintenance

Maintenance and update frequency
As needed 
 
 

Format

Title
File geodatabase, shapefile 
 
 

Contacts

  Point of contact

Cited responsible party

No information provided.
 
 

Keywords

Topic category
  • Environment
  • Oceans
DELWP Categories
 
 

Resource Constraints

Classification
Unclassified 
 
 

Lineage

Statement
The risk assessment framework defines risk as the “effect of uncertainty on objectives” and utilises likelihood and consequence to determine risk. Where likelihood is the probability of a coastal hazard occurring, and consequence is the impact of the coastal hazard on coastal values and uses, e.g. social, cultural, economic, and environmental. The first step of the risk assessment was the development of hazard extents and likelihoods based on the mapped ASCCIE and ASTaR. Likelihood defines the potential frequency of occurrence of a hazard occurring, and these were mapped to identify areas potentially at risk to cliff instability and/or erosion related to a likelihood. In this assessment a qualitative measure of likelihood was used. Likelihood is divided into five categories: rare, unlikely, possible, likely, almost certain. Each hazard scenario is assigned a particular likelihood and rated on this five-point scale which is considered increasingly likely over the long-term (2070-2100). Professional judgement was used to best define the likelihood of the hazard scenario for each timeframe. It is recognised that there are a range climate change trajectories and uncertainties regarding the impact of climate change on hazards. Note that the GIS exercise undertaken utilised only a single ASCCIE polygon (the most likely) for each timeframe in the analysis. The calculation of risk ratings assumes the same likelihood for each assessed timeframe across all coastal compartments, irrespective of differences in the underlying geology of coastal cliffs across coastal compartments. This limitation of the assessment is tied to the regional scale and deterministic approach adopted in the development of hazard inputs. For a regional/state-wide scale assessment it is not possible to adopt a probabilistic approach due to the large scale, total length of the shoreline and lack of site-specific data to build probability distributions around each parameter. The purpose of this regional/state-wide assessment is to identify high risk areas, where it would be prudent to undertake more detailed, probabilistic assessment on a local-scale or site-specific scale. Further information in the study report "Victorian Coastal Cliff Assessment - Stage 2 - Risk Assessment", Tonkin and Taylor, Sep 2023 
Description
Output derived from ASCCIE and ASTarR modelled datasets 
 
 

Metadata Constraints Metadata Constraints

Use limitation
Unknown 
Classification
Unclassified 
 
 

Quality

Attribute Quality
Positional Accuracy
Comments
The method utilised to produce the risk ratings presented in this report has delivered an effective overview of risks associated with coastal cliffs at the coastal compartment level. There is potential to further leverage the data underlying the assessment and to refine the outputs of the process for the benefit of end users. The following recommendations should be considered for future further development of risk assessments focused on areas susceptible to coastal instability and erosion hazards within Victoria.  Future third-pass risk assessments building on the second-pass risk assessment framework presented in this report should include a review of risk tolerability thresholds, and the likelihood and consequence criteria used in the calculation of risk ratings. Engagement with local stakeholders should be prioritised to ensure the perspectives and risk tolerance of Traditional Owners and key stakeholders are reflected in risk ratings derived from tertiary risk assessments. Future third-pass risk assessments should also consider additional localised features such as the specific geology of coastal cliffs. 
 
Conceptual Consistency
Missing Data
Excess Data
 
 


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