BUSHFIRE FUEL LOAD MANAGEMENT
BUILDING INFORMED RESPONSE PLANS FOR FUTURE BUSHFIRES Following on from the 2019/20 catastrophic bushfire season in Australia, the Royal Commission into National Natural Disaster Arrangements identified remote sensing technologies such as Light Detection and Ranging (LiDAR) as critical tools that have the potential to revolutionise how communities prepare for, manage, and mitigate bushfire hazards and risks. Aerometrex has developed an innovative methodology using LiDAR to produce regional bushfire fuel load datasets across large areas of eucalypt woodlands and forests typical of bushfire prone areas across many parts of Australia. Of the three main parameters that govern the behaviour and potential severity of a bushfire - fuel load, topography, and weather - fuel load is the only parameter that can be actively managed in order to help mitigate the risk associated with bushfires. Our Bushfire Fuel Load Data Suite provides end-users with a greater understanding of fuel load. They provide actionable information through a range of data from wide-scale maps to property-level insights. While the maps help generate informed mitigation and response strategies, property-level insights can increase community engagement to reduce risk on private land.
TECHNOLOGY THAT IS GREAT FOR UNDERSTANDING FUEL LOAD The unique way in which LIDAR pulses interact with vegetation make it possible to quantify the three-dimensional structure of the vegetation, including the density, horizontal continuity, and vertical connectivity to the level of detail required to describe its fuel load properties. LiDAR’s ability to measure the three-dimensional structure of vegetation accurately, across large areas of interest, means that traditional visual and physical fuel load measurements can be used to calibrate LiDAR-derived fuel load models which are accurate, continuous and less labour intensive.
WHAT IS LiDAR? LiDAR, which stands for Light Detection and Ranging, is an active remote sensing method that is used to accurately measure the landscape in three dimensions. When laser pulses emitted from a LiDAR sensor in an aircraft fall on vegetation, a portion of the energy is scattered or reflected towards the sensor by the top of the vegetation, and the remaining energy is transmitted through gaps in the foliage and interacts with lower branches, leaves or stems as well as the ground surface below.
Property blocks colour coded by average tonnes per hectare fuel load and scaled vertically by average fuel load vertical connectivity
BUSFIRE FUEL LOAD DATA SUITE This Aerometrex Data Suite provides fire management experts, at all levels, a holistic understanding of the threedimensional structure and spatial distribution of fuel loads. Currently, the datasets have been built for eucalypt woodlands and forests found throughout the Adelaide Hills and the methodology can be expanded to other regions and vegetation types with necessary assessments. Included within this suite are datasets that describe the density of the fuel, the vertical connectivity, and the amount of fuel across the landscape. Each of these is critical when planning fuel reduction programs, regional risk assessments and planning bushfire response strategies. All these datasets are supplied as 2D raster, making them functional, accessible and easy to understand within any standard local- or web-based GIS platform.
Bushfire Fuel Load Density Maps The density of the vegetation that contributes to the fuel load within each fuel layer. Layers are defined as: Near Surface Layer (0.25-0.7m), Elevated Layer (0.7-2.0m) and Lower Canopy Layer (2.0-3.0m). Fuel Density Layers Low
High
Cumulative Fuel Load Density The overall fuel load density, taking into account the Near Surface, Elevated and Lower Canopy Fuel, weighted in such a way that it is analogous to standardised “Overall Fuel Hazard Assessments” conducted in the field. Overall Fuel Density Low
Medium
High
Very High
Vertical Connectivity Index The Vertical Connectivity Index shows how continuous the vegetation is from ground to upper canopy, revealing how much ‘ladder fuel’ there is that can enable fires to climb from the ground surface into the canopy layer. Rate of Spread (m/hr) Low
High
Tonnes Per Hectare Fuel Load (t.Ha-1) This dataset shows Tonnes Per Hectare Fuel Load (t.Ha-1), modelled using LiDAR-derived bushfire fuel load attributes.
