Characteristics of Suspended Sediment and Resuspension Process in Wendeng Coastal Area, Shandong Peninsula

2013 ◽  
Vol 807-809 ◽  
pp. 1595-1599 ◽  
Author(s):  
Xiao Liu ◽  
Xiu Li Feng ◽  
Jie Liu

Based on the field observations and laboratory analysis data of the suspended sediment of Wendeng coastal area, this paper studied the change process of suspended sediment concentration and characteristics of surface sediment resuspension in the study area. In results: (1) In vertical, the suspended sediment concentration of each station increased gradually from surface to bottom, and the maximum value could reach 0.11 kg/m3; (2) Suspended sediment concentration is well correlated with velocity variation in a tidal cycle, and the peak of suspended sediment concentration occurs four times in a tidal cycle, indicating that there are four resuspension processes during a tidal cycle in the study area; (3) According to the suspended sediment concentration at different times and the content of the previous time, the maximum settlement is between 0.063~0.092kg/m3, and the maximum resuspension is between 0.057~0.125kg/m3 in the study area.

2012 ◽  
Vol 1 (33) ◽  
pp. 10
Author(s):  
Yukihiko Hasegawa ◽  
Masamitsu Kuroiwa ◽  
Yuhei Matsubara ◽  
Yasushi Icimura ◽  
Yoshiyuki Nagaishi

The objective of study is to develop a coastal area model for sandy beach with shore reef such as non-eroded hard bottom. The morphodynamics with exposure and bury of the shore reef are reproduced by advection and diffusion model for suspended sediment concentration. Firstly, model tests associated with sandy beaches with a detached breakwater and groins were carried out in order to investigate the performance of the presented model. Secondly, the presented model was applied to a filed site with both shore reef and sandy beach, the applicability of the model was investigated and discussed.


2018 ◽  
Author(s):  
Bismay Ranjan Tripathy ◽  
Kaliraj Seenipandi ◽  
Haroon Sajjad ◽  
Pawan Kumar Joshi ◽  
Bhagwan Singh Chaudhary ◽  
...  

Abstract. In the recent decades hydrologists, geologists, and stream ecologists have shown substantial interest in analyzing suspended sediments in water. Extracting information like suspended sediment concentration (SSC) in coastal waters is very important for assessment and monitoring of coastal settings and their effects on their ecology. This article demonstrates importance of Landsat 8 Operational Land Imager (OLI) for monitoring seasonal variation in SSC and movement (pre and post monsoon) along Thiruvananthapuram Coast in India. The data was converted into marine reflectance after correcting due atmospheric errors. SSC was extracted using spectral analysis data analysis. Movement of SSC was monitored using wave direction and significant wave height data. The results revealed that the SSC decreased rapidly with the increase in distance from the beach and depth of the seabed. Wave with higher frequency in deeper water caused sparely circulation of sediments and their concentration at the lower depth in high bathymetry. Thus, the suspended sediments were indirectly proportional to bathymetry and distance from the shoreline and directly proportion to wave direction and littoral current at off-shore. High concentration of sediments was found to be accumulated at shallow depth (


Ocean Science ◽  
2019 ◽  
Vol 15 (2) ◽  
pp. 307-319 ◽  
Author(s):  
Manel Grifoll ◽  
Pablo Cerralbo ◽  
Jorge Guillén ◽  
Manuel Espino ◽  
Lars Boye Hansen ◽  
...  

