Investigation of the effects of interactions of intersecting oblique fire lines with and without wind in a combustion wind tunnel

2019 ◽  
Vol 28 (9) ◽  
pp. 704
Author(s):  
Andrew L. Sullivan ◽  
William Swedosh ◽  
Richard J. Hurley ◽  
Jason J. Sharples ◽  
James E. Hilton

Quantification of the interaction of intersecting and non-intersecting fire perimeters over a range of shapes, sizes and orientations is essential to understanding the behaviour of high-intensity wildfires that have become discontiguous as a result of spot fires or effects of broken topography or fuels. One key configuration is that of the V-shaped fire where two individual lines of fire intersect at oblique angles. Previous work under calm conditions in pine needle litter and straw found the speed of propagation of the vertex of the intersection to increase non-linearly as the angle of intersection decreased. The present paper investigates this relation in dry eucalypt forest litter in both the absence and presence of wind (~1.0ms−1) and found that the increase in vertex speed under calm conditions was no greater than would be expected due to the geometry of the configuration. Conversely, in the presence of wind, the increase in the vertex propagation speed was substantially greater than explained by the geometry alone. Although these results suggest that fire line interactions can influence the behaviour and spread of coalescing fire fronts, further research is required to both identify the precise mechanisms driving this behaviour and quantify the resultant effects.

2017 ◽  
Vol 26 (10) ◽  
pp. 877 ◽  
Author(s):  
J. S. Gould ◽  
A. L. Sullivan ◽  
R. Hurley ◽  
V. Koul

Different methods can be used to measure the time and distance of travel of a fire and thus its speed. The selection of a particular method will depend on the experimental objectives, design, scale, location (in the laboratory or field), required accuracy and resources available. In this study, measurements from ocular observation (directly by eye), visible spectrum video imagery and thermocouple instrumentation were used to compare their performance in quantifying the time of arrival and rate of spread of a fire burning across a eucalypt forest litter fuel bed in a combustion wind tunnel. All methods gave similar results, but there were some significant differences depending on the dryness of the fuel and speed of the wind.


2019 ◽  
Vol 202 ◽  
pp. 17-27 ◽  
Author(s):  
Dean Howard ◽  
Katrina Macsween ◽  
Grant C. Edwards ◽  
Maximilien Desservettaz ◽  
Elise-Andrée Guérette ◽  
...  

Pedosphere ◽  
2014 ◽  
Vol 24 (5) ◽  
pp. 575-584 ◽  
Author(s):  
Xiu-Hong YANG ◽  
P. GARNIER ◽  
Shi-Zhong WANG ◽  
V. BERGHEAUD ◽  
Xiong-Fei HUANG ◽  
...  

Oikos ◽  
1982 ◽  
Vol 38 (3) ◽  
pp. 291 ◽  
Author(s):  
Björn Berg ◽  
Bengt Wessén ◽  
Gunnar Ekbohm ◽  
Bjorn Berg ◽  
Bengt Wessen

1982 ◽  
Vol 60 (8) ◽  
pp. 1561-1568 ◽  
Author(s):  
Håkan Staaf ◽  
Björn Berg

Plant nutrient dynamics in decomposing needle litter were measured during a 5-year period in a Scots pine forest in central Sweden. As seen over the whole 5-year period, the nutrients were retained (to a litter weight loss of about 75%) in the order Mn < Ca < K < Mg < S < N < P. During the first 1.5 years there was a net increase of N and P whereafter a net release took place. A similar but less pronounced development could be seen for S, whereas Ca, K, Mn, and Mg were released from the start of the incubation. It is suggested that P was the most limiting element for microbial activity during this first phase. There appeared to be only little initial leaching from the litter and the different behaviours of the elements could largely be explained by their concentration in litter in relation to the needs of microorganisms and to their solubility. K and Mg were the elements that were released at rates most similar to organic matter weight loss.


1998 ◽  
Vol 39 (2) ◽  
pp. 129-136 ◽  
Author(s):  
SHUN''ICHI HISAMATSU ◽  
TEI''ICHI KATSUMATA ◽  
YUKIO TAKIZAWA

2017 ◽  
Vol 102 (1-2) ◽  
pp. 29-37 ◽  
Author(s):  
Javier Andrés Márquez ◽  
Romina Elizabeth Principe ◽  
Luciana Cibils Martina ◽  
Ricardo Javier Albariño

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