Process-based suspended sediment carrying capacity of silt-sand sediment in wave conditions

Abstract The sediment carrying capacity is one of the fundamental issues in sediment simulation. It is of great importance both in theory and practice to develop process-based approaches for the sediment carrying capacity for a wider range of silt-sand sediment. The current study focuses on the approach for depth-averaged concentration of silt-sand sediment under non-breaking wave conditions. By integrating process-based suspended sediment concentration (SSC) profiles, new synthetic expressions for depth-averaged SSC for vortex rippled beds and sheet flow conditions were obtained. The proposed expressions involve several basic physical processes, including the effects of bed forms, stratification, hindered settling, mobile bed, etc. A number of experimental datasets were collected for verification and reasonable results were obtained. Discussions were made on the changes of sediment concentration under increasing wave dynamics conditions, which show that the proposed formulas can describe the phenomenon which has been observed in experimental tests that SSC does not always increase when wave dynamics increase due to the effects of bed forms. In short, the current research provides a process-based approach for wave-induced sediment carrying capacity, which is expected to be applicable for numerical modeling and engineering practice.