Wildfires are a natural part of the ecosystem in the U.S.. It is vital to classify wildfires using a comprehensive approach that simultaneously considers wildfire activity (the number of wildfires) and burned area. On this basis, the influence of hydrometeorological variables on wildfires can be further analyzed. Therefore, this study first classified wildfire types using a wildfire bivariate probability framework. Then, by considering six hydrometeorological variables, the dominant hydrometeorological variables for different wildfire types in 17 ecoregions of the United States were quantified. In addition, based on the results of this hydrometeorology-wildfire relationship analysis, we obtained new clusters that simultaneously considered wildfire characteristics and the impact of hydrometeorology on wildfires. In particular, the results were as follows: (1) Through the probability of wildfire bivariate statistical characteristics, wildfires could be classified into five types in this paper: WT-1 (mega-wildfire), WT-2 (joint wildfire-1), WT-3 (joint extremes), WT-4 (joint wildfire-2), and WT-5 (super frequent wildfires); (2) The dominant hydrometeorological variables under different wildfire types were discussed in 17 ecoregions of the United States; and (3) In the four new cluster regions, intensifying droughts are a concern in clusters 1 and 4, while there are multiple concerns in cluster 3, namely, stronger winds, higher temperatures, and more drought.

中文翻译：

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美国大陆不同生态区基于野火双变量概率框架的水文气象-野火关系分析


野火是美国生态系统的自然组成部分。使用同时考虑野火活动（野火数量）和过火面积的综合方法对野火进行分类至关重要。在此基础上，可以进一步分析水文气象变量对山火的影响。因此，本研究首先使用野火双变量概率框架对野火类型进行分类。然后，通过考虑六个水文气象变量，对美国 17 个生态区不同野火类型的主要水文气象变量进行了量化。此外，根据水文气象与野火关系分析的结果，我们获得了同时考虑野火特征和水文气象对野火影响的新聚类。具体结果如下：（1）通过山火双变量概率统计特征，本文将山火分为五类：WT-1（特大山火）、WT-2（联合山火-1） 、WT-3（联合极端火灾）、WT-4（联合野火-2）和 WT-5（超频繁野火）； (2) 讨论了美国17个生态区不同野火类型下的主导水文气象变量； (3) 在四个新的集群区域中，集群 1 和 4 中干旱加剧是一个问题，而集群 3 中则存在多重问题，即更强的风、更高的气温和更多的干旱。