MODIFICATION OF THE POROSITY-BED VARIATION MODEL CONSIDERING SHELTERING EFFECT

Abstract

 In phases of selective sediment transport such that sand was supplied gravel bed, characteristic sediment transport and riverbed fluctuation conditions occur, such as sheltering by exposed gravels, deposition of fine sediments in voids, and easy movement of fine sediments on the surface. Conventional exchange layer models cannot adequately represent such phenomena, and a model that can represent these phenomena is needed from the viewpoint of sediment management and river environment management. In this study, the modeling of the area rate of mobile sediments in the surface layer and the sediment exchange between modeling layers in the exchange layer were updated and applied to a sediment supply experiment in order to confirm the effectiveness of the model. As a result, the reproducibility of riverbed fluctuation and longitudinal profile of water surface was improved, and the model was confirmed to be useful.