Aagaard, T., and B. Greenwood, Longshore and Cross-Shore Suspended Sediment Transport At Far Infragravity Frequencies in a Barred Environment, Continental Shelf Research, 15 (10), 1235-1249, 1995.

Field measurements of near-bed current velocities and sediment concentrations within a barred nearshore environment revealed a large flux coupling at far infragravity frequencies (<0.005 Hz). In the presence of strong longshore currents (time- averaged maximum = 0.92 m s(-1)), up to 30% of the longshore and 65% of the cross-shore suspended sediment transport can be attributed to far infragravity oscillations. While the former was always directed with the longshore current, the latter was variable in direction both spatially and temporally. A number of features of the measured far infragravity energy fit characteristics of a shear wave: (a) a large positive correlation between the long wave energy magnitude and the longshore current velocity; (b) the presence of a preferred frequency for the measured long wave; (c) a spatial variability in the ratio of cross-shore to longshore velocity at the preferred frequency; (d) the relatively small surface expression of the long wave compared to the large magnitude velocities recorded at the preferred frequency.

Abramov, A.A., A.E. Mikhinov, and V.I. Ulyanova, Effect of horizontal turbulent viscosity on hydrodynamic instability of longshore currents generated by waves, Okeanologiya, 37 (3), 359-364, 1997.

A numerical model of the hydrodynamic instability of longshore currents generated in the surf-zone by not normal incident sea waves is proposed. As a result of the numerical analysis, of the Orr-Zommerfeld equation the contribution of the horizontal turbulent viscosity in to instability processes and hydraulic limits determining the realization of different types of the hydrodynamic instability in the surf-zone are estimated, The results of calculations by different models obtained by the authors are compared with field and laboratory data.

Abramov, A.A., A.Y. Mikhinov, and V.I. Ulyanova, The instability of longshore currents in the breaker zone, Computational Mathematics and Mathematical Physics, 36 (10), 1407-1413, 1996.

The problem in the title is reduced to finding the eigenvalues and eigenfunctions of the Orr-Sommerfeld equation. The formulation and method for the numerical solution of the problem are described. The model and the results obtained are discussed and compared with other models and the results of natural observations in the marine nearshore zone. (C) 1997 Elsevier Science Ltd. All rights reserved.

Ahrendt, K., and R. Koster, An artificial longshore bar at the west coast of the island of Sylt German Bight - First experiences, Journal of Coastal Research, 12 (1), 354-367, 1996.

A section of the beach at the west coast of the island Sylt near Kampen, which was particularly endangered by coastal erosion, was protected by means of an artificial longshore bar in 1990. Three years later a significant improvement in the coastal structure can be recognized. A high and wide longshore bar has developed and leeward, the beach has widened as well. The longshore sediment transport rate was reduced to C-a = 0.3345* C-o(0.8676) the mobility (duration) of the sand decreased (increased). The position, height and length of artificial longshore bars must agree with local, natural conditions.

Allen, J.R., Field Measurement of Longshore Sediment Transport - Sandy-Hook, New-Jersey, Usa, Journal of Coastal Research, 1 (3), 231-240, 1985.


Allender, J.H., and J.D. Ditmars, Field-Measurements of Longshore Currents On a Barred Beach, Coastal Engineering, 5 (4), 295-309, 1981.


Antia, E.E., On the significance of ebb-tidal deltas to the development of the subtidal longshore-rhythmic morphology (Sagezahnriffe) along the German North Sea coast, Zeitschrift Fur Geomorphologie, 40 (4), 477-485, 1996.

The significance of headlands (ebb-tidal deltas) to the development of the subtidal longshore-rhythmic morphology (Sagezahnriffe) along the German North Sea coast is assessed based on a comparative study of sounding charts of two neighbouring East Frisian barrier islands (Spiekeroog and Wangerooge). The morphology is well-developed along Spiekeroog Island, which is bounded at both ends by well-developed ebb tidal-deltas, but disappears abruptly along Wangeroog Island, whose east end is flanked by a less well-developed ebb-delta. This observation suggests that the rhythmic morphology might owe its origin to a longshore-standing edge-wave oscillation, which is generated when a progressive edge wave is effectively reflected at the ebb-deltas flanking each island. Due to the potentially poor reflection of an edge wave at the eastern ebb- delta of Wangerooge, the rhythmic form is expectedly less developed along the island. It is concluded that the morphology is unlikely to be sand waves or dunes, because the formation of flow-transverse bedforms is not controlled by the character of headlands.

Armon, J.W., and S.B. McCann, Longshore Sediment Transport and a Sediment Budget For Malpeque Barrier System, Southern Gulf-of-St-Lawrence, Canadian Journal of Earth Sciences, 14 (11), 2429-2439, 1977.


Armon, J.W., and S.B. McCann, Longshore Variations in Shoreline Erosion, Malpeque Barrier System, Prince Edward Island, Canadian Geographer-Geographe Canadien, 23 (1), 18-31, 1979.


Ashley, G.M., S.D. Halsey, and C.B. Buteux, New-Jersey Longshore-Current Pattern, Journal of Coastal Research, 2 (4), 453-463, 1986.


Austin, D.I., and P. Bettess, Longshore Boundary-Conditions For Numerical Wave Models, International Journal For Numerical Methods in Fluids, 2 (3), 263-276, 1982.


Baquerizo, A., M. Caballeria, M.A. Losada, and A. Falques, Frontshear and backshear instabilities of the mean longshore current, Journal of Geophysical Research-Oceans, 106 (C8), 16997-17011, 2001.

An analytical model based on Bowen and Holman [1989] its used to prove the existence of instabilities due to the presence of a second extremum of the background vorticity at the front side of the longshore current. The growth rate of the so-called frontshear waves depends primarily upon the frontshear but also upon the backshear and the maximum and the width of the current. Depending on the values of these parameters, either the frontshear or the backshear instabilities may dominate. Both types of waves have a cross-shore extension of the order of the width of the current; but the frontshear modes are localized closer to the coast than are the backshear modes. Moreover, under certain conditions both unstable waves have similar growth rates with close wave numbers and angular frequencies, leading to the possibility of having modulated shear waves in the alongshore direction. Numerical analysis performed on realistic current profiles confirm the behavior anticipated by the analytical model. The theory has been applied to a current profile fitted to data measured during the 1980 Nearshore Sediment Transport Studies experiment at Leadbetter Beach that has an extremum of background vorticity at the front side of the current. In this case and in agreement with field observations, the model predicts instability, whereas the theory based only on backshear instability failed to do so.

Bartholoma, A., H. Ibbeken, and R. Schleyer, Modification of gravel during Longshore transport (Bianco Beach, Calabria, southern Italy), Journal of Sedimentary Research, 68 (1), 138-147, 1998.

The 8 km Bianco Beach Is a wave-dominated high-energy beach composed of sand and gravel, The fluvial gravel output of the Laverde River feeding the Bianco Beach is well defined in terms of petrographic composition, sphericity, and roundness, During the high-energy (storm) stage the entire beach gravel population is transported 200 m offshore perpendicular to the coast, Strong attrition occurs and the amount of less resistant gneiss decreases, The net longshore transport is northward; roundness Increases but sphericity remains almost unchanged, During the medium energy (post-storm) stage, when fair-weather conditions begin to rebuild the beach berm, attrition and rounding are no longer significant, Instead, redistribution and redeposition according to grain size and shape dominates the cross shore gravel movement with a decrease of sphericity from the offshore to the backshore, Net longshore transport is still northward, sphericity again remaining almost unchanged, During the geologically ineffective low-energy (fair-weather) stage there is some sediment movement along the foreshore, but without ally significant gravel exchange between individual beach zones normal to the beach, Such extended fair-weather conditions conserve the sedimentological changes that occurred during higher-energy events, As a result, the proportion of gneiss decreases from 56% to 31% in the net transport direction, whereas the sphericity decreases only from 0.68 to 0.64, Perpendicular to shore the proportion of gneiss decreases seawards from 50% to 37% and the sphericity decreases landward from 0.70 (offshore) to 0.60 (backshore), In contrast, the sphericity frequency distribution of both river / beach and beach start / beach end are almost identical, By retaining its provenance signal, sphericity fails as a meaningful tool for the recognition of geological environments along the Calabrian coast, This inherited sphericity signature of the fluvial output is conserved along the beach and is differentiated only in the cross-shore direction, The overall roundness R increases alongshore by 0.14 (from 0.55 to 0.69) but does not show any trend normal to shore, Continuous and effective rounding along the foreshore during low energy stages should create much better rounding in this zone than in neighboring zones, which are active only during high-energy stages, The stable cross- shore roundness reflects the "event character" of sediment modification, Only high-energy events move the entire gravel population to yield homogeneous rounding, The results of this study therefore suggest that the Bianco Beach is almost exclusively the product of such high-energy events.

Beach, R.A., and R.W. Sternberg, Suspended Sediment Transport in the Surf Zone - Response to Incident Wave and Longshore-Current Interaction, Marine Geology, 108 (3-4), 275-294, 1992.

This paper reports the results of a field experiment carried out in the inner surf zone of a dissipative beach at San Marine, Oregon, in 1984. Observations were made at a location 70 m seaward of the mean high water line (mean depth 1.3 m) during a period when significant offshore wave heights were 3-5 m and the surf zone was 500 m wide. Instruments were deployed in a closely spaced array and measurements included cross-shore and longshore velocity, sea surface fluctuations, and sediment concentration profiles. The results reported in this paper are from a particular 44-min data run characterized by high waves and strong longshore currents. In the first section of this paper the field measurements are summarized to provide insight into the resuspension process and observed sediment concentrations and fluxes on time scales including incident and infragravity bands, and mean values for the entire data set. In the second section a numerical model is presented that incorporates the nonlinear interaction of waves and currents and calculates velocity profiles, boundary shear stress, suspended sediment profiles, and longshore and cross-shore particle flux over 0.5 s intervals throughout the time series. Finally, model calculations of mean suspended load and net longshore and cross-shore flux of sediment are compared to observations. The results show that the model calculates mean suspended load and net longshore and cross-shore flux of sediment within a factor of two of the observations. The model suggests that, for this data set, incident waves and longshore currents contribute equally to the suspended load. For the longshore particle flux, the current contribution is approximately 1.7 times the wave contribution (63% vs 37%), primarily because currents carry suspended sediment higher in the water column where it is advected by stronger longshore currents. Additionally, model results suggest that wave/current interactions enhance suspended sediment load and longshore sand transport by approximately 50-60% over the transport forced by waves alone.

