@article {bnh-8366, title = {Physics-based modelling of junction fires: Parametric study}, journal = {International Journal of Wildland Fire}, year = {2023}, month = {02/2023}, abstract = {

Background; Junction fires occur when two fire fronts merge. The ROS and HRR of the junction quickly increase more than that of each fire front; this effect is exacerbated by slopes. Aims; Numerical modelling of junction fires and an interpretation of their behaviour is given by examining the key factors that influence the fires. Methods; Physics-based simulations of laboratory-scale junction fires were performed for shrub fuel bed using FIRESTAR3D. Twenty cases were simulated to quantify the effect of slope (0{\textdegree} to 40{\textdegree}) and junction angles (15{\textdegree} to 90{\textdegree}). Key results; Accelerative and decelerative behaviours were observed for junction angles lower than 45{\textdegree}, but above this, deceleration was absent. The behaviour was firmly related to junction angle evolution which controlled the flame and the interactions between fire fronts. HRR followed similar trends; maximum HRR increased with increasing junction angle. Convection was found to be the primary heat transfer mode in the initial propagation phase. In non-slope cases, radiation was the dominant method of heat transfer, but convection dominated fires on slopes. Conclusions; The physics-based model provided great insight into junction fire behaviour. The junction angle was critical for determining ROS and fire behaviour. Implications; The research helped to assess the effects of some topographical parameters in extreme fires. Situational awareness, operational predictions, and firefighter safety will consequently improve.

}, keywords = {fire behavior, physics-based model}, url = {https://www.publish.csiro.au/WF/justaccepted/WF22121}, author = {Ahmed Hassan and Gilbert Accary and Duncan Sutherland and Khalid Moinuddin} } @article {bnh-5928, title = {Mapping bushfire hazards and impacts annual report 2018-2019}, number = {511}, year = {2019}, month = {09/2019}, institution = {Bushfire and Natural Hazards CRC}, address = {Melbourne}, abstract = {

This annual report is the output from the Bushfire and National Hazards CRC (BNHCRC), Project A1 {\textquoteleft}Mapping Bushfire Hazard and Impacts{\textquoteright}. It summarises the project objectives, introduces the team members as well as documents the project progress and outcomes during the financial year 2018/2019.

During this financial year we have:

  1. Worked on a comprehensive characterization of fire risk conditions through the integration of fire weather, dead Fuel Moisture Content (FMC) and total biomass into the Australian Flammability Monitoring System (AFMS);
  2. Worked on AFMS website version 3 that incorporated feedback on the trial utilisation of the data service;
  3. Evaluated the feasibility and benefits of the operational use of alternative satellite data in AFMS to ensure long-term data continuity;
  4. Coupled a process-based model that simulates litter fuel moisture and a distributed biophysical model (the Australian Water Resources Assessment system Landscape model) to predict dead fuel moisture content;
  5. Published six journal manuscripts, seventeen conference abstracts and one milestone reports with another one in preparation. We have also had eight appearances in the media;
  6. Hosted two international exchange visits and were approached by more than 30 domestic and international applicants for a PhD scholarship or postdoc position in bushfire research; and
  7. Submitted an application for utilisation funds from the BNHCRC to develop a high-resolution prototype version of AFMS.

Over the next year (2019-2020), this research project will focus on finishing the analysis on the fire risk index as well as using remote sensing data to derive spatial and temporal explicit fuel accumulation curves. In terms of utilization, we will liaise with Geoscience Australia (GA) on transitioning the AFMS as GA has agreed to be in charge of the long term operationalization and maintenance.

}, keywords = {bushfires, fire behavior, fire impacts, hazards, impacts, mapping}, issn = {511}, author = {Marta Yebra and Albert van Dijk and Geoffrey J. Cary and Li Zhao and Honghao Zeng} }