scholarly journals LONGSHORE TRANSPORT EVALUATIONS AT A DETACHED BREAKWATER

1980 ◽  
Vol 1 (17) ◽  
pp. 86 ◽  
Author(s):  
R.O. Bruno ◽  
R.G. Dean ◽  
C.G. Gable
Keyword(s):  
Sediment Transport ◽  
Engineering Research ◽  
Pressure Transducers ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Wave Energy Flux ◽  
Correlation Constant ◽  
Wave Induced ◽  
The Relationship ◽  
The Waves

A field experiment was conducted by the Coastal Engineering Research Center (CERC) to develop correlations between wave characteristics and longshore sediment transport. The waves were measured by two near-bottom mounted pressure transducers and the average longshore sediment transport rates were determined from sequential volumetric surveys behind an offshore breakwater which was regarded as a total trap. The data analyzed herein encompass a period of nine months during which a total accumulation of 675,000 m3 occurred as documented by eight surveys. Spectral analyses of the wave data were conducted and yielded one direction per frequency. The correlations include immersed weight sediment transport rate, I, versus (1) longshore component of wave energy flux at breaking, P&Sf and (2) the onshore flux of the longshore component of wave-induced momentum, S „. The most widely used correlation constant, K, in the relationship I = KPjig is 0,77. The best-fit values found from the data were K = 0.65 and 0.92 for linear and log best-fits, respectively, as based on the p£s values directed toward the trap. The corresponding values of KA (dimensional) relating I and Sxv are 4.98 m/s and 6.37 m/s, respectively. One feature of this type of trap is the potential for overtrapping if the waves are directed nearly normal to shore.

scholarly journals LONGSHORE TRANSPORT DETERMINED BY AN EFFICIENT TRAP

1982 ◽  
Vol 1 (18) ◽  
pp. 60 ◽  
Author(s):  
R.G. Dean ◽  
E.P. Berek ◽  
C.G. Gable ◽  
R.J. Seymour
Keyword(s):  
Sediment Transport ◽  
Field Component ◽  
Santa Barbara ◽  
Wave Characteristics ◽  
Nearshore Sediment Transport ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Correlation Constant ◽  
The Relationship ◽  
Best Fit

The Nearshore Sediment Transport Study (NSTS), sponsored by the National Sea Grant Office included a field component to quantify the total longshore sediment transport relationship. This component was conducted at Santa Barbara, California and encompassed a period of eighteen months during which ten surveys were conducted. To date, eight of these surveys have been analyzed, yielding seven intersurvey periods. A total of 288,600 m3 of net sediment transport was documented by these eight surveys. The wave characteristics are based on one of two Sxy gages located in a water depth of 7 m. The most widely used correlation constant, K, in the relationship I = KP, is 0.77. The values found from the data were 0.93 and 1.23 for linear and log best-fit values, respectively. The corresponding values of K4 relating I and S are 2.60 and 2.63 m/s, respectively.

scholarly journals LONGSHORE TRANSPORT AT A TOTAL LITTORAL BARRIER

1976 ◽  
Vol 1 (15) ◽  
pp. 70 ◽  
Author(s):  
Richard O. Bruno ◽  
Christopher G. Gable
Keyword(s):  
Sediment Transport ◽  
Accurate Determination ◽  
Coastal Engineering ◽  
Channel Islands ◽  
Shore Protection ◽  
Material Transport ◽  
Engineering Research ◽  
Longshore Sediment Transport ◽  
Longshore Transport

Analysis of longshore transport at a littoral barrier is presented. Channel Islands Harbor, California was selected as the study site because its offshore breakwater and jetties form a unique complete littoral barrier. Through repetitive surveys an accurate determination of longshore material transport in one direction was made. Measured transport rates ranged from 160,000 to 1,284,000 cubic meters per year. Utilizing visual observations of surf parameters, estimates of longshore wave thrust were computed. The range of wave thrust was 145 to 1,988 Newtons per meter. Comparison of the relation of wave thrust and longshore sediment transport is made. This study indicates that in an environment of high transport, nearly twice as much transport is predicted tinder corresponding wave thrust as that of the data summarized in the Coastal Engineering Research Center's Shore Protection Manual.

scholarly journals APPLICATION OF A SEMI-EMPIRICAL LONGSHORE TRANSPORT FORMULATION

