A novel strategy to enhance kinetic energy models by considering channelization processes of PDCs

Abstract

Kinetic energy models are tools able to provide an estimate to the inundation area of pyroclastic density currents (PDCs). We present here a novel strategy that allows improving these models in order to consider the occurrence of channelization processes of pyroclastic material. In this strategy, the inundation area associated with a basal collapse process, represented by a root conoid that interacts with the topography, is complemented with the inundation zones derived from the inclusion of secondary source points located in the expected zones of pyroclast channelization (represented by branch conoids). For that, we adopt a tree branch-like structure and appropriate assumptions for setting the position and the initial characteristics of the secondary source points. Two widely used kinetic models are modified by applying this strategy: the energy cone and the box model, giving place to two open-source and freely downloadable codes (ECMapProb and BoxMapProb). We tested these branching formulations by comparing their results with those derived from the traditional formulations of these kinetic energy models, with other numerical solvers, and with the invasion area of real PDC deposits. We show the capability of the presented strategy of improving the accuracy of kinetic models without adding new, unconstrained input parameters or significantly increasing the computational cost, allowing the assessment of volcanic hazards using a probabilistic approach. The application of this strategy represents a time-effective alternative to the use of more sophisticated models for describing PDC transport and deposition.