Appendix G - Bushfire Hazard Assessment & Management Plan

Bushfire Hazard Assessment & Management Plan v1                               NCES REF: J001050
Lot 3 on RP131369 – 96 Black Mountain Range Road, Black Mountain




3.6 Quantitative Modelling
Quantitative modelling of the potential bushfire conditions that may be experienced within the
identified hazardous vegetation unit; VHC 24.1 Acacia open forest on residuals, has been
undertaken to assist in determining the suitability of the development and any asset setback
requirements.
The models used comprise industry standard bushfire equations which have been built into
the FPAA endorsed FLAMESOL computer model. FLAMESOL allows numerous input
variables to be adjusted including fuel loads, fire danger index, site slope and distance to
vegetation. FLAMESOL uses the following algorithms:
    •    Rate of Spread – McArthur (1973) and Nobel et al. (1980)
    •    Flame Length – NSW Rural Fire Service (2001) and Nobel et al. (1980)
    •    Elevation of Receiver – Douglas and Tan (2005)
    •    Flame Angle – Douglas and Tan (2005)
    •    Radian Heat Flux – Drysdale (1999), Sullivan et al. (2003) and Douglas and Tan (2005)
The FLAMESOL Minimum Distance calculator has been used and comprises an AS
3959:2018 Method 2 (Appendix B) based calculator which will determine standard bushfire
behaviour variables as well as the minimum distances required to achieve a range of different
radiant heat levels (represented by BAL's).
Fuel load inputs have been drawn from Planning for Bushfire Resilient Communities (QFES
2019) based on the calculated potential fuel loads for VHC 24.1 (9.5 t/ha surface and near
surface fuels and 10.1 t/ha total fuels).
An 18º effective slope was adopted for the slope underlying the VHC 24.1 Acacia open forest
to the northwest, southwest, and west and a 24º effective slope was adopted for the slope
underlying the VHC 24.1 Acacia open forest to the southeast.
The default Flame Width of 100m was chosen given the large variance in the edge width of
the onsite and offsite VHC 24.1.
A Forest Fire Danger Index (FFDI) of 47 has been adopted for the site consistent with the
assignment by QFES (Catalyst 2020) (refer Plate 9).




                                    Plate 9 – FFDI (Source: QFES redi Map)

The Flamesol output results are shown in Plates 10 & 11.




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