Bushfire Hazard Assessment & Management Plan v4 - 7 Triller Court, Pomona

Bushfire Hazard Assessment & Management Plan v4                                NCES REF: J000841
Lot 4 on SP320405 – 7 Triller Court, Pomona




3.6 Quantitative Modelling
Quantitative modelling of the potential bushfire conditions that may be experienced within the
VHC 9.1 flanking the post development footprint to the north, west, and south 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 can determine a suite of bushfire
behaviour variables including the minimum distances required to achieve a range of different
radiant heat level exposures.
Fuel load inputs have been drawn from Planning for Bushfire Resilient Communities (QFES
2019) based on the calculated potential fuel loads for VHC 9.1 (21/ha surface and near surface
fuels and 24.2t/ha total fuels). 7º effective slope was adopted for the slope underlying the VHC
9.1 to the north, 9º effective slope was adopted for the slope underlying the VHC 9.1 to the
south, and 1º effective slope was adopted for the slope underlying the VHC to the west given
the hazardous vegetation is located upslope or across slope of the development area. A Flame
width of 100m has been adopted commensurate with the edge width of all VHC 9.1 units.
A Forest Fire Danger Index of 47 has been adopted for the site consistent with the assignment
by QFES (Catalyst 2020) (refer Plate 8).




                                   Plate 8 - FFDI (Source: QFES redi Map)

The Flamesol output result is shown in Plates 9-11.




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