An Empirical Model for the Effect of Wind on Fire Spread Rate

Fire

Fernandes, Paulo M.¹  Rossa, Carlos G.² 

[1] Author to whom correspondence should be addressed.;Centre for the Research and Technology of Agro-environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5001-801 Vila Real, Portugal

关键词: empirical modelling;    combustion rate;    fuel bed height;    flame height;   

DOI  :  10.3390/fire1020031

学科分类：植物学

来源: mdpi

【 摘 要 】

Predicting wind-driven rate of fire spread (RoS) has been the aim of many studies. Still, a field-tested model for general use, regardless of vegetation type, is currently lacking. We develop an empirical model for wind-aided RoS from laboratory fires (n = 216), assuming that it depends mainly on fire-released energy and on the extension of flame over the fuel bed in still air, and that it can be obtained by multiplying RoS in no-wind and no-slope conditions by a factor quantifying the wind effect. Testing against independent laboratory and field data (n = 461) shows good agreement between observations and predictions. Our results suggest that the fuel bed density effect detected by other work may be a surrogate for the amount of fuel involved in combustion, which depends on fuel load. Because RoS under windless conditions is unaffected by fuel load, the involved mechanisms differ from wind-aided propagation. Compared to shallow fuel beds, the wind effect is usually modest in deep vegetation, because tall fuel complexes are dominated by live fuels (high moisture content) and flames extend less above the vegetation when fuel moisture is high. The present work warrants further inspection in a broader range of field conditions.

【 授权许可】

CC BY