The US National Fire Danger Rating System (USNFDRS) supports wildfire management decisions nationwide, but it has not been updated since 1988. Here we implement new fuel moisture models, and we simplify the fuel models while maintaining the overall USNFDRS structure. Modeled and measured live fuel moisture content values were highly correlated ( with defaults and when species and location optimized). We also consolidated fuel models to five fuel types that eliminated significant index cross-correlation. Index seasonality compared between old (V2) and new USNFDRS models (v4) across six US National Forests was very similar ( 0.97). V4 was as good or better than V2 at predicting fire days in 92% of the cases tested and V4 effectively predicted wildfire days and large fire ignition days (AUCs 0.647 to 0.915). USNFDRS V4 can adequately depict spatial and temporal wildland fire potential and it can be adapted for worldwide use.

中文翻译：

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现代化美国国家火灾危险评级系统（第 4 版）：简化燃料模型并改进活燃料和死燃料水分计算


美国国家火灾危险评级系统 (USNFDRS) 支持全国范围内的野火管理决策，但自 1988 年以来就没有更新过。在这里，我们实施新的燃料水分模型，并在保持 USNFDRS 整体结构的同时简化燃料模型。建模和测量的活燃料水分含量值高度相关（与默认值以及物种和位置优化时）。我们还将燃料模型整合为五种燃料类型，消除了显着的指数互相关性。与美国六个国家森林的旧版 (V2) 和新版 USNFDRS 模型 (v4) 相比，指数季节性非常相似 (0.97)。在 92% 的测试案例中，V4 在预测火灾天数方面与 V2 一样好或更好，并且 V4 有效预测了野火天数和大火灾点火天数（AUC 0.647 至 0.915）。 USNFDRS V4 可以充分描述荒地火灾的空间和时间潜力，并且可以适应全球范围内的使用。