东海大桥邻近海域沉积动力环境变化  

Sedimentary Dynamic Environment Changes Adjacent to the East China Sea Bridge

作　　者：王泽 乔璐璐[1,2] 高飞[3] 李莉[4] 刘洋[5] 张思晨 张璐 WANG Ze;QIAO LuLu;GAO Fei;LI Li;LIU Yang;ZHANG SiChen;ZHANG Lu(College of Marine Geosciences,Ocean University of China,Qingdao,Shandong 266100,China;The Key Lab of Sea Floor Resource and Exploration Technique,Ministry of Education,Qingdao,Shandong 266100,China;Qingdao Institute of Marine Geology,China Geological Survey,Qingdao,Shandong 266071,China;Ocean College,Zhejiang University,Zhoushan,Zhejiang 316021,China;National Marine Environmental Forecasting Center,Beijing 100081,China)

机构地区：[1]中国海洋大学海洋地球科学学院,山东青岛266100 [2]海底科学与探测技术教育部重点实验室,山东青岛266100 [3]中国地质调查局青岛海洋地质研究所,山东青岛266071 [4]浙江大学海洋学院,浙江舟山316021 [5]国家海洋环境预报中心,北京100081

出　　处：《沉积学报》2024年第4期1252-1267,共16页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42076179,41476030,41976157);亚洲合作资金项目;国家地质调查项目(DD20221775)。

摘　　要：【目的】东海大桥是杭州湾和长江口水沙交换的重要通道,其对邻近海域悬沙分布和输运有重要影响。【方法】基于2011—2020年共26天每天8张连续潮时的高质量GOCI影像,反演获得东海大桥及邻近水域表层悬浮泥沙浓度,并结合理想数值模型和表层沉积物观测资料,研究了东海大桥对邻近海域沉积动力环境不同时间尺度的影响。【结果】在潮周期时间尺度上,东海大桥两侧悬浮泥沙浓度呈现明显的梯度分布,并随涨落潮表现为背流面悬沙浓度高于迎流面,这与背流面水位降低促进垂直运动和桥墩后方涡流加强扰动有关,其中在涨落潮中间时刻,大桥两侧悬浮泥沙浓度差异最大,涨憩时刻两侧差异最小。各季节涨落潮过程中大桥东西两侧悬沙浓度的差异变化不大,但浓度差值有所不同。从多年变化来看,东海大桥建成后两侧悬沙浓度差异的年际变化不大,邻近海域表层沉积物有变细趋势,可能与大桥阻流导致流速减弱有关。【结论】潮周期内悬沙浓度在大桥背流面高于迎流面的差异分布,不随季节和年际变化,该研究对完善不同时间尺度跨海大桥对海洋沉积动力环境影响的研究具有重要意义。[Objective]The East China Sea Bridge is located in the important passage between Hangzhou Bay and the Yangtze River Estuary where the exchange of water and suspended sediment occurs,which has a significant im⁃pact on the distribution and transportation of the suspended sediment in the adjacent area.Therefore,the variation characteristics of suspended sediment concentration(SSC)on both sides of the East China Sea Bridge for the tidal cy⁃cle,seasonal,and interannual scales are studied.[Methods]Based on 26 days of high-quality Geostationary Ocean Color Imager(GOCI)images with 8 continuous tidal hour per day from 2011 to 2020,the inversion equation was es⁃tablished to transfer remote sensing reflectance to SSC in the adjacent waters around the East China Sea Bridge.In addition,combined with the ideal numerical model and the observation data of seabed sediment,the influence of the East China Sea Bridge on the changes of suspended sediment and seabed sediment distribution at different time scales was studied.[Results]The results show that the SSC on both sides of the East China Sea Bridge presents an obvious gradient distribution,with the higher value on the lee side and lower value on the upstream face of the bridge during both the flood and ebb periods.The SSC difference reaches 300%,which is related to the vertical movement caused by the lower water level on the lee side of the bridge and strengthened disturbance induced by the vortex behind the piers.During the ebb and flood maximum times,the difference in SSC between the two sides of the bridge is the largest,and the difference between the two sides at the flood slack and fall is the smallest.During the ebb period,the difference of SSC on both sides of the bridge is significantly greater than that of high tide.The gradient distribution of SSC on the two sides of the bridge is not significantly different during the ebb and flood periods in different seasons,but the concentration difference is different.The difference of SSC on both sides of the bridge in wint

关 键 词：东海大桥 悬浮泥沙 GOCI 潮周期变化 

分 类 号：P512.2[天文地球—地质学]