Fuel description and fire behaviour : one method applied in different countries
Description de combustible et comportement du feu : une méthode appliquée dans différents pays
Résumé
The description and modelling of the fuels provide useful information to be used in pre-fire planning and therefore to improve forest fire management plans. But fuels are complex and variable according to ecological and bio geographical factors. They are composed of vegetal material enabling fire ignition and fire propagation. They have many properties that determine fire behaviour, which make them difficult to characterize. The aims of this paper are (i) to provide a state of the art on the different methods to characterize fuel in the laboratory and in the field, (ii) to explain a method that has been developed in different countries (iii) to give some examples from different countries in the Mediterranean Basin. Different kinds of descriptions provide information on fuel at different scales, from micro to macrostructure. Field sampling and complementary laboratory work are stored in a fuel database and are used as input in the Firetec physical model. This modelling enables the assessment of fire behaviour such as rate of fire spread and fire intensity, according to fuel types. Fuel microstructure is described at the particle level, as for example with bulk density measured according to the particle size. The main parameters for fuel particle characterization have been measured using the same method in different countries: shape, surface area to volume ratio, mass to volume ratio, high calorific value, specific heat, ash content. Different species have been described in different countries. Fuel macrostructure is described at forest stand level or landscape level, according to type, composition, density, cover and height. This paper describes the different steps of a method to describe fuel for fire behaviour assessment and provides some examples coming from Mediterranean Countries.