2012 ◽  
Vol 1 (33) ◽  
pp. 22
Author(s):  
Giuseppe Barbaro ◽  
Giuseppe Roberto Tomasicchio ◽  
Giovanni Malara ◽  
Felice D'Alessandro
Keyword(s):  
Sediment Transport ◽  
Transport Rate ◽  
Sediment Transport Rate ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Semi Empirical

The present paper deals with the determination of longshore sediment transport rate. Specifically, case study of Saline Joniche (Reggio Calabria, Italy, is discussed. This case is of interest because, in this location, an artificial basin was built in the 70’s. After few years, port entrance experienced total obstruction by sand. Actually, the area is abandoned and several projects have been proposed for revitalising port activities. This paper discusses a method for estimating the longshore sediment transport rate at Saline Joniche and complements previous methodology.

scholarly journals SIMULATION OF LONG-TERM SHORELINE CHANGE DRIVEN BY LONGSHORE AND CROSS-SHORE SEDIMENT TRANSPORT

2020 ◽  
pp. 31
Author(s):  
Yan Ding ◽  
Sung-Chan Kim ◽  
Richard B. Styles ◽  
Rusty L. Permenter
Keyword(s):  
Sediment Transport ◽  
Shoreline Change ◽  
Breaking Wave ◽  
Beach Profile ◽  
Shoreline Evolution ◽  
Longshore Sediment Transport ◽  
Wave Energy Flux ◽  
Semi Empirical ◽  
Evolution Modeling

Driven by wave and current, sediment transport alongshore and cross-shore induces shoreline changes in coasts. Estimated by breaking wave energy flux, longshore sediment transport in littoral zone has been studied for decades. Cross-shore sediment transport can be significant in a gentle-slope beach and a barred coast due to bar migration. Short-term beach profile evolution (typically for a few days or weeks) has been successfully simulated by reconstructing nonlinear wave shape in nearshore zone (e.g. Hsu et al 2006, Fernandez-Mora et al. 2015). However, it is still lack of knowledge on the relationship between cross-shore sediment transport and long-term shoreline evolution. Based on the methodology of beach profile evolution modeling, a semi-empirical closure model is developed for estimating phase-average net cross-shore sediment transport rate induced by waves, currents, and gravity. This model has been implemented into GenCade, the USACE shoreline evolution model.

scholarly journals TRANSPORT OF NILE SAND ALONG THE SOUTHEASTERN MEDITERRANEAN COAST

1984 ◽  
Vol 1 (19) ◽  
pp. 87
Author(s):  
Zev Carmel ◽  
Douglas L. Inman ◽  
Abraham Golik
Keyword(s):  
Sediment Transport ◽  
Transport Mechanism ◽  
Nile Delta ◽  
Mediterranean Coast ◽  
Longshore Sediment Transport ◽  
Transport Path ◽  
Directional Wave ◽  
Wave Induced ◽  
Annual Transport ◽  
Good Agreement

The potential for longshore sediment transport (LST) is estimated from a three-year set of directional wave data measured off Haifa, Israel. The resulting annual cycle of LST, together with an analysis of the wave and shore characteristics, suggests a wave-induced sediment transport mechanism with a uni-directional annual transport that gradually decreases along the transport path from the source (Nile delta) to sink (Haifa Bay). Existing estimates of the rates of transport of Nile sediment are in good agreement with this result.

scholarly journals COASTAL ARMORING: EFFECTS, PRINCIPLES AND MITIGATION

1986 ◽  
Vol 1 (20) ◽  
pp. 135 ◽  
Author(s):  
R.G. Dean
Keyword(s):  
Sediment Transport ◽  
Adverse Effects ◽  
Field Data ◽  
Surf Zone ◽  
Local Scour ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Severe Erosion ◽  
Substantial Distance ◽  
Factual Data

An attempt is made to conduct a rational assessment of the potential adverse effects of coastal armoring on adjacent shorelines and to propose methodology for mitigation, where appropriate. Specific attention is directed toward claims that armoring causes: profile steepening, increased longshore sediment transport, intensified local scour, transport of sand to substantial offshore distances, etc. The assessment presented here is based on a combination of sound principles and the availability or lack, of laboratory and field data to either support or refute the claims. Although it is found that data relating to coastal armoring effects are sparse, conclusions can be drawn. There seems to be no factual data to support the contentions that armoring causes profile steepening, increased longshore transport, transport of sand to a substantial distance offshore, or significantly delayed profile recovery following a severe erosion event. Armoring does have the potential to cause intensified local scour both in front of and at the ends of an armored segment. Reasons for these effects, based on knowledge of response of a natural profile, are presented. Additionally, armoring which projects into the active surf zone can act as a partial barrier to the net longshore sediment transport, thereby causing downdrift erosion. Methodology is presented for quantifying the appropriate mitigation for a particular armoring situation. The proposed mitigation is the annual placement of sand in the vicinity of the armoring to offset its potential adverse effects. The two potential adverse effects addressed in the methodology include the reduction of sediment supplied to the system as a result of the armoring and the blockage of longshore sediment transport by a protruding armoring installation.

