The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Jinyuan Li - One of the best experts on this subject based on the ideXlab platform.
-
tide induced bedload transport pathways in a multiple Sand Ridge system offshore of hainan island in the beibu gulf northwest south china sea
Earth Surface Processes and Landforms, 2018Co-Authors: Jinyuan LiAbstract:Modern Sand transport pathways in a multiple-Sand-Ridge system are elusive and have rarely been studied in recent years. We report herein a field with four en echelon linear Sand Ridges offshore of Hainan Island in the Beibu Gulf and describe the distribution and morphology of these Sand Ridges in detail for the first time. Dune crest comparisons and seismic profiles are also interpreted to assess Sand transport over the dunes. Based on a Delft 3D model, regional tidal currents and tide-induced bedload transport in the multiple-Sand-Ridge system were simulated to provide insights into the related bedload transport paths. The results show that bedload transport and residual flows are mostly directed to the south on the east side of the Sand Ridges and to the north on the west side, and these differences coincide with dune asymmetries and migrations. Cross-Ridge transport is weak and mostly converges on the crests of Sand Ridges from the two flanks. The bedload transport is unbalanced on either flank of the Sand Ridges, thus leading to the asymmetry and crest kinks of the Sand Ridges. A distinct correlation is not observed between the net cross-Ridge Sand transport and Sand Ridge asymmetry. In this system, cross-swale transport is significant between the neighboring Sand Ridges and helps construct the bedload transport circulation in the swales. Sand accretion also occurs in the swales and benefits from the southwestward bedload transport from the north end of Sand Ridge 3. Distinct evidence has not been found for closed bedload transport circulation around Sand Ridges in this multiple-Sand-Ridge system, although limited clockwise current vortices develop on several Sand Ridges. Additional field observations and simulations are required to characterize the suspended load transport in a multiple-Sand-Ridge system, and the effects of local Sand supply conditions on Sand transport also need further evaluation. Copyright (c) 2018 John Wiley & Sons, Ltd.
-
Tide‐induced bedload transport pathways in a multiple‐Sand‐Ridge system offshore of Hainan Island in the Beibu Gulf, northwest South China Sea
Earth Surface Processes and Landforms, 2018Co-Authors: Xiaochuan Ma, Jinyuan LiAbstract:Modern Sand transport pathways in a multiple-Sand-Ridge system are elusive and have rarely been studied in recent years. We report herein a field with four en echelon linear Sand Ridges offshore of Hainan Island in the Beibu Gulf and describe the distribution and morphology of these Sand Ridges in detail for the first time. Dune crest comparisons and seismic profiles are also interpreted to assess Sand transport over the dunes. Based on a Delft 3D model, regional tidal currents and tide-induced bedload transport in the multiple-Sand-Ridge system were simulated to provide insights into the related bedload transport paths. The results show that bedload transport and residual flows are mostly directed to the south on the east side of the Sand Ridges and to the north on the west side, and these differences coincide with dune asymmetries and migrations. Cross-Ridge transport is weak and mostly converges on the crests of Sand Ridges from the two flanks. The bedload transport is unbalanced on either flank of the Sand Ridges, thus leading to the asymmetry and crest kinks of the Sand Ridges. A distinct correlation is not observed between the net cross-Ridge Sand transport and Sand Ridge asymmetry. In this system, cross-swale transport is significant between the neighboring Sand Ridges and helps construct the bedload transport circulation in the swales. Sand accretion also occurs in the swales and benefits from the southwestward bedload transport from the north end of Sand Ridge 3. Distinct evidence has not been found for closed bedload transport circulation around Sand Ridges in this multiple-Sand-Ridge system, although limited clockwise current vortices develop on several Sand Ridges. Additional field observations and simulations are required to characterize the suspended load transport in a multiple-Sand-Ridge system, and the effects of local Sand supply conditions on Sand transport also need further evaluation. Copyright (c) 2018 John Wiley & Sons, Ltd.
Fei Xing - One of the best experts on this subject based on the ideXlab platform.