Behrens, E.W., and R.L. Watson, Sorting of Bivalves - an Indication of Longshore Drift E, Texas Journal of Science, 19 (4), 414-&, 1967.


Beloshapkov, A.V., To the Development of Energy Method For Calculation of Longshore Sediment Discharge, Okeanologiya, 28 (5), 803-809, 1988.


Berry, T., Encyclopedia of hurricanes, typhoons, and cyclones, Library Journal, 123 (15), 63-63, 1998.


Bodge, K.R., A Literature-Review of the Distribution of Longshore Sediment Transport Across the Surf Zone, Journal of Coastal Research, 5 (2), 307-328, 1989.


Bowen, A.J., Generation of Longshore Currents On a Plane Beach, Journal of Marine Research, 27 (2), 206-&, 1969.


Bowen, A.J., and R.A. Holman, Shear Instabilities of the Mean Longshore-Current .1. Theory, Journal of Geophysical Research-Oceans, 94 (C12), 18023-18030, 1989.


Bowman, D., H. Birkenfeld, and D.S. Rosen, The Longshore Flow Component in Low-Energy Rip Channels - the Mediterranean, Israel, Marine Geology, 108 (3-4), 259-274, 1992.

We examined in the field the near-bed longshore (v) flow component in rip channels at the Herzliyya beach, Israel, on the Southeastern Mediterranean. Field experiments, conducted under relatively calm wave conditions (T(sig) = 3-6 s, H(sig) = 0.3-1.1 m) included current and wave monitoring and morphological mapping. Time series of instantaneous and smoothed shore-parallel current velocities and of the orbital components, were analysed, including statistical and spectral processing. The peak instantaneous velocities of waves and currents combined were in excess of the threshold motion of the local sand, taken as 0.3 m/s. Some velocities even exceeded the threshold for sheet flow transport approximately 0.9 m/s. The feeder and the neck demonstrated the- highest longshore flow components, whereas the rip head, typically showed the lowest longshore velocities. The unsteadiness of the net longshore current was very high. Feeders typically showed a mean unidirectional longshore current. However, directional fluctuations gradually increased towards the rip head. The data suggest a clear spectral structure; most energy (46-67%) was in the gravity range with 13-35% subharmonic and minor (13-16%) in the infragravity band. Systematic cross-shore spatial trends of the energy spectra components were linked to bar morphology and to exposure to incident waves.

Brocchini, M., Eulerian and Lagrangian aspects of the longshore drift in the surf and swash zones, Journal of Geophysical Research-Oceans, 102 (C10), 23155-23168, 1997.

A theoretical study of the mean longshore mass flux and longshore drift velocities due to waves obliquely incident on a uniform sloping beach is presented. Analysis is performed using both Eulerian and Lagrangian representations of the flow. A number of results based on inviscid solutions are obtained concerning the mean longshore mass flux [M-y] inside the swash zone. Thus [M-y] depends on the parameters (wave amplitude, wave frequency, and wave number) of waves incident at a shoreline in a similar fashion to the dependence of the mass flux occurring between the crests and troughs of propagating waves on the same wave parameters. The mass flux depends on the square of the local wave amplitude, even for very steep waves which break before reaching the shoreline. A Lagrangian approach shows that particle paths are not closed even offshore of the breaking point and that "zigzag transport" is characteristic of Lagrangian particle paths in the two- dimensional horizontal flow seaward of the swash zone. The cross-shore profile of the longshore drift velocity is analyzed. Very weak longshore drift velocity characterizes the nonbreaking waves up to the swash zone. Onshore of the breaking point we find that the longshore drift velocity has a quasi- linear profile up to the maximum velocity reached near the shoreline. Effects of seabed friction are included in the computation of cross-shore profiles of the longshore drift velocity. A sensitivity analysis reveals that even for relatively small friction parameters (f approximate to 0.1), velocities inside the swash zone are greatly reduced. The reduction in longshore drift velocity is greater for the Lagrangian profile than for the Eulerian one, and for larger friction parameters (f greater than or equal to 0.1) the maximum longshore velocity moves toward the breaking point, where the friction effects are smaller. Finally, steady state profiles of the longshore drift velocities (Eulerian and Lagrangian) are computed.

Bruun, P., Longshore Currents and Longshore Troughs, Journal of Geophysical Research, 68 (4), 1065-&, 1963.


Bryan, K.R., and A.J. Bowen, Bar-trapped edge waves and longshore currents, Journal of Geophysical Research-Oceans, 103 (C12), 27867-27884, 1998.

Edge waves react to the presence of a mean longshore current as though the current was a change in bottom topography. In this way, the cross-shore shape of the edge wave can be amplified over the current, relative to the shoreline, in the same way as the edge wave shape can be amplified over bars. On a beach with both longshore currents and bars, the degree of edge wave amplification (or trapping) depends on the strength and location of the longshore current shear relative to the steepness of the bottom slope and also on the direction of edge wave propagation relative to the longshore current. Weak longshore current shear over well-developed bars does not significantly alter edge wave trapping over bars simply enhancing or reducing the existing bar trapping effect. Conversely, strong current shears over gentle topography can govern the existence and location of edge wave trapping, the extreme example being edge wave trapping on plane beaches where the amplification is entirely due to the existence of mean longshore currents. In reality the possibilities are restricted, since the shape of the longshore current profile is primarily determined by the pattern of incident wave breaking, which itself depends on the beach profile. The importance of realistic current shear relative to realistic bottom slope in determining edge wave shape is demonstrated using frequency- wavenumber spectra taken during the Duck Experiment on Low- Frequency and Incident-band Longshore and Across-shore Hydrodynamics (DELILAH) at Duck, North Carolina. These frequency-wavenumber spectra show a general dominance of edge waves traveling with the longshore current. In cases where the current shear is strong relative to the bottom slope, the location of edge wave trapping changes as the longshore current profile changes with the tide. When the bar was well defined, the longshore current shear was rarely strong enough to influence the existence or location of edge wave trapping, but could have a enhancing effect. While past work [i.e. Schonfeldt, 1995] has suggested that edge waves, trapped and amplified on longshore currents, may cause bars to form on plane beaches and bars to move on barred beaches, these observations suggest that under most conditions, edge wave trapping on longshore currents is a subtle effect, modulated by sea level changes, and is unlikely to produce significant morphological change unless the current is very strong.

Buffalow, G.C., Co-Employee Immunity Under the Longshore and Harbor Workers Compensation Act in States Permitting Co-Employee Actions For Damages, Journal of Maritime Law and Commerce, 17 (1), 89-103, 1986.


Burke, K., Longshore Drift, Submarine Canyons, and Submarine Fans in Development of Niger Delta, American Association of Petroleum Geologists Bulletin, 56 (10), 1975-&, 1972.


Bye, J.A.T., The General-Circulation in a Dissipative Ocean-Basin With Longshore Wind Stresses, Journal of Physical Oceanography, 13 (9), 1553-1563, 1983.


Calliari, L.J., Cross-Shore and Longshore Sediment Size Distribution On Southern Currituck Spit, North-Carolina - Implications For Beach Differentiation, Journal of Coastal Research, 10 (2), 360-373, 1994.

Beaches along the North Carolina coastline between Corolla and Oregon Inlet only a few kilometers apart are markedly different. Beaches at Duck are narrow and steep with strongly bimodal sediments. In contrast, beaches at Corolla and Coquina are broad and flat with mainly medium to fine unimodal sands. The occurrence of proximate beaches with different morphosedimentary characteristics provides a opportunity to improve our knowledge about the spatial and temporal grain-size distribution. across beaches. Using Q mode factor analysis, 178 surficial sediment samples from Duck and Coquina beaches representing three and one half years of sampling at monthly internals were analyzed. The cross-shore patterns which represent an average of the sedimentary processes occurring under fair weather and storm conditions indicate that coarse sediments are concentrated on the backshore. In contrast, fine sediments show a tendency to be concentrated landward or shoreward of this zone. Using the Q-mode factor model, 350 new sediment samples from beaches located between Duck and Oregon Inlet were ''mapped'' in the factor space defined by the Duck- Coquina data set. The study demonstrates that Q-mode factor analysis simplifies the relationship among the grain-size characteristics of sediment samples obtained across beaches with different sediment texture. The along-coast results indicate that these are several localized sources of coarse relict sediments between Duck and Oregon Inlet. Previous sedimentologic, stratigraphic and seismic data offshore and landward of the barrier substantiate these findings and demonstrate that differences in subaerial beach morphology and morphodynamic behavior in the area are primarily due to the availability of coarse relict sediments from the paleodrainage of the Albemarle River.

Camfield, F.E., and M.J. Briggs, Longshore Transmission of Reflected Waves, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 119 (5), 575-579, 1993.

A method is presented for determining the longshore travel distance of wave energy reflected from a coastal structure. These reflected waves may become trapped by refraction, causing reflected wave energy to impact the coastline some distance from the structure. The reflected waves may have a localized effect on coastal processes by adding wave energy to the incident waves along a reach of the coastline, and cause localized erosion as the shoreline adjusts its orientation to reach equilibrium with the reflected waves. The method incorporates consideration of the wave period, and gives results for directional spreading due to wave frequency. A plane bottom slope is assumed. The theoretical development is described and an example is given to illustrate the method. The method presented provides a quick, first-order solution that is an improvement on earlier methodology.

Campbell, E.E., and G.C. Bate, The Influence of Current Direction On Longshore Distribution of Surf Phytoplankton, Botanica Marina, 31 (3), 257-262, 1988.


Carr, A.P., Experiments On Longshore Transport and Sorting Pebbles - Chesil Beach, England, Journal of Sedimentary Petrology, 41 (4), 1084-&, 1971.


