Glossary

Area planned for treatment

The area planned for treatment is the total area in hectares of land parcels for which FFMVic and CFA have completed operational fuel management planning. A region selects the parcels in line with its regional Bushfire Management Strategy, and they become part of the rolling 3-year operational plan, the Joint Fuel Management Program (JFMP).

Area treated (by planned burning or non-burn fuel treatment)

The area treated is the area (in hectares) of land on which a fuel management treatment has been successfully undertaken to achieve a predefined fuel treatment objective. It is distinct from the Burnt area – refer to definition).

An example treatment is:

• treatment type: planned burning
• treatment objective: to reduce overall fuel hazard to below a moderate level over at least 70% of the planned area
• planned area (on JFMP): 100 hectares
• outcome: planned burning resulted in 80% of the planned area having an overall fuel hazard below a moderate level. The fuel treatment objective was achieved in full; the fuel hazard objective was more than achieved, and the area treated area (100 hectares) was equal to the planned area.

Burn window

The burn window is the suitable alignment of appropriate fuel moisture and weather conditions (both in the lead-up to and the days following the burn ignition). Appropriate fuel moisture conditions must align with suitable weather conditions before planned burning can be safely and effectively conducted. Weather is a key determinant of when and how much-planned burning can occur.

Burnt area

The burnt area is the total area in hectares that a planned burn burns or blackens within the area treated. Following a burn, the burnt area is mapped to ensure the most accurate information for risk modelling is acquired. Refining this mapping over time can have flow-on effects for fuel-driven bushfire risk calculations, and as such, risk figures may be updated from year to year retrospectively.

Bushifre management strategy

Each of DEECA's regions has a Bushfire Management Strategy. Each strategy explains the approach to fuel management and other bushfire risk reduction interventions for the region to minimise the potential impact of major bushfires on people, property, critical infrastructure and economic activity, environment and cultural values, and maintain and improve the resilience of natural ecosystems.

The strategies set out the location of fire management zones – Asset Protection Zone, Bushfire Moderation Zone, Landscape Management Zone and Planned Burning Exclusion Zone – on public land.

The strategies also identify a cross-tenure approach, which highlights where fuel management most effectively reduces risk across public and private land.

Bushfire management sector

The bushfire management sector comprises any entity with a role or function for bushfire management as defined under the State Emergency Management Plan (SEMP).

The bushfire management sector includes Forest Fire Management Victoria (comprised of the Department of Energy, Environment and Climate Action, Melbourne Water, VicForests and Parks Victoria), the Country Fire Authority, Emergency Management Victoria, Emergency Recovery Victoria, Fire Rescue Victoria, Department of Transport and Planning, Department of Government Services (which includes Local Government Victoria, regulators (including the Office of the Conservation Regulator), water authorities and local government.

The bushfire management sector collaborates with various organisations to achieve shared outcomes. This includes Traditional Owners, industry and communities. Partnerships with Traditional Owners will evolve over time as Victoria continues to support self-determination and Treaty.

Bushfire risk

Bushfire risk is the likelihood of a fire starting, spreading, and impacting people, property and the environment. This includes houses, critical infrastructure, water supply catchments, agricultural assets, and environmental and cultural values.

Victoria is particularly susceptible to large and intense bushfires that can spread across landscapes due to Victoria's terrain, naturally flammable vegetation and frequent exposure to hot, dry and windy weather.

Bushfire risk is affected by factors including the weather, the type and condition of fuels in the location and its topography, the location of people and assets, and the ability to prevent fires from igniting, suppress them once they ignite and avoid or reduce impacts to communities.

Community-based bushfire management

Community-based bushfire management is a community-led approach that supports communities and agencies to connect and make better-informed decisions. It includes working with communities to identify local priorities, develop mutual goals and solutions, build relationships and use locally tailored processes before, during and after bushfires.

Cross-tenure burn

A cross-tenure burn describes when a burn includes both public and private land. It is not a type of burn. See ‘Planned burning’ for definitions of types of burns.

Ecosystem resilience

Ecosystem resilience is the capacity of an area to absorb natural and management-imposed disturbance, but still retain its basic structure (the abundance and composition of its species, the function of its vegetation and its types of vegetation) over time.

