Probabilistic-numerical assessment of pyroclastic current hazard at Campi Flegrei and Naples city: Multi-VEI scenarios as a tool for “full-scale” risk management

The Campi Flegrei volcanic field (Italy) poses very high risk to the highly urbanized Neapolitan area. Eruptive history was dominated by explosive activity producing pyroclastic currents (hereon PCs; acronym for Pyroclastic Currents) ranging in scale from localized base surges to regional flows. Here we apply probabilistic numerical simulation approaches to produce PC hazard maps, based on a comprehensive spectrum of flow properties and vent locations. These maps are incorporated in a Geographic Information System (GIS) and provide all probable Volcanic Explosivity Index (VEI) scenarios from different source vents in the caldera, relevant for risk management planning. For each VEI scenario, we report the conditional probability for PCs (i.e., the probability for a given area to be affected by the passage of PCs in case of a PC-forming explosive event) and related dynamic pressure. Model results indicate that PCs from VEI

意大利坎皮佛莱格瑞火山群（Campi Flegrei volcanic field）对高度城市化的那不勒斯地区构成极高风险。其火山喷发历史以爆发活动为主，所产生的火山碎屑流（Pyroclastic Currents，下称PCs）规模跨度极广，从局地基浪到区域性火山碎屑流均有覆盖。本研究采用概率数值模拟方法，基于全面的流场属性与火山口位置谱系，生成火山碎屑流灾害图。上述灾害图已整合至地理信息系统（GIS）中，可提供该破火山口内不同喷发源对应的所有可能火山爆发指数（Volcanic Explosivity Index，VEI）情景，可为风险管理规划提供支撑。针对每一种VEI情景，本研究报告了火山碎屑流的条件概率（即当发生形成火山碎屑流的爆发事件时，给定区域受火山碎屑流流经影响的概率）及相关动压。模型结果表明，来自VEI的