A comment on the use of visually assessed fuel hazard ratings and scores for Australian fire management and research

Background

Assessment of fuel hazard has become the dominant method of describing Australian forest fuel complexes, despite a lack of evidence supporting the veracity of its underpinning assumptions.

Aims

To analyse and discuss the merits of fuel hazard ratings and scores in representing measurable fuel characteristics, such as fuel load and fire behaviour potential.

Methods

Published findings were reviewed, and available data analysed to investigate the validity of the Australian fuel hazard assessment concepts.

Key results

Multiple published studies showed the Australian fuel hazard assessment methods to be subjective and non-replicable. All available evidence shows no relationship between fuel hazard ratings and fuel quantity. No relationship between the ratings and fire behaviour potential was found.

Conclusions

The principles underpinning the use of fuel hazard ratings for fuel assessment were shown to be unfounded. The ratings cannot be converted into physical fuel characteristics or fire behaviour potential, and its application in Australian fire management is unwarranted.