The various landscapes around the Bellarine area require differing modelling approaches at differing resolutions. During the scoping phase of the project, areas of concern were identified. These were visited during the site inspection and potential flooding mechanisms were confirmed. Additional information for model detail was also gathered during the site visit, including potential flood paths that may not have been detected by the LiDAR, and the presence and condition of defences that were not included in the structures database. From this, the appropriate scale and resolution of modelling was determined for each compartment. Where recent detailed modelling was available, the scope of modelling was reduced accordingly. The modelling approaches are noted in Table 4-2.
Table 4-2 Modelling techniques
|Wave setup and runup||LITPROF and empirical calculations|
|Flooding / inundation||SOBEK for complex river / estuary environments|
|Coastal inundation through static modelling – for less complex areas|
The inundation modelling includes both dynamic and static modelling approaches. Dynamic modelling simulates the movement of water through the environment by accounting for the flow paths, friction of various surfaces and the time variation of sea-level and river flows. The dynamic methods are applied to the higher priority locations and where flow paths are more complex. The static modelling refers to the horizontal projection of the peak water-level across the terrain based on land elevation (i.e. “bathtub” method). This method is applicable for the medium and low-priority locations, where there are less complex inundation mechanisms e.g. low-lying areas with little or no dune and no defences. The static inundation does, however, include consideration of flow paths where possible and information relating to the event under which the inundation would be expected to occur, including the standard of protection of any foreshore structures.
Future tidal levels were also used to give an indication of the possible future shoreline location for low-lying areas.
Overtopping discharge volumes are given for information and to determine potential failure mechanisms and timeframes. The stated volumes should be checked if required for design purposes.
Identification of Hazards and Determining Priority
Determination of Design Conditions