Effect of vegetation heterogeneity on radiative transfer in forest fires

Pimont François, Dupuy Jean-Luc, Caraglio Yves, Morvan Dominique. 2009. Effect of vegetation heterogeneity on radiative transfer in forest fires. International Journal of Wildland Fire, 18 : 536-553.

Quartile : Q1, Sujet : FORESTRY

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Géographie-Aménagement-Urbanisme-Architecture

Résumé : Wildland fires are driven by the heat transferred from the fire source to the unburned fuel bed and this transfer is likely to be affected by the spatial heterogeneity of fuel element distributions at different scales from shoot to stand. In a context of theoretical fire modelling, we investigated the impact of a departure from randomness of fuel distributions on the radiative transfer of energy. Our methodology was derived from the approach developed for solar radiation in heterogeneous canopies or clouds and was modified to suit an analysis of fire behaviour. Some fine and coarse fuel distributions for several Mediterranean fuel types were derived from field measurements and plant architecture modelling. A comparison of the average irradiances in different fuels showed whether heterogeneity effects were significant or not. Results showed that both marked spatial variability in fuel distribution (low cover fraction and large clumps) and a high vegetation density were required to provide significant effects. The radiative transfer in heterogeneous maritime pines and in dense shrub stands was significantly affected by heterogeneity, mainly at crown and shoot scales. Less pronounced effects were observed in Aleppo pine stand and light shrubs. In terms of fuel modelling, the 2-m resolution used in a fire model such as FIRETEC seems to be sufficient for the fuel types investigated here, with the exception of dense small clumps in shrublands. An effective coefficient was proposed for these latter cases.

Mots-clés Agrovoc : incendie de forêt, Pinus halepensis, Quercus coccifera, Pinus pinaster

Mots-clés géographiques Agrovoc : région méditerranéenne

Classification Agris : U10 - Informatique, mathématiques et statistiques
F40 - Écologie végétale
K70 - Dégâts causés aux forêts et leur protection

Champ stratégique Cirad : Axe 6 (2005-2013) - Agriculture, environnement, nature et sociétés

Auteurs et affiliations

• Pimont François, INRA (FRA)
• Dupuy Jean-Luc, INRA (FRA)
• Caraglio Yves, CIRAD-BIOS-UMR AMAP (FRA)
• Morvan Dominique, UNIMECA (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/550612/)

Métriques

[ Page générée et mise en cache le 2024-10-08 ]