鱼咀及丁坝对长江口航道分流分沙的影响

利用水平二维水流、盐度、泥沙数学模型研究了长江口航道整治工程(一期)实施前后，航道的分水分沙特点，重点讨论了束水丁坝的长度、潜堤的方向对航道分流比、分沙比的影响．数值模拟结果表明，双导堤工程减少了航道的分沙量，这有利于维护航道的畅通，但同时也使航道的分流比减小．航道分流分沙比的改变可通过调整各水工建筑物的布置或尺寸来实现．与束水丁坝长度的影响相比，鱼咀工程潜堤方向的改变对航道分流分沙比的影响更大．

Influences of the Fish-Mouth Project and the Groins on the Flow and Sediment Ratio of the Yangtze River Waterway

A depth_integrated two_dimensional numerical model of current,salinity and sediment transport was proposed and calibrated by the observation data in the Yangtze River Estuary.It was then applied to investigate the flow and sediment ratio of the navigation channel,i.e.the North Channel of the Yangtze River Estuary,before and after the first phase waterway project is implemented.Particularly,the influences of groin length and the orientation of the submerged dam on the flow ratio and sediment load discharging into the North Channel were discussed.The numerical results demonstrate that less sediment load discharges into the navigation channel,which unburdens the waterway dredging,but in the meantime the flow ratio is also decreased.The flow and sediment ratio can be adjusted by changing layout and dimensions of the hydro_structures,such as the groin length,the top height,etc.The effect of the orientation of the submerged dam is more obvious than the groin lengh.