On the Validity and Limits of Continuous-Phase Modelling of Sediment Transport in Estuaries and Coastal Zones

2003 ◽  
pp. 207-210
Author(s):  
Erik A. Toorman
Keyword(s):  
Sediment Transport ◽  
Continuous Phase ◽  
Coastal Zones

scholarly journals Parallel algorithms for solving the problem of coastal bottom relief dynamics

2020 ◽  
pp. 196-206
Author(s):  
А.И. Сухинов ◽  
А.Е. Чистяков ◽  
Е.А. Проценко ◽  
В.В. Сидорякина ◽  
C.B. Проценко
Keyword(s):  
Sediment Transport ◽  
Parallel Algorithms ◽  
Stokes Equations ◽  
Water Environment ◽  
Continuous Model ◽  
State Equation ◽  
Navier Stokes ◽  
Coastal Zones ◽  
Navier Stokes Equations ◽  
Bottom Deformation

Предложена нестационарная 2D-модель транспорта донных отложений в прибрежной зоне мелководных водоемов, дополненная уравнениями Навье–Стокса, неразрывности и состояния водной среды. Дискретная модель транспорта наносов получена в результате аппроксимации соответствующей линеаризованной непрерывной модели. Поскольку задачи прогнозирования транспорта наносов требуют решения в реальном или ускоренном масштабах времени, на сетках, включающих 106–109 узлов, необходима разработка параллельных алгоритмов задач гидродинамики на системах с массовым параллелизмом. Представлены результаты работы созданного эффективного программного обеспечения для выполнения гидродинамических вычислительных экспериментов, позволяющие проводить численное моделирование деформации дна в прибрежной зоне водоема. Приведены результаты численных экспериментов. A nonstationary 2D model of bottom sediment transport in the coastal zones of shallow water reservoirs is supplemented with the Navier–Stokes equations, the continuity equation, and the state equation of the water environment. A discrete model of sediment transport is obtained by approximating the corresponding linearized continuous model. Since the problems of predicting sediment transport need to be solved in real or accelerated time scales, parallel algorithms for hydrodynamic problems on systems with mass parallelism should be developed on grids with 106–109 nodes. The paper contains the results obtained by an efficient software implemented to perform hydrodynamic computational experiments that allow the numerical modeling of bottom deformation in the coastal zones of reservoir. The results of numerical experiments are discussed.

scholarly journals The functionality of breakwaters systems for Mamaia Bay

2018 ◽  
Vol 27 (2018) ◽  
pp. 55-60
Author(s):  
Iulia-Alina Anton ◽  
Catalin Anton
Keyword(s):  
Sediment Transport ◽  
Human Impact ◽  
Coastal Zone ◽  
Coastal Erosion ◽  
Coastal Zones ◽  
Wave Regime ◽  
Protection Systems ◽  
Technical Construction

Year by year, the coastal zones are constantly changing due to the action of waves, tides, and human impact. The shoreline has been particularly influenced by the human impact over the years, especially by the location of hydro-technical construction to prevent erosion or floods. Thus, the problem of coastal erosion appears as an effect of sediment transport, modifying shore morphology. In this paper, we intend to study the hydrodynamic of the Romanian Coastal zone and the wave regime alteration due to the protection systems.

scholarly journals PREDICTION ON MORPHOLOGICAL RESPONSE OF DREDGED SAND-BORROW PITS

2011 ◽  
Vol 1 (32) ◽  
pp. 74 ◽  
Author(s):  
Qimiao Lu ◽  
Robert B. Nairn
Keyword(s):  
Sediment Transport ◽  
Environmental Impacts ◽  
Transport Model ◽  
Atlantic Coast ◽  
Coastal Zones ◽  
Morphological Response ◽  
Concept Model ◽  
Simple Concept ◽  
Sediment Transport Model

Dredged pits in coastal zones are generally required for sand borrows for beach nourishment. The morphological response of borrow pits is important to evaluate future environmental impacts and potential impacts to adjacent seabed infrastructure such as pipelines. This paper will present the development of a simple concept model for the prediction of morphological response of dredged pits. A 3D hydrodynamic and sediment transport model was applied to verify the developed simple concept model. The case study for a sand-borrow pit on the offshore of Louisiana at the Atlantic coast of USA will be updated. The strengths and limitations of the developed model will be also discussed.

