Numerical Modeling Of Sediment Transport Research Articles

Ship-Forced Sediment Transport: A New Model for Propeller Jet Flow

A numerical model is presented for ship-induced sediment transport, focusing on the fundamental role of propeller jet flow. The new module has been implemented in the open-source numerical model FUNWAVE in order to reproduce the effect of the propeller on sediment transport. Numerical simulations have been performed for both stationary and moving vessel cases, as well as for different values of propeller revolution speed. Numerical results are presented for the propeller-induced velocity field and the resulting morphological evolution of the seabed. Qualitative similarities are observed between the numerical results and literature experimental findings, showing the ability of the model to mimic complex morphodynamic processes induced by ship propellers. Compared to stationary vessel cases, smaller scour depths are generated in moving vessel cases. It is concluded that the effect of the propeller provides a major contribution to the mobilization and suspension of seabed sediment, and it should not be neglected in numerical models for ship-induced sediment transport.

Controls on Sediment Transport From a Glacierized Catchment in the Swiss Alps Established Through Inverse Modeling of Geomorphic Processes

AbstractAs climate warms, hydrology and geomorphology in glacierized catchments are evolving, changing sediment export from these catchments, thus impacting downstream ecosystems and communities. Currently, much uncertainty persists regarding interactions among geomorphic processes that evacuate sediment from glacierized catchments. Here, we present a catchment‐scale numerical model of subglacial and proglacial sediment transport with debris meltout processes. We apply the model in a Monte Carlo framework to suspended sediment data collected over 2014–2020 from the Fieschertal catchment in the Swiss Alps, assessing possible combinations of geomorphic processes responsible for suspended sediment discharge. The ensemble of model outputs quantifies the interaction of different geomorphic processes, including the trade‐off between bedrock erosion and sediment previously stored in the catchment. Model runs suggest that, at some periods, up to 20% of the sediment leaving the glacier is deposited in the proglacial area relative to the catchment's total sediment discharge. This shows that the model captures the proglacial area change from sediment source to sediment sink in different hydrological and glaciological conditions. Furthermore, the findings highlight the impact of glacier retreat on the catchment's sediment dynamics, which both reduces the proglacial area's slope and introduces additional sediment to the proglacial area through debris meltout. The model outputs and the parameters quantify the interaction among geomorphic processes, yielding key insights into the drivers of sediment transport in alpine regions. The implications of these interactions are discussed in the context of interpreting processes responsible for controlling erosion rates from glacierized regions and modeling sediment transport in glacierized catchments.

Application of the tidally averaged equilibrium cohesive sediment concentration for determination of physical parameters in the erosion-deposition fluxes

A puzzling fact for the Partheniades-Krone formula is the adoption of very contrasting values for the empirical parameters (e.g., the erosion coefficient and the critical shear stresses) but satisfactory reproduction of the suspended sediment concentration (SSC). Here, a theoretical equation for the tidally-averaged equilibrium (TAE) condition is derived by setting the integrated erosion flux throughout a tidal period equivalent to the integrated deposition flux throughout the same tidal period, leading to a new constraint condition on these parameters if values of the TAE-SSC are available. A preliminary check using the measured data of the Yangtze Estuary shows that a larger critical shear stress for erosion would require a smaller critical shear stress for deposition, both of which must be enhanced if the erosion coefficient further increases. Contrasting sets of parameter values derived by this constraint are fed into a coupled hydro-sediment-morphodynamic model to simulate cohesive sediment transport in the Yangtze Estuary. The results confirm that very contrasting parameter values can indeed lead to satisfactory reproduction of the temporal variations of the SSC (e.g., those in July 2016, including both spring tide and neap tide). This is further demonstrated by the numerical modelling of cohesive sediment transport in an idealized symmetrical estuary. These results indicate that the TAE condition can be used as a constraint for determining the erosion coefficient and the critical shear stresses for erosion and deposition. In addition, two simplified equations of the bed sediment mass conservation (no erosion version and the no deposition version) are derived as complements for obtaining a unique set of the three parameter values, provided that the simultaneous measured time series of SSC, bed shear stress and bed level can be collected at the same gauging station.

