Bushfire risk to life and property
The figure below shows the Grampians region’s risk profile for the period 1980–2019 and projected changes in bushfire risk until 2022. It shows that:
- in 2018–19, fewer opportunities for planned burning led to an increase in bushfire risk, to 67%
- bushfire risk fell in 1983 after the Ash Wednesday bushfires, which caused large losses of life and property in the Mt Macedon area
- bushfire risk steadily increased after the Ash Wednesday fires as fuel re-accumulated across the landscape, peaking at 84% in 2003 before steadily falling, due to an increased and more-strategic planned burning program and a significant fire event in 2006, to a low of 55% in 2015
- planned fuel management activities will reduce risk to a projected 58%, but without any fuel management, we project bushfire risk will increase to 82% by 2022.
Bushfire risk profile, Grampians Region, 1980–2022
Bushfire risk to the environment
The figure below shows the tolerable fire interval (TFI) status of vegetation on public land in the Grampians region since 1980.
The figure shows that in 2018–19, 47% of the vegetation was below minimum TFI. Between 2007 and 2015, the proportion of the vegetation below minimum TFI increased from 35% to about 50% as a result of major bushfires in the Grampians in 2006, 2013 and 2014 and in the west of the landscape in 2006 and 2012. In 2018–19, less than 1% of the vegetation in this landscape was burnt by bushfire or planned burning while below TFI. We use strategic fuel management planning to carefully undertake planned burning to reduce impacts on vegetation below minimum TFI.
TFI status of vegetation on public land, Grampians region 1980–2019
The figure below shows the growth stage structure (GSS) status of vegetation on public land in the Grampians region since 1980.
The figure shows that in 2018–19, about 29% of the landscape was in the juvenile and adolescent growth stages, and about 42% was in the mature and old growth stages. Over the decade to 2015, major bushfires increased the proportion of vegetation in the juvenile and adolescent growth stages from about 20% to about 44%. In recent years, some of this vegetation has started to grow to the mature stage.
GSS status of vegetation on public land, Grampians region 1980–2019
The TFI and GSS cannot be determined on public land with no recorded fire history.
Activities to reduce bushfire risk
Table 9: Grampians region fuel management, 2018–19
Fuel reduction | Hectares |
|---|---|
Area treated by planned burning:
| 6,018 |
Area treated by other fuel management methods | 2,039 |
Total area treated to reduce bushfire risk | 8,057 |
Victorian Bushfire Monitoring Program
We combine pre- and post-burn fuel hazard monitoring with burn severity mapping to help us understand whether we have met our burn objectives. These results are shared with burn crew leaders to discuss how well a burn was conducted, where we could improve and any new solutions we find. We collected fuel hazard data at 60 sites pre-burn and 59 sites post-burn.
Our risk and ecological resilience modelling relies on accurate fire history data, and much of our fire history data older than 10 years is inexact. We commissioned a consultant to assess the feasibility of using historical satellite imagery and other historical records to update and improve our fire history data for the Grampians region. The consultant found doing this is suitable for about 80% of the region.
During 2018–19, we undertook monitoring across the Wombat and Enfield areas to assess the impact of planned burns on Greater Gliders and Brush-tailed Phascogales and to evaluate the effectiveness of mitigation measures to retain hollows habitat and minimise canopy scorch. We monitored habitat attributes and did spotlighting for Greater Gliders at 120 sites pre-burn and 60 sites post-burn. We set up remote cameras at 112 sites to monitor for Brush-tailed Phascogales. Initial results indicated that we can improve mitigation measures for Brush-tailed Phascogales by concentrating our mitigation works on high-activity areas and on habitat trees with specific hollow dimensions. We will continue to work closely with operational staff to improve how we implement mitigation measures.
During the year, we started a multi-species monitoring project for the northern extent of Red-tailed black cockatoo habitat. The project aims to improve our understanding of the distribution of key species in the West Wimmera area and their growth-stage and time-since-fire preferences, to create a fuel management approach that maximises diversity for species that depend on heathy vegetation. We monitored in the Jilpanger Nature Conservation Reserve, where a recent report indicated some heathy vegetation types are declining due to lack of fire. We monitored at 25 sites using 250 pitfall trapping buckets, 50 remote cameras and 25 vegetation surveys. In all, we collected 33 fauna species and 120 flora species. Many of the fauna species had not been recorded on public land in the West Wimmera for more than 25 years including small, ground-dwelling mammals (such as Silky mouse, Little and Western pygmy possums, Yellow-footed antechinus and Rosenberg’s and Lace monitors).
The Bushfire Behaviour and Management Group from The University of Melbourne finalised the Fuel Accumulation Project, which started in 2017. The project assessed how fuel types around high-risk towns in the Midlands fire district accumulate after a fire. The project analysed 1,200 fuel hazard samples. The project found our models overestimated the amount of fuel that accumulates around these towns, so we adjusted our models and accordingly risk for the relevant areas decreased. We used this information for the region’s strategic bushfire management plan and to decide the intensity and frequency of our planned burns in these areas.
Page last updated: 23/12/20