Our People

Simon Heemstra
End User Rep

About

Lead end user

This project is using high-resolution modelling, together with a range of meteorological data, to better understand and predict important meteorological natural hazards, including fire weather, tropical cyclones, severe thunderstorms and heavy rainfall. The outcomes from the project will contribute to reducing the impact and cost of these hazards on people, infrastructure, the economy and the environment.
This project is applying physics-based approaches to fire scenarios. It attempts to simulate fire with unprecedented detail and in the process obtain useful application tools for end-users.
This study is identifying the thresholds beyond which dynamic fire behaviour becomes a dominant factor, the effects that these dynamic effects have on the overall power output of a fire, and the impacts that such dynamic effects have on fire severity. This will necessarily include consideration of other factors such as how fine fuel moisture varies across a landscape. The research team is investigating the conditions and processes under which bushfire behaviour undergoes major transitions, including fire convection and plume dynamics, evaluating the consequences of eruptive fire behaviour (spotting, convection driven wind damage, rapid fire spread) and determining the combination of conditions for such behaviours to occur (unstable atmosphere, fuel properties and weather conditions).
This research into interactions with topography, potential for pyro-convection, potential for three dimensional interactions, potential for winds to change substantially around a fire, water vapour dry slots, plume development and spotting process will be integrated into a formal, quantitative system for use with the current fire forecasting system.
Research team:

Fire behaviour in dry eucalypt forests in Australia (and in many other vegetation types to a lesser extent) is characterised by the occurrence of spotfires—new fires ignited by the transport of burning debris such as bark ahead of an existing fire. Under most burning conditions, spotfires play little role in the overall propagation of a fire, except where spread is impeded by breaks in fuel or topography and spotfires allow these impediments to be overcome. However, under conditions of severe bushfire behaviour spotfire occurrence can be so prevalent that spotting becomes the dominant propagation mechanism and the fire spreads as a cascade of spotfires forming a ‘pseudo’ front. It has long been recognised that the presence of multiple individual fires affects the behaviour and spread of all fires present. The converging of separate individual fires into larger fires is called coalescence and can lead to rapid increases in fire intensity and spread rate, leading to the phenomenon of a ‘fire storm’. This coalescence effect is frequently used in prescribed burning, with multiple point ignitions used to rapidly burn out large areas.

The team has demonstrated the performance advantages of fire propagation models incorporating curvature dependence when applied to simple wind-driven fires at both laboratory and field scales. The research has also produced fundamental insights into how the shape of the fire line affects the dynamic behaviour of the fire as a whole. Coupled fire-atmosphere modelling was used to investigate how fire-induced air movements (pyroconvection) can produce significantly enhanced rates of spread for certain fire shapes.

Resources credited

Type Released Title Download Key Topics
Presentation-Audio-Video 22 Mar 2016 Severe and High Impact Weather - cluster overview Save (0 bytes) fire, modelling, scenario analysis
Presentation-Audio-Video 07 Jul 2017 Building bushfire predictive services capability - Simon Heemstra Save (0 bytes) fire, fire impacts, modelling

All the resources from our 2016 conference

Research program in detail

Where, why and how are Australians dying in floods?

2015-2016 year in review

Bushfire planning with kids ebook