Vegetation

The type and extent of vegetation may help indicate where a fire will start and the direction it may approach from. Vegetation acts as the primary source of fuel for a bushfire and can burn differently depending on the amount, type, arrangement and moisture content.

Interactions between the weather and vegetation largely influence the intensity and duration of a bushfire. The most important factors to consider relating to vegetation and fuel are:

• Fine fuels such as leaf litter readily dry out, ignite and can be carried as embers.
• Shrubs, vines and other elevated fuels can act as ladder fuels, allowing fire to climb into the canopies of trees, significantly increasing bushfire intensity.
• Finer fuels such as grasses burn more quickly, and more substantial fuels burn with greater intensity.

North and north-west facing slopes are more likely to dry out quickly in summer. Therefore, they will ignite and burn vegetation more easily than vegetation on a south facing slope.

Breaking up the continuity of the vegetation can limit the spread of fire. How or if this can be achieved will vary depending on the proposal.

Key consideration for planning decision making:

A fire run is an area of continuous vegetation where a fire can ‘run’ (move) through a given landscape. It is expressed as a distance (km or m). They show how large a bushfire may become before it impacts on a location.

Fire runs located north-west and south-west of a proposal will be of interest to decision makers. Dominant winds in Victoria will push any bushfire in these areas towards a proposal.

Fire runs are shown on a bushfire hazard landscape assessment.