In this paper, the two common approaches to account for wave randomness, the spectral approach and the wave-bywave approach, are compared through numerical experiments conducted with the coupling of a surf zone hydrodynamic model and a bedload sediment transport model. Special attention is paid to the wave nonlinearity and net cross-shore bedload transport predictions. The two approaches are fo...

A discrete particle model is described which simulates bedload transport over a flat bed of a unimodal mixed-sized distribution of particles. Simple physical rules are applied to large numbers of discrete sediment grains moving within a unidirectional flow. The modelling assumptions and main algorithms of the bedload transport model are presented and discussed. Sediment particles are represente...

The thickness of the bedload layer is a crucial parameter for evaluating sediment transport rates in open channel flow, but it is often determined empirically. Based on the concept of the hydrodynamic diffusion related to particle-particle interactions, an analytical model is proposed in this study for computing the thickness of the bedload layer. The coefficient of diffusion is assumed to be a...

Bedload sheets are low-amplitude bedforms the are formed by sorting patterns in mixed-size sediment (gravel or gravel-sand mixtures). The features have been functionally linked to dune forms developed in sandy sediments and gravel dunes formed in river channels. There have been a number of attempts to place bedload sheets on extended versions of the bedform phase diagrams used to predict sand b...

Continuous seismic records near river channels can be used to quantify the energy induced by river sediment transport. During the 2011 typhoon season, we deployed a seismic array along the Chishan River in the mountain area of southern Taiwan, where there is strong variability in water discharge and high sedimentation rates. We observe hysteresis in the high-frequency (5-15 Hz) seismic noise le...

Alternate bars were formed by sediment transport in a flume with Froude-modelled flow and relative roughness characteristic of gravel-boulder channels with steep slopes. The flume (0.3 m wide x 7.5 m long) was filled with a sand-gravel mixture, which was also fed into the top of the flume at a constant rate under constant discharge. Channel slope was set at 0.03. Initially, coarse particles acc...

Sediment routing in gravel-bed rivers refers to the intermittent transport and storage of bedload particles, where short-duration steps are separated by periods of inactivity. Channel morphology governs sediment routing, but morphologic effects on routing in headwater systems are not well understood compared to lowland systems. RFID tracers are a valuable tool that can be employed to characteri...

Bed surface particle size patchiness may play a central role in bedload and morphologic response to changes in sediment supply in gravel-bed rivers. Here we test a 1-D model (from Parker ebook) of bedload transport, surface grain size, and channel profile with two previously published flume studies that documented bed surface response, and specifically patch development, to reduced sediment sup...

The local granular rheology is investigated numerically in turbulent bedload transport. Considering spherical particles, steady uniform configurations are simulated using a coupled fluid-discrete-element model. The stress tensor is computed as a function of the depth for a series of simulations varying the Shields number, the specific density and the particle diameter. The results are analyzed ...

Sediment transport relates to suspended sediment and bedload. The suspended sedi‐ ment plays the most important role on the land-ocen sediment flux. On the other hand, the bedload should be considered in order to assess the impacts of dams on sediment transport and sediment yield. Recent effects of dam construction have been widely reported. The sediment load has been reduced by more than 75% f...