摘要: |
为了研究人工鱼礁区基本水动力特征,本文利用人工鱼礁投放区的座底海床基获取半年以上的水动力观测资料,通过谱分析、调和分析、滤波等方法分析了该海区潮汐、潮流特征,并讨论了余流特征。结果表明,该海域属于不规则半日潮,具有显著的全日潮周期和半日潮周期,潮汐性质指数为0.98,平均潮差为0.95m,最大可能潮差为2.25m。潮流为典型的往复潮,潮流主向为NNE-SSW,优势分潮为M2分潮。垂向上,流速大小随深度增加显著降低,海底1m的流速较表层降低约30%,流向向沿鱼礁布设方向偏转。该海域余流较小,欧拉余流与斯托克斯余流大小相当,分别为1.35cm/s,1.41cm/s,均为向岸输运,欧拉余流表层受风影响较大,拉格朗日余流为2.76cm/s,方向SEE。该海域流场垂向结构与人工鱼礁投放后底摩擦增加、鱼礁对近底层水流的阻滞作用有关。底层温度具有显著的季节变化与日变化特征,短期高频变化存在显著的全日周期与半日周期,冬春季由于垂向混合加强,全日信号更为显著。底层浊度的升高主要由大风过程加强垂向混合的引起。 |
关键词: 人工鱼礁 潮流 余流 调和分析 |
DOI:10.11693/hyhz20170900226 |
分类号:P731 |
基金项目:国家自然科学基金项目,41406029号,U1406403号;山东半岛近岸海域生态模拟试验项目,270006-FZLX-2015-00-1号。 |
|
HYDRODYNAMIC CHARACTERISTICS IN THE ARTIFICIAL REEFING CONSTRUCTION AREA IN LAIZHOU BAY: BASED ON: A CONTINUOUS LONG-TERM OBSERVATION |
ZOU Tao1, ZHANG Li-Bin2, ZHANG Hua1, LI Dong1
|
1.Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China;2.Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
|
Abstract: |
Artificial reefing (AR) is important for restoring coastal fishery resources with the better ecological environment of the coastal water. However, little is known of the local hydrodynamic characteristics. Based on an over-6-month in-situ observation with mooring in a seabed platform, we studied the tidal spectra, tidal current, and tidal residual current using low-pass filtering and harmonic analysis. The results show that the tide was an irregular semi-diurnal tide with a tidal form of 0.98, the mean tidal range of 0.95m, and the maximum possible tidal range of 2.25m. The tidal current signal was also irregular semi-diurnal dominated by M2 component. The motion type of the principal tidal current was inclined to reciprocate with a maximum tidal velocity in direction of NNE-SSW. The magnitude of velocity significantly reduced 30% from the surface to bottom. Meanwhile, the tidal flow tended to clockwise. The residual current was very weak and the Euler and the Stokes residual current was 1.35cm/s and 1.41cm/s, respectively, in direction of SEE, showing a landward transport. The Lagrangian residual current was 2.76cm/s, in direction of SEE. The hydrodynamic characteristics were closely related to bottom friction increase and retardation effects due to artificial reefs. The bottom temperature varied frequently in the semi-diurnal and diurnal period. In addition, seasonal variation was notable. In winter, the signal of the diurnal period was dominant due to the strong vertical mixing. The vertical mixing affected by spring wind, resulting in bottom turbidity variation. Therefore, we shall study AR on a small scale to understand the bottom boundary layer dynamics and on a large scale the coastal current system. |
Key words: artificial reef tidal current residual current harmonic analysis |