METHODOLOGICAL ASPECTS OF THE SUSPENDED SEDIMENT CONCENTRATION MEASUREMENT IN THE COASTAL ZONE

Author(s):  
Рубен Косян ◽  
Ruben Kosyan ◽  
Marina Krylenko ◽  
Marina Krylenko

Results of the suspended sediment concentration study in the coastal zone on the basis of field and laboratory experiments are analyzed. Data from field experiments, performed in the coastal zone of the North, Mediterranean and Black seas, are used. The laboratory researches were fulfilled in the Big Wave Channel of the Hannover University. It is shown that to increase the accuracy of measurement it is necessary to take into account the convective mechanism of the sediment suspension, as well as the size, the direction of the rotation axis and other parameters of the turbulent vortices transporting sand sediments. The presented information will help to improve the quality of field data collection.

Author(s):  
Рубен Косян ◽  
Ruben Kosyan ◽  
Marina Krylenko ◽  
Marina Krylenko

Results of the suspended sediment concentration study in the coastal zone on the basis of field and laboratory experiments are analyzed. Data from field experiments, performed in the coastal zone of the North, Mediterranean and Black seas, are used. The laboratory researches were fulfilled in the Big Wave Channel of the Hannover University. It is shown that to increase the accuracy of measurement it is necessary to take into account the convective mechanism of the sediment suspension, as well as the size, the direction of the rotation axis and other parameters of the turbulent vortices transporting sand sediments. The presented information will help to improve the quality of field data collection.


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2189
Author(s):  
Zekun Song ◽  
Weiyong Shi ◽  
Junbiao Zhang ◽  
Hao Hu ◽  
Feng Zhang ◽  
...  

Based on the 2013 field survey data of hydrology, suspended sediments and bottom sediments in the Central Hangzhou Bay, this paper explores the dynamic mechanism of suspended sediments in Hangzhou Bay by employing material flux decomposition. Meanwhile, the migration trends of bed sediments are also investigated by analyzing grain size trends. The results show that during an ebb or flood tide, the hydrograph of suspended sediment concentration of Hangzhou Bay is dominated by an M shape (bimodal), which is attributed primarily to the generation of a soft mud layer and a separate fluid mud layer. Laterally, the distribution of suspended sediment concentration is high in the south and low in the north. From a macroscopic perspective, the net sediment transport in the study area displays a “north-landward and south-seaward” trend, presenting a “C”-shaped transport mode. That is, the sediments are transported from the bay mouth to the bay head on the north side and from the bay head to the bay mouth on the south side. The sediment transports by advection and tidal pumping are predominant, while the sediment transport by vertical circulation makes little contribution to the total sediment transport. Moreover, the sediment transport in the center of the reach area is dominated by advection, whereas that near both sides of the banks is controlled by tidal pumping. The asymmetry of the tides, i.e., flood-dominance in the north and ebb-dominance in the south, is the primary cause of the dynamic mechanism for the overall “C”-shaped transport mode in Hangzhou Bay. Additionally, coupled with the narrow-head wide-mouth geomorphology, Hangzhou Bay remains evolving by south shore silting and north shore scouring.


Author(s):  
М. Крыленко ◽  
M. Krylenko ◽  
Й. Грюне ◽  
Y. Gryune ◽  
Р. Косьян ◽  
...  

In the presented paper some peculiarities of suspending and distribution of sand particles under influence of the regular waves in time interval less than the wave period are discussed using data from laboratory experiment “Hannover 2008”. The experiment was carried out in the Large Wave Channel (GWK). The presented data show that fluctuations of suspended sediment concentration are very largely initiated by individual waves.


The aim of this study was to assess the applicability of indirect techniques for streamflow and suspended sediment concentration estimation and their use in the calculation of suspended sediment transport rate in the small mountain watersheds of Madeira Island, Portugal. Emphasis was given to the application of salt dilution gauging to the indirect determination of the flow rate and the use of water turbidity data to estimate the concentration of suspended sediments. The field and laboratory work carried out are briefly described, and the main experimental results and the field data from the short measurement campaign performed in the Ribeira Seca stream in Faial, on the north side of the island, are presented and discussed. Whilst the measurement campaign carried out was temporally and spatially limited, it was pioneering for Madeira and allowed to verify the applicability of the indirect hydrometric and sedimentometric techniques used in this exploratory study.


