近岸典型养殖海区的潮流垂直结构特征

The Features of Vertical Structures of Tidal Current in a Typical Coastal Mariculture Area of China

2006年7月在我国北方典型养殖海域桑沟湾进行现场观测,探讨养殖生物和养殖设施影响下潮流垂直结构的特征。结果显示:①夏季的桑沟湾,大量养殖生物和养殖设施的存在造成了潮流垂直结构中出现了潮流上边界层这一独特现象;②建立1个双阻力模型来描述这个现象,得到湾口北侧海带养殖区的潮流上边界层平均阻力系数■=5.4×10-2和底边界层平均阻力系数■=1.5×10-2;湾中部贝藻兼养区的■=4.9×10-2,■=1.9×10-3,并与同在黄海的自然海区青岛外海做比较;③在半日潮占优的桑沟湾海区,养殖阻力和底应力均具有1/4潮周期特征。在养殖阻力大于底应力的情况下,该海区出现了表层海水先涨/落潮的现象,这与浅海潮流底层海水先涨/落潮的一般规律截然不同。

In this paper, an observation was carried out in Sanggou bay, a typical mariculture area of northern China, July 2006, in order to learn the features of vertical structures of tidal current influenced by plen.ty of aquaculture organisms and establishments. The conclusions show that： （1） In summer, a peculiar tidal upper boundary layer is formed in Sanggou Bay because of lots of aquaculture organisms and aquaculture establishments being still in the surface. （2） Based on this phenomenon, a modified conceptually double-drag model is put forward to describe its vertical structures of tidal current. As a result, in the kelp culture area around the northern bay mouth, the averaged drag coefficient on tidal upper boundary layer -↑CDB is 5.4 ×10^-2, and the averaged drag coefficient on tidal bottom boundary layer -↑CDS iS 1. 5 × 10^-2. And in the seashell-and-kelp culture area around center of the bay, -↑CDS is 4.9 × 10^-2, and -↑CDB is 1.9 ×10^-3. Furthermore they are compared with a natural sea area in the Yellow Sea such as Jiaozhou Bay. （3） Sanggou bay is dominated by semidiurnal tidal components. Both the aquaculture drag and the bottom stress have significant 1/4 tidal cycle. When the aquaculture drag induced by these organisms and establishments exceeds the bottom shear stress, significant earlier ebb and earlier flooding appear in upper layer which distinctively offends the rule that earlier ebb and earlier flooding in bottom boundary layer in coastal water.