High resolution fire behavior monitoring and plume simulation in the context of experimental fire

Coupled fire-atmosphere systems are currently developed to respond to the need of operational system in air quality and fire attack management. This work participates to this effort by proposing a simulation strategy where the plume is simulated using fire observation. Such approach can provide reference test case for more complex coupled fire- atmosphere simulation. Using the Forefire-MesoNH system, we simulate the plume evolution of a landscape scale burn where the fire is not simulated as a spreading front but rather prescribed from multiple fix burners controlled with observation data. The simulation of the plume formed from a 7-hectare savannah fire conducted in Kruger National Park in 2014 is demonstrated using helicopter-borne observations georeferenced at 1-m resolution and post-processed to extract information of heat fluxes at pixel level.Postprint (published version

Fires at the wildland-industrial interface. Is there an emerging problem?

Over the past years, wildfires have raged with unprecedented intensity across the world, becoming a growing problem, as weather conditions conductive to wildfire ignition and spread will increase in frequency and severity worldwide. This, coupled with a growing human expansion, leads to an increase in wildfire risk and in the threat to wildland-urban interface (WUI) communities. Commonly, definitions for WUI areas consider homes, commercial facilities, office and public buildings. This excludes industrial installations, where wildfires can trigger accidents or cascading events leading to extremely dangerous situations for the population causing enormous economic losses. In this paper, the problem associated to the wildland-industrial interface (WII) is analyzed. A methodology to obtain a global WII map is described, and the first WII maps for Europe and Asia are provided. Results show that, in Europe, 2.5% of the land and 6% of vegetated areas are WII, while in Asia these are respectively 0.24% and 0.5%. An analysis of how wildfire triggered industrial accidents can be considered when performing quantitative risk assessments (QRA) in industrial sites is also performed, identifying the current state of the art and research gaps, with the aim of helping industry, public authorities and policy makers, for better accident prevention, preparedness and response.This research is funded by the project PID2020-114766RB-100 of MCIN/AEI/10.13039/501100011033 and the project 2021_SGR_00251 of Generalitat de Catalunya. A. Àgueda is a Serra Hunter fellow.Peer ReviewedPostprint (published version

Orthorectification of helicopter-borne high resolution experimental burn observation from infra red handheld imagers

To pursue the development and validation of coupled fire-atmosphere models, the wildland fire modeling community needs validation data sets with scenarios where fire-induced winds influence fire front behavior, and with high temporal and spatial resolution. Helicopter-borne infrared thermal cameras have the potential to monitor landscape-scale wildland fires at a high resolution during experimental burns. To extract valuable information from those observations, three-step image processing is required: (a) Orthorectification to warp raw images on a fixed coordinate system grid, (b) segmentation to delineate the fire front location out of the orthorectified images, and (c) computation of fire behavior metrics such as the rate of spread from the time-evolving fire front location. This work is dedicated to the first orthorectification step, and presents a series of algorithms that are designed to process handheld helicopter-borne thermal images collected during savannah experimental burns. The novelty in the approach lies on its recursive design, which does not require the presence of fixed ground control points, hence relaxing the constraint on field of view coverage and helping the acquisition of high-frequency observations. For four burns ranging from four to eight hectares, long-wave and mid infra red images were collected at 1 and 3 Hz, respectively, and orthorectified at a high spatial resolution (<1 m) with an absolute accuracy estimated to be lower than 4 m. Subsequent computation of fire radiative power is discussed with comparison to concurrent space-borne measurementsPeer ReviewedPostprint (published version