Carter, R.W.G., Longshore Variations in Nearshore Wave Processes At Magilligan Point, Northern-Ireland, Earth Surface Processes and Landforms, 5 (1), 81-89, 1980.


Caviglia, F.J., Computation of Longshore Currents and Sediment Transport, Computers & Geosciences, 20 (6), 905-917, 1994.

A numerical model for the steady-state profile of the longshore current induced by regular, obliquely incident, breaking waves is presented. The wave parameters must be given at an arbitrary depth. A rapid convergent numerical algorithm is described for the solution of the governing equation. The model is solved using a nonlinear bottom friction law in which the friction coefficients are a function of the bottom roughness which is computed at each point using an empirical formula. The predicted current profiles are combined with some of the known formulae for sediment transport computations.

Chandramohan, P., V.S. Kumar, B.U. Nayak, and K.C. Pathak, Variation of Longshore-Current and Sediment Transport Along the South Maharashtra Coast, West-Coast of India, Indian Journal of Marine Sciences, 22 (2), 115-118, 1993.

The longshore current velocity varied between 0.1 and 0.33 m.sec-1. The longshore current direction was predominantly southward at Ratnagiri, Ambolgarh, whereas it was variable at Vengurla during the study period. Based on the field measurements, the estimated longshore sediment transport rates at Ratnagiri, Ambolgarh and Vengurla were 1.19 x 10(5), 1.9 x 10(5) and 0.53 x 10(5) m3.y-1 respectively and the direction was southward. Significance of field measurement is emphasized here, in view of the large variation in the computed longshore sediment transport rates reported in earlier studies.

Chandramohan, P., and B.U. Nayak, Longshore Sediment Transport Model For the Indian West-Coast, Journal of Coastal Research, 8 (4), 775-787, 1992.

Longshore sediment transport rates for the Indian west coast from Cochin to Porbandar are estimated from ship observed wave data (1968 to 1986). The sediment transport rate is relatively high during the southwest monsoon period from June to September. Annual gross sediment transport rate is high (1.5-2 x 10(6) m3) along north Kerala, north Karnataka and south Gujarat coasts. Maharashtra coast shows relatively low annual net transport (0.1 x 10(6) m3). The annual net transport is south along north Kerala and Karnataka coasts. Coasts near Malvan, Dabhol, Murud and Tarapur appear to be nodal drift points with equal volume of transport in either direction annually.

Chandramohan, P., and B.U. Nayak, Longshore Sediment Transport Along the Indian Coast, Indian Journal of Marine Sciences, 20 (2), 110-114, 1991.

An empirical sediment transport model has been developed based on longshore energy flux equation. Ship reported waves, publised in Indian Daily Weather Reports, are compiled for 19 y and used for estimation of sediment transport. Annual gross sediment transport rate is high (15-20 x 10(5)m3) along the coasts of south Orissa, north Tamilnadu, south Kerala, north Karnataka and south Gujarat, whilst, it is comparatively less (5-10 x 10(5)m3) along the south Tamilnadu coast. Maharashtra coast and the part between Pondicherry and Point Calimere in Tamilnadu, show negligible order of annual net transport. Annual net transport along the east coast is in north and along the west coast in south but for south Gujarat coast.

Chandramohan, P., B.U. Nayak, and V.S. Raju, Application of Longshore Transport-Equations to the Andhra Coast, East Coast of India, Coastal Engineering, 12 (3), 285-297, 1988.


Chandramohan, P., B.U. Nayak, and V.S. Raju, Longshore-Transport Model For South Indian and Sri-Lankan Coasts, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 116 (4), 408-424, 1990.


Chandramohan, P., B.U. Nayak, and V.S. Raju, Longshore-Transport Model For South Indian and Sri-Lankan Coasts - Closure, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 118 (1), 122-124, 1992.


Chandramohan, P., and T.V.N. Rao, Study of Longshore-Current Equations For Currents in Visakhapatnam Beach, Indian Journal of Marine Sciences, 13 (1), 24-27, 1984.


Chase, R.R.P., Coastal Longshore Pressure-Gradient - Temporal Variations and Driving Mechanisms, Journal of Geophysical Research-Oceans and Atmospheres, 84 (C8), 4898-4904, 1979.


Chen, Y.Z., and R.T. Guza, Resonant scattering of edge waves by longshore periodic topography: finite beach slope, Journal of Fluid Mechanics, 387, 255-269, 1999.

The resonant scattering of low-mode progressive edge waves by small-amplitude longshore periodic depth perturbations superposed on a plane beach has recently been investigated using the shallow water equations (Chen & Guza 1998). Coupled evolution equations describing the variations of edge wave amplitudes over a finite-size patch of undulating bathymetry were developed. Here similar evolution equations are derived using the full linear equations, removing the shallow water restriction of small (2N + 1)theta, where N is the maximum mode number considered and theta is the unperturbed planar beach slope angle. The present results confirm the shallow water solutions for vanishingly small (2N + 1)theta and allow simple corrections to the shallow water results for small but finite (2N + 1)theta. Additionally, multi-wave scattering cases occurring only when (2N + 1)theta = O(1) are identified, and detailed descriptions are given for the case involving modes 0, 1, and 2 that occurs only on a steep beach with theta = pi/12.

Chen, Y.Z., and R.T. Guza, Resonant scattering of edge waves by longshore periodic topography, Journal of Fluid Mechanics, 369, 91-123, 1998.

The resonant scattering of topographically trapped, low-mode progressive edge waves by longshore periodic topography is investigated using a multiple-scale expansion of the linear shallow water equations. Coupled evolution equations for the slowly varying amplitudes of incident and scattered edge waves are derived for small-amplitude, periodic depth perturbations superposed on a plane beach. In 'single-wave scattering', an incident edge wave is resonantly scattered into a single additional progressive edge wave having the same or different mode number (i.e. longshore wavenumber), and propagating in the same or opposite direction (forward and backward scattering, respectively), as the incident edge wave. Backscattering into the same mode number as the incident edge wave, the analogue of Brgg Scattering of surface waves, is a special case. In 'multi- wave scattering', simultaneous forward and backward resonant scattering results in several (rather than only one) new progressive edge waves. Analytic solutions are obtained for single-wave scattering and for a special case of multi-wave scattering involving mode-0 and mode-1 edge waves, over perturbed depth regions of both finite and semi-infinite longshore extent. In single-wave backscattering with small (subcritical) detuning (i.e. departure from exact resonance), the incident and backscattered wave amplitudes both decay exponentially with propagation distance over the periodic bathymetry, whereas with large (supercritical) detuning the amplitudes oscillate with distance. In single-wave forward scattering, the wave amplitudes are oscillatory regardless of the magnitude of the detuning. Multiwave solutions combine aspects of single-wave backward and forward scattering. In both single- and multi-wave scattering, the exponential decay rates and oscillatory wavenumbers of the edge wave amplitudes depend on the detuning. The results suggest that naturally occurring rhythmic features such as beach cusps and crescentic bars are sometimes of large enough amplitude to scatter a significant amount of incident low-mode edge wave energy in a relatively short distance (O(10) topographic wavelengths).

Church, J.C., and E.B. Thornton, Effects of Breaking Wave-Induced Turbulence Within a Longshore- Current Model, Coastal Engineering, 20 (1-2), 1-28, 1993.

A longshore current model which includes a modification of the bottom stress term due to the effects of breaking-wave induced turbulence is developed and applied to field data from both barred and planar beaches. This turbulence is postulated as producing a vertical mixing which alters the near-bottom vertical profile of the longshore current. As a result, the bottom fiction coefficient, c(f), used to relate the free stream current velocity to the bottom stress is modeled as consisting of two components, c(fl), a spatially constant value which is assumed to be related to bottom characteristics and c(fr), which is dependent upon breaking-wave induced near- bottom turbulence levels. Employing a one-dimensional turbulent kinetic energy equation to model this breaking-wave induced turbulence, a spatially varying bottom friction coefficient is obtained. The spatially constant c(fl) is estimated based on data taken seaward of the surf zone, where the wind stress is assumed to be balanced by the bottom stress. The concept is demonstrated without the inclusion of horizontal mixing in the longshore current model formulation. The model predicted cross- shore profiles of longshore current show improved agreement with observations compared with treatments using constant c(f) values.

Ciavola, P., N. Dias, O. Ferreira, R. Taborda, and J.M.A. Dias, Fluorescent sands for measurements of longshore transport rates: a case study from Praia de Faro in southern Portugal, Geo-Marine Letters, 18 (1), 49-57, 1998.

A field experiment was carried out on a meso-tidal reflective beach to relate longshore sand transport rates to wave measurements in medium-energy conditions (H-rms = 0.6 m; T-m = 6.5 sec; alpha = 20 degrees). Dispersion of fluorescent sand tracers was analyzed using the spatial integration method (SIM). The measured sand transport rate was three times larger than the prediction computed using the longshore wave power approach, while the K factor was determined empirically as 2.32. The study concluded that there is a need to calibrate bulk longshore transport predictors before applying them to steep gradient slopes under plunging waves.

Ciavola, P., R. Taborda, O. Ferreira, and J.A. Dias, Field measurements of longshore sand transport and control processes on a steep meso-tidal beach in Portugal, Journal of Coastal Research, 13 (4), 1119-1129, 1997.

A field experiment was carried at Culatra Beach in Algarve (Southern Portugal) to determine longshore transport rates and sand mixing depth on a steep (slope 0.11) meso-tidal beach. The experiment was undertaken over one and a half tidal cycles using sand tracers in conjunction with wave and current monitoring. Variation of mean significant wave height during the experiment was limited (0.34-0.37 m) with mean zero-up crossing periods of 5.1-5.8 sec. Mean longshore current velocities in the breaker zone reached a peak in the second tide (0.28 m sec(-1)), while they were one order of magnitude smaller during the first (0.02 m sec(-1)) and third tide (0.04 m sec(-1)). The increase in current speed was due to a moderate wind that was blowing along shore during the second tide. Average advection velocity of the tracer cloud and longshore currents showed a good correlation, leading to calculation of much larger transport rates for the second tide (1.38X10(-2) m(3) sec(-1)) than for the other two (0.23X10(-2) m(3) sec(- 1)). Average depth of sand mixing of 10.6 cm in the beach face was 29% of breaking wave height and showed a marked uni-modal distribution, with maximum of 15 cm in the breaker zone. Previously published empirical formulae do not predict satisfactorily this behavior in depth of sand mixing that seems to be peculiar of steep beaches under plunging waves. Empirical formulae were used to compute theoretical longshore transport and compare it with field observations. They all underestimated measured transport rates of about one order of magnitude, thus confirming that the morphodynamics of steep beaches are characterized by relatively high sediment transport even in relatively low energy regimes.

