@article {bnh-5830, title = {Determining threshold conditions for extreme bushfire behaviour annual report 2018-2019}, number = {508}, year = {2019}, month = {09/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

Crown fires in forest ecosystems can pose a major threat to life and property due to their high intensities and rapid rates of spread. However, research into the prediction of crown fire dynamics in the Eucalyptus forests of Australia is limited. Previous studies have focused on coarse temporal scales, utilised low resolution weather based predictors, and often disregard the spatial nature of crown fires. Our study aimed to use observations from large wildfires in eucalypt forests to develop an empirical model to predict the likelihood of crown fire events using environmental predictors at an hourly scale. Our study was conducted in south-eastern Australia using data from fifteen large wildfires that occurred between 2009 and 2015. Fire severity maps were created for each fire at a 30\ m resolution using Landsat imagery from which we calculated the proportion of 30 m pixels experiencing crown fire within a 150 x 150 m window (2.25 ha). Predictor variables were chosen to represent the four key environmental drivers of fire behaviour, namely fuel moisture (i.e. live and dead fuel), fuel load and structure (i.e. surface, elevated, and bark fuels, and tree height), fire weather (i.e. vapour-pressure deficit, wind speed, relative wind direction) and topography (i.e. slope and ruggedness). Random Forests were used to model the effect of environmental drivers on the proportion of crown fire. Fuel moisture content variables were the best predictors of probability of crown consumption. Topographic variables and fire weather had only an intermediate influence and fuel load and structure had the lowest influence. Crown fire runs largely occurred when thresholds in vapour-pressure deficit (\<4\ kPa) and dead fuel moisture content (\<7\%) were exceeded. Predictions from the model showed a high degree of agreement with the raw fire severity maps. The proposed models have the potential to provide guidance on the likelihood of crown fire during fire events.

}, keywords = {Bushfire, extreme bushfires, fire behaviour., weather conditions}, issn = {508}, author = {Alex Filkov and Thomas Duff and Trent Penman} } @conference {bnh-6523, title = {Utilisation of fire spread simulators to assess power network fire risk }, booktitle = {AFAC19 powered by INTERSCHUTZ - Bushfire and Natural Hazards CRC Research Forum}, year = {2019}, month = {12/2019}, publisher = {Australian Institute for Disaster Resilience}, organization = {Australian Institute for Disaster Resilience}, address = {Melbourne}, abstract = {

Western Power is a Western Australian State Government owned power network and energy corporation. In 2013, an external review commissioned by Western Power, recommended the development of an improved bushfire risk map for the network based on the consequences of potential network bushfire ignitions. In response to the review Western Power entered into a joint collaboration with the Department of Fire and Emergency Services (DFES) and Landgate to develop a multiple ignition point based bushfire risk analysis product suitable for use on the power network across the south west of Western Australia.

The objective of this project is to assist Western Power in prioritising their asset renewal and maintenance budget to ensure they{\textquoteright}ve addressed sites with the highest potential consequences, realising better public safety out-comes. The utilisation of the fire spread simulator system Aurora, to model the consequences of a bushfire ignition from power poles and wires has been investigated to provide this intelligence. Western Power maintains approximately 800,000 power poles within the south west of Western Australia. The development of an appropriate methodology to provide the required intelligence for the prioritisation of appropriate asset renewal and maintenance implementation programs in response to the risk of bushfire ignition, has proven to be challenging.

Aurora is a web-based bushfire spread prediction system that simulates the probable direction, intensity and rate of bushfire spread. The simulator considers ignition location, vegetation, time of last burn, fuel accumulation models, forecasted weather, drought factor, grassland curing and slope to calculate fire behaviour and spread. For this project, the simulator architecture uses 99.5th percentile Forest Fire Danger Index (FFDI) weather conditions for each of the 8 cardinal wind directions to produce 6 million fire spread
simulations. These simulations together with a building location dataset are used to estimate asset numbers that could potentially be impacted by a fire running for one hour, from each power pole. Using this methodology maintenance can be prioritised for individual power poles based on the potential impact of a bushfire caused by a fault.

The successful completion of this project will result in a welldeveloped methodology, Information Communication and Technology (ICT) system infrastructure and potential consequence datasets with the potential to utilise multiple activities and assets as potential ignition sources, therefore providing DFES with enhanced evidence-based datasets to support strategic decision making for early community warning and preparedness.

Download the full non-peer reviewed research proceedings\ from the Bushfire and Natural Hazards CRC Research Forumhere.

}, keywords = {Fire risk, prediction system, risk management, simulator, weather conditions}, url = {https://knowledge.aidr.org.au/resources/australian-journal-of-emergency-management-monograph-series/}, author = {Parker, Jackson and Allen, Adrian} }