In order to investigate the complex hydrodynamics and associated sediment movement resulting from the ship passages in heavy shipping traffic waterways, field measurements were performed in a heavy shipping traffic waterway. Based on the collected waves, flow velocity and water turbidity data, the analyses of the ship-induced hydrodynamics and associated sediment suspension phenomena were conducted. The low-frequency primary wave and high-frequency secondary wave were more pronounced for a barge and yacht in the wave structure, respectively, and contributed more to the flow velocity fluctuations and the bottom shear stress. The ship-induced bottom shear stress can cause significant suspended sediment concentration increase, and there is a correlation between the maximum suspended sediment concentration and maximum ship-induced drawdown height, which can provide a reference for the waterway management.

Knowledge of the hydrodynamic behavior of carbonate bioclasts is essential for solving coastal morphodynamic problems in marine carbonate depositional environments. Marine carbonate grains are produced within the sedimentary system itself and are deformed by subsequent hydrodynamics, resulting in particle densities, sizes and shapes that are distinct from those of terrigenous sediments. In this study, we investigated the shapes and settling characteristics of gravel‐size natural coral debris collected from the coasts of Okinawa Prefecture, Japan. Based on the shape parameters and settling velocities obtained using image analysis techniques and settling tube experiments, respectively, a correlation model for predicting the settling velocity of coral gravel particles was developed by extending the previous formula of Dietrich (1982, https://doi.org/10.1029/wr018i006p01615) over particle Reynolds number values ranging from 384.23 to 4439.76. The model determines the settling velocity as a function of particle nominal diameter, form, roundness, and surface texture parameters that were selected after examining several other shape descriptors. Compared with other models, the proposed model showed better settling velocity predictive skills for coral gravel particles classified into four shape types. The proposed model also determines how the drag coefficient of coral gravel particles should be modified from that for spherical particles, by accounting for the abovementioned coral gravel particle shape parameters. The obtained data set of settling velocity and modification of the drag coefficient can be used for quantitative interpretation of suspension, transport, and sedimentation processes in marine carbonate depositional environments.

In light of the forebay of a lateral pump station in Shaanxi Province, numerical simulation and engineering tests were employed to analyze the correlation between the formation of multiple vortices and sediment deposition in the lateral forebay. Building upon this foundation, a total of 24 distinct rectification measures were proposed to scrutinize the alteration in flow regime within the lateral forebay, followed by an engineering test to validate the optimal scheme in the absence of rectification measures. The findings from the engineering test of the lateral forebay were consistent with the outcomes of the numerical simulation. This marked the inaugural proposition of a trapezoidal array clapboard within a lateral forebay. By adjusting the position, rotating the clapboard angle, and selecting the optimal scheme 24, the flow velocity uniformity at section C1-2 reached 93.16%, the deflection angle measured 94.32°, and the vortex area reduction rate was 87.73%, significantly mitigating the vortex impact on this section. Within section C1-3, the flow velocity uniformity attained 96.58%, the deflection angle measured 86.43°, and the vortex area reduction rate in this section amounted to 81.26%. Through the analysis of these two sections, the scheme's accuracy was validated. Additionally, the sediment deposition thickness decreased by 2.39 m under scheme 24, thus ensuring favorable operational conditions for the inlet forebay of the lateral pump station.

Ship waves could alter the hydrodynamic field and play an important role for sediment movement and morphological changes, especially in shallow water regions of inland waterways. However, the response of riverbed morphology to ship waves is still unclear. In this paper, the impacts of ship waves on the bed profile in inland waterways are investigated by means of laboratory experiments. Observations of ship waves and bed profile changes exposed to different ship wave conditions are conducted. There exists a power exponential relationship between the corresponding polygon area and perimeter of the cross-sectional bed profile after the action of ship waves, which indicates that the bed profile is only adjusted in the geometric direction. Moreover, the dimensionless local scour depth is well predicted through the dimensionless expression of ship-induced near-bed velocity, ship draft, and offshore distance, which describes the impacts of ship waves on the bed morphology in inland waterways.

In navigable canals, ship hydrodynamics compared to water flow have been the most dominant dynamic factors that influence the evolution of cross-sectional morphology, so that the existing hydraulic geometry relations used for natural alluvial rivers are not applicable to navigable canals. In this paper, a time-dependent hydraulic geometry relation was derived as a function of channel bottom width, cross-sectional average water depth above the lowest design navigable water level, and time and coefficients based on the concepts of entropy and probability. Field surveys were conducted at two segments of the Grand Canal in Jiangsu Province, China to obtain measured hydraulic and morphologic variables. Then, the coefficients in the derived relation were analyzed in combination with ship hydrodynamics, and compared with the common used value, which shows better accuracy with larger determination coefficient of 0.744 and 0.904 for the two segments, respectively. Furthermore, comparisons between the calculated and measured hydraulic geometry of fixed cross-sections of the two segments were made. The obtained relative error of 59% and 18% of all predicted results is less than 5% and between 5% and 10%, respectively, indicating that the derived relation can be applied in navigable canals.

The ship waves and related hydrodynamics over a sloping bed are investigated numerically in this paper, and we aim to clarify the characteristics of ship wave deformation and its hydrodynamic effects. Laboratory experiments are performed with a self-propelled ship model to produce various wave conditions over a sloping bed in the water flume, providing the datasets for validation works of numerical simulations. With the implementation of model sensitivity analysis, numerical calculations of ship-induced waves and flow velocities are completed using the non-hydrostatic model in XBeach and compared against experimental measurements. The results show that the model is not only able to calculate primary and secondary waves well, but also the ship-induced near-bed velocity when ship waves are prominent in the water flume. Further numerical investigations of ship wave transformation and associated hydrodynamic effects are conducted over a sloping bed under different ship speed conditions. The ship wave height and run-up variations along the cross-shore transect clearly indicate the wave energy dissipation due to breaking and bottom friction. The ship-induced flow velocities are found to be mainly contributed by the low-frequency primary waves in our numerical experiments.