scholarly journals Why and How Do We Study Sediment Transport? Focus on Coastal Zones and Ongoing Methods

Water ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 390 ◽  
Author(s):  
Sylvain Ouillon
Keyword(s):  
Sediment Transport ◽  
Coastal Zones

scholarly journals TEMPORAL VARIABILITY OF LONGITUDINAL SEDIMENT TRANSPORT ON THE BRAZILIAN CONTINENTAL SHELF

2019 ◽  
Vol 18 (1) ◽  
pp. 15
Author(s):  
T. B. Trombetta ◽  
W. C. Marques ◽  
P. H. Oleinik ◽  
R. C. Guimarães ◽  
T. F. Leal ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Wavelet Analysis ◽  
Temporal Variability ◽  
Wave Climate ◽  
Brazilian Coast ◽  
Coastal Zones ◽  
Empirical Formulas ◽  
Northern Regions ◽  
Management Plans ◽  
Alongshore Sediment Transport

The sediment transported along the coast can alter the existing balance in certain environments, causing or accelerating erosive processes, and resulting in economic and environmental damages. In this way, predicting changes in the coastal zone and understanding the beach processes is an essential source of information for the elaboration of coastal management plans. In this context, the present work aims to estimate the alongshore sediment transport (LST) in several sectors of the Brazilian Coast, identifying the annual average and the predominant transport. This study was conducted for the period between the years 1979 and 2015, using computational modeling to investigate the behavior of the waves, and empirical formulas to calculate the LST rates. In addition, the temporal variability was investigated through the wavelet analysis. The results showed a great diversity in the wave climate behavior along the Brazilian Coast, presenting a good correlation in terms of magnitude between the estimation of LST and past studies in the different sectors analyzed. The place where transport has become pronounced understands the sector between Alagoas and Rio Grande do Norte states, while the opposite was observed in the Southern part of Bahia. The wavelet analysis showed that the spectrum of LST time series has a significant amount of energy for processes with a seasonal and annual variability, indicating that the northern regions of Brazil are most affected by the interannual processes. In this sense, informations along the Brazilian coast are presented, that may be considered in future projects, involving the sustainable management of the coastal zones.

scholarly journals The Influence of Wave Nonlinearity on Cross-Shore Sediment Transport in Coastal Zone: Experimental Investigations

2020 ◽  
Vol 10 (12) ◽  
pp. 4087
Author(s):  
Yana Saprykina
Keyword(s):  
Energy Transfer ◽  
Sediment Transport ◽  
Second Harmonic ◽  
Breaking Waves ◽  
Wave Transformation ◽  
Experimental Investigations ◽  
Harmonic Amplitude ◽  
Linear Wave ◽  
Coastal Zones ◽  
Non Linear

On the basis of field experiment data, the main features of influence of non-linear wave transformation scenarios on cross-shore sediment transport in coastal zones were investigated. The bottom deformations due to the non-linear wave transformation follow the specific scenario. The increase in the second non-linear harmonic amplitude leads to the erosion of the underwater slope at the distances corresponding to this process, with the subsequent accumulation of sandy material closer to the shore at distances where the amplitude decreases during the backward energy transfer to the first harmonic. This can be explained by the change in the phase shift between harmonics during non-linear wave transformation. The second harmonic maximum provides the point near which the bottom deformations occur in different directions. Scenarios of non-linear wave transformation in which backward energy transfer from the second non-linear harmonic to the first is close to the shoreline will contribute to the transport and accumulation of the sediment on the coast. These scenarios are more characteristic of “small waves”. The scenario without a periodical exchange of wave energy between non-linear harmonics (with an increase in the second harmonic only) that is characteristic of large storm waves and plunging breaking waves will lead to the erosion of the underwater bottom profile.

scholarly journals VERTICAL VARIABILITY OF COASTAL SEDIMENT TRANSPORT

1988 ◽  
Vol 1 (21) ◽  
pp. 126
Author(s):  
Ryszard B. Zeidler
Keyword(s):  
Sediment Transport ◽  
Eddy Diffusivity ◽  
Sediment Concentration ◽  
Continuous Functions ◽  
Mathematical Tool ◽  
Vertical Profiles ◽  
Coastal Zones ◽  
Vertical Coordinate ◽  
Time Space ◽  
Waves And Currents

