北槽坝田环流特征及环流对坝田冲淤的影响

摘要

通过建立二维模型,对长江口北槽深水航道水沙运动及冲淤状况进行模拟,分析了北槽坝田局部环流的特征及形成原因,并结合北槽洪季冲淤状况,分析了坝田形成冲刷区的水动力原因及环流对坝田冲淤的影响.分析表明,坝田环流在不同时刻、不同区域具有相应的特征及成因,且坝田环流的位置,平面尺寸及出现与否都对坝田冲淤有影响,大范围的、中心更靠近滩槽的环流有利于坝田的淤积.%A two-dimensional model has been established to simulate water sediment movement,scour and deposition within the range of Beicao deep water channel at the estuary of Yangtze River.The simulation results involve the characteristics and causes for partial circular flow in Beicao groins.Based on the scour and deposition of Beicao channel during flood season,an analysis is made for the hydrodynamic cause for the scour in the groins and the impact of circular flow on the scour and deposition of the groins.The results show that the characteristics and causes for the circular flow in the groins vary in the case of different time and areas.The position,plane dimensions even the occurrence or not of the circular flow influence the scour and deposition of the groins.The groins can be easily deposited due to greater-range circular flow,the center of which is closer to the channel.