Bushfire risk to life and property
The figure below shows the Gippsland region’s risk profile for the period 1980–2019, and projected changes in bushfire risk until 2022. It shows:
- in 2018–19, bushfire risk was 72%
- bushfire risk fell sharply after major bushfires in the early 1980s and then increased as fuel slowly re-accumulated
- bushfire risk fell again in the period 2003–10 to historically low levels after major bushfires in Alpine areas
- planned burning and large bushfires in 2013 and 2014 kept bushfire risk down but it has since increased as fuel has re-accumulated in bushfire-affected areas
- we project that implementing our fuel management strategy on public land will keep bushfire risk below the levels seen before the 2003 and 2006–07 bushfires
- fuel management activities will reduce risk to a projected 63% by 2022, but without any fuel management, we project bushfire risk will increase to 82%
- risk fell 2018–19 as a result of several large bushfires, some of which impacted communities: in particular, the Rosedale fire, the Walhalla fire and fires near Licola.
Bushfire risk profile, Gippsland Region, 1980–2022
Bushfire risk to the environment
The figure below shows the tolerable fire interval (TFI) status of the vegetation on public land in the Gippsland region since 1980. The figure shows that in 2018–19 about 64% of the vegetation was below minimum TFI. It also shows that the proportion of vegetation below minimum TFI has been relatively high over the last decade, peaking at around 70% in 2015 and 2016. This corresponds with the occurrence of several large bushfires in Gippsland since 2007. The figure also shows that the proportion of vegetation below TFI has declined by around 6% since 2015. This has been accompanied by an increase in the proportion of vegetation within and above TFI. It appears that areas of vegetation affected by previous large bushfires are influencing this, with some vegetation communities reaching reproductive maturity following the 1939 fires (such as Tall Mixed Forest) and the 2002-03 fires (such as Forby Forest). This vegetation succession of previously fire-affected vegetation has tempered the effects of the 2018-19 bushfires on the TFI status.
During 2018–19, around 5% of vegetation was burnt while below minimum TFI due to bushfires, while around 1% was burnt while below minimum TFI due to planned burning.
TFI status of vegetation on public land in the Gippsland region, 1980–2019
The figure below shows the growth stage structure (GSS) status of the vegetation on public land in the Gippsland region since 1980. It shows about 51% of the landscape was in the juvenile and adolescent growth stages in 2018–19. The landscape will have a large proportion of young vegetation for some time, because it can take decades for many types of vegetation to move through the growth stages after significant fire disturbance.
The relatively low proportion of vegetation in the mature and old growth stages is a legacy of the 2006–07 bushfires. From 2008-9 to 2016-17, the proportion of vegetation in the landscape in these growth stages had stabilised at about 20–25%. However, this trend has shifted in the last couple of years, with the amount of mature vegetation reaching around 39% in 2018, before slipping back to around 36% in 2019. This is due the combined effects of previously burnt vegetation reaching reproductive maturity, as well as the occurrence of large bushfires last summer.
Maintaining older vegetation growth stages in the landscape is important for many reasons (such as to provide habitat for animal species that rely on hollow-bearing trees or on coarse, woody debris).
GSS status of vegetation on public land in the Gippsland region, 1980–2019
The TFI and GSS cannot be determined on public land with no recorded fire history.
Activities to reduce bushfire risk
Table 8: Gippsland region fuel management, 2018–19
Fuel reduction | Hectares |
---|---|
Area treated by planned burning:
| 81,691 |
Area treated by other fuel management methods | 3,128 |
Total area treated to reduce bushfire risk | 84,819 |
Victorian Bushfire Monitoring Program
During the year, we undertook pre-burn fuel hazard assessments at 89 individual sites and post-burn assessments at 53 individual sites across nine burns. We completed the assessments for 19% of the 2018–19 planned burning program. This was slightly lower than the target of 20% of planned burns, as the wildfire season extended into the autumn planned burning program and as a result, priorities for planned burning changed considerably, affecting the planned program and our planned monitoring, evaluation and reporting activities. The assessments help us determine how we have reduced fuel and therefore bushfire risk as a result of the planned burning program.
Fire severity mapping for autumn 2019 Gippsland burns cost about $73,000 for 36 burns. Currently, we have analysed about one-third of the severity mapping imagery using Google Earth Engine, the CSIRO severity tool and by interpreting the imagery directly. We plan to add the severity mapping to the fire history layer, to give us a better understanding of the burnt and unburnt areas within planned burn areas, to accurately calculate bushfire risk to life and property and the effects of bushfire on biodiversity values.
We completed mitigation field assessments for one burn: Nowa Nowa Radar Hill. This will help us plan, prepare and ignite burns.
We undertook remote camera surveys of New Holland mouse in three locations of known populations during 2018–19:
- 2018 Wilsons Promontory National Park (50,000 images)
- 2019 Providence Ponds Flora and Fauna Reserve (35,000 images)
- 2019 Gippsland Lakes Coastal Park Loch Sport (11,000 images).
The data from the surveys will improve our burn scheduling and help us protect this threatened species and its habitat.
We are currently developing two research projects for priority species. These projects will use a web-based platform to record data about threatened species during our 2019–20 monitoring program. The projects will improve how we apply mitigation measures when doing planned burning and help us schedule burns.
Page last updated: 23/12/20