First attack

First attempt suppression work on a fire.

Fuels

Bushfire fuels are the leaves, bark, twigs and shrubs that are burnt by fire. The fuel type, dryness, size, moisture content and arrangement can all affect the speed, size and intensity of a bushfire.

Fuel-driven bushfire risk

Fuel-driven bushfire risk is the component of bushfire risk that is attributable to bushfire fuels, that is, vegetation that influences fire behaviour, such as the speed and intensity of a bushfire.

Fuel (vegetation) is a key element of fire behaviour, and therefore is a major component of overall bushfire risk. However, it is not a full measure of bushfire risk, because fuel is not the only factor that affects fire behaviour, or the likelihood and consequence of bushfires impacting people and the things they care about. In general, the influence of fuel on fire behaviour decreases as fire weather conditions become more severe.

The sector models (using a computer program called Phoenix Rapidfire) what impact planned burning has on reducing fuel-driven bushfire risk to inform fuel management planning and performance evaluation.

This impact is calculated and expressed as the percentage of fuel-driven bushfire risk ‘left over’ after bushfire fuels have been reduced, either through fuel management activities or bushfires (noting that currently, this calculation can only consider the contribution of planned burning and not non-burn fuel treatments such as slashing and mowing).

This approach focuses on the role that planned burns have in moderating the severity of bushfires at large scales and the consequential likely reduction in impacts.

In previous years’ reports, fuel-driven bushfire risk was referred to as residual risk.

Fuel management

Fuel management activities include:

• planned burning (see definition)
• mechanical and other non-burn fuel treatments (see definition)
• management of storm debris
• construction and upgrades of strategic fuel breaks

Fuel management activities alter the amount and structure of bushfire fuel, reducing the likelihood of ignition, helping limit their spread and intensity when they occur, making it easier for firefighters to control them, and lessen their impacts.

Fuel treatment delivery plan (Burn Plan)

Each planned burn must have an approved fuel treatment delivery plan. For FFMVic planned burns, the requirements are specified in the Code of Practice for Bushfire Management on Public Land 2012. A plan includes a land management and treatment objective, the area of the burn, the type of fire management zone (FFMVic burns), how impacts on values will be minimised, and how the outcome of the burn will be monitored, evaluated and reported.

Growth stage structure

The growth stage structure (GSS) of an area of vegetation is its mix of vegetation of different ages, from juvenile to old. Vegetation's GSS depends on when it was last burnt or otherwise disturbed. It is assumed that the diversity of GSSs and habitats across a landscape ensures a diversity of species, which helps maintain and improve ecosystem resilience. As a result, fuel is managed to ensure an acceptable mix of growth stages in the landscape and protect important areas of older growth stages.

The growth stages are:

• juvenile: from immediate post-fire renewal to establishment up to the point when the full suite of species is reproductive
• adolescent: when vegetation is relatively young, and all species are reproductive but not at the rate that characterises mature vegetation
• mature: when the dominant species are fully reproductive through to stasis when vegetation structure and reproductive capacity stabilise
• old: when reproduction of the dominant species is declining and propagule banks are decreasing; if left undisturbed, vegetation may become senescent and is then unlikely to be reconstituted after a fire.

There is more information about vegetation GSS on the Safer Together web page.

Hazard class

Hazard Class is used by the CFA to define the type of risk for a given area. Each brigade area may contain multiple hazard classes.

Hazard Class 2 (Medium Urban): Significant urban areas which are primarily residential including commercial centres, clusters of industrial and/or high-density community services e.g., schools, correctional facilities, hospitals.

Hazard Class 3 (Low Urban): All urban areas that are not included in Hazard Class 2 and include predominantly residential occupancies and small industries.

Hazard Class 4 (Rural): Primarily involves natural surroundings in terms of bush and grassland, but also involves isolated dwellings and structures within those areas.

Hazard Class 5 (Remote Rural): Covers very remote locations and very isolated dwellings

Heap

See windrow.

Joint Fuel Management Program (JFMP)

The JFMP is the statewide 3-year rolling program of fuel management works on public and private land. The JFMP includes operations managed by FFMVic and the CFA for the upcoming 3 years. It also includes cultural burns nominated by Traditional Owners. It incorporates and supersedes Fire Operations Plans.

