Analysis of Variation in Distance, Number, and Distribution of Spotting in Southeast Australian Wildfires
1
Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, NSW 2522, Australia
2
School of Science, University of New South Wales (UNSW), Canberra, ACT 2600, Australia
3
Bushfire and Natural Hazards Cooperative Research Centre, Melbourne, VIC 3002, Australia
*
Author to whom correspondence should be addressed.
Fire 2020, 3(2), 10; https://doi.org/10.3390/fire3020010
Received: 2 April 2020 / Revised: 16 April 2020 / Accepted: 25 April 2020 / Published: 28 April 2020
Spotting during wildfires can significantly influence the way wildfires spread and reduce the chances of successful containment by fire crews. However, there is little published empirical evidence of the phenomenon. In this study, we have analysed spotting patterns observed from 251 wildfires from a database of over 8000 aerial line scan images capturing active wildfire across mainland southeast Australia between 2002 and 2018. The images were used to measure spot fire numbers, number of “long-distance” spot fires (> 500 m), and maximum spotting distance. We describe three types of spotting distance distributions, compare patterns among different regions of southeast Australia, and associate these with broad measures of rainfall, elevation, and fuel type. We found a relatively high correlation between spotting distance and numbers; however, there were also several cases of wildfires with low spot fire numbers producing very long-distance spot fires. Most long-distance spotting was associated with a “multi-modal” distribution type, where high numbers of spot fires ignite close to the source fire and isolated or small clumps of spot fires ignite at longer distances. The multi-modal distribution suggests that current models of spotting distance, which typically follow an exponential-shaped distribution, could underestimate long-distance spotting. We also found considerable regional variation in spotting phenomena that may be associated with significant variation in rainfall, topographic ruggedness, and fuel descriptors. East Victoria was the most spot-fire-prone of the regions, particularly in terms of long-distance spotting.
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MDPI and ACS Style
Storey, M.A.; Price, O.F.; Bradstock, R.A.; Sharples, J.J. Analysis of Variation in Distance, Number, and Distribution of Spotting in Southeast Australian Wildfires. Fire 2020, 3, 10. https://doi.org/10.3390/fire3020010
AMA Style
Storey MA, Price OF, Bradstock RA, Sharples JJ. Analysis of Variation in Distance, Number, and Distribution of Spotting in Southeast Australian Wildfires. Fire. 2020; 3(2):10. https://doi.org/10.3390/fire3020010
Chicago/Turabian StyleStorey, Michael A.; Price, Owen F.; Bradstock, Ross A.; Sharples, Jason J. 2020. "Analysis of Variation in Distance, Number, and Distribution of Spotting in Southeast Australian Wildfires" Fire 3, no. 2: 10. https://doi.org/10.3390/fire3020010
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