FFDI bushfire hazard data for the National Climate Risk Assessment

Brief description

FFDI bushfire hazard regional change summaries for the National Climate Risk Assessment (NCRA). The FFDI hazard has been summarised for boundaries relating to the assessment of terrestrial natural environments.

Australian Climate Service (ACS) fire hazard datasets (https://github.com/AusClimateService/hazard_fire)
1. FFDI - Forest Fire Danger index, a measure of fire weather, modelled as a function of wind speed, temperature, humidity, and past and recent rainfall
The FFDI hazard is represented as the number of days in a year where the index exceeds 50 (FFDI50), and where the index exceeds 75 (FFDI75).

Each hazard dataset includes an ensemble of climate models for four global warming levels (GWLs), 1.2, 1.5, 2.0 and 3.0 degrees Celsius, above a pre-industrial mean for 1850 to 1900.

The absolute change (difference to GWL1.2) was calculated for each of the higher GWLs compared to GWL1.2.

Regions of interest boundaries
1. Australia
2. NCRA regions
3. Aggregate Ecological Groups (AEGs)
4. Combined NCRA regions and AEGs

For each hazard/GWL-change combination, a set of statistics (the mean, 10th percentile, 50th percentile, 90th percentile and standard deviation) was calculated for each climate model in the ensemble over the regions of interest areas. From these, the median of each statistic from all the models in the ensemble was calculated.

Collection data files
The outputs are tabular data in comma-separated value (csv) files with one file per hazard/GWL-change combination. The columns are ID and region name that link to the boundary datasets for visualising in GIS software, and the medians of the statistics. Rows are the individual region of interest polygons.
Lineage: DATASETS
Hazard data
The National Climate Risk Assessment (NCRA) hazard data were supplied by the Australian Climate Service (ACS) from data stored on the National Computational Infrastructure (NCI) as part of Project ia39. The hazard data came in the form of an ensemble of climate models, with outputs for four global warming levels (GWLs) from each of the individual models. The GWLs are 1.2, 1.5, 2.0 and 3.0 degrees Celsius above a pre-industrial mean for 1850 to 1900.

Australian Climate Service (ACS) fire hazard dataset (https://github.com/AusClimateService/hazard_fire) used in this collection:
1. FFDI - Forest Fire Danger index, a measure of fire weather, modelled as a function of wind speed, temperature, humidity, and past and recent rainfall

The FFDI hazard is represented as the number of days in a year where the index exceeds 50 (FFDI50), and where the index exceeds 75 (FFDI75).

Regions of interest boundaries
The hazard data were summarized by regions of interest using polygon shape files for the following areas:
1. Australia - 2021 - Shapefile (https://www.abs.gov.au/statistics/standards/australian-statistical-geography-standard-asgs-edition-3/jul2021-jun2026/access-and-downloads/digital-boundary-files)
2. NCRA regions (https://www.acs.gov.au/datasets/4f8b960fd3694fc28d6ff3d1278e9e75_0/about)
3. Aggregate Ecological Groups (AEGs) derived from National Vegetation Information System (NVIS) data (https://data.csiro.au/collection/csiro:64128)
4. Spatially combined NCRA and AEG polygons (https://data.csiro.au/collection/csiro:64133)


METHODS
The FFDI50 and FFDI75 hazard datasets were summarised for each set of region of interest boundaries using methods and code from the ACS (https://github.com/AusClimateService/plotting_maps).

The absolute change (difference to GWL1.2) was calculated for each of the higher GWLs compared to GWL1.2 for FFDI50 and FFDI75 using the Australia, NCRA, AEG and combined NCRA-AEG boundaries.

For each hazard/GWL-change combination, a set of statistics (the mean, 10th percentile, 50th percentile, 90th percentile and standard deviation) was calculated for each climate model in the ensemble over the regions of interest areas. From these, the median of each statistic from all the models in the ensemble was calculated. For a more detailed description of the methods, see the 'Spatial data processing methods' file in the Supporting Documentation section.


OUTPUTS - COLLECTION DATA FILES
The outputs are tabular data in comma-separated value (csv) files with one file per hazard/GWL-change combination. The columns are ID and region name (linking to the boundary datasets for visualising in GIS software), and the medians for each of the statistics. Rows are the individual region of interest areas (polygons).