scholarly journals TOWARDS MODELLING COASTAL SEDIMENT TRANSPORT

1988 ◽  
Vol 1 (21) ◽  
pp. 144 ◽  
Author(s):  
Peter Nielsen
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Littoral Drift ◽  
Transport Models ◽  
Wave Flume ◽  
Oscillatory Velocity ◽  
Waves And Currents ◽  
Coastal Sediment Transport ◽  
Normal Transport ◽  
Insight Into

Sediment transport data from the field and laboratory tests are used to gain insight into two fundamental questions. Firstly: What is the relative importance of coexisting waves and currents for the resulting sediment transport? Secondly: Is the influence of grain size as strong as traditional models predict, or is it as weak as the empirical CERC-formula indicates? Wave tank data reveal that the oscillatory velocity will in most cases determine the direction as well as the magnitude of the shore normal sediment transport, and wave flume data on shore normal transport as well as field data on littoral drift show weaker grain size dependance than traditional sediment transport models predict. It is suggested that wave dominance as well as weak grain size dependence are manifestations of the fact that the dominant transport mechanisms are often more organised than the diffusion process on which many traditional models are based.

scholarly journals RIDGE-RUNNEL MIGRATION

2012 ◽  
Vol 1 (33) ◽  
pp. 46
Author(s):  
Jens Figlus ◽  
Nobuhisa Kobayashi ◽  
Christine Gralher
Keyword(s):  
Free Surface ◽  
Sediment Transport ◽  
Numerical Model ◽  
Fluid Velocity ◽  
Transport Mechanisms ◽  
Free Surface Elevation ◽  
Wave Flume ◽  
Mobile Bed ◽  
Dry Zone ◽  
Insight Into

The recovery of beaches after a storm can be influenced significantly by ridge-runnel migration. Ridges are made up of large volumes of sand which is important for the coastal sediment budget. The experiment described in this paper gives an insight into the complex hydrodynamics and sediment transport mechanisms related to onshore ridge-runnel migration. Detailed water free surface elevation, fluid velocity and sediment transport rate measurements were taken in a mobile bed wave flume with a focus on the effect of water ponding and runnel drainage on the profile evolution. The measured results have been used to calibrate the time-averaged numerical cross-shore model CSHORE. The model has the capability to deal with the effect of a pronounced profile depression (water-filled runnel) forming on the intermittently wet and dry zone of the beach. Results of the experiment compared with the corresponding numerical model computations show that the rapid onshore migration of a ridge-runnel system under fairly energetic wave conditions can be computed with CSHORE but further improvements of the model are necessary.

scholarly journals COMPARISON OF SEDIMENT TRANSPORT MODELS WITH IN-SITU SAND FLUX MEASUREMENTS AND BEACH MORPHODYNAMIC EVOLUTION

2012 ◽  
Vol 1 (33) ◽  
pp. 19
Author(s):  
Adrien Cartier ◽  
Philippe Larroudé ◽  
Arnaud Héquette
Keyword(s):  
Sediment Transport ◽  
Mediterranean Coast ◽  
Sand Transport ◽  
Transport Models ◽  
In Situ Data ◽  
Flux Measurements ◽  
Coastal Sediment Transport ◽  
Set Up ◽  
Sand Flux

The aim of this study is to set up a procedure of linking of three codes to be able to simulate realistic coastal sediment transport and associated morphological change. In order to calibrate sediment transport formulae, comparisons of our simulations were carried out with in-situ data of sand transport measured on macrotidal beaches of northern France on the shore of the English Channel and Dover Strait. This technique of simulation was then used to compare and investigate the efficiency of several sediment transport models on the site of Sète (microtidal beach on the Mediterranean coast) during two storms events.

scholarly journals Coastal Sediment Transport along Kalpakkam using Sediment Trend Exploaration and Numerical Modelling

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3011-3015
Keyword(s):  
Grain Size ◽  
Sediment Transport ◽  
Numerical Model ◽  
Numerical Modelling ◽  
Trend Analysis ◽  
Coastal Sediment ◽  
Sediment Grain Size ◽  
Coastal Sediment Transport ◽  
The Impact ◽  
Grain Size Trend Analysis

The impact of coastal sediment transport in the nearshore region is significant and the need for improved sediment quantification techniques appears to be universally accepted. The coastal sediment transport models presently in use were derived empirically from very sparse measurements of waves and currents and from laboratory experiments. The shoreline of Kadalur fishing villages near Kalpakkam has been experiencing erosion due to occurrence of cyclones every monsoon. Palar River with its confluence in the Bay of Bengal at the northern tip of the Kadalur villages has its mouth closed due to negligible river flow. The purpose of this study is to assess sediment dynamics in the Kalpakkam coast using two independent approaches; namely Sediment Trend Analysis (STA) and two dimensional numerical modelling. The latter can track the movement of individual particles. Numerical modelling approach is based on Delft3D model which allows the coupling of flow and wave modules. STA and numerical modelling results can provide sediment transport direction. The combination of both approaches provides a means of verification of sedimentation processes. The basic assumption in STA is that sediment transport can be responsible for the differences in sediment grain size distributions. For Grain Size Trend Analysis, grab samples were collected throughout the nearshore area. Grain Size Trend Analysis was then carried out and subsequent results were plotted to obtain the sediment transport pattern for the region. The results obtained are compared with the numerical model results and also used for validation of sediment transport evaluated using the numerical model.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

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