A probabilistic mitigation system by eruptive event-trees, eruption-scenarios and risk assessments, evaluated by volcanic disasters records during past 2,000-year in Japan

建立了日本火山灾害地图数据库。目前的版本包括为110座活火山中的40座出版的160张地图和手册。在过去的2000年里，有关火山灾害的记录总共有1162次。大约有20 000名受害者，其中80%以上的死亡是由于火山海啸造成的，其次是火山泥流，包括泥石流或泥石流、火山碎屑坠落、碎屑雪崩和火山碎屑流造成的死亡。火山爆发的频率分布分析显示了每次VEI的平均频率。VEI 5级喷发每180年发生一次，VEI 4级喷发每50年发生一次。VEI 3和VEI 2分别每18年和4年爆发一次。我们期望当地行政官员利用现有的概率缓解系统，实施风险评估、火山事件树和情景结果，提出强大的应对策略，以便在未来火山事件发生时实施。

A database of volcanic hazard maps in Japan was worked out. Current version includes 160 maps and handbooks published for 40 of the 110 active volcanoes. Records dealing with volcanic disasters have been obtained for a total of 1,162 eruptions over the past 2,000 years. There were approximately 20,000 victims and over 80% of the deaths were due to volcanic tsunami, followed by deaths from lahars, including mudflows or debris flows, pyroclastic falls, debris avalanches, and pyroclastic flows. Frequency-distribution analyses for eruptions show the average frequency for each of VEI. The VEI 5 eruptions occur once every 180 years, and VEI 4 occur once every 50 years. VEI 3 and VEI 2 eruptions occur once every18 years and 4 years. We expect local administrative officials to use present probabilistic mitigation system implemented with risk assessments, eruption event-trees and scenarios results to propose robust counter-measure strategies to implement when future volcanic events occur.