Cimini, M.H., and S.L. Behrmann, Longshore Settlements, Monthly Labor Review, 116 (12), 65-65, 1993.


Cipriani, L.E., and G.W. Stone, Net longshore sediment transport and textural changes in beach sediments along the southwest Alabama and Mississippi barrier islands, USA, Journal of Coastal Research, 17 (2), 443-458, 2001.

A nearshore sediment transport model is developed and presented for the southwest Alabama and Mississippi barrier island coast along the northern Gulf of Mexico, USA. A cellular-type nearshore transport system, supplied by differential sediment sources, characterizes the present day study area, in contrast with previously formulated hypotheses of a net unidirectional, integrated nearshore transport system supplied by a single sediment source. Computer simulations of net longshore sediment transport between Dauphin Island, Alabama, and West Ship Island, Mississippi predict six distinct transport cells characterized by net westward longshore sediment transport. Along eastern Dauphin Island, net longshore transport is eastward toward Mobile Pass. Granulometric trends and changes in the composition of foreshore (step), beach (mid-tide level) and foredune sediments support transport predictions and suggest the possibility of onshore sediment transport along the western flank of the study area. Step and mid-tide sediment grading (coarsening downdrift) is evident along Dauphin Island, and shows a strong relationship with predicted breaker wave height. West of Dauphin Island, sediment samples are characterized by higher concentrations of calcium carbonate (shell) by weight, and heavy minerals, coinciding with a decrease in the inner shelf slope. Field observations and historic shoreline trends are in agreement with longshore sediment transport predictions. For example, chronic shoreline retreat along Dauphin Island, coincides with an increase in net longshore sediment transport, and the highest erosion rate is localized at the net longshore sediment transport reversal (nodal point). Contemporary drift cells appear to experience minimal net sediment exchange because of net longshore transport values approaching zero at most cell termini and ongoing maintenance dredging at the inlets, implying that they function as sediment sinks. Alternative sources of sediment appear to be internal on these barriers.

Cohen, E.G., School-Desegregation Research - New Directions in Situational Analysis - Prager,J, Longshore,D, Seeman,M, Contemporary Psychology, 32 (7), 608-609, 1987.


Csanady, G.T., Longshore Pressure-Gradients Caused By Offshore Wind, Journal of Geophysical Research-Oceans and Atmospheres, 85 (C2), 1076-1084, 1980.


Dalrymple, R.A., Longshore Currents With Wave Current Interaction - Closure, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 109 (1), 141-141, 1983.


Dalrymple, R.A., Longshore Currents With Wave Current Interaction, Journal of the Waterway Port Coastal and Ocean Division-Asce, 106 (3), 414-420, 1980.


Das, M.M., Review of Longshore Sediment Transport Data, Transactions-American Geophysical Union, 52 (4), 257-&, 1971.


Das, S., Numerical Modeling and Computer-Simulation of Longshore Sediment Transport Rate in Sandy Nearshore Zone, Indian Journal of Marine Sciences, 17 (4), 276-282, 1988.


Davies, J.L., and J.P. Hudson, Differential Supply and Longshore Transport As Determinants of Sediment Distribution On the North Coast of Tasmania, Marine Geology, 77 (3-4), 233-245, 1987.


Dodd, N., On the Destabilization of a Longshore-Current On a Plane Beach - Bottom Shear-Stress, Critical Conditions, and Onset of Instability, Journal of Geophysical Research-Oceans, 99 (C1), 811-824, 1994.

The effect on the stability of a wave-driven longshore current of varying the bottom shear stress is investigated. The shear stress is assumed to be quadratic and parameterized (as usual) through a bottom friction coefficient (c(d)). The bottom shear stress affects both the mean longshore current (which it opposes) and the onset (or otherwise) of a shear instability in the longshore current through its aforementioned effect on the mean current (and therefore the current shear) and by damping instabilities directly. Reducing ed can destabilize the longshore current by increasing its strength, thereby increasing the current shear so as to overcome the damping of bottom friction and thus leading to the development of instabilities. At the same time, this decrease in ed directly reduces the damping experienced by the instabilities that develop. It is also shown that while the primary effect of bottom friction is to damp instabilities, there are other effects, notably linked to the flow curvature, which act to destabilize the flow. Both the weak- and the strong-longshore- current approximations are examined. For the weak-current approximation it is shown that curvature effects are particularly important in providing a destabilizing mechanism. It is also shown that for both approximations a ''global'' cutoff frequency is likely to exist, below which no linear instability will develop. Critical conditions are identified for each approximation (and therefore for two different longshore current profiles), beyond which instabilities will start to develop. Results suggest that a critical shear will exist for any plane beach and that for Leadbetter Beach, Santa Barbara (examined in the 1980 Nearshore Sediment Transport Study (NSTS)), the current will not become unstable until an offshore shear of about 0.03 s(-1) is reached. This was apparently not achieved during NSTS.

Dodd, N., and A. Falques, A note on spatial modes in longshore current shear instabilities, Journal of Geophysical Research-Oceans, 101 (C10), 22715-22726, 1996.

Spatially growing disturbances in an alongshore current are considered. In many other types of shear flows these spatially growing modes describe the initial development of instabilities more satisfactorily than do the more commonly considered temporally growing modes. Here the spatial stability theory is applied to these wave-driven, semi-infinite types of flows for the first time. Both model [Thornton and Guza, 1986] and measured [Reniers et al., 1994] longshore current and beach profiles are analyzed, using both the temporal and spatial theories. Results of the two theories are compared using the approximate relations of Gaster [1962]. For the Thornton and Guza profile, predictions of the spatial theory and those from the transformed temporal theory are seen to be extremely close. For the profile of Reniers et al., which exhibited destabilization and spatially growing instabilities, the two sets of predictions are again very close. This implies that the simpler temporal stability theory, which has been used exclusively in previous studies, may be applied even when the spatial theory would clearly be more appropriate (such as in the experimental study examined here) by transforming the temporal predictions via Gaster's relations, Moreover, it appears that the predicted wavelength and period of the fastest growing mode (FGM) of untransformed temporal theory will be fairly good indicators of the same quantities for spatial modes and perhaps may be used as such when estimates of the group velocity from the temporal theory cannot be made with much certainty, such as when points are very sparse. It is shown that the basic structure of the fastest growing disturbance or mode (FGM) is similar for both theories for the Reniers et al. profile, although it would be a mistake to rely on the details of the linear eigenfunctions given by temporal theory.

Dodd, N., J. Oltmanshay, and E.B. Thornton, Shear Instabilities in the Longshore-Current - a Comparison of Observation and Theory, Journal of Physical Oceanography, 22 (1), 62-82, 1992.

Low-frequency (< 0.01 Hz) oscillations in the surf zone longshore current with wavelengths too small (< 300 m) to be surface gravity waves were observed during the 1986 SUPERDUCK experiment at Duck, North Carolina. The observations suggest that these oscillations are dynamically linked to the mean longshore current in the surf zone, leading Bowen and Holman to propose that the observed oscillations are manifestations of a shear instability in the longshore current. In this paper, field data from both the SUPERDUCK experiment (a barred beach) and the 1980 NSTS experiment, at Leadbetter Beach, Santa Barbara, California (a plane beach), are used to compare quantitatively the model of Bowen and Holman (which is extended to include the effects of dissipation due to bottom friction) with observation. Observed frequency-cyclic wavenumber (f-K) spectra (constructed from along shore arrays of velocity measurements made in about 1.5-2 m of water in the trough of the bar at SUPERDUCK, and in about 1 m at NSTS) are compared with theoretical predictions. Quantitative agreement is found between observation and theory at SUPERDUCK, where these motions dominate the observed f-K spectra, theoretical growth rates of the temporal instability tend to be large, and the mean longshore current varied between 0.35 and 1.0 m s-1. This comparison supports the shear instability hypothesis. Results from Leadbetter Beach (where the mean longshore current was always less than 0.5 m s-1) are less conclusive because of scatter in the observed f-K spectra; however, observation and theory agree on the f-K quadrant and on the general area within it. Finally, stability properties at the two beaches are compared. It is shown that longshore current profiles over a plane and a barred beach may give rise to different stability properties, suggesting that shear instabilities may be a more common feature on barred beaches.

Dolan, T.J., and R.G. Dean, Multiple Longshore Sand Bars in the Upper Chesapeake Bay, Estuarine Coastal and Shelf Science, 21 (5), 727-743, 1985.


Dong, P., and K. Anastasiou, A Numerical-Model of the Vertical-Distribution of Longshore Currents On a Plane Beach, Coastal Engineering, 15 (3), 279-298, 1991.

A numerical method is developed to calculate longshore currents generated by monochromatic long-crested waves breaking on a plane beach. The method is based on the linearized time- averaged momentum equation in the longshore direction. The equation is solved numerically using a Galerkin method with a series of cosine functions as basis functions. Longshore current profiles across the surf zone at a range of elevations over vertical direction are presented and compared with experimental data. Although the turbulence model used at this stage is only a simple eddy viscosity model, reasonable agreement between computed and experimental results has been achieved.

Donn, T.E., Longshore Distribution of Donax-Serra in 2 Log-Spiral Bays in the Eastern Cape, South-Africa, Marine Ecology-Progress Series, 35 (3), 217-222, 1987.


Dugan, J.E., and A. McLachlan, An assessment of longshore movement in Donax serra Roding (Bivalvia : Donacidae) on an exposed sandy beach, Journal of Experimental Marine Biology and Ecology, 234 (1), 111-124, 1999.