The Joint Fuel Management Program web page has maps showing all planned fuel management activities for the upcoming 3-year period. The JFMP does not include burns managed by private landholders or industry.

Mechanical and other non-burn fuel treatment

Mechanical and other non-burn fuel treatments are used to manage bushfire fuels through activities other than planned burning. Examples include mowing, slashing, mulching, spraying, rolling and grazing.

Mechanical fuel treatments are used to maintain the network of fuel breaks or to treat small, discrete, or complex areas that may be difficult to burn safely (such as in steep gullies) or to complement planned burning where the geography (community, vegetation, terrain) is complex, and planned burning opportunities are very limited. Mechanical fuel treatments are more expensive than planned burning and the area that can be treated each year is usually much less than through planned burning.

Native vegetation improvements

Native vegetation improvements are activities undertaken to compensate for impacts to biodiversity resulting from FFMVic’s bushfire fuel management actions. These improvements are carried out in areas of high biodiversity value throughout the state, including projects to remove invasive plant species.

Scientists and local land managers provide input into selecting which projects are funded. These projects contribute to implementing Protecting Victoria's Environment - Biodiversity 2037, Victoria’s plan to stop the decline of native plants and animals and improve the natural environment.

Planned burning

Planned burning is the lighting and managing of planned fires at times of lower bushfire risk for various reasons (such as to reduce leaf litter, twigs, bark and undergrowth). Planned burns may be ignited all year round including over summer, but most are in autumn and spring.

Planned burns are classified into:

• fuel reduction burns, to reduce the amount of fuel available to a bushfire, which can reduce a bushfire intensity and rate of spread, improving opportunities for firefighters to suppress it and reducing impacts on assets
• cultural burns, led by Traditional Owners for cultural purposes
• ecological burns, to achieve ecological objectives (such as to protect environmental assets, and maintain and improve ecological resilience)
• other burns, which are ad hoc burns not included in the JFMP, but still undergo a planning and approval process. For example:
  • regeneration burns, to regenerate species or vegetation types (such as after timber harvesting)
  • windrow/heap burns at point locations, which are to burn debris piles, usually from other land management operations (such as clearing woody weed species).

You can search the Planned burning in Victoria web page by postcode, locality, park or address to see the planned burns intended to be delivered over the next 10 days, weather and conditions permitting.

Planned burn breach

A planned burn is considered to have breached the control line if it:

• spreads beyond the area designated in the fuel treatment delivery plan
• cannot be readily controlled with onsite or planned resources, or
• compromises the burn objectives.

An FFMVic planned burn that has breached the control line is classified as either a breach or a bushfire, depending on its extent and impact on the community or the environment.

A breach is defined as being beyond the type and extent that is routine, anticipated and resourced as part of the fuel treatment delivery plan, not readily controlled with onsite or planned resources and does not pose a significant threat to or have a significant impact on assets or the community.

A bushfire is declared when a breach of the control line threatens or is likely to threaten public safety or private or public assets and is likely to have a greater impact on the environment. A planned burn may be declared a bushfire even if no breach of the control line occurs.

The Office of Bushfire Risk Management is notified of all breaches of the control line from an FFMVic planned burn, including planned burns declared as bushfires, and assures the investigation process to ensure any lessons are identified and drive continuous improvement in the systems and processes FFMVic uses to deliver safe and effective burns.

Residual risk

See fuel-driven bushfire risk.

Risk-based approach

A risk-based approach is a bushfire management approach that combines in-depth local knowledge with the latest science and technology to reduce bushfire risk on both public and private land. The approach directs resources and investment to where they will have the greatest impact in keeping Victorians, and the things they value safe.

Victoria has a risk-based approach to bushfire management. This approach was adopted by the Victorian Government in 2016, and is articulated in Safer Together – a new approach to reducing the risk of bushfire in Victoria.

