Riverbank erosion is a natural process in rivers that can become exacerbated by direct and indirect human impacts. Unfortunately, riverbank degradation can cause societal impacts such as property loss and sedimentation of in-stream structures, as well as environmental impacts such as water quality impact. The frequency, magnitude, and impact of riverbank collapse events in China and worldwide are forecasted to increase under climate change. To understand and mitigate the risk of riverbank collapse, experimental/field data in real conditions are required to provide robust calibration and validation of hydraulic and mathematical models. This paper presents an experimental set of tests conducted to characterize riverbank erosion and sediment transport for banks with slopes of 45 • , 60 • , 75 • , and 90 • and quantify the amount of sediments transported by the river, deposited within the bank toe or settled in the riverbed after having been removed due to erosion. The results showed interesting comprehension about the characterization of riverbank erosion and sediment transport along the river. These insights can be used for calibration and validation of new and existing numerical models.

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes.

As one of the major sediment sources in rivers, bank collapse often occurs in the Ningxia–Inner Mongolia catchment and, to date, it caused substantial social, economic and environmental problems in both local areas and downstream locations. To provide a better understanding of this phenomenon, this study consisted of modifying the existing Bank Stability and Toe Erosion Model (BSTEM), commonly used to investigate similar phenomena, introducing new assumptions and demonstrating its applicability by comparing numerical results obtained against field data recorded at six gauging stations (Qingtongxia, Shizuishan, Bayan Gol, Sanhuhekou, Zhaojunfen, and Toudaoguai). Furthermore, the impact of multiple factors typical of flood and dry seasons on the collapse rate was investigated, and insights obtained should be taken into consideration when completing future projects of river adaptation and river restoration.

SUMMARY In this paper, the standard Smagorinsky's algorithm is embedded into the multiple relaxation time (MRT) lattice Boltzmann model (LBM) for large eddy simulation (LES) of turbulent shallow water flows (MRT‐LABSWETM). The model is based on the two‐dimensional nonlinear shallow water equations, giving the depth‐averaged features. It is verified by applying the model in three typical cases in engineering with turbulence: (i) the flow around a square cylinder, (ii) plane cavity flow, and (iii) flows in a junction of 90°. The results obtained by the MRT‐LABSWETM are compared with BGK‐LABSWETM results and experimental data. The objectives of this study are to validate the MRT‐LABSWETM in a turbulence simulation and perform a comparative analysis between the results of BGK‐LABSWETM and MRT‐LABSWETM. Copyright © 2012 John Wiley & Sons, Ltd.

As one of the most important components of river mechanics, sediment transport capacity of sediment-laden flows has attracted much attention from many researchers working on river mechanics and hydraulic engineering. Based on the time-averaged equation for a turbulent energy equilibrium in solid and liquid two-phase flow, an expression for the efficiency coefficient of suspended load movement was derived for the two-dimensional, steady, uniform, fully-developed turbulent flow. A new structural expression of sediment transport capacity was achieved. Using 115 runs of flume experimental data, which were obtained through two kinds of sediment transport experiments in the state of equilibrium, in combination with the basic rheological and sediment transporting characteristics of hyperconcentrated flow, the main parameters in the structural expression of sediment transport capacity were calibrated, and a new formula of sediment transport capacity for hyperconcentrated flow was developed. A large amount of field data from the Yellow River, Wuding River, and Yangtze River, etc. were adopted to verify the new formula and good agreement was obtained. These results above contribute to an improved theoretical system of river mechanics and a reliable tool for management of rivers carrying high concentration of sediments. hyperconcentrated flow, turbulent energy equilibrium, efficiency coefficient, sediment transport capacityIn the Yellow River, hyperconcentrated flood occurs frequently during the rainy seasons. Both the historical maximum concentration of 1600 kg/m 3 and the mean annual amount for sediment transport of 1600 million tons are the highest values worldwide. According to the statistical results coming from the sedimentation bulletin of Chinese Rivers and the Yellow River 1)2) , and the analysis of the field data from Tongguan, Huayuankou, and Lijin Hydrological Stations along the