-
tidal hydrodynamics and fine grained sediment transport on the radial Sand Ridge system in the southern yellow sea
Marine Geology, 2012Co-Authors: Fei Xing, Ya Ping Wang, Harry V WangAbstract:Abstract The large radial Sand Ridge (RSR) system located in the southern Yellow Sea off the Jiangsu coast is characterized by a radial current field and high suspended sediment concentrations (SSCs). Significant rectilinear currents are present over the northern Sand Ridge area, whereas rotary currents prevail over the southern area, the transition between the two being dominated by a locally generated trapped wave. Observations undertaken in 2006 and 2007 indicate a seasonal pattern in the SSC and associated dynamic characteristics. The results of a calibrated hydrodynamic model show that the M2 tide dominates the RSR area, the maximum tidal amplitude in the core region close to land being approximately 2 m. An amphidromic point is located some distance north of the RSR off the abandoned Yellow River mouth (121.686° E, 34.6° N). Specifically, the Eulerian and Lagrangian residual currents flow southward in both summer and winter, whereas the Stokes' drift is directed southward in the north and northward in the south. Moreover, in deep water the Lagrangian residual current is mainly determined by the Eulerian residual current, whereas it is strongly influenced by the Stokes' drift in shallow water. The seasonal variation in the residual current in the southern Yellow Sea is a good indicator for the location of the Yellow Sea Warm Current (YSWC) in both summer and winter. Measurements show that a SSC peak appears off the abandoned Yellow River delta in response to the strong currents and plentiful supply of fine-grained sediment from coastal erosion. Another SSC peak lying close to the North Branch of the Changjiang River mouth is related to the abundant suspended sediment supplied by the river. Seasonal variations in SSC are observed in the study area, maximum average values and widest diffusion from land occurring in winter, this being contrasted by minimum mean values in summer. Sensitivity experiments demonstrate that the main factor influencing the distribution of SSC is the tide, while river discharge, wind, and wave effects are small and very localized. To explain the seasonal variation in SSC, the role of hydrodynamics, initial conditions, and temperature are tested in the model. The results show that the hydrodynamics play a significant role, whereas the initial conditions only have a minor regional influence. Temperature, on the other hand, is also shown to greatly influence the seasonal variation in SSC because of substantial changes in the viscosity of the water and the erosion shear stress. The modeled results are used to calculate sediment fluxes, which are shown to be consistent with the Lagrangian residual current pattern, while wind waves can significantly change the fluxes in winter. Bed elevations change substantially on a monthly time scale. In general, the deep channels are undergoing erosion, while the shallow Ridges and coastal tidal flats are accreting, the net sediment transport being directed towards the coastal tidal flat and the Changjiang (Yangtze) River subaqueous delta.
Soo C. Park - One of the best experts on this subject based on the ideXlab platform.
-
Depositional patterns of Sand Ridges in tide-dominated shallow water environments: Yellow Sea coast and South Sea of Korea
1994Co-Authors: Soo C. ParkAbstract:The continental shelf of the Yellow Sea and the Korean South Sea is a tide-dominated shelf. A number of Sand Ridges occur in this area which form bathymetric highs. Surveyed were one large Sand Ridge (Jangan Satoe) along the western (Yellow Sea) coast and a group of mid-shelf Sand Ridges in the South Sea, to delineate their depositional pattern and probable origin in tide-dominated shallow water environments. Analyses of sediment samples, side-scan sonographs, and seismic profiles reveal that these Ridges show regionally different characteristics in morphology, bedforms, and sediment. The Sand Ridge in the Yellow Sea shows a composite form of various bedforms including Sand waves and megaripples
-
Depositional patterns of Sand Ridges in tide-dominated shallow water environments: Yellow Sea Coast and South Sea of Korea
Marine Geology, 1994Co-Authors: Soo C. ParkAbstract:Abstract The continental shelf of the Yellow Sea and the Korean South Sea is a tide-dominated shelf. A number of Sand Ridges occur in this area which form bathymetric highs. Surveyed were one large Sand Ridge (Jangan Satoe) along the western (Yellow Sea) coast and a group of mid-shelf Sand Ridges in the South Sea, to delineate their depositional pattern and probable origin in tide-dominated shallow water environments. Analyses of sediment samples, side-scan sonographs, and seismic profiles reveal that these Ridges show regionally different characteristics in morphology, bedforms, and sediment. The Sand Ridge in the Yellow Sea shows a composite form of various bedforms including Sand waves and megaripples. This Ridge is interpreted to be in an accretional active stage, maintained by strong tidal currents. In contrast, the Sand Ridges on the mid-shelf of the South Sea show rounded, single forms without bedforms on them. They are interpreted to represent moribund-type Sand Ridges in the shelf environment, which were formed near the shoreline during the Holocene sea-level transgression. These Ridges developed off the paleo-Seomjin River during a period of a stillstand or slow sea-level rise approximately between 10,000 and 7000 yrs B.P.
Harry V Wang - One of the best experts on this subject based on the ideXlab platform.
