Terrain or slope
Developing the next generation of nationally standardised, reference terrain/slope datasets.
An image of the Nandewar Range NSW that shows varying terrain
Fire behaviour modelling incorporates the influence of terrain or slope.
The slope of the landscape in the direction of fire progression has a strong influence on the fire’s rate of spread (ROS).
The fire progression speed and intensity increases if going upslope and decreases when going downslope.
Fire behaviour modelling incorporates evaluation of the change to the ROS using topographic slope derived from a bare earth (excluding trees, buildings, and any other surface objects) digital elevation model (DEM).
Current national datasets have errors associated with them, particularly in heavily forested areas.
Using cutting edge technology, we are amalgamating available bare-earth terrain Digital Elevation Model (DEM) products to provide accurate terrain/slope estimates for application in fire behaviour modelling.
We identify suitable datasets, assess errors and adapt methods to enable the production of accurate, high-resolution terrain/slope datasets.
An image that shows 4 representations of slope data from different datasets.
Note how different remote sensing Digital Elevation Model (DEM) products produce different quality slope data.
The composite image shows remote sensing slope maps for a 5 km x 5 km area of undulating terrain with a maximum slope of 5 degrees:
a) LIDAR: Light Detection and Ranging, only available for small areas and used to evaluate national scale DEM products
b) FABDEM: Forest And Building removed Copernicus DEM product
c) DEM-S: a smoothed DEM derived from the NASA Shuttle Radar Topographic Mission (SRTM) product
d) final slope map generated from FABDEM after a smoothing filter has been applied
Note: dark blue is low slopes and greens to yellow are steeper slopes
Existing products
Stage 1 data: Geoscience Australia’s Shuttle Radar Topographic Mission (SRTM) Smoothed Digital Elevation Model (DEM-S).
Methodology: Section 4 of the Stage 1 Methodology
Planned products
Stage 2 data: National amalgamated terrain datasets of bare-earth Digital Elevation Model, slope and aspect.
Methodology: Updates to Stage 1 Methodology
Use cases
Examples of how the terrain/slope data has been applied.
Forthcoming