Transport and deposition processes of the sediment depocenter off the Shandong Peninsula: An observational study

Qi，Fukang1; Wu，Xiao2,3; Wang，Zhiwen2; Wang，Chenghao2; Duan，Haiqin4; Liu，Meng1; Xu，Jingping1,3

2022-07-15

10.1016/j.csr.2022.104763

CONTINENTAL SHELF RESEARCH   影响因子和分区

0278-4343

1873-6955

The long-distance transport of Yellow River sediments has formed an omega-shaped (‘Ω’) distal muddy deposit in the Yellow Sea. Numerous studies have investigated the sediment dynamics and sedimentary evolution of the deposit, but several key questions remain unanswered due to insufficient observations. To reveal the mechanisms of sediment dynamics and quantify sediment transport and deposition processes, this study collected field datasets in the depocenter of the muddy deposit off the Shandong Peninsula. Bottom mounted tripods were deployed from August 18 to 27, 2017, and from February 23 to March 2, 2018, during which two strong wind events with speeds of over 10.8 m/s occurred. The results showed that near-bed suspended sediment concentration responded directly to varying hydrodynamic conditions, and significant differences in suspended sediment concentration between two wind events could be ascribed to a number of factors (e.g., tidal current, wave periods, wind stress, turbulence). The harmonic analysis demonstrated that suspended sediment variations during the spring tide were directed mainly by resuspension, while resuspension and advection contributed equally at neap tide. The variations in background suspended sediment concentration can be ascribed to the residual current. Furthermore, the sediment transport pattern is similar to the pattern of water circulation. Generally, the along-shore suspended sediment flux is about one order of magnitude higher than the cross-shore flux. In summer, the suspended sediment was transported mainly downcoast. In winter, sediment was transported downcoast during wavy periods and upcoast during calm periods. Advection dominated sediment flux in most cases, except during wavy periods when local resuspension increased significantly, and the contribution of resuspension term to along-shore flux was up to 87%. Meanwhile, cross-shore flux also increased significantly under strong winds, which was simultaneously modulated by downcoast and offshore winds. After statistical analysis, we found that offshore winds controlled the cross-shore sediment transport in winter. Using parameterized calculation and statistical analysis, the average accumulation rate of the study site was estimated to be 0.6 cm/yr. During calm periods, lower background sediment concentration in summer led to lower deposition rates than in winter. In addition, the frequent strong wind events in winter cause extremely high erosion rates. This study provides new perspectives on quantitative variations in suspended sediment transport and regional erosion/deposition from synoptic to seasonal variations in the distal mud deposit.

Accumulation rate Coastal sediment dynamics Muddy deposit Strong wind events Suspended sediment transport

SCI

英语

第一 ; 通讯

National Natural Science Foundation of China[41530966];National Natural Science Foundation of China[U1606401];

Oceanography

Oceanography

WOS:000808571400002

PERGAMON-ELSEVIER SCIENCE LTD

PLANT & ANIMAL SCIENCE

2-s2.0-85131536061

Scopus

1.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,1088 Xueyuan Rd.,518055,China
2.College of Marine and Geosciences,Ocean University of China,Qingdao,238 Songling Rd.,266100,China
3.Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao,1 Wenhai Rd.,266061,China
4.North China Sea Environmental Monitoring Center,Ministry of Natural Resources,Qingdao,22 Fushun Rd.,266100,China

Qi，Fukang,Wu，Xiao,Wang，Zhiwen,et al. Transport and deposition processes of the sediment depocenter off the Shandong Peninsula: An observational study[J]. CONTINENTAL SHELF RESEARCH,2022,244.

Qi，Fukang.,Wu，Xiao.,Wang，Zhiwen.,Wang，Chenghao.,Duan，Haiqin.,...&Xu，Jingping.(2022).Transport and deposition processes of the sediment depocenter off the Shandong Peninsula: An observational study.CONTINENTAL SHELF RESEARCH,244.

Qi，Fukang,et al."Transport and deposition processes of the sediment depocenter off the Shandong Peninsula: An observational study".CONTINENTAL SHELF RESEARCH 244(2022).