2015 ◽  
Vol 34 (1) ◽  
Author(s):  
Abd Rahman Matamin ◽  
Fadhli Ahmad ◽  
Mustafa Mamat ◽  
Khiruddin Abdullah ◽  
Shahariah Harun

AbstractGulf of Martaban is located at the north of Andaman, and is one of the world most turbid areas. The presence of suspended sediment concentration (SSC) in the water body could reduce the underwater transmittance. This study has been conducted to investigate the variation of SSC over the Gulf of Martaban. Remote sensing reflectance (Rrs) of 667 nm is used as a proxy to represent the sediment SSC variation over the study area. The data for the period of July 2002 to March 2014 acquired from MODIS Aqua 4 km resolution are used in this study. As a result, there is no obvious yearly variation in the SSC cover area. The SSC variation over this study area is found to be seasonal. High homogenous SSC covers area observably during the northeast (NE) monsoon season that occurs from December to January. The sediment cover area could reach the latitude of 15°N that located at the south of the gulf. During southwest (SW) monsoon season that occurs from May to September, low and sparse SSC cover area is observed. As a consequence, the area covered by the SSC is higher during the NE monsoon season as compared to the SW monsoon season. Hence, the SSC cover area during the NE monsoon season is greater than the yearly averaged SSC cover area. Meanwhile the SSC cover area during the rainy SW monsoon season is less than the yearly and NE monsoon season.


Author(s):  
S. Pradhan ◽  
R. N. Samal ◽  
S. B. Choudhury ◽  
P. K. Mohanty

<p><strong>Abstract.</strong> Chilika lagoon, one of the largest brackish water lagoons in Asia located along the east coast of India. The rivers draining into the lagoon carry about 13 million tonnes of sediments annually. Because of the cohesiveness properties of the fine sediments, nutrients, heavy metals and other polluted substances tend to bind to the sediment’s surface. Consequently, pollutants can be concentrated in the inlets/estuaries, thus being of great environmental interest. In addition, the mudflats occurring are important biotopes for a large number of micro- and macro-faunal species and act as feeding places for a number of birds. To understand the cohesive sediment dynamics, a numerical model, MIKE 21 Mud Transport (MT) coupled with hydrodynamic (HD) was used. The model simulated the relative bed level height and suspended sediment concentrations. The sediment interchange and accumulation between each sectors and Bay of Bengal were evaluated. The suspended sediment concentration is high in the north-east portion of the lagoon while medium and low suspended loads are observed in the eastern and western portion of the lagoon. Bed thickness is very high in the north-western corner of the lagoon covered with Phragmites Karka which facilitate sediment trap. Total bed thickness change is very much pronounced in the northern sector which receives most of the sediments from the Mahanadi river systems as well along the periphery of the lagoon due to drainage. The eastern lagoon shows a net deposition accumulated fraction (5–15<span class="thinspace"></span>kg/m<sup>2</sup>) and hence gives enough indication of the sedimentation processes in the lagoon. Further, the results also warrant immediate attention to check and monitor suspended sediment concentration to find out the net deposition trend in the lagoon environment in order to take decisions in minimizing the sediment load.</p>


2012 ◽  
Vol 256-259 ◽  
pp. 2573-2576 ◽  
Author(s):  
Chao Feng Tong ◽  
Tao Yin ◽  
Jian Shi ◽  
Yu Yang Shao

For the construction of water conservancy project in the upstream of the Yangtze River and the human activities, the runoff and sediment discharge from the upstream to East China Sea have changed greatly. To explore the distribution characteristics of suspended sediment in Yangtze Estuary under the new upstream boundary condition, a 2-D flow-sediment numerical model including the Yangtze Estuary and the Hangzhou Bay was established. Four different runoffs, which are 4,620m³/s, 11,000m³/s, 75,900m³/s and 90,000m³/s respectively, and the correspond sediment discharges were considered. The result indicates that, with the increase of upstream runoff, the sediment intrusion from the top of the North Branch into the North Branch decreases and the suspended sediment concentration field in the South Branch changes is greater than that in the North Branch. In the same region, the sediment concentration decreases during rising tide while it increases at low tide. The change of the core position for suspended sediment field is insignificant.


Sign in / Sign up

Export Citation Format

Share Document