scholarly journals Structure of turbulence and sediment stratification in wave-supported mud layers

2015 ◽  
Vol 120 (4) ◽  
pp. 2430-2448 ◽  
Author(s):  
Abbas Hooshmand ◽  
Alexander R. Horner-Devine ◽  
Michael P. Lamb
Keyword(s):  
Sediment Stratification

scholarly journals Sensitivities of Bottom Stress Estimation to Sediment Stratification in a Tidal Coastal Bottom Boundary Layer

2020 ◽  
Vol 8 (4) ◽  
pp. 256
Author(s):  
Yun Peng ◽  
Qian Yu ◽  
Yunwei Wang ◽  
Qingguang Zhu ◽  
Ya Ping Wang
Keyword(s):  
Velocity Distribution ◽  
Critical Role ◽  
Sediment Concentration ◽  
Distribution Models ◽  
Bottom Boundary ◽  
Field Investigations ◽  
Bottom Boundary Layers ◽  
Direct Covariance ◽  
Stress Estimation ◽  
Sediment Stratification

The bottom friction velocity (U*), which controls seabed erosion and deposition, plays a critical role in sediment transport in tidal coastal bottom boundary layers. Approaches have been proposed to calculate U*, including the log profile (LP) estimation, the direct covariance (COV) measurement, and the turbulent kinetic energy (TKE) method. However, the LP method assumes homogeneous flow and the effects of stratification need to be taken into account. Here, field investigations of hydrodynamics and sediment dynamics were carried out on the Jiangsu Coast, China. Two acoustic Doppler velocimeters (ADV) velocity measurements at 0.2 and 1 m above the seabed have been used to estimate U*, based on the aforementioned three methods. The COV and TKE methods provided reasonable estimations of U*, while a pronounced overestimation was identified when using the LP method. This overestimation can be attributed to the stratification effects associated with the vertical suspended sediment concentration (SSC) gradient near the bottom. Then, three models were utilized to correct the overestimation, in which the gradient/flux Richardson number was modified with empirical constants α, β, and A to parameterize the stratification effects in the logarithmic velocity distribution. The values of α, β, and A derived from the observation are smaller than the results from previous investigations. These modified logarithmic velocity distribution models can be applied in numerical simulations when sediment stratification is important.

Observations of suspended sediment stratification from acoustic backscatter in muddy environments

2013 ◽  
Vol 336 ◽  
pp. 24-32 ◽  
Author(s):  
Cihan Sahin ◽  
Ilgar Safak ◽  
Tian-Jian Hsu ◽  
Alexandru Sheremet
Keyword(s):  
Suspended Sediment ◽  
Acoustic Backscatter ◽  
Sediment Stratification

scholarly journals Synergetic CT, XRF and Geoelectric Imaging for Non-Destructive Soil and Sediment Stratigraphic Study

2021 ◽  
Vol 11 (20) ◽  
pp. 9575
Author(s):  
Pavlos Avramidis ◽  
Alexandros Emmanouilidis ◽  
Paraskevas Paraskevopoulos ◽  
Zafeiria Roumelioti ◽  
Pantelis Barouchas
Keyword(s):  
Clay Content ◽  
Geophysical Research ◽  
Undisturbed Soil ◽  
Sediment Properties ◽  
Soil Sediment ◽  
Xrf Scanning ◽  
Ground Truthing ◽  
Non Destructive ◽  
Sediment Stratification ◽  
Soil And Sediment

This paper presents the application of three non-destructive techniques in the study of an agricultural area on the west coast of Peloponnese, Greece. The applied methods include (a) electromagnetic geophysical research using a handheld EM profiler (EMP-400 GSSI), (b) computed tomography (CT) with coring data, and (c) X-ray Fluorescence (XRF) scanning. As electrical conductivity is mainly influenced by the bulk soil, including water content, clay content and mineralogy, organic matter, and bulk density, a comparison of the three applied techniques indicates the same soil stratification and same soil properties with depth. Moreover, the ground-truthing by the undisturbed soil and sediments core retrieved in the centre of the site as well as the laboratory analyses of soil and sediment properties confirm the reliability of the geophysical research and the revealed soil/sediment stratification.

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