The radial tidal current field accounts for the formation of the radial sand ridges in the South Yellow Sea. Understanding the formation and evolution of this radial tidal current field is vital to assessing the morph...The radial tidal current field accounts for the formation of the radial sand ridges in the South Yellow Sea. Understanding the formation and evolution of this radial tidal current field is vital to assessing the morphodynamic features in the area. A semi-enclosed rectangular basin with and without a coastal barrier was schematized from the topography of the Bohai Sea and Yellow Sea. The 2D tidal current field in this basin was simulated using the DELFT3D-FLOW model. The concept of tidal wave refraction, which highlights the effect of the sloped or stepped submarine topography on the propagation of the tidal waves, was introduced to explain the formation of the radial tidal current field. Under the effect of tidal wave refraction, co-phase lines of the counterclockwise rotating tidal wave and incident tidal wave are transformed into clockwise and counterclockwise deflections, respectively, leading to the convergence and divergence of the flow field. Regardless of whether a coastal barrier exists or not, the outer radial tidal current field might emerge over certain topography. The responses of the radial tidal current field in this basin to the environmental variations such as coastline changes and bottom erosions were discussed. Results show that local protrusion near the focal point of the radial tidal current field will have limited effects on the location of the tidal system. However, a remarkable shift of the amphidromic point toward the entrance and central axis of this basin and a movement of the focal point of the radial tidal current field toward the entrance could be caused by the significant seaward coastline advance and submarine slope erosion.展开更多
Semi-enclosed sea basins have difficulty in recharging their waters due to limited communication with larger water bodies, with understandable consequences for their environmental status. This paper aims at the comput...Semi-enclosed sea basins have difficulty in recharging their waters due to limited communication with larger water bodies, with understandable consequences for their environmental status. This paper aims at the computational simulation of the hydrodynamic characteristics of the waters of the Pagasitikos Gulf (Greece), which has limited communication and water exchange with the Aegean Sea and is subject to intense environmental pressures The Estuary, Lake & Coastal Ocean 3d hydrodynamic Model (ELCOM 2.2) combined with its later version Aquatic Ecosystem Model-3d (AEM3D) were used for the simulation. The simulation included the topography of the area, the bay’s bottom geometry, atmospheric loadings, tides, the influence of the Coriolis force and boundary conditions. The hydrodynamic behaviour of the bay, water circulation, velocities at the surface and in depth, water recharge and residence time throughout the bay, density variation and other factors were examined to determine the impact of all these on the aquatic ecosystem.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.51179067,51379072)the Special Funds for Scientific Research on Public Welfare of Ministry of Water Resources of China(No.201201045)the College Graduate Research and Innovation Project of Jiangsu Province,China(No.CXZZ12_0254)
文摘The radial tidal current field accounts for the formation of the radial sand ridges in the South Yellow Sea. Understanding the formation and evolution of this radial tidal current field is vital to assessing the morphodynamic features in the area. A semi-enclosed rectangular basin with and without a coastal barrier was schematized from the topography of the Bohai Sea and Yellow Sea. The 2D tidal current field in this basin was simulated using the DELFT3D-FLOW model. The concept of tidal wave refraction, which highlights the effect of the sloped or stepped submarine topography on the propagation of the tidal waves, was introduced to explain the formation of the radial tidal current field. Under the effect of tidal wave refraction, co-phase lines of the counterclockwise rotating tidal wave and incident tidal wave are transformed into clockwise and counterclockwise deflections, respectively, leading to the convergence and divergence of the flow field. Regardless of whether a coastal barrier exists or not, the outer radial tidal current field might emerge over certain topography. The responses of the radial tidal current field in this basin to the environmental variations such as coastline changes and bottom erosions were discussed. Results show that local protrusion near the focal point of the radial tidal current field will have limited effects on the location of the tidal system. However, a remarkable shift of the amphidromic point toward the entrance and central axis of this basin and a movement of the focal point of the radial tidal current field toward the entrance could be caused by the significant seaward coastline advance and submarine slope erosion.
文摘Semi-enclosed sea basins have difficulty in recharging their waters due to limited communication with larger water bodies, with understandable consequences for their environmental status. This paper aims at the computational simulation of the hydrodynamic characteristics of the waters of the Pagasitikos Gulf (Greece), which has limited communication and water exchange with the Aegean Sea and is subject to intense environmental pressures The Estuary, Lake & Coastal Ocean 3d hydrodynamic Model (ELCOM 2.2) combined with its later version Aquatic Ecosystem Model-3d (AEM3D) were used for the simulation. The simulation included the topography of the area, the bay’s bottom geometry, atmospheric loadings, tides, the influence of the Coriolis force and boundary conditions. The hydrodynamic behaviour of the bay, water circulation, velocities at the surface and in depth, water recharge and residence time throughout the bay, density variation and other factors were examined to determine the impact of all these on the aquatic ecosystem.