Abstract. In this study we investigate the variability in near-bottom turbidity in Alfacs Bay (in the northwestern Mediterranean Sea). The bay is characterized by a micro-tidal environment and seiching activity that may lead to flow velocities of more than 50 cm s−1. A set of current meters and optical sensors were mounted near the sea bottom to acquire synchronous hydrodynamic and optical information from the water column. The time-series observations showed an evident relation between seiche activity and sediment resuspension events. The observations of turbidity peaks are consistent with the node–antinode location of the fundamental and first resonance periods of the bay. The implementation of a coupled wave–current numerical model shows strong spatial variability of the potential resuspension locations. Strong wind events are also a mechanism responsible for the resuspension of fine sediment within the bay. This is confirmed by suspended sediment concentration maps derived from Sentinel-2 satellite imagery. We suggest that the sequence of resuspension events plays an important role in the suspended sediment concentration, meaning that the occurrence of sediment resuspension events may increase the suspended sediment in subsequent events. The suspended sediment events likely affect the ecological status of the bay and the sedimentary process over a long-term period.


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 611
Author(s):  
Man Jiang ◽  
Chongguang Pang ◽  
Zhiliang Liu ◽  
Jingbo Jiang

The influence of sea ice on the hydrodynamics, sediment resuspension, and suspended sediment concentration (SSC) in the coastal area of Qinhuangdao was systematically investigated using 45-day in situ measurements at two stations (with ice at station M1 and without ice at station M2) in the Bohai Sea in the winter of 2018. It was found that the daily fluctuations of temperature and salinity at M1 are more significant than those at M2. During a typical seawater icing event on January 28, the temperature and salinity of the bottom water at M1 were decreased by 1.77 °C and increased by 0.4 psu, respectively. Moreover, due to the shielding effect of the sea ice, the residual current was much less affected by the wind at M1 than at M2. For the vertical distribution of current velocity, it changed from a traditional logarithmic type under ice-free conditions to parabolic type under ice-covered conditions due to the larger drag coefficient of the water body on the solid ice surface. For the SSC and turbidity at the bottom layer, the average values were 4.9 μL/L and 8.6 NTU at M1, respectively, approximately half of those at M2. The smaller SSC and turbidity at M1 can be attributed to the lower near-bottom turbulent kinetic energy (TKE). At M2, however, the larger SSC is closely related to the strong wind forcing, which could induce higher TKE without sea ice cover, and hence stronger turbulent resuspension. The seabed sediment analysis results showed that in the study area, fine sand is most likely to resuspend, while cohesive particles would resuspend only under strong hydrodynamic conditions.


Author(s):  
John Z. Shi

ABSTRACTHangzhou Bay is a typical funnel-shaped high turbid estuary along a mesotidal coast of the East China Sea. In this paper, field studies are undertaken in an attempt to better understand tide-induced fine sediment transport processes in the Bay. Field observations were made mainly of current velocities (speeds and directions) and suspended sediment concentrations at six different relative depths and two stations in September 1992. Results show that (1) high near-bed suspended sediment concentrations varied from 1·81 to 4·00 kg m−3 during the spring tide and from 1·04 to 8·00 kg m−3 during the neap tide; (2) tide-induced near-bed fine sediment resuspension processes are indicated by several periodic suspended sediment concentration peaks; and (3) a hysteresis effect, or suspension-lag, occurs in suspended sediment concentration and resuspension events. Tide-induced fine sediment processes are mainly responsible for very high concentration suspensions of fine sediments in Hangzhou Bay. The occurrence of the suspension-lag phenomenon is likely to be common in other similar muddy tidal environments.


2013 ◽  
Vol 11 (4) ◽  
pp. 457-466

Artificial neural networks are one of the advanced technologies employed in hydrology modelling. This paper investigates the potential of two algorithm networks, the feed forward backpropagation (BP) and generalized regression neural network (GRNN) in comparison with the classical regression for modelling the event-based suspended sediment concentration at Jiasian diversion weir in Southern Taiwan. For this study, the hourly time series data comprised of water discharge, turbidity and suspended sediment concentration during the storm events in the year of 2002 are taken into account in the models. The statistical performances comparison showed that both BP and GRNN are superior to the classical regression in the weir sediment modelling. Additionally, the turbidity was found to be a dominant input variable over the water discharge for suspended sediment concentration estimation. Statistically, both neural network models can be successfully applied for the event-based suspended sediment concentration modelling in the weir studied herein when few data are available.


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