Modelling scenarios
Modelling projects allow you to run, organise, and track risk scenarios. Each scenario experiments with how different treatments or lack of treatments could impact the bush fire risk of the modelling project area.
Different project types have different scenarios. For more information, see Types of modelling projects and the overviews for each project type.
Within a scenario, you have runs. These are how you test your scenario. They predict the fire's spread across the landscape at a specific time and evaluate the risk to assets.
A scenario run has a parent-child structure—the parent run is called the Fire Behaviour run, and the child runs are called Impact Analysis runs. You can have multiple Impact Analysis runs for a single Fire Behaviour run.
Parent run: Fire Behaviour run
The parent Fire Behaviour run predicts fire across the landscape by utilising Phoenix RapidFire based on the inputs and configurations. You can run each scenario multiple times and change inputs in the Phoenix RapidFire settings (for example, a change in fuel inputs, suppression inputs, and ignition points) to test different outcomes. Outputs from a Fire Behaviour run are a compilation of the raw Phoenix outputs plus summaries of the Phoenix outputs weighted by fire danger rating (FDR). These FDR values are based on the weather data rating (Low-moderate, High, Very High, Severe, Extreme, Catastrophic).
Child run: Impact Analysis run
The child Impact Analysis run determines the risk to assets based on the summary produced from the fire behaviour run.
An Impact Analysis run is a two-part process:
Part 1: Analysing the assets
For residential assets, it calculates the probability of loss for each 180m2 grid cell using a house loss formula.
For SFPPs (Special Fire Protection Purpose buildings) and each economic asset type, vulnerability curve values and cost values are input into a Bayesian network with the probability of Fire Danger Rating (FDR) and FDR ignition values to calculate the probability of asset loss in each grid cell. These probabilities are converted into risk values by considering the number of assets, the recovery time, and the asset cost metrics you specify in the run configurations. There are four metric options:
Each Point, Line, Polygon (where the number of assets in each grid cell is the metric)
180m2 grid (Point, Line, Polygon) (only one asset in a 180m2 grid cell contributes to the risk and additional assets in the same grid cell do not increase the risk output)
km (line)
hectare (polygon)
Vulnerability curves represent the relationship between the risk and level of damage to an asset.
For a list of economic assets, see Impact Analysis inputs.
Part 2: Producing the outputs
The residential, SFPP, and economic asset risk results are converted to a lower resolution raster.
Each economic asset's risk values are combined to create an economic risk value for each cell.
The aggregated rasters are categorised into risk categories: Lowest, Low, Moderate, High, and Highest.
You can run scenarios multiple times, changing inputs and configurations until satisfied with the outputs. When you are satisfied, you can Accept a run, which indicates that the inputs and configurations of that run are accurate. You can clone the inputs and configurations for subsequent runs within the same project. Note that there are cost implications each time you run a scenario.