Peak abundances of intertidal populations of a donacid bivalve, Donax serra, occur 10-23 km from major river mouths along exposed sandy beaches of log-spiral bays on the coast of southeast Africa. Postsettlement eastward movement of D. serra from areas of spat settlement by prevailing longshore currents has been suggested as the mechanism which results in the observed population distributions. To estimate the net rates of longshore movement in intertidal D. serra on one of these exposed beaches, we developed and used a novel technique. A metal detector was used to track net change in the positions of intertidal juvenile and adult clams (37-67 mm shell length, 1-3 + years) with aluminum tags glued to the shells over a 3-month period during the austral fall and winter. Estimated net longshore movement of tagged clams ranged from 0.19 to 0.80 m day(-1). The net movement of tagged clams was primarily to the east along the beach but the direction of longshore movement varied during the study. Net rates of longshore movement were not correlated with clam size. The burrowing rates acid the condition of recaptured tagged individuals were not significantly different from untagged clams after 2 months. The results of this study suggest that average longshore movement rates of intertidal clams, > 1 year of age, along the beach are low and the animals are relatively sedentary. The technique developed and used here to estimate net longshore movement rates in D. serra allowed us to successfully recapture and track tagged individuals with very minimal disturbance to the intertidal habitat and associated fauna. Use of this novel technique could potentially enhance investigations of postsettlement movement, growth, zonation, competitive interactions and other aspects of the ecology of mobile soft sediment macrofauna. (C) 1999 Elsevier Science B.V. All rights reserved.

Earle, M.D., Longshore Currents Generated By Waves With a Rayleigh-Wave Amplitude Distribution, Transactions-American Geophysical Union, 55 (4), 321-322, 1974.


Engelund, F., Buoyant Surface Jet in Tidal Longshore Current - Discussion, Journal of the Hydraulics Division-Asce, 105 (6), 764-765, 1979.


Falques, A., and V. Iranzo, Edge Waves On a Longshore Shear-Flow, Physics of Fluids a-Fluid Dynamics, 4 (10), 2169-2190, 1992.

A theoretical analysis of the effect of a longshore mean shear flow on edge waves is performed in the framework of linear shallow water equations. A single equation describing edge waves as well as neutral shear waves is obtained. A numerical method of calculation is given for the dispersion relations and the wave pattern, accounting for any beach topography and any mean flow profile (remaining constant alongshore and with a straight shoreline). Numerical calculations are presented for a simple exponential flow profile and for a plane bottom. A Doppler shift in the frequencies and a variation in the offshore extension of the waves are found, depending on the maximum local Froude number of the current, F, defined as F = [V(x)/square-root gH-(x)]max, where V(x) stands for the mean longshore current, H(x) for the depth, and g for the gravity. The maximum shift in frequency is for wave numbers of about V(x)(0)2/gm and frequencies of about V(x)(0), where V(x)(0) is the shear at the shoreline and m is the beach slope. For instance, these maximum differences may reach about 40% for F=0.5. Waves of any wavelength can always propagate downstream, but they can propagate upstream only for F<F(c) approximately 0.7. For mean flows with F > F(c) only waves shorter or longer than some forbidden wavelengths can propagate against the current. An analytical dispersion relation of asymptotic general validity for short waves (corresponding to the gravity range in real beaches) is given. The numerical model as well as this analytical dispersion relation is tested by means of a nonplanar real topography.

Falques, A., V. Iranzo, and A. Montoto, Resonance of Longshore Currents Under Topographic Forcing, Physics of Fluids a-Fluid Dynamics, 5 (12), 3071-3084, 1993.

The steady perturbation caused in a longshore flow by a bottom undulation is considered. The bedforms are assumed to be alongshore periodic, with crests in the cross-shore direction and with a small amplitude in order for linear theory to be applicable. The inviscid shallow-water equations are considered in order to investigate topographic resonance, that is, the condition under which the perturbation in the flow reaches a maximum. Since upstream edge waves held stationary by the mean flow are solutions to the homogeneous resonance equations, the existence of such flows gives rise to the existence of resonances of infinite amplitude (linear, inviscid theory). For a maximum local Froude number of the basic flow F of less than 1, the flow is found to behave subcritically according to classic channel flow theory. In addition, neither steady edge waves nor infinite amplitude resonances exist in this case. However, by numerical simulation, a finite maximum in the flow perturbation as a function of bedform wavelength is found. This topographic resonance is rather weak and wide banded. For a bedform height of 1% the local water depth, the perturbation on the flow;nay typically be 4% of the mean current. The resonant wavelength is between two and three times the distance of the peak longshore current to the shoreline, l(V), when the current profile has a maximum at some distance offshore, or nearly four times the cross-shore length scale of the sandbars, l, for a flow profile monotonically increasing to a constant current far offshore. For F > 1 resonances of infinite amplitude are found. For every F, l(V), and l, there is an infinite set of resonant modes with an increasing cross-shore complexity when the mode number increases, similarly to edge waves. The resonant wavelength increases with F and with l(V). Some implications on the growth of transverse sandbar families and cuspidal coast are discussed.

Falques, A., A. Montoto, and V. Iranzo, Bed-flow instability of the longshore current, Continental Shelf Research, 16 (15), 1927-&, 1996.

An initially uniform longshore current on a plane erodible beach is considered and a linear stability analysis of the bed- flow system is performed in order to investigate the growth of alongshore periodic topographic features such as transverse or oblique bars. A numerical model based on the shallow water equations and a simple sediment transport formula is used. For a wide range of parameters instability is found, leading to the growth of large-scale topographic features (lengthscale of the order of the current width) downflow progressing. The growth rates and the dominant unstable mode depend mainly on R = c(d)/beta parameter, where ed is the bottom friction coefficient and beta is the beach slope. For a small R, say less than 0.1, instability is very weak, probably negligible. For R between 0.1 and 0.7 instability increases with R, leading typically to a quire simple transverse bars pattern. A further increase in R produces a far more complicated behaviour where complex patterns with downcurrent oriented oblique bars, bumps and holes can be dominant. In this region growth rates may either decrease or increase with R depending on the beach slope and the maximum Froude number of the basic flow, F. Usually, the most complex behaviour is found for gently sloping beaches. The physical mechanism of the instability is found to lie on the disturbances of potential vorticity caused by topographically induced differences in bottom friction. In this sense it is similar to the alternate bars growth in a river rather than the dunes or antidunes occurrence for 1D channel how. The predictions of the model compare well with the available experimental data. The alongshore wavelength, lambda, typically of the order of one to four times the width of the current, is close to four times for the most common values of R. The typical growth time is proportional to lambda(2) and for a wavelength of 100 m can be of the order of one day, depending on the sediment transport rate. The migrational speed is inversely proportional to ii, in accordance to earlier field data reported by Sonu [(1969) Collective movement of sediment in littoral environment. Proceedings of the 11th Intel national Conference on Coastal Engineering, A.S.C.E., New York.]. Copyright (C) 1996 Elsevier Science Ltd

Fandry, C.B., and D.R. Jackett, Tides On Continental Shelves With Longshore Topographic Variations, Continental Shelf Research, 7 (5), 519-534, 1987.


Faria, A.F.G., E.B. Thornton, T.P. Stanton, C.V. Soares, and T.C. Lippmann, Vertical profiles of longshore currents and related bed shear stress and bottom roughness, Journal of Geophysical Research-Oceans, 103 (C2), 3217-3232, 1998.

The vertical structure of the mean wave-driven longshore current over a barred beach is examined on three strong current days during the DUCK94 experiment, and it is found that the bottom boundary layer is well described by a logarithmic profile (mean correlation coefficient for all 22 profiles, 0.98). The logarithmic profile fits better in the trough, where turbulent bottom boundary layer processes predominate, than over the bar, where breaking-wave-induced turbulence generated at the surface modifies the profile. The surface layer in the presence of waves is well described by adjusting the logarithmic profile for the intermittent presence of water and adding the alongshore component of the mass transport velocity (slope of the least squares linear regression between model predictions and observations, 1.005 and root-mean-square (rms) error of 7%). Bed shear stresses calculated from logarithmic velocity profiles are equated to a quadratic bottom shear stress formulation. The associated bed shear stress coefficients vary by more than an order; of magnitude across the surf zone (0.0006-0.012). Bottom roughness was measured throughout the nearshore using a sonic altimeter mounted on a moving platform. The bed shear stress coefficients are positively correlated with bottom roughness (linear correlation coefficient, 0.6). A higher linear correlation coefficient (0.8) is obtained by subtracting skin friction from the total bed shear stress.

Finlay, W., One Occupation, 2 Labor-Markets - the Case of Longshore Crane Operators, American Sociological Review, 48 (3), 306-315, 1983.


Finlay, W., Industrial-Relations and Firm Behavior - Informal Labor Practices in the West-Coast Longshore Industry, Administrative Science Quarterly, 32 (1), 49-67, 1987.


Fox, W.T., and R.A. Davis, Computer-Model of Wind, Waves, and Longshore Currents During a Coastal Storm, Journal of the International Association For Mathematical Geology, 11 (2), 143-164, 1979.


Galvin, C., Longshore-Transport Model For South Indian and Sri-Lankan Coasts - Discussion, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 118 (1), 120-122, 1992.


Galvin, C., The Continuity Equation For Longshore-Current Velocity With Breaker Angle Adjusted For a Wave Current Interaction, Coastal Engineering, 11 (2), 115-129, 1987.


Galvin, C., Laboratory Measurements of Uniform Longshore Currents - Comments, Coastal Engineering, 18 (3-4), 333-341, 1992.


Galvin, C., Longshore Currents in 2 Laboratory Studies - Relevance to Theory, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 117 (1), 44-59, 1991.

