NBIC-ACS Stage 2 Forest Fire Danger Index - baseline scenario, 20% and 10% annual exceedance probabilities

The McArthur Forest Fire Danger Index (FFDI) is a fire weather potential index that describes how current weather conditions and recent precipitation patterns could support a fire in forested areas. FFDI calculations are based on McArthur, A.G. (1967) and dependent on air temperature, relative humidity, wind speed. The metric was developed with the worst bushfire event at the time – Victoria 1939 – corresponding to a value of 100. Here we provide predicted upper-bound FFDI values across the Australian landscape, defined for a set of Annual Exceedance Probabilities. We calculate FFDI based on the latest Bureau of Meteorology historical weather reanalysis BARRA-R2, reporting modelled hourly weather conditions from 1979 to current at a spatial resolution of approximately 11 kilometres. More than 400,000 data points at every location are then processed using the National Bushfire Intelligence Capability (NBIC) Extreme Values Analysis to predict extreme daily maximums and their likelihood. FFDI was historically used to define bushfire hazard, including the official Fire Danger Rating issued by operational agencies. While its use in this context is no longer recommended, FFDI remains a widely recognised fire weather metric that is commonly understood and informs jurisdictional policies and building standards. All these characteristics result in datasets that are a significant advancement in defining extreme fire weather, surpassing previous approaches and offering a robust foundation for informed decision-making in managing and mitigating Australia’s growing bushfire risks in a changing climate.\nLineage: The McArthur Forest Fire Danger Index (FFDI) data - baseline scenario is calculated using the historical weather reanalysis BARRA-R2 by Bureau of Meteorology (https://dx.doi.org/10.25914/90rq-d839). Variables used are near surface air temperature, precipitation, near surface relative humidity and near surface wind speed.\nThose inputs are combined using the equations developed by Noble et al (1980) [1] based on the work by McArthur (1967) [2]. McArthur Drought Factor is calculated using the modified formulation published in Finkele et al (2006) [3].\n\nFFDI is calculated for more than 43 years of hourly weather data, and then processed using extreme values analysis to model the expected FFDI values at annual exceedance probabilities.\n\n[1] Noble, I.R., Gill, A.M. and Bary, G.A.V., 1980. McArthur's fire‐danger meters expressed as equations. Australian journal of ecology, 5(2), pp.201-203. https://doi.org/10.1111/j.1442-9993.1980.tb01243.x\n[2] McArthur, A.G., 1967. Fire behaviour in eucalypt forests: Forestry and Timber Bureau Leaflet 107. Forestry and Timber Bureau: Canberra, Australia.\n[3] Finkele, K., Mills, G.A., Beard, G. and Jones, D.A., 2006. National gridded drought factors and comparison of two soil moisture deficit formulations used in prediction of Forest Fire Danger Index in Australia. Australian Meteorological Magazine, 55(3), pp.183-197.\n\nImportant Disclaimer:\nCSIRO advises that the information contained in this dataset comprises general statements and information based on scientific research. The user is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.

麦克阿瑟森林火险指数（McArthur Forest Fire Danger Index, FFDI）是一类火险天气潜力指数，用于刻画当前气象条件与近期降水格局对林区火灾发生的助力潜力。FFDI的计算依据McArthur, A.G.（1967）的研究方法，依赖气温、相对湿度与风速三个核心参数。该指标依托1939年维多利亚州丛林大火——当时最严重的丛林火灾事件——进行开发，此次火灾对应的FFDI值为100。

本数据集提供澳大利亚全境的预测FFDI上限值，针对一系列年超越概率（Annual Exceedance Probabilities）进行定义。我们基于澳大利亚气象局最新发布的历史气象再分析数据BARRA-R2计算FFDI，该数据集涵盖1979年至今的逐小时模拟气象条件，空间分辨率约为11公里。

随后，通过国家丛林火灾智能能力（National Bushfire Intelligence Capability, NBIC）极值分析方法，对每个格点超过40万个数据点开展处理，以预测极端日最大FFDI值及其发生概率。

历史上，FFDI曾用于界定丛林火灾风险等级，包括业务机构发布的官方火险等级。尽管目前不再推荐沿用该场景下的应用方式，但FFDI仍是一项被广泛认可的火险天气指标，其公众认知度较高，可为辖区政策制定与建筑标准编制提供科学依据。

上述特性使得本数据集在极端火险天气界定方面取得了显著进展，超越了以往的研究方法，可为气候变化背景下管理和缓解澳大利亚日益严峻的丛林火灾风险提供坚实的决策支撑。

数据溯源：本数据集的麦克阿瑟森林火险指数（FFDI）基准情景，由澳大利亚气象局基于历史气象再分析数据BARRA-R2计算得出（https://dx.doi.org/10.25914/90rq-d839）。所用输入变量包括近地面气温、降水、近地面相对湿度与近地面风速。

上述输入变量通过Noble等人（1980）[1]基于McArthur（1967）[2]的研究开发的公式进行整合计算。麦克阿瑟干旱因子（McArthur Drought Factor）则采用Finkele等人（2006）[3]发表的改进公式进行计算。

本数据集基于43年以上的逐小时气象数据计算FFDI，随后通过极值分析方法建模，得到不同年超越概率下的预期FFDI值。

[1] Noble, I.R.、Gill, A.M. 与 Bary, G.A.V.，1980年。以公式形式表达的麦克阿瑟火险指数。《澳大利亚生态学杂志》，5(2)，第201-203页。https://doi.org/10.1111/j.1442-9993.1980.tb01243.x

[2] McArthur, A.G.，1967年。桉树林火灾行为：林业与木材局手册107。澳大利亚堪培拉：林业与木材局。

[3] Finkele, K.、Mills, G.A.、Beard, G. 与 Jones, D.A.，2006年。澳大利亚森林火险指数预测中使用的全国网格化干旱因子与两种土壤水分亏缺公式的对比。《澳大利亚气象杂志》，55(3)，第183-197页。

重要免责声明：
澳大利亚联邦科学与工业研究组织（Commonwealth Scientific and Industrial Research Organisation, CSIRO）提示，本数据集所包含的信息均为基于科学研究的一般性陈述与内容。提示用户需知晓，此类信息可能存在不完整性，或无法适配特定应用场景。因此，在未获取专业、科学与技术咨询之前，不得依赖该信息或据此采取行动。在法律允许的最大范围内，CSIRO（包括其雇员与顾问）不对因直接或间接使用本出版物（全部或部分）及其包含的任何信息或材料而产生的任何后果承担责任，包括但不限于所有损失、损害、成本、费用及任何其他赔偿。