Autogenic masking of allogenic inputs: Numerical modelling of signal preservation in deep-water fan strata

Variations in climate, sea-level and tectonic processes can be recorded in various ways in strata, and recognising and measuring such external signals preserved in strata is an important aspect of deciphering Earth history. Key questions are what type of signals are likely to be preserved; how input signals may be shredded, over-printed or otherwise reduced before preservation, by stochastic or autogenic processes; and how allocyclic products may be mimicked and masked by autogenic processes. A reduced-complexity numerical forward model of down-slope sediment erosion, transport and dispersive deposition of submarine fan strata is the simplest-possible formulation that produces reasonably realistic strata that can be robustly analysed for signal content across model realisations with a range of external forcing amplitudes and periods. Three different initial topographic surfaces that include increasing influence of random noise allow comparison of the signal preserved with different levels of random influence on the deterministic model. Spectral analysis, with rigorous testing for statistical significance, shows that the signal recorded depends strongly on the level of noise present in the underlying topography, that short-period high-amplitude allocyclic signals are the most likely to be preserved in this case, and that autogenic dynamics in the modelled system can effectively mask even long-period high-amplitude input signals because they have similar periodicities. Autogenic processes in this model can also produce 5:1 bundling of cyclical strata commonly assumed to be strong evidence for orbital forcing. This analysis suggests that we might be substantially underestimating the complexity involved in extracting a signal of external forcing from strata where any autogenic processes operate, to the extent that the two different effects may often be practically indistinguishable, indicating that a multiple hypothesis approach is important to account for the resulting uncertainty.

Numerical Modeling of Sediment Transport and Bed Evolution in Nonuniform Open-Channel Flows

Abstract The shallow-water and multilayer hydrostatic models have been commonly used to analyze the problems of a sediment-laden, plane open-channel flow. The models are adequate to solve a quasi-hydrostatic flow problem, but their accuracy deteriorates as the e ects of the vertical acceleration gain in significance. Herein, a higher-order numerical model for treating the problems of unsteady, plane open-channel flow over a movable bed is proposed. In this model, the flow hydrodynamics is governed by the depth-averaged Boussinesq-type equations, and the bed morphodynamics is determined by an Exner-type equation and additional equations describing the non-equilibrium transports of suspended load and bed load. A hybrid finite-volume and finite-di erence scheme was used to discretize and solve the governing equations, yielding solutions that are in satisfactory agreement with the experimental data. Overall, the results of the proposed model for the temporal free-surface profile and bed evolution were fairly adequate. For the two particular cases considered, however, the quality of its results was moderately a ected by the e ects of the three-dimensional characteristics of the dam-break flow and the sliding of the dike body due to sub-surface flow. The results of this investigation highlight the importance of including a higher-order Boussinesq-type correction for refining sediment transport computations.

Hydromorphological response of heavily modified rivers to flood releases from reservoirs: A case study of the Spöl River, Switzerland

AbstractReleasing experimental floods as part of environmental flow programs aims to restore river beds by moving and restoring sediments to improve hydromorphological conditions of the river. However, it remains a challenge to understand how flood release characteristics affect channel morphology, sediment transport, and hydrodynamics. In this study, field surveys and a 2D hydro‐morphodynamic and sediment transport numerical model were used to determine how differences in flood magnitude and falling limb alter hydrogeomorphic conditions within a 4 km reach of the lower Spöl River. The model was constrained by drone flight‐derived high‐resolution digital elevation models and two field‐measured flood releases. The highest flood magnitude of 40 m3/s resulted in 2,700 m3 of total sediment transport, 2,000 m3 of net total volumetric change and 16 900 m2 more wetted area after the flood. The same flood, simulated with an increase in falling limb slope, resulted in a decrease in the duration of full sediment mobility and a corresponding reduction of 8% in net total volumetric change and 5.3% in the total wetted area. Contrastingly, the lowest flood magnitude of 25 m3/s produced 130% lower total sediment transport, 105% lower net total volumetric changes and 10% less wetted area after the flood. Overall, we show that hydro‐morphodynamic modelling of river erosion and deposition combined with spatially rich topographic datasets are extremely useful in forming designed environmental flood scenarios to optimise sediment transport and thus hydrogeomorphic changes to set environmental flows. We contend that scenario modelling is necessary to help water managers optimise the amount of water allocated to environmental flows and to simultaneously restore and maintain riverine dynamics in heavily modified rivers.

