Articles | Volume 12, issue 1
Geosci. Model Dev., 12, 69–87, 2019
Geosci. Model Dev., 12, 69–87, 2019

Development and technical paper 03 Jan 2019

Development and technical paper | 03 Jan 2019

RandomFront 2.3: a physical parameterisation of fire spotting for operational fire spread models – implementation in WRF-SFIRE and response analysis with LSFire+

Andrea Trucchia1,2, Vera Egorova1, Anton Butenko3,4, Inderpreet Kaur5, and Gianni Pagnini1,6 Andrea Trucchia et al.
  • 1BCAM–Basque Center for Applied Mathematics, Bilbao, Basque Country, Spain
  • 2Department of Mathematics, University of the Basque Country UPV/EHU, Bilbao, Basque Country, Spain
  • 3Space Research Institute of Russian Academy of Sciences, Moscow, Russia
  • 4Institute of Geography, University of Bremen, Bremen, Germany
  • 5Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, Mainz, Germany
  • 6Ikerbasque–Basque Foundation for Science, Bilbao, Basque Country, Spain

Abstract. Fire spotting is often responsible for dangerous flare-ups in wildfires and causes secondary ignitions isolated from the primary fire zone, which lead to perilous situations. The main aim of the present research is to provide a versatile probabilistic model for fire spotting that is suitable for implementation as a post-processing scheme at each time step in any of the existing operational large-scale wildfire propagation models, without calling for any major changes in the original framework. In particular, a complete physical parameterisation of fire spotting is presented and the corresponding updated model RandomFront 2.3 is implemented in a coupled fire–atmosphere model: WRF-SFIRE. A test case is simulated and discussed. Moreover, the results from different simulations with a simple model based on the level set method, namely LSFire+, highlight the response of the parameterisation to varying fire intensities, wind conditions and different firebrand radii. The contribution of the firebrands to increasing the fire perimeter varies according to different concurrent conditions, and the simulations show results in agreement with the physical processes. Among the many rigorous approaches available in the literature to model firebrand transport and distribution, the approach presented here proves to be simple yet versatile for application to operational large-scale fire spread models.

Short summary
Wildfires are a concrete problem and impact on human life, property and the environment. An extremely dangerous phenomenon is so-called fire spotting, i.e., the generation of secondary ignitions responsible for dangerous flare-ups during wildfires. The aim of this research was to improve the tools used for risk management through the inclusion of fire spotting in operational wildfire simulators used by forest service agencies.