Safer Together marked a shift in Victoria’s approach. The Victorian Government transitioned to a risk-based approach following independent recommendations from the Bushfire Royal Commission Implementation Monitor (2012, 2013, 2014) and the Victorian Inspector-General for Emergency Management’s 2015 Review of performance targets for bushfire fuel management on public land. These independent review processes found that a hectare-based target to guide fuel management on public land was not the most effective way to deliver on the primary objective of the Royal Commission’s recommendation to maximise the protection of life.

Safer together

Safer Together is the Victorian Government’s approach to reducing bushfire risk and involves fire and land management agencies working with communities to combine in-depth local knowledge with the latest science and technology to reduce bushfire risk across public and private land.

See more information on the Safer Together website.

Sector

See Bushfire Management Sector.

Strategic Fuel Break

A strategic fuel break is a strip of land where vegetation has been modified to form a safe and effective platform for fighting and controlling bushfires. Strategic fuel breaks may be natural areas of low fuel but are typically constructed using machinery to modify or remove vegetation (such as grasses, shrubs and trees) which allows firefighters to control fires through direct firefighting methods or indirect firefighting methods (e.g., backburning).

A strategic fuel break network is currently being expanded across Victoria to provide a last line of defence to protect townships and critical infrastructure, and to break larger blocks of forest into more manageable units to help keep fires as small as possible. This network of strategic fuel breaks ensures that firefighters can respond to fires as quickly as possible, and complement a range of other fire prevention and preparedness activities.

There are 3 categories of strategic fuel breaks:

• Establishing or new construction: DEECA will build a strategic fuel break on a new footprint, where no previous fuel break was previously established.
• Upgrading or renewing: DEECA will upgrade/renew a fuel break that was previously established (such as during emergencies), which is not up to current specifications. Unlike new construction, there is already an existing disturbed footprint.
• Maintaining: This includes periodic candling of bark hazards, annual slashing, and mulching of regrowing vegetation to keep the SFBs operationally effective.

Tolerable fire interval

For any given plant community, the minimum and maximum tolerable fire intervals (TFIs) between successive burns are determined by the time required for key fire response species to mature and set seed, as well as their time to senescence without fire disturbance.

TFI thresholds provide minimum and maximum time intervals of fire frequency to ensure ecosystem resilience.

TFI status is reported as the proportion of vegetation on public land below minimum TFI, within TFI, above TFI or with no fire history.

• The proportion of vegetation on public land below minimum TFI is the percentage of land currently under the minimum time threshold recommended between successive burns for the vegetation on that land. For example, if the recommended minimum TFI is 15 years for a given vegetation type and it was last burnt 10 years ago, the land is below the minimum TFI and will continue to be for another 5 years.
• The proportion of public land above maximum TFI is the percentage of land that has not burnt for a longer period than recommended. For example, if the vegetation on that land last burnt 35 years ago, and its maximum TFI is 30 years, the land has been above the maximum TFI for 5 years.
• The proportion of public land within TFI is the percentage of that land on which the vegetation is currently recorded as being within the recommended minimum and maximum TFIs.
• The proportion of public land with no fire history is the percentage of land for which there is no record of fire, or of the land with vegetation that does not have a recommended TFI.

The larger the areas in a landscape below minimum TFI and above maximum TFI, the less resilient ecosystems are likely to be. Burning vegetation regularly while below minimum TFI increases the risk of fundamental changes in its structure and functioning. However, sometimes vegetation that is below minimum TFI is burnt to reduce risk to life and property in specific areas and to reduce potential damage to important ecosystems by major bushfires.

It is recognised that TFI is a coarse measure of ecosystem resilience that doesn’t recognise finer-scale vegetation responses to fire or the differing severity of planned burning and bushfires. But it can still help us with regional-scale decision-making. Regional Bushfire Management Strategies aim to minimise areas burnt while below minimum TFI, where feasible, without failing to deliver on other regional objectives.

There will also be instances (such as large bushfire footprints) where fuels become flammable before ecological maturity is reached. In those cases, fire will need to be applied below minimum TFI to prevent larger areas from being burnt by more intense bushfires.

There is more information about TFI on the Safer Together web page.

Total Fire Ban

Total Fire Bans are declared by the CFA’s Chief Officer on days of heightened fire danger to reduce the risk of a fire starting.

Windrow

Small debris piles burn at point locations.