Efficient numerical model for sediment transport on vortex ripple bed in wave-induced oscillatory flow

Sediment motion on rippled bed under wave action plays an important role in coastal landforms, but the application of traditional numerical model is limited by large computational work or bottom sediment condition due to unsteady effects. A single-phase model is proposed to maintain low computation and high accuracy for the vortex structure development and suspended sediment motion on vortex rippled bed in wave-induced oscillatory flow. The 2D bottom sediment condition takes into account the acceleration effect and asymmetric boundary layer development under nonlinear waves as well as the sediment phase-lag. The particle inertia and wake flow around sediment particle are considered in sediment turbulence, and the SST k-ω turbulence model which is suitable for inverse pressure gradient flow on rippled bed is selected to close the Reynolds stress. The single-phase model well predicts the velocity on vortex ripples, periodic concentration at fixed points and vertical distribution of averaged sediment concentration. The results show qualitative formation, development and ejection of vortex, and demonstrate quantitative development of vortex center, radius and strength in symmetric and asymmetric flows. In addition, the model well performs the development of sediment cloud referring to vortex structure.

REPEATABILITY OF MORPHOLOGICAL CHANGE ON A SANDY BEACH ACROSS MULTIPLE TIMESCALES

The swash zone is a highly dynamic region of the nearshore in terms of both hydro- and sediment dynamics. Previous work has demonstrated that the majority of swash events transport only small amounts of sediment and net beachface volume change over several hours tends to be small. However, a small number of individual swash events can deposit or remove hundreds of kilograms of sediment per metre width of beach. These events are typically associated with swash flows that involve one or more highly turbulent swash-swash interactions, causing enhanced suspension and transport of sediment (Blenkinsopp et al. 2011). The timing and location of these interactions is complex and small changes in either can lead to very different local flow conditions. The complexity of these flows make sediment transport prediction on a swash-by-swash basis very challenging, and raises the question whether deterministic physical and numerical modelling of swash sediment transport is warranted.

NUMERICAL MODELING OF SHINNECOCK INLET, NEW YORK, FOR COASTAL EROSION CONTROL SUPPORT AND INLET SEDIMENT MANAGEMENT

The Shinnecock Inlet on the south shore of Long Island, New York, has experienced chronical erosion at the down-drift beaches which require periodic nourishment to stabilize the local shoreline. The potential sand borrow site is selected outside the inlet with minimum impact to the natural bypass process at the inlet. Supported by the US Army Corps of Engineers (USACE) District, New York, a numerical sediment transport modeling study is presently conducted to explore engineering solutions for the sand borrow area and structural alternatives to reduce the down-drift beach erosion. New field surveys have indicated a drastic decrease of sand outside inlet and along the adjacent coast. The modeling result shows a partial ebb shoal borrow area design without structural alternatives performs better together with the down-drift beach nourishment applications.

Developing a numerical model for sediment transport in channel network by considering multigrade bed load sediment

ABSTRACT Predicting transport rates is difficult for the morphological features of marine, river, and coastal ecosystems. To design a model bed load sediment transport rate along with the surface layer, a mesh-based numerical method is used, and for the sediment transport the governing equations are employed and depth-averaged is used to create open channel flow and in three-dimensional horizontal space the evaluation is performed. By utilizing the governing equations, the open channel flow discretization and the numerical hydrodynamic model of sediment transport rate are calculated, and in the flow channel by using the solution method the settling velocity is determined. The complex issues involved nonlinear equations for the numerical modelling with solution methodology. The chicken swarm optimization algorithm is revealed by multi-objective metaheuristics optimization, and a better outcome is acquired by optimization. Finally, if polygonal mesh modelling is used in the diversion flow channel and curved bend channel, several experimental models were employed in the model experiments. A numerical measured and improved model is used to estimate the results in comparison, and the optimally developed model forecast rates with accuracy. In some open-channel flows such as reservoirs and rivers, the struggling flow and bed load sediment transport were dealt with in this model. Based on the results obtained, the proposed technique demonstrates significant improvements in both accuracy and prediction performance compared to the existing techniques. The proposed technique achieves an accuracy of 96.87%, outperforming the BCNN technique with an accuracy of 89.77% and the H-ANN-FA technique with an accuracy of 84.65%. Moreover, the proposed technique exhibits a lower RMSE value of 0.12, indicating a substantial reduction in the average deviation between predicted and observed values. Based on the NSE and R2 results, the proposed technique demonstrates remarkable improvements in prediction accuracy compared to the other techniques. The proposed technique achieves an NSE value of 0.998 and R2 value of 0.99, compared to the existing technique with an improvement of 46.47% and 11.24%.