Most post-1970 theoretical studies of longshore current velocity extend the radiation stress theory of Longuet-Higgins. Of the two larger sets of laboratory data (1949, 1963) available to test theories, Longuet-Higgins used the 1963 data and considered but did not use the 1949 data. Most post-1970 theories reverse these judgments and rely on the 1949 data. Such theories must be reevaluated. The 1949 data are 37 experiments, of which 22 were run on slopes steeper than all but the steepest natural foreshores; 12 of 37 published breaker angles exceed the generator angle; breaker depth-to-height ratios for the steep laboratory slopes were computed (not measured) using empirical curves from flat field slopes; and dimensionless velocities have a unique distribution. Breaker angle is the most sensitive variable determining longshore current velocity. Properly defined breaker angles require duplicate measurements along the test beach. The test velocity seselected to compare with theory must account for the nonuniformity of most laboratory currents. An erroneous column heading in a 1967 listing of the 1963 data misled some subsequent investigators.

Galvin, C., The Continuity Equation For Longshore-Current Velocity With Breaker Angle Adjusted For a Wave Current Interaction - Reply, Coastal Engineering, 13 (4), 385-386, 1989.


Galvin, C.J., Longshore Current Velocity - a Review of Theory and Data, Reviews of Geophysics, 5 (3), 287-&, 1967.


Galvin, C.J., Longshore Energy Flux, Longshore Force, and Longshore Sediment Transport, Transactions-American Geophysical Union, 54 (4), 334-334, 1973.


Gandolfi, G., A. Mordenti, and L. Paganelli, Composition and Longshore Dispersal of Sands From the Po and Adige Rivers Since the Pre-Etruscan Age, Journal of Sedimentary Petrology, 52 (3), 797-805, 1982.


Gimenez, L., and B. Yannicelli, Longshore patterns of distribution of macroinfauna on a Uruguayan sandy beach: an analysis at different spatial scales and of their potential causes, Marine Ecology-Progress Series, 199, 111-125, 2000.

Spatial distribution of macrofauna along the longshore axis was studied on an exposed (Uruguayan) sandy beach in order to assess (1) its dependence on beach topography, and (2) the validity to extrapolate local distribution patterns to larger spatial scales (i.e, km). The distribution of the isopods Excirolana armata and Excirolana braziliensis, the sand crab Emerita brasiliensis and several species of insects was analyzed at 3 spatial scales. A grid sampling was used at small scale (intersample distance: 4 mi extension sampled: 30 to 40 m), a transect design at meso scale (intersample distance 4 to 20 m; extension sampled: 100 to 120 m), and random sampling at large scale (intersample distance: 100 m; extension sampled: 3000 m). Spatial distribution at small and meso scales were described using autocorrelation functions, and tested for effects of topography at meso and large scales using ANOVA and paired t-tests. We found that at small and meso scales the distribution of E, armata and E, brasiliensis was patchy and affected by cusp topography. At large scales, the effect of cusp topography was restricted to E, armata. E, armata and E. brasiliensis showed large-scale aggregations, and E. braziliensis and insects showed large-scale patchiness associated with longshore variability in sediment water content and dune characteristics. We conclude that cusp topography affects longshore distribution patterns, and that it is not valid to extrapolate local longshore distribution to larger scales for every species. We suggest that different processes affecting spatial distribution must be operating at different scales. At small scales, patterns of distribution may be affected by swash transport of food and/or organisms, involving factors such as beach topography, swash and animal movements. At larger scales, in addition to larval and food supply, sediment transport by the wind would play an important role. Spatial patterns of sand transport by the wind may be affected by longshore changes in vegetation cover on the dune field. We further suggest that there may be a link between the beach and the dune habitats operating at large spatial scales.

Giosan, L., H. Bokuniewicz, N. Panin, and I. Postolache, Longshore sediment transport pattern along the Romanian Danube delta coast, Journal of Coastal Research, 15 (4), 859-871, 1999.

Measurements of shoreline change between 1962 and 1987 were used to construct a sediment budget and to derive net longshore sediment transport rates for the Romanian Danube delta coast. The resulting pattern was in good agreement with the potential longshore transport pattern predicted by the wave energy flux based on wave measurements between 1972 and 1981. Due to the general coast orientation, the longshore sand transport is almost unidirectional southwardly all year long. Hence estimates for the net longshore transport were as high as high 2,350,000 m(3)/year. Because of this high intensity longshore transport and also due to a reduction of Danube sediment and the interruption of longshore transport by shore-perpendicular structures, much of the coast is undergoing erosion. Near the Sfantu Gheorghe mouth, a rapidly migrating barrier island acts as a substantial sink for littoral sand producing a downdrift deficit in the sand budget.

Godfrey, J.S., and K.R. Ridgway, The Large-Scale Environment of the Poleward-Flowing Leeuwin Current, Western-Australia - Longshore Steric Height Gradients, Wind Stresses and Geostrophic Flow, Journal of Physical Oceanography, 15 (5), 481-495, 1985.


Greenwood, B., and D.J. Sherman, Longshore-Current Profiles and Lateral Mixing Across the Surf Zone of a Barred Nearshore, Coastal Engineering, 10 (2), 149-168, 1986.


Guillen, J., and J.A. Jiminez, Processes Behind the Longshore Variation of the Sediment Grain- Size in the Ebro Delta Coast, Journal of Coastal Research, 11 (1), 205-218, 1995.

The longshore variation of the sediment grain size in the Ebro Delta coast was investigated to estimate which processes control its distribution. Thirty-two control points along the coast were used in which a representative sample was obtained by averaging four samples taken in the inner part of the surf zone during eight field campaigns (32 samples per control point). The obtained distribution was related to the longshore variation of a get of parameters characterising beach processes: shoreline evolution trends, net longshore sediment transport rates and nearshore wave power. The beachface presents a narrow range of sediment sizes due to the existence of a single external source of sediment (Ebro River) supplying a low amount of homogeneous sand. These supplies are mainly restricted to the northern hemidelta, where the pediment is finer than in the southern part. The sediment grain size distribution along the Ebro Delta coast shows a non-monotonic longshore sorting process of sediment related to the alongshore variations of the main driving agents (longshore transport and wave power). In general, coarser sediments are present in erosive zones, with high wave power and positive longshore transport gradients. Finer sediments are characteristic of depositional areas, with lower power and negative longshore transport gradients. However, the littoral dynamics along the Ebro Delta coast cannot be fully inferred from sediment grain size distribution because several parameters control the sediment distribution. In this way, some coastal stretches showing similar grain sizes under different patterns of longshore transport rates and incident wave power were identified.

Guillen, J., and A. Palanques, Longshore Bar and Trough Systems in a Microtidal, Storm-Wave Dominated Coast - the Ebro Delta (Northwestern Mediterranean), Marine Geology, 115 (3-4), 239-252, 1993.

The Ebro Delta coast is a microtidal, sandy shoreline affected by a low-energy mean wave climate. Consecutive topographical and bathymetrical surveys during the years 1990 and 1991 have allowed us to identify nine major longshore bar and trough systems as the main morphological feature of the Ebro coast. Bar systems show high mobility, both cross-shore and longshore. The cross-shore migration of these systems may be landward or seaward, with mean migration rates of up to 0.25 m/day. The longshore migration is produced by the longitudinal growth of the bar systems in the downdrift direction, with rates of up to 11 m/day. The major morphological changes in the nearshore zone occurred during storm periods, when the nearshore profile is modified as a consequence of shoreline erosion and the cross- shore migration and longshore growth of the bar systems produced by these events. The modifications in the nearshore profile may continue during some months after the storm, before attaining a new equilibrium profile. A descriptive model relating the shoreline displacement with the cross-shore migration and the longshore growth of the bar and trough systems is proposed.

Guza, R.T., E.B. Thornton, and N. Christensen, Observations of Steady Longshore Currents in the Surf Zone, Journal of Physical Oceanography, 16 (11), 1959-1969, 1986.


Hallenberg, A., Encyclopedia of hurricanes, typhoons, and cyclones, Reference & User Services Quarterly, 38 (2), 197-198, 1998.


Hameed, T.S.S., M. Baba, and K.V. Thomas, Computation of Longshore Currents, Indian Journal of Marine Sciences, 15 (2), 92-95, 1986.


Hamilton, D.G., and B.A. Ebersole, Establishing uniform longshore currents in a large-scale sediment transport facility, Coastal Engineering, 42 (3), 199-218, 2001.

A large-scale laboratory facility for conducting research on surf-zone sediment transport processes has been constructed at the U.S. Army Engineer Research and Development Center. Successful execution of sediment transport experiments, which attempt to replicate some of the important coastal processes found on long straight beaches, requires a method for establishing the proper longshore current. An active pumping and recirculation system comprised of 20 independent pumps and pipelines is used to control the cross-shore distribution of the mean longshore current. Pumping rates are adjusted in an iterative manner to converge toward the proper settings, based on measurements along the beach. Two recirculation criteria proposed by Visser [Coastal Eng. 15 (1991) 563] were also used, and they provided additional evidence that the proper total longshore flow rate in the surf zone was obtained. The success of the external recirculation system and its operational procedure, and the degree of longshore uniformity achieved along the beach, are the subjects of this paper. To evaluate the performance of the recirculation system, and as a precursor to sediment transport experiments, two comprehensive test series were conducted on a concrete beach with straight and parallel contours (1:30 slope), one using regular waves and the other using irregular waves. In the regular wave case, the wave period was 2.5 s and the average wave height at breaking was approximately 0.25 m. In the irregular wave case, the peak wave period was 2.5 s and the significant breaking wave height was approximately 0.21 m. The longshore current recirculation system proved to be very effective in establishing uniform mean longshore currents along the beach in both cases. This facility and the data presented here are unique for the following reasons: (1) the high cross-shore resolution of the recirculation system and the ease with which changes can be made to the longshore current distribution, (2) the degree of longshore uniformity achieved as a percentage of the length of the basin (even near the downdrift boundary), (3) the scale of the wave conditions generated, and (3) the relatively gentle beach slope used in the experiments (compared to previous laboratory studies of the longshore current). Measured data are provided in an appendix for use in theoretical studies and numerical model development and validation. (C) 2001 Elsevier Science B.V. All rights reserved.

Hardisty, J., Measurement of Shallow-Water Wave Direction For Longshore Sediment Transport, Geo-Marine Letters, 8 (1), 35-39, 1988.


Harrison, W., Empirical Equation For Longshore Current Velocity, Journal of Geophysical Research, 73 (22), 6929-&, 1968.


