Northern jarrah forest prescribed burn
Northern jarrah forest
prescribed burn - Photo © DPaW

What is prescribed burning?

Prescribed burning is the process of planning and applying fire to a predetermined area, under specific environmental conditions, to achieve a desired outcome.

Prescribed, controlled and planned burns are the same thing.

In Western Australia, they are referred to as prescribed burns because they follow a ‘prescription’ with a number of conditions that need to be met.

Why does the Department of Parks and Wildlife conduct prescribed burns?

The department uses prescribed burning for a number of purposes:

  • to maintain biodiversity,
  • to mitigate the severity of bushfires and to help protect lives and property by reducing the build-up of flammable fuel loads, and
  • to rehabilitate vegetation after disturbance, such as timber harvesting and mining
  • to undertake research on fire and its interaction with our environment.
Mild prescribed burning
Mild prescribed burning. - Photo © DPaW

What is involved in prescribed burning?

Prescribed burning involves careful planning, consultation and monitoring, including:

  • determining what vegetation needs to be burnt and what needs to be left unburnt (mosaic), the desired fire intensity and the season
  • considering the history and variety of past fire events over the landscape
  • studying and measuring the quantity, arrangement and moisture content of fuels
  • determining, monitoring and forecasting the right weather conditions for igniting a burn using knowledge about fire behaviour
  • determining the best time of day to ignite a burn in a specified pattern and sequence to achieve the desired outcomes and to prevent fire from escaping
  • monitoring the results of a burn to determine how well the operation met the objectives set for the burn
  • using knowledge gained and lessons learned to improve future prescribed burning operations.

All of this is underpinned by a rigorous approvals process. The section on planning for prescribed burning has more detail on what is involved.

Pre-burn checklist briefing given prior to ignition to prescribed burn
Pre-burn checklist briefing given prior to
ignition to prescribed burn. - Photo © DPaW

When does burning occur?

In the regions with distinct seasons, prescribed burning takes place in spring and autumn when conditions are cooler, vegetation and fuel moisture levels are higher and weather conditions are more stable.

In regions with wet and dry seasons, such as the Kimberley, burning is conducted from May to September (late wet to early dry season), when winds are predictable and the ground vegetation is not fully cured, and fires tend to be relatively low intensity, patchy and limited in extent. Also night conditions are conducive to fires extinguishing. The section on fuel loads and fire intensity has more information about burning in different seasons.

Who is involved in prescribed burning?

In Western Australia, prescribed burning involves many players as part of a shared responsibility. Parks and Wildlife is responsible for prescribed burning on land that it manages. The department works effectively alongside and consults with the community, Department of Fire and Emergency Services (DFES), local governments and industries such as grape growers and other landholders. Wherever feasible, Parks and Wildlife, DFES and local government will conduct their prescribed burning programs as a joint exercise.

Hand prescribed burning with drip torches
Hand prescribed burning
with drip torches. - Photo © Leigh Sage

Is prescribed burning safe?

Community safety is our primary concern when carrying out prescribed burns. Prescribed burning is a simple concept that depends on complex factors that are not always predictable; therefore there is always an element of risk associated when burning. Each prescribed burn is heavily scrutinised and has to pass a rigorous approvals process before any burning can begin. Prescribed burning does not mean that there will never be large damaging bushfires however it does help to make them less likely.

Is prescribed burning effective?

Yes. Scientific research shows that prescribed burning is very effective, especially when managing bushfires. We know from experience over a wide range of weather conditions and vegetation types that direct attack on bushfires with flame heights of more than three meters or where fires are moving faster than 200 metres per hour (in forest) is not likely to succeed. Fire behaviour is directly affected by the amount of available fuel. Therefore, direct attack on the flanks of a fire is likely to succeed where fires run into recently burnt areas of low fuel.

The special inquiry report of the 2011 Perth Hills bushfire ‘A Shared Responsibility’ highlights an example of the effectiveness of prescribed burning.

“The reduced fire intensity and rate of spread observed when bushfires enter a reduced fuel area allows firefighters greater opportunity to effectively combat the fire and to limit its impact. In fact, the Special Inquiry heard evidence that the Roleystone-Kelmscott fire was extinguished on one front when it entered a section of the Banyowla Regional Park that had been the subject of a prescribed burn by DEC (now the Department of Parks and Wildlife) four years ago, as discussed later in this chapter”.

The 2011 Perth Hills bushfire caused serious damage but the destruction in this fire prone area was limited by prescribed burns undertaken in the previous four years at strategic locations.

For another example of how effective burning is read 'Prescribed burning helps protect Bungle Bungle rock art'.

How does Parks and Wildlife manage the risk of escapes?

Prescribed burning is not without risk. However the department, through scientific research and experience has made changes and implemented procedures to minimise the risk of potential escapes.

The department has recently undergone some major changes to ensure deliberate and pro-active risk management is applied to keep the risks associated with prescribed fire as low as reasonably practicable and aligning its risk management processes with the international standard ISO 31000 for risk management.

The Western Australian Government, through the newly created Office of Bushfire Risk Management (OBRM), has endorsed the department’s new approach to bring its prescribed burning into line with ISO 31000.

OBRM is responsible for the facilitation of bushfire risk management and the coordination of related activity across the agencies responsible and for promoting community understanding about prescribed burning and bushfire risks.

OBRM is working with agencies such as the Department of Fire and Emergencies Services (DFES) and local governments to align Western Australia’s fire business with ISO 31000.

What techniques are used for prescribed burning?

The pages on planning for prescribed burning detail how Parks and Wildlife carries out prescribed burns.

Where can I get more information?

To find out more, including what’s happening in your area, contact your local Parks and Wildlife regional and metropolitan office.

 

Articles in this category:

Title Modified Date
Daily risk monitoring and management Wednesday, 10 July 2013 13:37
Planning for prescribed burning Monday, 07 October 2013 12:03
Smoke alert information Thursday, 27 June 2013 14:48
Smoke management Tuesday, 09 July 2013 12:33