To what extent tsunami source information can be extracted from tsunami deposits? Implications from the 2011 Tohoku-oki tsunami deposits and sediment transport simulations

A quantitative understanding of paleotsunamis is a significant issue in tsunami sedimentology. Onshore tsunami deposits, which are geological records of tsunami inundation, are used to reconstruct paleotsunami events. Numerical models of tsunami hydrodynamics and tsunami-induced sediment transport are utilized in such reconstructions to connect tsunami deposit characteristics, flow conditions, and (paleo-) tsunami sources. Recent progress in tsunami numerical modeling has increased the possibility of developing a methodology to estimate paleotsunami sources from tsunami deposits. Several previous studies have estimated paleotsunami sources using tsunami sediment transport simulations. However, the accuracy of paleotsunami source estimation has not yet been explored. Thus, to bridge this research gap, in this study, we showed the potential and limitations of deposit-based tsunami source estimation based on the 2011 Tohoku-oki tsunami deposit data on the southernmost part of the Sendai Plain, northeastern Japan. The tsunamigenic megathrust along the Japan Trench was divided into ten subfaults having similar lengths and widths. The hypothetical source models with varying slips on each subfault were examined by comparing the depositional volume and sediment source of onshore tsunami deposits. Due to limited information on the depositional area of the tsunami deposits used in the modeling, slips only in some parts of the entire tsunami source region could be estimated. The fault slip was slightly overestimated but could be compared with previous well-constrained source models. Thus, these results indicated that vast high-quality datasets of tsunami deposits can improve the accuracy of paleotsunami source estimation. It is also suggested that the amplitude of the receding wave affects the erosion pattern from the shoreface to the nearshore area. Although sufficient data for paleotsunami source estimation are lacking, an effective combination of tsunami deposit data and sediment transport simulations potentially improves the accuracy of the source estimation. The results will contribute to developing a framework of deposit-based paleotsunami source modeling and assessing its accuracy.

Coastal protection system design at the Indonesian Mangrove Center in Pekalongan, Central Java – Indonesia

The Pekalongan area suffered from coastal flooding and heavy coastal erosion due to land subsidence and increasing wave condition in the last decade. Pekalongan government built a land dike in 2018 to protect Pekalongan city from coastal flooding. This study aims to determine a suitable coastal protection system, consisting of hard-structures and mangroves, to solve the erosion problem at the Pekalongan coast, specifically at the future Pekalongan Mangrove Information Centre (PIM). Environmental data, i.e., wind, wave, current, tidal, sediment, and soil data, were obtained by field survey and secondary data collection from open-source data. The selection of the most suitable coastal protection design concepts was performed by comparing several alternatives of structure materials. Coastal protection layout was obtained based on a numerical sediment transport model result using Delft3D software. From environmental data processing and analysis with various design aspects, the top elevation of the coastal protection structure is +4.5 m MSL (Mean Sea Level). The configuration of the mangrove planting media consists of ‘guludan’ structure technique with dimension 10 m x 5 m x 4 m.

Net sheet-flow sediment transport rate: Additivity of wave propagation and nonlinear waveshape effects

Net wave-induced sheet-flow sediment transport rate, Qnet, can be produced by two co-existing effects: nonlinear waveshape and wave propagation, which alter the intra-wave boundary layer flow and sediment concentration. A intriguing question is whether the two effects can be simply added (the additivity hypothesis). This paper addresses this question based on simulations of a one-phase numerical model for sheet-flow sediment transport and examinations of the governing equations for boundary layer flow and sediment concentration. The additivity for the mean velocity (or streaming) is first demonstrated under typical field conditions. The main reason is that the two driving forces, i.e., momentum transfer produced by wave propagation and intra-wave asymmetry of flow turbulence produced by nonlinear waveshape, do not affect each other. The net sediment flux is separated into wave- and current-related components. Since the mean concentration profile is determined by the first-order process, the ‘current’-related flux produced by the two effects, following the mean velocity, can be superimposed. After examining the leading Fourier components, the wave-related flux is also found to follow the additivity hypothesis. The findings are confirmed by numerical experiments. The implication of this work is that a practical formula for Qnet can be designed with two separate components for nonlinear-waveshape and wave-propagation effects.