The semiempirical theory of turbulent diffusion may be used as a mathematical tool for description of suspended sediment mechanics. The Author's solutions, with their exponential vertical profiles of sediment concentration, are presented in various ranges of time, space, and external factors. The inherent concept of eddy diffusivity K is shown to be ambiguous and incoherent. Therefore it is purposeless to investigate thoroughly the vertical profiles and other details of K. Accordingly, the Author makes use of his own and alien laboratory and field findings to propose such estimates of K under regular waves and currents which are not continuous functions of the vertical coordinate but instead are locally averaged over depth layers. These estimates become more complex in real coastal zones due to the randomness of waves and currents, wave breaking, three-dimensionality and nonstationarity of nearbed turbulence, a variety of interactions, and other sources of sediment dispersion. Hence gross estimates of averaged K seem even more appropriate; some formulae are put forward. The vertical profiles of sediment concentration are presented herein along with examples of sediment transport rates measured in nearshore zones.

scholarly journals SCALE RELATIONS FOR EQUILIBRIUM BEACH PROFILES

1978 ◽  
Vol 1 (16) ◽  
pp. 90 ◽  
Author(s):  
Hideaki Noda
Keyword(s):  
Sediment Transport ◽  
Scaling Law ◽  
Experimental Tests ◽  
Coastal Engineering ◽  
Scale Model ◽  
Light Weight ◽  
Coastal Zones ◽  
Scale Models ◽  
Model Law ◽  
Movable Bed

There are many practical problems related to coastal engineering, which may be solved by using movable bed scale models of the coastal zone. The scale model must obey the laws of sediment transport in order to obtain satisfactory results. However, sediment transport in the coastal zones is so complex that the mechanism is not fully understood. Some authors have attempted to find a model law relationship for equilibrium beach profiles. Yalin-'-^ derived a scale law for the offshore zone using a bed velocity based on laminar boundary conditions. Brebner, Karaphuis and Paul^' have performed extensive experimental tests on movable-bed models using light weight sediment, and Le Mehaute^) presented a scaling law for coastal movable-bed models in the breaker zones. The purpose of this study is finally to determine the scale law relationship for coastal movable-bed model. As first step, this paper concerns itself with the derivation of proper scale laws for modeling of equilibrium beaches.

scholarly journals Comparison of computational efficiency of explicit and implicit schemes for the sediment transport problem in coastal zones

2015 ◽  
pp. 328-338
Author(s):  
А.И. Сухинов ◽  
Е.А. Проценко ◽  
А.Е. Чистяков ◽  
С.А. Шретер
Keyword(s):  
Sediment Transport ◽  
Transport Model ◽  
Three Dimensional ◽  
Critical Shear Stress ◽  
Physical Parameters ◽  
Variable Geometry ◽  
Coastal Zones ◽  
Sediment Transport Model ◽  
Level Elevation ◽  
Wind Flows

Рассмотрена нестационарная пространственно-двумерная модель транспорта наносов в прибрежной зоне водоемов, учитывающая следующие физические параметры и процессы: пористость грунта; критическое значение касательного напряжения, при котором начинается перемещение наносов; турбулентный обмен; динамически изменяемую геометрию дна и функцию возвышения уровня; ветровые течения; трение о дно. Построены и программно реализованы на кластере распределенных вычислений пространственно-трехмерная модель гидродинамики в прибрежной зоне водоемов и модель транспорта взвешенных частиц. Приведены результаты численных экспериментов. An unsteady spatial two-dimensional sediment transport model in coastal zones is considered. The model takes into account the following physical parameters and processes: the soil porosity; the critical shear stress at which the sediment displacement begins; the turbulent exchange; the dynamically variable geometry of the bottom and the level elevation function; the wind flows; and the bottom friction. A spatial three-dimensional hydrodynamic model for coastal zones and a transport model for suspended particles are proposed and implemented on a computing cluster. Some numerical results are discussed.

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