温州瓯飞浅滩及其附近海域枯季悬沙输运机制研究

Study on flow and suspended sediment load in the Oufei Shoal and adjacent area in dry season

基于2013年4月瓯飞浅滩大范围海域的潮流和含沙量同步观测资料,运用机制分解法分析悬沙从小潮至大潮的输运特征,探讨不同水动力因子对悬沙输运的贡献率。结果表明:余流从小潮到大潮期间逐渐增加,河口区余流值最大,其次是北部岛屿区,南部海域最小。欧拉余流绝大部分方向向海,而斯托克斯余流方向向陆。单宽输水量以北部岛屿区最大,向陆输运,其次是瓯江口,向海输运,输沙量以大潮输移为主,其输沙强度和输沙方向在空间上差异明显。瓯江口和鳌江口、南部北部岛屿区和海域向海输运,而飞云江口和中部海域向陆输运。在各个输沙项中,河口区以平流输沙为主,而北部岛屿区、中部海域和南部海域以潮泵输沙为主。

Based on data of flow and suspended load concentration observed in Oufei Shoal and adjacent sea in April 2013,the mechanism decomposition method was used to analyze transport mechanism of flow and suspended sediment during a neap-spring tide cycle. Results show that the residual current velocity increases gradually from neap tide to spring tide,and the direction of Euler residual current is seaward and the direction of Stokes residual current is landward in the study area. The net water transport of the North Island area is the largest and landward,and the next is Oujiang estuary and seaward. The absolute sediment transport was mainly depended on spring tide transport. The net sediment transport is seaward in Oujiang estuary,Aojiang estuary,North area and South area,but Feiyun estuary and Middle area are landward. The advection transport term was the principal constituent of the suspended sediment transport in the estuary and the tidal pumping transport term was the principal constituent of the suspended sediment transport in the area of North Islands,Middle area and South area.