Three-Dimensional Numerical Modeling of Flow Hydrodynamics and Cohesive Sediment Transport in Enid Lake, Mississippi

Enid Lake is one of the largest reservoirs located in Yazoo River Basin, the largest basin in the state of Mississippi. The lake was impounded by Enid Dam on the Yocona River in Yalobusha County and covers an area of 30 square kilometers. It provides significant natural and recreational resources. The soils in this region are highly erodible, resulting in a large amount of fine-grained cohesive sediment discharged into the lake. In this study, a 3D numerical model was developed to simulate the free surface hydrodynamics and transportation of cohesive sediment with a median diameter of 0.0025 to 0.003 mm in Enid Lake. Flow fields in the lake are generally induced by wind and upstream river inflow, and the sediment is also introduced from the inflow during storm events. The general processes of sediment flocculation and settling were considered in the model, and the erosion rate and deposition rate of cohesive sediment were calculated. In this model, the sediment simulation was coupled with flow simulation. In this research, remote sensing technology was applied to estimate the sediment concentration at the lake surface and provide validation data for numerical model simulation. The model results and remote sensing data help us to understand the transport, deposition and resuspension processes of cohesive sediment in large reservoirs due to wind-induced currents and upstream river flows.

Simulation of Sediment Transport in River Ogunpa Using Winxpro Software

The numerical modelling of sediment transport of a river has long been developed. Rivers across Nigeria has interdicted researchers on modelling sediment transport. The environmental problem makes sediment transport study an important area among morphological mechanisms. This research studied the Simulation and modelling of sediment transport in River Ogunpa using WinXspro software. Suspended Sediment concentration was measured from November 2015 to June 2016 across the upstream, midstream and downstream of River Ogunpa using standard methods. The values of manning’s roughness factor used varied from 0.012 – 0.018. Sediment discharges (QS) were computed across the river using Acker and White approach. The average Suspended Sediment Concentration (SSC) across River Ogunpa varied from 2 – 64mg/L. The mathematical relationship for the sediment discharge value was QS = 64625Q + 12922. The estimated Qs varied from 0.00 – 23012kg/s. The variation in measured and validated discharge ranged between 0.95 – 4.19%. Sediment discharge across River Ogunpa was simulated using Winxpro software. The sediment discharge value can be a piece of useful information for dredging operation on River Ogunpa.

A Numerical Study on Bank Erosion of a Braided Channel: Case Study of the “Tangail and Manikganj Districts Along the Brahmaputra River”

Brahmaputra River comprises the characteristics of a braided channel and suspended sediment-dominant river. Frequent changes in the river course have led to severe bank erosion. In particular, Tangail and Manikganj districts have recently become bank erosion-prone areas. To predict vulnerable locations based on bank erosion, we aimed to understand the behavior of the braided channel by conducting a numerical simulation and satellite data analysis in this study. We employed a depth-integrated 2-D numerical model for water and sediment transport, which was originally proposed by Takebayashi et al. and modified by Harada et al. by introducing a new treatment of suspended sediment. In addition, bathymetry data were created using a series of satellite data information to successfully conduct the simulation. In this study, we focused on two aspects. The first point is the skewing of flow discharge along multiple channels, which belongs to the area of interest, as a large-scale phenomenon. The second point is changing the local geometry of the sand bar and changing the flow pattern, as a small-scale phenomenon. To consider the two different scales, we employed the computation domain as an entire channel. Our results indicate that the numerical model is successfully verified using satellite data information, and the two-scale phenomena are successfully described. Regarding the large-scale phenomenon, our results indicate that the distribution of higher flow rates activates various geomorphological changes, including riverbed evolution, channel changes, and bank erosion. On the other hand, small-scale phenomena, such as the rapid appearance of sand bars and changes in the water course, are directly related to bank erosion.

Numerical modelling of sediment transport in southwest coast of Nigeria: Implications for sustainable management of coastal erosion in the Bight of Benin

Coastal erosion is widespread across the Bight of Benin owing to the perturbation of the sediment transport by the installation of the major ports of Lomé (Togo), Cotonou (Benin), and Lagos (Nigeria), among other factors. While different coastal management measures have been put in place to mitigate the effects of this hazard, they have seldom lessened the damage caused by it. To this end, this study examined the coastal processes in Southwest Nigeria (Barrier-Lagoon and Mud coast sections) through the numerical modelling of the hydrodynamic, spectral-wave, and sediment transport for three months to apprehend the poor performance of the management measures. Model results reveal that the nearshore current is mainly directed eastward with the persistent exposure of the area to wave-action. Two major sediment transports; the eastward/south-eastward and westward/north-westward sediment transports, were also identified. The predominance of these sediment transport patterns implies that the continuous adoption of reactive, site-specific hard-engineering coastal management approaches will give counter-productive results. Thus, to sustainably manage the coastal erosion problem across the Bight of Benin, there is the need to adopt a long-term, regional perspective with a cascade of coastal management measures covering all areas under the influence of the predominant sediment transports.

