Numerical study of high intensity experimental field fires across Corsican shrubland vegetation

Abstract

Field-scale experiments have been conducted on steep sloped terrains in Speluncatu and Letia, north-western and southern regions of Corsica. This work lies within the GOLIAT project framework and it was provided by the Fire and Rescue Service of North Corsica and the Corsican DFCI (Défense de la Forêt Contre l’Incendie) Group. This work reported high intensity fires propagating through shrub vegetation areas (Genista Salzmannii) lying between 60 cm and 85 cm. These sites were selected because of the density of the vegetation, the high slope angle values with a wind direction aligned with the main slope, which can generate a fire close to wildfire behaviour. A detailed experimental protocol is used in order to determine the propagation conditions and the fire behaviour using UAV cameras and heat flux gauges. In order to investigate the different phenomena encountered in these types of fires, numerical simulations were conducted using a complete physical fire model, based on multiphase formulation, namely FireStar2D. Numerical predictions were used to examine the fire front dynamics related to the fire’s rate of spread and fireline intensity. Despite the unfavourable wind and humidity conditions, experimental results analysis showed that the fireline intensity was higher than 7 MW/m, which means that these fires fall into the category of the very high fire severity. Numerical results predicting the fire’s rate of spread, fireline intensity and fire impact were in good agreement with the experimental data.