Context

Proximity of landcover elements to each other will enable or constrain fire spread. Assessments of potential fire propagation across landscapes typically involve empirical or simulation models that estimate probabilities based on complex interactions among biotic and abiotic controls.

Objectives

We developed a metric of landscape fire exposure based solely on a grid cell’s proximity to nearby hazardous fuel capable of transmitting fire to its location. To evaluate accuracy of this new metric, we asked: Do burned areas occur preferentially in locations with high exposure?

Methods

We mapped exposure to hazardous fuels in Alberta, Canada using a neighbourhood analysis. Correspondence between exposure and 2331 fires that burned 2,606,387 ha following our 2007 assessment was evaluated and exposure changes between 2007 and 2019 were assessed.

Results

In all eleven ecological units analysed, burned area surpluses occurred where exposure was ≥ 60% and corresponding deficits occurred where exposure was < 40%. In seven ecological units, the majority of burned areas had pre-fire exposure ≥ 80%. Between 2007 and 2019, land area with exposure ≥ 80% increased by almost a third.

Conclusions

Exposure to hazardous fuels is easily quantified with a single thematic layer and aligns well with subsequent fires in Boreal, Foothills and Rocky Mountain natural regions. The resulting fire exposure metric is a numeric rating of the potential for fire transmission to a location given surrounding fuel composition and configuration, irrespective of weather or other fire controls. Exposure can be compared across geographic regions and time periods; and used in conjunction with other metrics of fire controls to inform the study of landscape fire.

中文翻译：

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景观火暴露的简单指标

语境

土地覆盖要素之间的距离将使或限制火势蔓延。跨景观潜在火势蔓延的评估通常包括经验模型或模拟模型，这些模型基于生物和非生物控制之间的复杂相互作用来估计概率。

目标

我们仅根据网格单元与附近能够将火势传递到其附近的危险燃料的距离，开发了一种景观火势度量标准。为了评估此新指标的准确性，我们问：在高曝光量的位置上是否优先发生烧伤区域？

方法

我们使用邻域分析绘制了加拿大艾伯塔省有害燃料的暴露图。在我们进行2007年评估之后，评估了暴露与2331起火灾（燃烧了2,606,387公顷）之间的对应关系，并评估了2007年至2019年之间的暴露变化。

结果

在所分析的所有11个生态单元中，当暴露量≥60％时，发生燃烧面积过剩，而当暴露量<40％时，发生相应的赤字。在七个生态单元中，大多数燃烧区的火灾前暴露≥80％。在2007年至2019年之间，暴露度≥80％的土地面积增加了近三分之一。

结论

仅需一个主题层即可轻松量化有害燃料的暴露量，并与随后在北方，山麓丘陵和落基山自然地区发生的大火相吻合。所得的火源度量标准是将火传播到给定位置周围的燃料组成和配置的位置的可能性的数字等级，而与天气或其他火控无关。可以跨地理区域和时间段比较暴露情况；并与其他防火控制指标结合使用，以研究景观火灾。