Unstructured Finite-Volume Model of Sediment Scouring Due to Wave Impact on Vertical Seawalls

The numerical modeling of sediment transport under wave impact is challenging because of the complex nature of the triple wave–structure–sediment interaction. This study presents three-dimensional numerical modeling of sediment scouring due to non-breaking wave impact on a vertical seawall. The Navier–Stokes–Exner equations are approximated to calculate the full evolution of flow fields and morphodynamic responses. The bed erosion model is based on the van Rijn formulation with a mass-conservative sand-slide algorithm. The numerical solution is obtained by using a projection method and a fully implicit second-order unstructured finite-volume method in a σ-coordinate computational domain. This coordinate system is employed to accurately represent the free-surface elevation and sediment/water interface evolution. Experimental results of the velocity field, surface wave motion, and scour hole formation hole are used to compare and demonstrate the proposed numerical method’s capabilities to model the seawall scour.

Two-dimensional (2D) numerical modelling of rainfall induced overland flow, infiltration and soil erosion: comparison with laboratory rainfall-runoff simulations on a two-directional slope soil flume

Abstract This paper presents a two-dimensional (2D) numerical model of soil erosion and sediment transport resulting from rainfall induced overland flow. It is a spatial and temporal dynamic model combining physical and empirical laws and comprises: i) An overland flow module that solves the two-dimensional unsteady water flow equations on an infiltrating surface; ii) A soil infiltration module that uses a combined Horton-SCS scheme; and iii) A soil erosion and sediment transport module that solves the two-dimensional sediment transport equation, distinguishing between rill erosion, interrill erosion and sediment deposition. The performance of the model was evaluated by comparing its results with observed data from laboratory rainfall-runoff experiments on a two-directional 2.00 × 2.00 m2 soil flume set at 1% and 10% slopes in the x- and y-directions, respectively. The x-direction produced remarkably lower runoff and transported sediments than the y-direction. The numerical model significantly underestimated x-direction lower values of runoff and transported sediments. However, in the y-direction the model presented very good performance. Overall, in total terms (x- plus y-direction), the numerically simulated graphs of runoff and sediment transport were in very good agreement with corresponding experimental measurements, demonstrating the laboratory proof-of-concept of the model.

Large-scale 3D numerical modelling of flood propagation and sediment transport and operational strategy in the Three Gorges Reservoir, China

Sediment deposition carried by flood flow is the main cause of reservoir sedimentation. This can be reduced by an appropriate operational strategy of flood flow and sediment in the reservoir. High-precision and large-scale hydrodynamic models to predict flood propagation and sediment transport in reservoirs are extremely important for an efficient flood forecasting and real-time joint regulation of water and sediment in reservoirs. In the present study, the three-dimensional (3D) numerical semi-implicit cross-scale hydroscience integrated system model (SCHISM) was adopted to model the flood propagation and sediment transport in the approximately 280-km-long reach in the Three Gorges Reservoir. This model is mainly focused on analysing the asynchronous movement characteristics of flood propagation and sediment transport and the operational strategy of sediment peak regulation. The flood event in July 2013 was reproduced by the numerical model, which was validated by a comparison with the measured data. The results indicated that the numerical model has the ability to accurately simulate the flood propagation and sediment transport processes. The time that the sediment peak lags behind the flow discharge peak increases as the flood waves propagate downstream, reaching 8.1 days at the dam site. During the rising period of the flood, the discharged flow is lowered to reduce the flood peak, and when the sediment peak reaches the dam, the discharged flow is increased to release high concentration sediment during the flood recession period so as to reduce sedimentation in the reservoir. The model results agreed well with the measured results. The 3D numerical model can be used for the real-time prediction of the arrival time of the flow discharge and sediment peaks for the joint regulation of water and sediment in the Three Gorges Reservoir.