Abstract. Hazard magnitude scales are widely adopted to facilitate communication regarding hazard events and the corresponding decision making for emergency management. A hazard magnitude scale measures the strength of a hazard event considering the natural forcing phenomena and the severity of the event with respect to average entities at risk. However, existing hazard magnitude scales cannot be easily adapted for comparative analysis across different hazard types. Here, we propose an equivalent hazard magnitude scale, called the Gardoni Scale after Professor Paolo Gardoni, to measure hazard strength across multiple types of hazards. Using global historical records of hazard magnitude indicators and impacts of events of 12 hazard types from 1900 to 2020, we demonstrate that an equivalent hazard magnitude on the Gardoni Scale can be derived as correlated with the expectation of an impact metric of hazard event. In this study, we model the impact metric as a function of fatalities, total affected population, and total economic damage. Our results show that hazard magnitudes of events can be evaluated and compared across hazard types. For example, we find that tsunami and drought events tend to have large hazard magnitudes, while tornadoes are relatively small in terms of hazard magnitude. In addition, we demonstrate that the scale can be used to evaluate hazard equivalency of historical events. For example, we show that the hazard magnitude of the February 2021 North American cold wave event affecting the southern states of the United States of America was equivalent to the hazard magnitude of Hurricane Harvey in 2017 or a magnitude 7.5 earthquake. Future work will expand the current study in hazard equivalency to modelling of local intensities of hazard events and hazard conditions within a multi-hazard context.

中文翻译：

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等效危害量表

摘要。危害等级量表被广泛采用，以促进关于危害事件和应急管理的相应决策的交流。危害量级标度考虑了自然强迫现象和事件相对于处于风险中的平均实体的严重性来衡量危害事件的强度。但是，现有的危害等级量表无法轻松地用于不同危害类型之间的比较分析。在这里，我们提出了一个等效的危害量表，以Paolo Gardoni教授的名字命名为Gardoni量表，用于测量多种危害类型的危害强度。利用全球历史记录中的危害程度指标和1900年至2020年12种危害类型事件的影响，我们证明，可以得出与危险事件影响度量标准的期望相关的Gardoni量表上的等效危险大小。在这项研究中，我们将影响指标建模为死亡人数，总受影响人口和总经济损失的函数。我们的结果表明，可以评估各种危害类型的事件的危害程度并进行比较。例如，我们发现海啸和干旱事件的危害程度往往较大，而龙卷风的危害程度相对较小。此外，我们证明了该量表可用于评估历史事件的危害当量。例如，我们显示，2021年2月北美冷浪事件的危害程度影响了美国南部各州，相当于2017年哈维飓风的危害程度或7.5级地震。未来的工作将把对危害当量的当前研究扩展到在多危害环境下对危害事件和危害条件的局部强度进行建模的过程。