By Roberto Tonini1, Laura Sandri2, Jacopo Selva1, Warner Marzocchi

1. Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna, Italy 2. Istituto Nazionale di Geofisica e Vulcanologia

Compute long-term volcanic hazard using the Bayesian Event Tree for Volcanic Hazard (BET_VH) model

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Version 2.1 - published on 21 Jan 2016

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The main purpose of this software is to provide a graphically supported computation of long-term probabilities of volcanic hazardous phenomena (i.e., lava flows, tephra fall, pyroclastic flows, lahars, etc.) through the Bayesian Event Tree model for Volcanic Hazard (BET_VH, Marzocchi et al., 2010). The model represents a flexible tool to provide probabilities of any specific event at which we are interested in, by merging all the available information, such as models, a priori beliefs, and past data. It is mainly based on a Bayesian procedure, in order to quantify the aleatory and epistemic uncertainty characterizing the impact of volcanic eruptions in terms of hazard assessment. The method deals only with long-term forecasting, therefore in principle it can be useful for land use planning. This version introduces as main outputs the Hazard Curves (HC), showing the exceeding probability as function of the chosen intensity measure (e.g., the tephra load in kg/m2). The HC are provided together with their uncertainties (percentiles) through Bayesian inference and the user can explore the hazard results visualizing both Probability and Hazard Maps. 

More datails on the PyBetVH software can be found in Tonini et al. (2015). A general user guide for all PyBet tools can be found at and for further information you can visit the group page at


Marzocchi W., Sandri L., Selva J. (2010) BETVH: a probabilistic tool for long-term volcanic hazard assessment, Bull. Volcanol., 72, 705-716, DOI:10.1007/s00445-010-0357-8

Tonini R., Sandri L., Thompson M. A. (2015) PyBetVH: a Python tool for probabilistic volcanic hazard assessment and for generation of Bayesian hazard curves and maps, Comput. Geosci., doi:10.1016/j.cageo.2015.02.017

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  • Roberto Tonini; Laura Sandri; Jacopo Selva; Warner Marzocchi (2016), "PyBetVH,"

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