Attachment C - Bushfire Management Plan · 132008.1128.04

                                                                          Bushfire Emergency Provisions
                                      Residential Aged Care Facility – 6 Grasstree Court, Sunrise Beach

Radiant Heat Flux
Exposure to radiant heat remains one of the leading causes of fatalities associated with bushfire
events. Measured in kilowatts per m2, radiant heat is the heat energy released from the fire front
which radiates to the surrounding environment, deteriorating rapidly over distance. In terms of
impacts on buildings, radiant heat can pre-heat materials making them more susceptible to ignition,
or can cause non-piloted ignition of certain materials if the energy transmitted reaches a threshold
level. Radiant heat can also damage building materials such as window glazing, allowing openings
into a building through which embers may enter. Radiant heat impact is an especially important
factor in building-to-building ignition.

In terms of radiant heat exposure for humans, it can cause pain to unprotected skin in milder
situations or life threatening and fatal injury in higher exposure thresholds.




              Figure 3 - The effects of radiant heat (NSWRFS, 2006; Drysdale, 1999, CFA, 2012)

Fire Driven Wind
The convective forces of bushfire typically result in strong to gale force fire-driven winds which in
itself, can lead to building damage. The typical effects of fire driven wind include the conveyance
of embers, damage from branches and debris hitting the building, as well as direct damage to
vulnerable building components such as lifting roofs or roof materials and the damage / breakage
of windows.

Smoke
Smoke emission remains a secondary effect of bushfire and is one which is typically not addressed
by bushfire hazard assessment. Irrespective, it is important to note the potentially severe impact of
smoke emission on the human respiratory system. It can lead to difficulties in breathing, severe
coughing, blurred or otherwise compromised vision, and can prove fatal. It is also important to note
that toxic smoke can occur during bushfire, particularly where buildings or materials are ignited.
With regard to evacuation, it can reduce visibility and create difficulties for particularly vulnerable
persons.

Vegetation Communities
Fuel load and arrangement represents a considerable component in dictating to a large degree
the behaviour of fire in terms of intensity, rate of spread and flame height, and typically relates to


Status: Provisions                                                                          December 2018
Project No.: 18-030                                                                               Page 9