Tonnes Per Hectare 0.0-7.5 7.5-10.0
10.0-15.0
15.0-20.0
20.0-25.0
20+
A WIDE RANGE OF APPLICATIONS These datasets can be utilised for diverse and broad applications by fire management experts to help fire officers assess the risk associated with fuel loads at a range of scales. Aerometrex’s innovative methodology to produce quantitative tonnes per hectare (t.Ha-1) fuel load maps across larges areas means that it is now possible to model the behaviour of potential bushfire with spatially continuous data, as opposed to limited, discrete visual and physical field measurements. LiDAR-derived tonnes per hectare fuel load datasets can be incorporated into national standard bushfire behaviour models for dry eucalypt forests, as well as up-to-date meteorological information, to provide a detailed understanding of how managed and un-managed bushfires might behave on any given day.
Planning Safer Fuel Reduction Activities The below images show bushfire behaviour model outputs for the meteorological conditions in the Adelaide hills on the 15th of February 2022, using the Leaflet 80 model. The slope adjusted rate of spread for a hypothetical prescribed burn is shown at 10:30am and 1:30pm respectively. Airborne LiDAR-derived tonnes per hectare fuel load information is combined with wind-speed, temperature, and relative humidity predictions (acquired from the Bureau of Meteorology). As the day progresses, prescribed burns are predicted to move at a faster rate due to an increase in temperature and wind-speed coupled with a reduction in relative humidity. Information such as this can be vital for the safe planning of fuel reduction activities.
Rate of Spread (m/hr) 0.01
1800
Supporting Community Engagement When combined with datasets such as state-wide cadastres or building footprints, Aerometrex’s LiDAR-derived fuel load metrics can provide valuable tools for Local Governments to help educate land-owners about the risks associated with fuels on private land. It can also help develop targeted community engagement initiatives to increase the public’s involvement in fuel management. The image below shows properties within our 2021 survey, colour-coded by the average tonnes per hectare fuel load on that property.
Average Tonnes Per Hectare Low
High
Location:
Branch Rd, Aldgate SA 5154
State: Parcel Type:
SA
Jurisdiction ID:
D/5348/A/9
Local Gov Area:
Adelaide Hills Council
Area:
62989.56
MEAN t.Ha:
22.094997
MEAN VCI:
0.685841
Parcel ID:
F/11274/A/1
Lot
PARTNER WITH US This data suite is the first step towards using airborne LiDAR to analyse bushfire fuel load for different vegetation types in other states and territories. With the newly acquired knowledge, Aerometrex and partnering stakeholders can help drive continued innovation in bushfire science across Australia. There is extensive data contained within the Aerometrex fuel load capture region. To aid in accessing the relevant datasets, the following information is provided as a guide: •
Where vegetation is woodland or healthy eucalypt, Aerometrex can provide the datasets with appropriate stratification. There is opportunity for additional stratification where required.
•
In regions of mallee, rainforest, dense eucalypt or grasses, additional studies can be obtained as needed to ensure appropriate analytical data is available for your designated location.
•
Raster layers, 3D cloud generation and full data ingestion within your own applications is possible for complete functional awareness for your teams.
We are hopeful that this Bushfire Fuel Load Data Suite can provide critical information to all levels of government and emergency services that will deliver numerous benefits to the community.
RESOURCES Aerometrex Resources •
Aerometrex Website
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Press Release and Channel 9 Coverage
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Blog Post on Bushfire Fuel Load Management
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AFAC21 Presentation I “LIDAR-derived bushfire load metrics for eucalypt woodlands and forests using optimised acquisition methods” - Presented by Dr. Samuel Holt
External Resources •
The Royal Commission into National Natural Disaster Arrangements Report
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Overall fuel hazard guide for South Australia
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Bushfire best practice guide: BAL Assessment - CSIRO
Related Topics •
LiDAR Product Guide by Aerometrex
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MetroMap. More Than Just Maps.
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Working towards a greener, more resilient Adelaide – Presented by Dr. Samuel Holt at SID21
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Greener, cooler and more sustainable communities – Presented by Dr. Samuel Holt at TREENET 2021
08 8362 9911 aerometrex.com.au