DEVELOPMENT OF A 3D NUMERICAL MODEL OF WOODY DEBRIS FOR DESIGNING A DEBRIS RETENTION FACILITY IN RIVERS

Abstract

 Predicting woody debris behavior in rivers is a very important task for designing a debris retention facility. This study developed 3D numerical models for simulating woody debris motion and discussed the difference in simulation accuracy based on hydraulic experiments with a debris retention facility at the channel bend. The applicability of three numerical models to the experimental data was shown to clarify the model performances and the issues associated with the models. We concluded that a numerical model using the third-order upwind difference schemes has the best applicability to reproduce the experiment observations regarding the flow structure resulting from vortex formation, the woody debris behavior from conveyance to accumulation, and the rate of debris accumulation by the retention facility.