Debris flow and Dam-break Flooding Waves : Dynamics Rheology and Modelling

To predict flood and debris flow dynamics a numerical model,based on 1D De Saint Venant (SV) equations ,was developed.The Cormack-Jameson shock capturing scheme was employed for the solution of the equations ,written in a conservative law form.This technique was applied to determine both the propagation and the profile of a two-phase debris flow resulting from the instantaneous and complete collapse of a storage dam. The full two-phase model features mas and momentum conservation equations for each phase ,along with an interaction force between the two phases. The latter eases ,on the one hand, the propagation of the solid phase,while ,on the other hand,plays a friction role with regard to the clear water. On the whole,the model proposed can easily be extended to channels with arbitrary cross sections for debris flow routing ,as well as for solving different problems of unsteady flow in open channels by incorporating the appropriate initial and boundary conditions. The great advantages of the technique developed are based on the strng shock capturing ability of the McCormack-Jameson numerical scheme as well as on the simplicity of the resulting algorithm when considering 1D debris flow phenomena.