Hickey, B.M., The Fluctuating Longshore Pressure-Gradient On the Pacific Northwest Shelf - a Dynamical Analysis, Journal of Physical Oceanography, 14 (2), 276-293, 1984.


Hickey, B.M., A. Huyer, R.L. Smith, and J.D. Smith, Longshore Coherence in Low-Frequency Currents On Central Continental-Shelf Off British-Columbia, Washington and Oregon During Wisp, Transactions-American Geophysical Union, 56 (12), 1010-1010, 1975.


Holman, R.A., and A.J. Bowen, Longshore Structure of Infragravity Wave Motions, Journal of Geophysical Research-Oceans, 89 (C4), 6446-6452, 1984.


Howd, P.A., A.J. Bowen, and R.A. Holman, Edge Waves in the Presence of Strong Longshore Currents, Journal of Geophysical Research-Oceans, 97 (C7), 11357-11371, 1992.

A form of the linear, inviscid shallow water wave equation which includes alongshore uniform, but cross-shore variable, longshore currents and bathymetry is presented. This formulation provides a continuum between gravity waves (either leaky or edge waves) on a longshore current, and the recently discovered shear waves. In this paper we will concentrate on gravity wave solutions for which V(x)/c < 1, where V(x) is the longshore current, and c is the edge wave celerity. The effects of the current can be uniquely accounted for in terms of a modification to the true beach profile, h'(x) = h(x) [1 - V(x)/C]-2, where h(x) is the true profile and h'(x) is the effective profile. This is particularly useful in conceptualizing the combined effects of longshore currents and variable bottom topography. We have solved numerically for the dispersion relationship and the cross-shore shapes of edge waves on a plane beach under a range of current conditions. Changes to the edge wave alongshore wavenumber, kappa, of over 50% are found for reasonable current profiles, showing that the departure from plane beach dispersion due to longshore currents can be of the same order as the effect of introducing nonplanar topography. These changes are not symmetric as they are for profile changes; \kappa\ increases for edge waves opposing the current flow (a shallower effective profile), but decreases for those coincident with the flow (a deeper effective profile). The cross-shore structure of the edge waves is also strongly modified. As \kappa\ increases (decreases), the nodal structure shifts landward (seaward) from the positions found on the test beach in the absence of a current. In addition, the predicted variances away from the nodes, particularly for the alongshore component of edge wave orbital velocity, may change dramatically from the no-current case. Many of the edge wave responses are related to the ratio V(max)/c, where V(max) is the maximum current, and to the dimensionless cross-shore scale of the current, \kappa\x(V(max), where x(V(max) is the cross- shore distance to V(max). This is most easily understood in terms of the effective profile and the strong dependence of the edge waves on the details of the inner part of the beach profile. Inclusion of the longshore current also has implications regarding the role of edge waves in the generation of nearshore morphology. For example, in the absence of a current, two phase-locked edge waves of equal frequency and mode progressing in opposite directions are expected to produce a crescentic bar. However, in the presence of a current, the wavenumbers would differ, stretching the expected crescentic bar into a welded bar. A more interesting effect is the possibility that modifications to the edge waves due to the presence of a virtual bar in the effective profile could lead to the development of a real sand bar on the true profile. These modifications appear to be only weakly sensitive to frequency, in contrast to the relatively strong dependence of the traditional model of sand bar generation at infragravity wave nodes.

Hsueh, Y., Scattering of Continental-Shelf Waves By Longshore Variations in Bottom Topography, Journal of Geophysical Research-Oceans and Atmospheres, 85 (C2), 1147-1150, 1980.


Hubertz, J.M., Observations of Local Wind Effects On Longshore Currents, Coastal Engineering, 10 (3), 275-288, 1986.


Huthnance, J.M., Effects of Longshore Shelf Variations On Barotropic Continental-Shelf Waves, Slope Currents and Ocean Modes, Progress in Oceanography, 19 (2), 177-220, 1987.


Jaramillo, E., M. Pino, L. Filun, and M. Gonzalez, Longshore Distribution of Mesodesma-Donacium (Bivalvia, Mesodesmatidae) On a Sandy Beach of the South of Chile, Veliger, 37 (2), 192-200, 1994.

Monthly samples were taken from February 1989 to january 1990 to evalute the longshore distribution and density of the bivalve Mesodesma donacium in a dissipative beach in southern Chile. The results showed that its distribution was patchy. Adult clams were confined to the surf zone, while the vast majority of juveniles occurred in the swash zone. The highest densities of adults were found in summer and autumn (up to 1.59 individuals per 0.25 m2 in February 1989), while the minimum occurred during winter. juveniles had similar densities all year round (up to 16-20 individuals per 0.25 m2). Most clams collected in the surf zone had similar shell lengths (70-75 mm); those collected in the swash zone were smaller than 25 mm. No relationships were found between distribution and abundances of clams and variability in textural characteristics of the surf or swash zone. Due to the limited longshore variability in grain size and sorting of sands, it is suggested that the variabilities in distribution and abundances of clams may be related to large-scale habitat characteristics rather than to small-scale textural variability.

Jayappa, K.S., Longshore sediment transport along the Mangalore coast, west coast of India, Indian Journal of Marine Sciences, 25 (2), 157-159, 1996.

Longshore currents and sediment transport along the beaches of Mangalore have been studied over a period of one year. The sector-wise average longshore current velocity was high (0.18, 0.16 and 0.17 m/s in the northern, middle and southern sectors respectively) from March to November. Net sediment movement was towards south in all the three sectors and maximum (4.10 x 10(5)m(3)/yr) in the southern sector.

Jena, B.K., P. Chandramohan, and V.S. Kumar, Longshore transport based on directional waves along north Tamilnadu coast, India, Journal of Coastal Research, 17 (2), 322-327, 2001.

The accurate assessment of longshore sediment transport pattern along Nagapattinam-Poompuhar coastline bears significance due to the historical erosion and its geographical location adjoining the sheltered Palk Bay. Directional waves were measured off Nagapattinam coastline for one year to estimate the longshore sediment transport rate. It shows that the transport rate is relatively high about 0.1 x 10(6) m(3)/month in November and December and is low showing less than 0.03 x 10(6) m(3)/month in March, April and July. Though the annual gross transport is found to be 0.6 x 10(6) m(3)/year, the annual net transport is very low showing less than 0.006 x 10(6) m(3)/year (towards north), indicating the coastline tends to be a nodal drift regime. The temporary rise in wave activities during the cyclonic days often increases the southerly drift, which partly gets deposited in the Palk Bay and causes deficit for the northerly drift.

Johnson, A.S., and G. Nelson, Ekman estimates of upwelling at Cape Columbine based on measurements of longshore wind from a 35-year time-series, South African Journal of Marine Science-Suid-Afrikaanse Tydskrif Vir Seewetenskap, 21, 433-436, 1999.

Cape Columbine is a prominent headland on the south-west coast of Africa at approximately 32 degrees 50'S, where there is a substantial upwelling tongue, enhancing the ambient upwelling on the shelf, produced by wind-stress curl. From hourly records of wind measured there, the longshore component of wind stress was calculated and the consequent Ekman transport arising through the coastal divergence was estimated.

Kahn, J.H., and R. Dolan, Longshore Bars and Shoreline Erosion Along the Chandeleur Islands, Louisiana, Zeitschrift Fur Geomorphologie, 29 (1), 89-97, 1985.


Kanth, T.A., and V. Asthana, Size-Longshore Transport Velocity Relationship Along the Puri Beach, Indian Journal of Marine Sciences, 11 (1), 83-85, 1982.


Keeley, J.R., and A.J. Bowen, Longshore Variations in Longshore Currents, Canadian Journal of Earth Sciences, 14 (8), 1897-1905, 1977.


Killworth, P.D., Coastal Upwelling and Kelvin Waves With Small Longshore Topography, Journal of Physical Oceanography, 8 (2), 188-205, 1978.


Kim, C.S., and D.A. Huntley, On Time Delays in the Nearshore Zone Between Onshore and Longshore Currents At Incident Wave Frequencies, Journal of Geophysical Research-Oceans, 91 (C3), 3967-3978, 1986.


Kobayashi, N., E.A. Karjadi, and B.D. Johnson, Dispersion effects on longshore currents in surf zones, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 123 (5), 240-248, 1997.

A time-dependent model for obliquely incident shallow-water waves with small incident angles is developed to elucidate the dispersion effects due to the vertical variations of instantaneous horizontal fluid velocities on the cross-shore variations of the wave height, setup, and longshore current in surf zones. The three equations for the cross-shore continuity, momentum, and momentum flux correction are solved numerically to predict the water depth and the cross-shore depth-averaged and near-bottom velocities. The two equations for the alongshore momentum and momentum flux correction are derived and solved to predict the alongshore depth-averaged and near- bottom velocities. The developed model is compared with laboratory and field data for planar beaches. The dispersion effects on the wave height and setup are shown to be minor. The dispersion effects on the longshore current are significant for regular waves but secondary for irregular waves. The model is also shown to predict the vertical shape of the longshore current in the surf zone but not outside the surf zone.

Komar, P.D., Longshore Current Generation, Transactions-American Geophysical Union, 53 (4), 421-&, 1972.


Komar, P.D., Beach-Slope Dependence of Longshore Currents, Transactions-American Geophysical Union, 59 (12), 1103-1103, 1978.


Komar, P.D., Beach-Slope Dependence of Longshore Currents, Journal of the Waterway Port Coastal and Ocean Division-Asce, 105 (4), 460-464, 1979.


Komar, P.D., Selective Longshore Transport Rates of Different Grain-Size Fractions Within a Beach, Journal of Sedimentary Petrology, 47 (4), 1444-1453, 1977.


Komar, P.D., Computer Models of Delta Growth Due to Sediment Input From Rivers and Longshore Transport, Geological Society of America Bulletin, 84 (7), 2217-2226, 1973.


Komar, P.D., and D.L. Inman, Longshore Transport of Sand On Beaches, Transactions-American Geophysical Union, 50 (4), 191-&, 1969.


