Longshore sediment transport and a sediment for the Malpeque barrier system, southern Gulf of St. Lawrence

1977 ◽  
Vol 14 (11) ◽  
pp. 2429-2439 ◽  
Author(s):  
J. W. Armon ◽  
S. B. McCann
Keyword(s):  
Sediment Transport ◽  
Transport System ◽  
Prince Edward Island ◽  
Barrier Island ◽  
Sediment Budget ◽  
Budget Analysis ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Principal Source ◽  
Wave Hindcasting

Wave hindcasting and refraction techniques were used to establish inshore wave conditions and longshore sediment transport rates along a 43 km barrier island shoreline at Malpeque, Prince Edward Island, in the southern Gulf of St. Lawrence. Net longshore sediment transport is directed southeastwards, at rates varying from 40 000 m3 year−1 to greater than 200 000 m3 year−1. The information on longshore transport was combined with volumetric estimates of shore normal sedimentary exchanges to define the sediment budget of the barrier sands at Malpeque. The results of the budget analysis indicate that subtidal erosion in the shoreface zone is the principal source of sand for the longshore transport system.

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 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 A COMPREHENSIVE SEDIMENT BUDGET FOR THE MISSISSIPPI BARRIER ISLANDS

2012 ◽  
Vol 1 (33) ◽  
pp. 81 ◽  
Author(s):  
Dirk-Jan Walstra ◽  
J. De Vroeg ◽  
J. Van Thiel de Vries ◽  
C. Swinkels ◽  
A. Luijendijk ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Transport Model ◽  
Barrier Islands ◽  
Sediment Budget ◽  
Littoral Drift ◽  
Island Restoration ◽  
Mississippi Sound ◽  
Longshore Transport ◽  
Sound Side ◽  
Order Of Magnitude

In order to conceive any realistic plan for post-Katrina island restoration, it is necessary to understand the physical processes that move sand along the littoral drift zone off the coast of Mississippi. This littoral zone influences the character of the Mississippi barrier islands as they exist in an ever changing cycle. To help in this understanding, a sediment transport model was conducted to establish a current sediment budget for the islands. This study evaluated the existing regional sediment transport magnitudes and directions for the Mississippi and Alabama barrier islands fronting Mississippi Sound including daily conditions and hurricanes. A method was developed to incorporate all relevant hurricanes from 1917 to 2010 in the analysis. For the long term average net longshore transport along the southern shorelines of the barriers (i.e. exposed to the Gulf of Mexico), the contribution of year-averaged conditions and hurricanes are of similar order of magnitude, although the mean annual percentage occurrence of hurricanes is no more than about 3%. Along the northern shores (Mississippi Sound side) the transport is considerably smaller and the contributions of cold fronts and hurricanes to the sediment transports are more or less equal. For the year-averaged conditions (excluding hurricanes) a westward directed net transport is found. The net effect of the historic hurricanes is also westward in direction. However, for individual hurricanes (e.g. Camille and Katrina) the net transport along Ship Island can be directed eastward due to the dominance of ebb flows after the eye of the hurricane had passed.

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 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 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.

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