Model of Pyroclastic Flow and Method of Forcasting the Doposit area

Abstract

A gravity flow of granular bodies is considered as a model of main body of pyroclastic flow. Characteristics of the granular flow can be described by Kanatani's constitutive equations, which are obtaind in consideration of the energy loss caused by the only interparticle friction by the collison between the particles. Using above model, the 1991 pyroclastic flow at Mt. Unzen-dake were reproduced by the numerical simulation. The result of calculations roughly agree with the actual phenomena.