Debris flow and dam-break flooding waves : Model calibration and comparison with experimental tests

To predict flood and debris flow dynamics a numerical two phase model, based on 1D De Sain Venant (SV) equations ,was developed. To validate the model ,comparisons have been made between its predictions and laboratoty measurements concerning flows of water and homogeneous granular mixtures in a uniform flume reproducing dam-break waves. Agreements between computational and experimental results are considered very satisfactory for mature (non-stratified) debris flows, which embrace most real cases. To better predict immature ( stratified )flows,the model should be improved in order to feature ,in a more realistic way,the distribution of the particles of different size within the mixture. 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.