-
tidal hydrodynamics and fine grained sediment transport on the radial Sand Ridge system in the southern yellow sea
Marine Geology, 2012Co-Authors: Fei Xing, Ya Ping Wang, Harry V WangAbstract:Abstract The large radial Sand Ridge (RSR) system located in the southern Yellow Sea off the Jiangsu coast is characterized by a radial current field and high suspended sediment concentrations (SSCs). Significant rectilinear currents are present over the northern Sand Ridge area, whereas rotary currents prevail over the southern area, the transition between the two being dominated by a locally generated trapped wave. Observations undertaken in 2006 and 2007 indicate a seasonal pattern in the SSC and associated dynamic characteristics. The results of a calibrated hydrodynamic model show that the M2 tide dominates the RSR area, the maximum tidal amplitude in the core region close to land being approximately 2 m. An amphidromic point is located some distance north of the RSR off the abandoned Yellow River mouth (121.686° E, 34.6° N). Specifically, the Eulerian and Lagrangian residual currents flow southward in both summer and winter, whereas the Stokes' drift is directed southward in the north and northward in the south. Moreover, in deep water the Lagrangian residual current is mainly determined by the Eulerian residual current, whereas it is strongly influenced by the Stokes' drift in shallow water. The seasonal variation in the residual current in the southern Yellow Sea is a good indicator for the location of the Yellow Sea Warm Current (YSWC) in both summer and winter. Measurements show that a SSC peak appears off the abandoned Yellow River delta in response to the strong currents and plentiful supply of fine-grained sediment from coastal erosion. Another SSC peak lying close to the North Branch of the Changjiang River mouth is related to the abundant suspended sediment supplied by the river. Seasonal variations in SSC are observed in the study area, maximum average values and widest diffusion from land occurring in winter, this being contrasted by minimum mean values in summer. Sensitivity experiments demonstrate that the main factor influencing the distribution of SSC is the tide, while river discharge, wind, and wave effects are small and very localized. To explain the seasonal variation in SSC, the role of hydrodynamics, initial conditions, and temperature are tested in the model. The results show that the hydrodynamics play a significant role, whereas the initial conditions only have a minor regional influence. Temperature, on the other hand, is also shown to greatly influence the seasonal variation in SSC because of substantial changes in the viscosity of the water and the erosion shear stress. The modeled results are used to calculate sediment fluxes, which are shown to be consistent with the Lagrangian residual current pattern, while wind waves can significantly change the fluxes in winter. Bed elevations change substantially on a monthly time scale. In general, the deep channels are undergoing erosion, while the shallow Ridges and coastal tidal flats are accreting, the net sediment transport being directed towards the coastal tidal flat and the Changjiang (Yangtze) River subaqueous delta.
Feng Weibing - One of the best experts on this subject based on the ideXlab platform.
-
A two-dimension coupled wave-current model using in the radial Sand Ridge field
World Automation Congress 2012, 2012Co-Authors: Sun Dawei, Feng WeibingAbstract:The numerical calculation method is based on unstructured mesh well adaptability to the complex boundary, and the FVM (Finite Volume Method) form good conservation to the convective term flux. This coupled model adopting Roe second-order upwind scheme of FVM numerical analyzed to shallow water equation, and successfully introduced mild slope equation with weakly nonlinear amplitude dispersion, using the improved interpolating technology of rectangular grid to the triangular grid that cooperates with the FVM format on triangle mesh to calculate the complex flow field model. In order to avoid immobile water fictitious flowing in the complex terrain, this model uses the Rogers method to balance process for flux gradient terms and source terms. At measuring point in the radial Sand Ridge field, the model with wave-current interactions led velocity variation.
-
A two dimensional numerical model of suspended sediment transport using in the radial Sand Ridge field
2011 International Conference on Mechatronic Science Electric Engineering and Computer (MEC), 2011Co-Authors: Sun Dawei, Feng WeibingAbstract:For the evolution of the coastal, suspended sediment transport is an important factor. A large amount of suspended sediments transported under the wave and current action in the radial Sand Ridge field of the South Yellow Sea. This article introduces a numerical model which has adaptability to the complex border and the FVM (Finite Volume Method) conservation character. The character of this model use triangular grid and the second-order Roe-type upwind format to solve the two-dimensional suspended sediment transport equation. The triangular grid FVM has quasi steady characteristics. The suspended sediment transport model with well-balanced performance in discretization the source terms, and incorporate upwind numerical fluxes. Roe-Sweby limiter maintains the monotonicity and oscillation suppression of reconstruction. The suspend sediment concentration data from experiment in the radial Sand Ridge field of South Yellow Sea were use to verify the suspended sediment transport model, and the results show it is fine.
-
numerical simulation of wave fields in radial Sand Ridge filed of southern yellow sea
Journal of Hohai University, 2010Co-Authors: Feng WeibingAbstract:To study the wave characteristics of the radial Sand Ridges filed in the southern Yellow Sea and to guide the construction of harbors in this sea area,a mathematical model of wave refraction-diffraction was employed to simulate the wave transformation over the sea area. The simulated results of the wave fields under different situations were analyzed. A conclusion is drawn as follows: (a) the contours of wave heights distribute like an arc with Jianggang as its circle center; (b) the waves break for many times; (c) the locations of wave-energy-convergent zones generated by incident waves with different directions are different; (d) the period of incident waves has significant influence on the wave fields.
-
numerical study on distribution of suspended sediment over radial Sand Ridge field on continental shelf of south yellow sea
Journal of Waterway and Harbor, 2010Co-Authors: Feng WeibingAbstract:In order to ascertain the characteristics of suspended sediment and guide the construction of port in South Yellow Sea area,it was necessary to investigate the distribution of the suspended sediment.A model of suspended load was described,which was composed of artificial neural network,2-D tidal current numerical model,weather chart and measured data.Firstly,the function relation between measured sediment concentration and measured water velocity was calculated by the artificial neural network.Secondly,the water depth,flow rate and wind velocity were substituted into the equation.Lastly,the sediment distribution of this area was calculated. The calculation results show that:the hydrodynamic characteristics of this sea are wave-lifting-Sand and tidal-current-transporting-Sand.Xiyang stays erosional,which is propitious to the maintenance of deep trough.The shape of sediment isoline is similar to the isobath.
