The results of simulated tidal current field, wave field and storm-induced current field are employed to interpret the depositional dynamic mechanism of formation and evolution of the radial sand ridges on the Yellow Sea door. The anticlockwise rotary tidal wave to the south of Shandong Peninsula meets the following progressive tidal wave from the South Yellow Sea, forming a radial current field outside Jianggang. This current field provides a necessary dynamic condition for the formation and existence of the radii sand ridges on the Yellow Seadwr. The resuits of simulated "old current field (holocene)" show that there existed a convergent-divergent tidal zone just outside the palaeo-Yangtze River estuary where a palaeo-underwater accumulation was developed. The calculated results from wave models indicate that the wave impact on the topography, under the condition of high water level and strong winds, is significant. The storm current induced by typhoons landing in the Yangtze River estuary and turning away to the sea can have an obvious influence, too, on the sand ridges. The depmitional dynamic mechanism of formation and evolution of the radial sand ridges on the Yellow Sea seafloor is "tidal current-induced formation-storm-induced chang-tidal current-induced recovery".

用辐射沙脊群水域潮流场、波浪场和风暴流场的数值模拟结果解释了黄海海底辐射沙脊群形成演变的动力机制。山东半岛南侧的逆时针旋转潮波和南黄海的后继前进潮波在港外海辐聚，形成辐射状的潮流场。该潮流场为形成和维持辐射沙脊群提供了必要的动力环境。全新世古流场的模拟结果指出，在古河口外有一潮流辐聚辐散带，在其作用下发育了古河口堆积体。波浪场的计算结果说明，只有在高潮位和大风速下，沙脊区的波高普遍较大，对海底地貌的影响才较明显。长江口登陆型和海上转向型台风的风暴流场对沙脊区有明显影响。辐射沙脊群的形成机制是潮流形成——风暴破坏——潮流恢复。

建立了长江口平面二维流场数学模型，上游开边界取在徐六泾断面，外海开边界在佘山以东。上游流速开边界条件采用新的流量过程校正法进行订正，较好地反映了上游径流对河口流场的效应，弥补了当缺乏上游实测流速资料时，用普通的流速开边界处理方法所引起的计算偏差。

建立了σ坐标系下长江口斜压诊断模式三维流场数学模型，采用k-kl二方程紊流闭合模型求解垂向涡粘系数，计算域内恒定、非均匀盐度场反映了计算域密度斜压效应。验证结果表明，斜压诊断模式的模拟成果较切合实际。模型成功复演了长江口水域由往复流向旋转流过渡的流场特性；潮波从四条汊道传入后在分汊口附近相遇形成多个会潮点，其位置随着径流的大小、潮汐的强弱、汊道的形态等因素而变化。

建立了σ坐标系下长江口正压、斜压诊断及斜压预报模式三维流场数学模型，采用k-kl二方程紊流闭合模型求解垂向涡粘系数。通过正压模式与斜压诊断模式、斜压诊断模式与斜压预报模式流场模拟结果的定量比较，说明了各种模式对长江口流场模拟精度影响的程度，推荐了长江口流场数值模拟采用的模式。