Bushfire Risk Analysis in Australia Using GIS: A Step-by-Step Guide”
Introduction
Australia is one of the most bushfire-prone countries in the world due to its dry climate, dense vegetation, and seasonal weather patterns. Accurate bushfire risk assessment is critical for protecting lives, property, and biodiversity. In this blog, we’ll explore how Geographic Information Systems (GIS) can be used to assess bushfire risk in Australia, using freely available datasets and tools.
Key Datasets for Bushfire Risk Analysis in Australia
Here are the main spatial datasets you’ll need:
1. Topography
- Source: Geoscience Australia – ELVIS
- Use DEM data to derive slope and aspect
2. Vegetation & Fuel Load
- Source: Australian Vegetation Attribute datasets (DELWP VIC, NSW Government SEED portal)
- Alternative: Sentinel-2 imagery from Copernicus Open Access Hub
- Use NDVI to assess vegetation density (fuel)
3. Bushfire History
- Source: National Bushfire Boundaries – Data.gov.au
- Useful for modeling future risk based on historical ignition points
4. Climate and Weather
- Source: Bureau of Meteorology (BoM)
- Includes temperature, wind speed, and humidity
5. Infrastructure and Population
- Source: ABS (Australian Bureau of Statistics) & OpenStreetMap
- Urban areas, roads, and critical infrastructure
GIS Tools You Can Use
| Tool | Description |
|---|---|
| QGIS | Free and open-source GIS software |
| ArcGIS Pro | Commercial with advanced spatial tools |
| Google Earth Engine | Good for remote sensing & time-series |
| AFDRS | Australian Fire Danger Rating System |
Step-by-Step Workflow for Bushfire Risk Analysis in GIS (Australia)
Step 1: Prepare the Data
- Import and reproject all layers to GDA2020 or GDA94
- Clip data to your study area (e.g., NSW coastal region)
- Clean and harmonise formats (vector/raster)
Step 2: Derive Slope & Aspect from DEM
- Fires travel faster uphill and on north-facing slopes
- Use the Slope and Aspect tools in QGIS or ArcGIS
Step 3: Map Fuel Loads
- Use NDVI from Sentinel-2 or pre-classified vegetation layers
- NDVI > 0.6 = high vegetation density → high fuel
Step 4: Create Proximity Buffers
- Buffer urban areas and roads
- Distance to ignition sources increases risk
Step 5: Assign Risk Factors (Weighted Overlay)
| Layer | Risk Factor |
|---|---|
| Slope > 20° | High |
| North-facing | High |
| NDVI > 0.6 | High |
| < 1 km from road | Medium |
| > 5 km from urban area | Low |
Use Raster Calculator or Multi-Criteria Evaluation (MCE) tools to combine them into a final Bushfire Risk Map.
Example Output Maps
Include:
- Slope Map
- NDVI/Fuel Load Map
- Bushfire Risk Classification Map (High/Medium/Low)
Include screenshots from QGIS with legends and colour ramps.
Bonus: Add Historical Fire Overlay
Overlay past bushfire events from data.gov.au to validate the model:
- Do high-risk zones overlap past fire zones?
- Use this for accuracy check or model refinement
Real-World Applications
- Emergency evacuation planning (RFS, CFA)
- Urban development zoning (avoid fire-prone zones)
- Insurance risk analysis
- Environmental impact studies
Conclusion
GIS is a powerful tool for bushfire risk assessment, especially when paired with Australia’s robust open data. By integrating topography, vegetation, climate, and infrastructure data, we can create risk maps that inform decision-making and save lives.
