【作者】 严立文；

【导师】 黄海军；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 环境科学， 2008， 博士

【摘要】 本文整合大量表层沉积物、悬浮体(大面和垂直站位)、短柱状样品、水文站水文观测资料、生态环境调查资料、遥感影像、水深图及前人文献资料等,通过多种技术手段较为系统地研究黑泥湾海带养殖海区的表层沉积物分布规律、悬浮泥沙输移扩散、水下沉积过程信息的历史记录、海带养殖活动对黑泥湾海区水动力条件与环境条件演变的影响。结果表明,大规模海带养殖使黑泥湾湾内底床趋于稳定,海带养殖架群区外边界紊流作用加强导致该处底床变化较大。大规模海带植被体的充填使海区的悬浮泥沙运移路径和空间分布形态发生改变,养殖边界处悬浮体浓度梯度较大,外围高浓度的悬浮体对海带养殖筏架区影响较小。自1980’s大规模海带养殖活动以来沉积物粒度呈细化趋势,LOI揭示的有机质含量则呈增长趋势,海带养殖繁盛期(春季)黑泥湾营养盐DIN损耗明显。SWAN模式结果表明,海带架群的消浪作用显著,其消浪作用强弱与海带筏架数量、入射波强度等密切相关,黑泥湾养殖区的消浪系数(Cd)约在0.2～0.4之间。更多还原

【Abstract】 This paper addresses the evolution of sediment environment and the alteration of hydrodynamics in the Harny Bay, which is a representative region of kelp(Laminaria Japonica) culture, in light of hydrological records, field measurements, station–based monitoring, remote sensing interpretation, bathymetric charts and so on. Due to the large–scale culture of kelp, the seabed under kelp canopy come to steadier than before and contrastly the regions outside on the boundary turn unsteadier owing to stepped–up turbulent flow. Thinning tendency of grain size and enrichment of organic matter is both indicated. The kelp rafts block the upper 5 m water, forcing transmission path of SPM altered and changing spatial distribution of SPM. The grain size of surficial SPM is mainly affected by coupling of wave field and tidal currents, dissimilarly grain size of bottom SPM on water–sediment interface under kelp canopy is obviously finer than outside regions, indicating the possible role of kelp. Based on multi–source images analysis, SPM contour showed that high–value SPM outside is hardly attain kelp–farming area. Additionally, environmental evolution information arisen by kelp cultural activities is also recorded by Sediment core. The results showed that Ever since 1980’s Grain–size of Core HN01 turns thinner gradually and the vertical distribution of OC contents also indicated that biological accumulation is faster owing to biological detritus released from kelp (Laminaria Japonica). The distribution of nutrients indicates that the consumption of DIN in farming area is evident. As to the hydrodynamic force under kelp canopy, evidence provided that large–scale kelp(Laminaria Japonica) have alter the erosion/accretion pattern of seabed in the cultural area by means of reducing the hydrodynamics condition(most likely wave damping and flow confusion). The analog results from SWAN model indicate that the wave damping effect is related to the rafts quantity and the magnitude of incoming wave energy. The wave damping coefficient result from kelp rafts varies from 0.2 to 0.4 based on in–situ observation. The interaction among kelp rafts and water in the boundary regions is so complicated that reflection, diffraction and energy dissipation among boundary should be included to interpret evolution of sedimentary environment.更多还原