Fire Development, Transitions and Suppression : Final Report

Environmental Sciences not elsewhere classified

Sullivan, Andrew ; Gomes Da Cruz, Miguel ; Ellis, Peter ; Gould, Jim ; Plucinski, Matt ; Hurley, Richard ; Koul, Vijay

CSIRO Ecosystem Sciences

DOI  :  10.4225/08/584d96b58c0ff
RP-ID  :  EP1312986

学科分类：地球科学(综合)

澳大利亚|英语

来源: CSIRO Research Publications Repository

【 摘 要 】

All bushfires start small. Understanding how they progress from ignition to conflagration, from surface fire to high intensity crown fire, is critical to a range of needs, including planning appropriate suppression strategies, ensuring firefighter safety and issuing public warnings. The period between the initial ignition of a fire and when that fire completes its development phase and attains its potential rate of spread for the prevailing conditions represents the only time when effective initial attack suppression can be undertaken. All existing operational fire prediction systems assume a fire has completed its development phase and is spreading at its steady-state rate of spread and thus may over-predict the spread of fire and under-predict the potential affect fire suppression may have on fire behaviour.This project investigated factors important in influencing the occurrence of bushfires, the successful initiation of spot fires from firebrands, the rate of growth and development of new fires to steady state rate of spread, and the transitions of such fires through vertical fuel strata as it develops in intensity.From this knowledge, predictive models about the probability, number, size, and potential growth rate of fire ignitions were developed. These models can be used to determine the most effective allocation and deployment of suppression resources, on both a seasonal and incident basis, within a framework of suppression resource allocation also developed during this project.Specifically, the results of this project include:•A fire occurrence model derived for the case study area of south-west Western Australia that utilises readily available information on fire history, weather and fuel conditions to determine the potential for fire to occur within a given region and the potential number of fires that may occur. (Chapter 2)•A model for the initiation potential of fire starting from firebrands or similar forms of ignition, from both flaming combustion and glowing combustion. (Chapter 3)•A model for the rate of growth of ignitions (in terms of rate of spread, perimeter increase and area increase) up to the steady state rate of spread. (Chapter 4)•A model for the likely transition of fire through horizontally stratified fuel layers, incrementally increasing fireline intensity as it does. (Chapter 5)•A framework for the incorporation of these predictive models into a tool for determining the likelihood of fire occurrence, the success rate of new ignitions to readily sustain combustion and the rate of development of new ignitions.The results of this project will enable fire authorities to better determine the necessary level of suppression readiness required for given weather and fuel conditions, the potential for any fire outbreak to develop beyond initial attack resources before they arrive and allow the prioritisation of suppression of fire outbreaks.