CAJ | 학술논문

大河河口的动力沉积过程一直是陆海相互作用研究的核心内容，其中水体泥沙的垂向交换是河口动力-沉积机制分析中的关键环节。基于2011年12月对长江河口及其邻近海湾采集的大范围、高密度的近底层悬沙、海床表层1～2 cm（表层沉积物）和垂向向下约2～10 cm 的沉积物（次表层沉积物）同步3组303个样品，利用经验正交函数方法，对河口地区的悬沙和沉积物交换过程进行研究。结果表明：近底层水体悬沙的空间分布模式主要以粉砂粒级为主，空间分布差异性不大；表层及次表层沉积物的空间分布模式相似，但较近底层水体悬沙的分布复杂，存在明显的区域性特征，其中南汇边滩水域中部辐散区的沉积物表现为粗粉砂-细砂模式，其他区域由粉砂组分模式组成。近底层水体悬沙、表层和次表层沉积物的第一模态主要反映了粒径较细的泥沙运动，第二模态主要反映了粒径较粗的泥沙运动。在近底层水体悬沙与表层沉积物的垂向交换中，主要交换粒级为粉砂组分粒级。在表层沉积物与次表层沉积物的垂向交换中，南汇边滩中部辐散区的主要交换粒级为粗粉砂-细砂组分粒级，其他区域主要为粉砂组分粒级。
대하하구적동력침적과정일직시륙해상호작용연구적핵심내용，기중수체니사적수향교환시하구동력-침적궤제분석중적관건배절。기우2011년12월대장강하구급기린근해만채집적대범위、고밀도적근저층현사、해상표층1～2 cm（표층침적물）화수향향하약2～10 cm 적침적물（차표층침적물）동보3조303개양품，이용경험정교함수방법，대하구지구적현사화침적물교환과정진행연구。결과표명：근저층수체현사적공간분포모식주요이분사립급위주，공간분포차이성불대；표층급차표층침적물적공간분포모식상사，단교근저층수체현사적분포복잡，존재명현적구역성특정，기중남회변탄수역중부복산구적침적물표현위조분사-세사모식，기타구역유분사조분모식조성。근저층수체현사、표층화차표층침적물적제일모태주요반영료립경교세적니사운동，제이모태주요반영료립경교조적니사운동。재근저층수체현사여표층침적물적수향교환중，주요교환립급위분사조분립급。재표층침적물여차표층침적물적수향교환중，남회변탄중부복산구적주요교환립급위조분사-세사조분립급，기타구역주요위분사조분립급。
The large estuarine sediment dynamic process has been the core content of the land ocean interactions in the coastal zone research.The vertical exchange for sediments in the different water depth of the estuary is a key in the analysis of estuarine dynamics and deposition mechanism.Here,a large-scale and dense sediment samples cruise of the Changjiang (Yangtze)Estuary was carried out in December 2011,where three sets with 303 sediment sam-ples including suspended sediment near the bottom,surface deposition with a vertical thickness of 1 to 2 cm,and subsurface deposition with a vertical thickness of 2 to 10 cm were simultaneously taken by grabber instrument. Thereafter,based on the collected sediment samples,the empirical orthogonal function method was applied to dis-cuss the exchange process of the suspended load near the bottom and bed sediments.The results are shown as fol-lows:the spatial distribution patterns of the suspended load near the bottom of the Changjiang Estuary are mainly composed of silt with a small difference in spatial distributions.The spatial distribution patterns of surface bed sed-iments and subsurface bed sediments are similar with regional characteristics.Their spatial distributions are more complex than that of the suspended load near the bottom.In the central district of Nanhui Shoal,sediments were characterized by coarse silt and fine sand,and the sediments distributed in other areas were characterized by silt. Furthermore,the first mode of the sediments by EOF could mainly reflect the sediments movement of fine particle size,and the second mode mainly reflects the sediments movement of coarse particle size.The vertical exchange be-tween the suspended load and the surface bed sediments with main grain size is silt components.However,during the exchange process between the surface bed sediments and subsurface bed sediments in the central district of Nanhui Shoal,the dominant exchange component is coarse silt,and fine sand exchange occurred in other regions. Taken altogether,grain size with silt components of the Changjiang Estuary should play a dominant role in bed sed-iments exchange process.