scholarly journals MODELING SEDIMENTATION AT INLET AND COASTAL REGION

1972 ◽  
Vol 1 (13) ◽  
pp. 44
Author(s):  
Pang-Mou Lin
Keyword(s):  
Sediment Transport ◽  
Coastal Region ◽  
Shear Stresses ◽  
Wave Steepness ◽  
Coastal Regions ◽  
Longshore Sediment Transport ◽  
Flume Tests ◽  
Bed Materials ◽  
The Relationship ◽  
Fluid Characteristic

Sediment transport In the vicinity of inlets and coastal regions depends on the combined bottom shear stresses due to both currents and waves. The modeling of the movement of bedload is controlled by the Proude law, bottom shear stress, wave steepness, and friction factor. Assuming Einstein's theory of bedload function can be applied to this study, an analysis was performed after conducting experiments in the flume and model basin. A series of results obtained from the flume tests is to Insure the relationship between the fluid characteristic and the movement of bedload. The final results concerning the longshore sediment transport appeared satisfactory with the estimated curves. The bottom configurations in the Inlet after each test were also shown satisfactorily similar. The sedimentologlcal time scale for the three bed materials were not In satisfactory agreement, however, more discussion of the results was presented in this paper.

scholarly journals CAPACIDAD DE TRANSPORTE POTENCIAL LONGITUDINAL DE SEDIMENTOS A ESCALA INTRAANUAL EN PUNTA YARUMAL, DELTA DEL RÍO TURBO, GOLFO DE URABÁ, A PARTIR DE LA SIMULACIÓN DE UN CLIMA MARÍTIMO

2016 ◽  
Vol 43 (2) ◽  
Author(s):  
Luis Gabriel Molina Flórez ◽  
Andrés Fernando Osorio Arias ◽  
Luis Jesús Otero Díaz
Keyword(s):  
Sediment Transport ◽  
Eastern Margin ◽  
Area Of Interest ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Del Rio

In this article we estimate the rate of intra-annual and annual longshore sediment transport, inflenced by waves in the delta formed by the mouth of the Turbo river, located on the eastern margin of the Gulf of Urabá, specifially Punta Yarumal, from three equations proposed by various authors. The article contains an overview of the area of interest, a summary of the chosen methodology to develop this study, and fially, once the estimated longshore transport rates are calculated, the results, discussion and conclusions are presented.

Sea wave propagation from offshore to Maputo's coast. Application to longshore sediment transport assessment

2014 ◽  
Vol 69 (12) ◽  
pp. 2438-2445
Author(s):  
Cristina N. A. Viola ◽  
Manel Grifoll ◽  
Jaime Palalane ◽  
Tiago C. A. Oliveira
Keyword(s):  
Wave Propagation ◽  
Sediment Transport ◽  
Coastal Region ◽  
Wave Theory ◽  
Wave Climate ◽  
Linear Wave ◽  
Engineering Research ◽  
Longshore Sediment Transport ◽  
Mesh Resolution ◽  
Offshore Wave

This study aims to characterize the wave climate near the coastal region of Maputo (Mozambique), and to provide a first assessment of the sediment transport load in this area. A time-series of 13 years' worth of offshore wave data, obtained from reanalysis products, was propagated to the coast. Wave propagation was performed using Linear Wave theory and the numerical model, Simulating WAves Nearshore (SWAN). Propagations with SWAN were carried out considering different scenarios in order to evaluate the influence of parameters such as wind, tidal level, frequency spectrum and numerical mesh resolution on wave characteristics along the coast. The prevalent waves propagated came from between east and southwest directions. Results from linear propagation were used to estimate the potential longshore sediment transport. The Coastal Engineering Research Center formula was applied for a stretch of beach in the Machangulo Peninsula. A net potential rate of longitudinal sediment transport (of the order of 105 m3/year, along an extension of the coast of 21 km) was directed northwards, and was consistent with the frequent wave directions.

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