@article {bnh-5194, title = {How do weather and terrain contribute to firefighter entrapments in Australia?}, journal = {International Journal of Wildland Fire}, volume = {27}, year = {2018}, month = {02/2018}, pages = {85-98}, chapter = {85}, abstract = {

Adverse weather conditions and topographic influences are suspected to be responsible for most entrapments of firefighters in Australia. A lack of temporally and spatially coherent set of data however, hinders a clear understanding of the contribution of each weather type or terrain driver on these events. We investigate coronial inquiries and internal fire agencies reports across several Australian states from 1980 to 2017 and retrieve 45 entrapments. A first analysis reveals that most entrapments happen during large fires and that the number of deaths has decreased over the last few decades. Comparing the meteorological and topographical conditions of the entrapments with the conditions of a reference set of fires without entrapment, we build a linear regression model that identifies the main contributors to firefighter entrapment. A change in wind direction, which was associated with 42\% of the incidents examined, is the main factor contributing to entrapments. Interaction between strong winds and steep slopes also influences the likelihood of entrapment and suggests that dynamic fire behaviours may also play important roles. As further details of this relationship between dynamic fire propagation and firefighter entrapment is now required, the understanding of weather and terrain contribution is a first step to produce comprehensive safety guidance.

}, doi = {https://doi.org/10.1071/WF17114}, url = {https://www.publish.csiro.au/WF/WF17114}, author = {Lahaye, S and Jason J. Sharples and Stuart Matthews and Heemstra, S and Owen Price and Badlan, R} } @conference {bnh-4333, title = {What are the safety implications of dynamic fire behaviours?}, booktitle = {22nd International Congress on Modelling and Simulation}, year = {2017}, month = {12/2017}, address = {Hobart}, abstract = {

Many firefighters in the world have been injured or killed due to a forest fire entrapment, caught by the fire heat or smoke. Some case studies have pointed out that dynamic fire behaviour may have played a role. We investigate here how changes in wind direction, channelling (i.e. vorticity-driven lateral spread on a leeward slope) and long distance spotting could contribute to entrapments through a process model, simplified in Figure 1. There are three situations likely to entrap firefighters:

We review fire agencies archives in Australasia and Europe from 1979 to 2017 and retrieve 106 entrapments, investigating weather, terrain and location of fire front during entrapment. We also compare the Australasian subset with fires without entrapment using a binomial regression function.

In Australia, changes in wind direction induced by cold front passes is the main factor contributing to entrapment. These sudden changes in wind direction switch long smooth burning flanks of fire in violent fronts and lead to S1 situations. S2, sudden lateral spread, occurs in rough terrain. There, leeward slopes may generate channelling, causing entrapment several hundred meters far away from the fire flank. S3 appears when fire danger index reaches highest values. When fuel drought combines with adverse weather conditions, mass spotting propagates fire at long distance. Then, firefighters may be entrapped whatever the terrain.

This work improves our understanding of the process from dynamic fire behaviour to firefighter entrapment. Identifying three different situations, the model should help fire agencies to adapt their safety warnings regarding the local daily conditions.

}, author = {Lahave, S and Jason J. Sharples and Stuart Matthews and Heemstra, S and Owen Price} }