16/11/2019
Are we backburning or doing a hazard reduction?
The media and the public are rightly confused when it comes to fire terminology, however it isn’t that complicated.
Hazard reduction is a term that describes the methods used in preparation for the upcoming fire season to reduce fuels in the landscape or close to property. These methods include mechanical clearing of vegetation, the creation of fire breaks, or what is commonly referred to as prescribed burning.
Prescribed burning aims to reduce fuels whilst also meeting a ‘prescription’ that will not result in an uncontrolled fire, protects soils and streams, provides opportunity for fauna to move and does not involve damage to the tree canopy. By reducing ground fuels and the shrub layers of forests, a fire is less likely to become a wildfire and get into the canopy.
Backburning is lit only during fire fighting operations. It is lit ‘back against the wind (or slope)’ to suppress the fuel loads in the direction that a bushfire is travelling. However, backburning must be carefully planned as these fires may get out of control when conditions are too severe. Backburning is a dangerous operation and must be adequately resourced.
Hazard reduction plays a significant role in managing future bushfires, however, fuels will progressively recover over time. This recovery means that after a few years, fuels will accumulate, limiting their effectiveness over time. This is where home owners can also assist by managing fuels within their own properties.
Households can create asset protection zones, which are usually mechanically treated through mowing, trimming lower limbs and clearing woodpiles and other flammable materials from around the house. Buildings that are within 100-150 metres from bushland are particularly at risk if not suitably prepared. Maintaining gardens by removing dead fuels and replacing mulch with gravels can all assist in reducing the impacts of a bushfire on a home. This is because most homes are lost through ember attack, generated from fine fuels such as bark, leaves and smaller pieces of wood associated with mulches. Clearing gutters (installing gutter guards are better) of debris prior to the fire season can assist in preventing fires accessing the roof space. Flame contact and radiant heat is more likely in rural areas where located close to forested areas.
When planning a garden, don’t plant shrubs near windows or doors, and locate taller shrubs or trees more than 10 metres from the house. Plantings should be clumped with clear spaces and trees and shrubs should not be co-located.
Photo: NPWS Fire fighters conducting a backburn on the North Coast of NSW.
