Data and model output improvements

Victoria’s bushfire management sector continually works to improve the data and science that inform its decisions. As technology improves, better data becomes available, research programs elicit new knowledge, or mapping accuracy is enhanced, the models improve and metrics, such as fuel-driven bushfire risk or ecosystem metrics, are recalculated.

Each year, updates are made to this report to respond to these improvements ensuring the best-available models and data inform public reporting.

Readers should compare this report and past and future reports in that context. For the most accurate view of current and historical figures, you should always consult the most recent bushfire risk management report.

Changes to reported fuel-driven bushfire risk

This year’s report includes improvements as they were made to fire history data leading to the re-calculation of fuel-driven bushfire risk across multiple years. This reflects Victoria's commitment to continuous improvement of models and datasets.

Table 41: State-wide changes to reported fuel-driven bushfire risk resulting from continuous improvement of fire history layer.

Report year2017-182018-192019-202020-212021-222022-23
Reported fuel-driven bushfire risk at the end of the 2021-22 season68%70%63%63%62%N/A
Recalculated fuel-driven bushfire risk as at EOFY 2022-2368%69%63%62%62%65%

Table 42: Changes to reported regional risk levels, Victoria, 2020–21.

RegionBarwon South WestGippslandGrampiansHumeLoddon MalleePort Phillip
Reported 2021-22 fuel-driven bushfire risk58%43%75%67%68%84%
Recalculated 2021-22 fuel-driven bushfire risk as at EOFY 2022-2358%43%76%67%70%85%

The accuracy of areas treated by planned burning is the primary source of fluctuation in fuel-driven bushfire risk numbers from year to year – as fire severity information is improved, this often changes the modelled risk to houses. This applies to a lesser extent to bushfires, where updated coverage and severity mapping can sometimes influence risk profiles.

Changes to reported ecosystem resilience

As with reported fuel-driven bushfire risk, the improvements in mapping and accounting of areas treated by planned burning and subsequent re-modelling influence the calculation of ecosystem resilience metrics.

Changes to reported TFI and GSS are shown in Table 43 and Table 44 respectively. There were no adjustments to the reported TFI and GSS for 202122, however, this does not mean improvements weren’t made.

Table 43: Changes to reported Tolerable Fire Interval, Victoria, 2020–21.

YearBelow Min TFIWithin TFIAbove Max TFINo Fire History
2021-22 Reported55%23%2%20%
2021-22 Adjusted with fire history improvements55%23%2%20%

Table 44: Changes to reported Growth Stage Structure, Victoria, 2020–21.

YearJuvenileAdolescentMatureOld GrowthNo Fire History
2021-22 Reported24%18%33%4%20%
2021-22 Adjusted with fire history improvements24%18%33%4%20%

Changes to FFMVic reported costs

Changes in the split between direct and indirect costs have been applied retrospectively in Table 45 to enable a direct comparison between the financial years shown, based on the accounting method developed in 2018–19 and applied in subsequent years.

FFMVic’s fuel management program investment is split between direct and indirect costs. Specific amendments have been made to better capture the activities related to fuel management and non-fuel management investment, possibly due to improvements made to the accounting method and categorisation of expense types over time.

The changes reported in this section for direct and indirect investment for the fuel management program from 2016–17 to 2021–22 are the result of changes made to the categorisation of costs as being direct, indirect and/or non-fuel management expenses.

Direct costs relate to investment that can be directly and reliably assigned to individual fuel management operations (such as materials, plant and aircraft hire, overtime and allowances, overnight accommodation and meals).

Indirect fuel management costs include expenses relating to base salaries, training, vehicles, equipment, planning and community engagement.

This year, indirect costs also include investment in native vegetation improvements, which are activities undertaken to offset impacts to biodiversity resulting from FFMVic’s bushfire fuel management activities.

Non-fuel management expenses are typically those relating to preparedness and fire and emergency response activities (such as fire radio network costs, systems and aviation spending). These are not reflected in Table 45.

Table 45: Changes to reported FFMVic fuel management investment from 2016-17 to 2021–22.

Report year2016-17 ($m)2017-18 ($m)2018-19 ($m)2019-20 ($m)2020-21 ($m)2021-22 ($m)2022-23 ($m)
Total fuel management investment reported in current year (based on the current accounting method)97.9113.5121.7109.2155.8151.0141.1
Direct fuel management investment 11.214.618.210.942.437.324.2
Indirect fuel management investment86.798.9103.598.2113.4113.7117
Total fuel management investment reported in that year107.9107.8121.7109.2155.8151.0141.1
Direct fuel management investment was reported in that year. 40.030.418.210.942.437.324.2
Indirect fuel management investment reported in that year67.977.4103.598.2113.4113.7117
Net change in fuel management reported investment-10.05.7n/an/an/an/an/a