Appendix B - Bushfire Hazard Assessment

3.0     LOCAL HAZARD MAP
3.1     GENERAL
The SPP reference documentation sets out the following methodology for preparing a Local Hazard Area
Map:
     Categorising the vegetation within the site in accordance with the vegetation hazard classes
        derived from QFES (2019) (Refer to Figure 1)
     Using the patch and corridor filtering process to remove narrow corridors and small patches of
        hazardous vegetation (Refer to Figure 1)
     Subdividing the identified vegetation hazard classes into bushfire hazard sub-units based on
        slope differences and vegetation hazard classes (Refer to Figure 2)
     Assigning SPP Potential Bushfire Intensity classes to the sub-units (Refer to Figure 2)
     Application of 100m Potential Impact Buffers to the amended sub-units to derive an overall Local
        Hazard Map (Refer to Figure 3)

3.2     PATCH AND CORRIDOR FILTERING
Section 4.2.6 of Bushfire Resilient Communities (QFES, 2019) outlines the patch and corridor filtering
process to modify potential intensity of small patches and corridors (based on Leonard et. al. 2017). The
process involves the following four stages:
      Remove small, isolated patches of a single Vegetation Hazard Class less than 1ha if they are
         further than 100m from any other continuous fuel greater than 2 hectares in size
      Downgrade the intensity of small patches (0.5 to 3 ha). This process downgrades the effective
         fuel load of continuous vegetation patches 0.5 to 2ha by 66%, and 2 to 3ha by 50% if they are
         completely surrounded by either no fuel or by discontinuous fuel further than 100m from any
         other continuous-fuel vegetation patch greater than 2 hectares in size
      Removing narrow corridors of vegetation less than 50m wide. These small patches are merged
         with surrounding vegetation by allocating a patch to the Vegetation Hazard Class that is most
         common to the patch boundary.
      Removing small patches of vegetation less than 0.5ha. These small patches are merged with
         surrounding vegetation by allocating a patch to the Vegetation Hazard Class that is most common
         to the patch boundary
In this assessment, all VHC 8.1 vegetation units within the assessment area consist of narrow units of
vegetation which are less than 50m in width. In this regard, they have been merged with the surrounding
VHC 40.4 vegetation which adjoins the patch boundary of the VHC 8.1.




NOVEMBER 2022                          BUSHFIRE HAZARD ASSESSMENT                                Page: 12
                                   157 LAWNVILLE ROAD, BLAK MOUNTAIN