Appendix C - Bushfire Hazard Assessment and Management Plan

     VHC 41.4 – Discontinuous low grass or tree cover – which is attributed a combined surface/near-
      surface fuel of 2.5t/ha and a total potential fuel load of 3t/ha

2.1.3 Maximum Landscape Slope
The slope of the land is a major determinant of fire behaviour. Fire burns faster as it travels up a slope,
via the preheating of unburnt fuels ahead of the fire, increasing the rate of spread and fireline intensity.
Conversely, fires move more slowly as they travel downslope. Fireline intensity (kW/m) is a function of
the rate of spread. As a general rule, the rate of fire spread (and fireline intensity) doubles up a 10-degree
slope and quadruples up a 20-degree slope (QFES, 2019).

The hazardous vegetation to the north of the cottage is located downslope of the development area on a
slope of 4.5 degrees, with vegetation to the west located upslope and vegetation to the south located
across slope. Where the slope under hazardous vegetation is located across slope, it is assessed as being
upslope irrespective of the slope of land between the site and the edge of the hazardous vegetation. Note
that for the purposes of undertaking a bushfire hazard assessment, where the topography is flat or where
vegetation is located upslope of an assessment site, a slope of 1 degree is required to be used to satisfy
the mathematical formula, however it has negligible impact on the calculations.

2.1.4   Fire Danger Index
The Queensland government produce a publicly available data package which includes selected inputs
and information used by the CSIRO in conjunction with the QFES to prepare the State-wide Bushfire
Hazard Area (Bushfire Prone Area) mapping (July 2014). The data includes Fire Weather Severity (Fire
Danger Index - FDI). A review of the dataset for the assessment area indicates that the site is located
within a band of FDI 47.

2.1.5   Additional Input Parameters
The assumed flame temperature is set at 1,200K and the ambient temperature is set to 35 ̊C in accordance
with Section 7.6 and the fit-for-purpose guidance provided in Bushfire Resilient Communities - Technical
Reference Guide for the State Planning Policy State Interest ‘Natural Hazards, Risk and Resilience –
Bushfire (QFES (2019).




JULY 2022                     BUSHFIRE HAZARD ASSESSMENT & MANAGEMENT PLAN                            Page: 10
                                          296 KIDD ROAD, POMONA