The Castlemaine Forum was given a summary of the bushfire risk profile developed by DEPI in cooperation with various research bodies. The profile is a working document rather than a set of conclusions, and is about risk to human life and assets: no way has yet been developed in this system of assessing risk to the environment in current burning practices [p 7].
According to DEPI computer modelling, risk to people and property has been reduced by 40% since 2002 by a combination of major bushfires [mainly] and controlled burning. The report adds:
‘Since 2008–09, fuel reduction on public land in Victoria has held the residual risk at approximately 60 per cent. Without fuel reduction, particularly planned burning, modelling suggests the risk would have increased rapidly towards maximum levels.
‘Modelling indicates that a significant proportion of bushfire risk is driven by fuel on private land and on public land which is unsuitable for treatment by planned burning. This tells us that planned burning must be part of an integrated plan to reduce bushfire risk, with private land holders and broader communities playing critical roles.’
The conclusions are hedged about with qualifications: ‘These results suggest that an absolute maximum of 60–70% of Victoria’s bushfire risk is potentially manageable to some degree through fuel reduction on public land.’ [our emphasis]
What’s more, the report’s assessment of the effectiveness of planned burning is based on a scenario where all treatable land is burned at once: that is, to create a moment when fuel reduction is at an absolute maximum. This is clearly a preposterous idea, which the report more or less admits:
‘It is important to note that these are purely theoretical tests of the absolute limits. They represent burning 100% of the treatable portion of the landscape at once to determine the limits.
‘Actual contemporary burning regimes would never reach these levels, perhaps never achieving less than moderate to high residual risk. This emphasises even further the significance of private bush and grassland fuel hazard.’
All the same, the Department is positive about the potential of its modelling system: ‘DEPI believes that the system lays a strong foundation for quantifying bushfire risk and the ways in which it can be managed and reduced. Future investment, validation and expansion of the system’s capabilities will increase its value.’