Komar, P.D., and D.L. Inman, Longshore Sand Transport On Beaches, Journal of Geophysical Research, 75 (30), 5914-&, 1970.


Komar, P.D., and J. Oltmanshay, The Continuity Equation For Longshore-Current Velocity With Breaker Angle Adjusted For a Wave Current Interaction, Coastal Engineering, 13 (4), 379-386, 1989.


Kraus, N.C., and T.O. Sasaki, Influence of Wave Angle and Lateral Mixing On the Longshore Current, Marine Science Communications, 5 (2), 91-126, 1979.


Kumar, V.K., C.S. Murty, S.S.C. Shenoi, and A.K. Heblekar, Wave Refraction and Longshore-Current Patterns Along Calangute Beach (Goa), West-Coast of India, Indian Journal of Marine Sciences, 18 (3), 184-188, 1989.


Kumar, V.S., P. Chandramohan, K.A. Kumar, R. Gowthaman, and P. Pednekar, Longshore currents and sediment transport along Kannirajapuram Coast, Tamilnadu, India, Journal of Coastal Research, 16 (2), 247-254, 2000.

The objective of the study was to estimate longshore current and sediment transport from measured wave data and from the observations on the littoral environment. A directional wave rider buoy was deployed at 12m water depth, 11 km off Kannirajapuram. Wave data at 3 hourly intervals from March 1997 to February 1998 were recorded. The first wave direction corresponding to the peak of the spectrum and second wave direction corresponding to the secondary peak were estimated since wave spectrum at this location was mainly double peak spectrum. Daily observations on surf zone width and longshore currents were carried out at Kannirajapuram beach during March 1997 to February 1998. The longshore currents and sediment transport were estimated considering first and second breaker angles and resultant was estimated considering the ratio of the first and second spectral energy peaks. Comparison of measured and computed longshore current shows that currents can be reasonably well estimated based on Galvin's equation and sediment transport based on Walton's equation.

Kuriyama, Y., and T. Nakatsukasa, A one-dimensional model for undertow and longshore current on a barred beach, Coastal Engineering, 40 (1), 39-58, 2000.

A one-dimensional model was developed for undertow and longshore current. The model predicts time- and depth-averaged undertow and longshore current velocities with longshore uniformity in depth, waves and current, It was calibrated with field data obtained over longshore bars at Hazaki Oceanographical Research Station (HORS). Verification with the other field measurements and large-scale experiments showed that the present model predicted well the undertow velocities over the longshore bars, while a previous model, calibrated with small-scale experiment data, underestimated the velocities. The verification also showed that although the cross-shore distributions of the longshore current velocity over the longshore bars predicted with the previous model had peak velocities seaward of the bar crests, the distributions predicted with the present model had peaks shoreward of the crests and fitted those measured in the field. (C) 2000 Elsevier Science B.V. All rights reserved.

Lamberti, A., and G.R. Tomasicchio, Stone mobility and longshore transport at reshaping breakwaters, Coastal Engineering, 29 (3-4), 263-289, 1997.

Physical model tests have been performed in two different wave flumes to analyse the threshold of stone movement and quantify the frequency and length of displacements due to head-on wave attacks at a reshaping breakwater, Data on stone movements were obtained from the observation of cumulative displacements at the end of each wave attack and from video records during the attack. Threshold conditions, frequency of movement and displacement length are expressed as function of a suitably modified stability number. A simple model is defined relating longshore transport due to oblique wave attack to stone mobility, The transport model is based on the assumption that movement statistics is affected by obliquity only through the appropriate mobility index and that stones move during up- and down-rush in the direction of incident and reflected waves, Without any calibration, results compare favourably with experimental data available in literature in the range of low mobility conditions where movement statistics was observed. A calibration is provided in order to obtain an accurate transport formula valid in a wide mobility range, i.e. for reshaping breakwaters and up to gravel beaches.

Lanfredi, N.W., and M.B. Framinan, Field-Study and Prediction of Longshore Currents, Argentine Coast, Journal of Coastal Research, 2 (4), 409-417, 1986.


Larson, M., and N.C. Kraus, Numerical-Model of Longshore-Current For Bar and Trough Beaches, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 117 (4), 326-347, 1991.

This paper describes a numerical modeling system called NMLONG that was developed to calculate the wave height, wave direction, mean water level, and steady-state time-averaged longshore current velocity across a multiple bar and trough beach profile. The modeling system includes the longshore current and change in mean water surface elevation produced by waves and wind, lateral mixing, wave driving by monochromatic or random waves as options, linear or quadratic bottom friction law as options, and wave-current interaction as an option. The principal requirement for use of the model is longshore uniformity in bathymetry and waves. Verification against laboratory and field measurements of the wave height, longshore current, and mean water surface elevation (laboratory only) indicates that default values of the model calibration parameters should be acceptable for most engineering applications. Techniques are employed to minimize computer execution time, including efficient time averaging of the nonlinear bottom friction stress and a skillful first approximation in the iterative solution of the longshore current using the nonlinear bottom friction law, allowing the model to run effectively on a desktop computer.

Lau, J., and B. Travis, Slowly-Varying Stokes Waves and Submarine Longshore Bars, Transactions-American Geophysical Union, 54 (4), 214-214, 1973.


Lau, J., and B. Travis, Slowly Varying Stokes Waves and Submarine Longshore Bars, Journal of Geophysical Research, 78 (21), 4489-4497, 1973.


Lee, K.K., Sediment Transport and Longshore Currents in Western Shore of Lake-Michigan, Transactions-American Geophysical Union, 55 (4), 253-253, 1974.


Lee, K.K., Longshore Currents and Sediment Transport in West Shore of Lake-Michigan, Water Resources Research, 11 (6), 1029-1032, 1975.


Leontev, I.O., Prediction of Waves, Wave-Induced Currents and Longshore Sediment Fluxes in the Near-Shore Zone, Okeanologiya, 33 (3), 429-434, 1993.

A predictive model is presented to calculate wave heights, longshore current velocities and sediment transport rates induced by storm random waves. Quantitative description of wave shoaling and breaking is based on integration of energy and momentum balance equations. Current velocities are derived from equation of momentum balance parallel to the shore. Turbulent mixing is modeled taking into account the actual wave parameters. Sediment transport rates are determined with taking into consideration the excess nearbed turbulence caused by wave breaking. Calculated values are verified using the field data.

Leontiev, I.O., Longshore Sediment Transport By Random Waves On Gentle Slope, Okeanologiya, 25 (4), 638-644, 1985.


Li, M.Z.L., and P.D. Komar, Longshore Grain Sorting and Beach Placer Formation Adjacent to the Columbia River, Journal of Sedimentary Petrology, 62 (3), 429-441, 1992.

Extensive black-sand placers are found on the beaches adjacent to the mouth of the Columbia River in the Northwest United States. Beachface sand samples were collected along 70 km of shoreline north and south from the river and were analyzed to determine the sorting patterns in order to understand the processes responsible for the formation of these placers. The heavy minerals are highly concentrated close to the river, reaching 60 to 70% of bulk samples from the summer beach. The concentrations decrease systematically with longshore distance, being reduced to less than 2% after 20 km of longshore transport from the river mouth. The median grain sizes of the principal minerals generally become finer with longshore distance, but an away-from-source coarsening is found within 5 to 8 km from the river where the placers achieve their maximum development. Measurements of grain settling velocities show that sorting associated with this parameter may explain the bulk characteristics of the beach sediments but cannot account for the enrichment of the dense minerals and detailed sorting patterns responsible for the placer formation. Minerals requiring higher selective entrainment stresses and having lower bedload transport rates are those most concentrated in the placer deposits. This is the case for settling-equivalent fractions within the sands, as well as for the samples as a whole. We conclude that, as the sand is transported alongshore north and south away from the river, sorting is controlled initially by the differential settling velocities of the grains. However, close to the river mouth where the placer is most concentrated, the sorting patterns are best explained by selective entrainment and transport in the swash zone, with the highest density and finest grains being most difficult to mobilize and thus remaining within the placer. The transformation of dominant sorting modes is determined by the pattern of beach erosion which has been greatest adjacent to the jetties constructed at the mouth of the Columbia River.

Li, Z., and B. Johns, A three-dimensional numerical model of surface waves in the surf zone and longshore current generation over a plane beach, Estuarine Coastal and Shelf Science, 47 (4), 395-413, 1998.

A three-dimensional numerical model is developed for the propagation of shallow-water short-period surface waves in the surf zone and longshore current generation over a plane beach topography. This model, which is based on Reynolds-averaged non-linear shallow-water (NSW) equations and, hence, includes implicitly the classical radiation stress concept, resolves time- and space-dependence of the sea surface elevation and the velocity fields during one wave cycle (short-wave-resolving). The generation of turbulence by wave breaking and vertical fluid shear above the beach is parameterized by the application of a generalized turbulence energy closure scheme. The instantaneous position of the moving shoreline is determined from the model equations during the simulated propagation process. In the case of a single incoming wave train, the wave amplitude, wave period and angle of incidence are prescribed at an offshore open boundary by application of a forced radiation condition. For uniform alongshore topographic conditions, when cyclic boundary conditions are appropriate at alongshore open boundaries whose positions are determined by the alongshore component of wavelength in an incoming single wave train, the model is used to determine the (mean) longshore current during one wave cycle. It is shown that the maximum longshore depth- averaged current occurs at an approximate offshore position where the generation of turbulence energy through wave breaking is a maximum. It is further shown that the cross-shore gradient of the longshore momentum flux is of predominant importance in generating longshore currents. Experiments are described that determine the dependence of the computed longshore current on the bottom roughness and the length scale prescription in that part of the turbulence closure scheme pertaining to the parameterization of the wave breaking process. The implications of the model results are discussed in the context of the longshore bedload transport of sedimentary material. Finally, a comparison is made between the model predictions and observational data on longshore currents and wave heights. (C) 1998 Academic Press.

Liu, P.L.F., and R.A. Dalrymple, Bottom Frictional Stresses and Longshore Currents Due to Waves With Large Angles of Incidence, Journal of Marine Research, 36 (2), 357-375, 1978.


Longueth.Ms, Longshore Currents Generated By Obliquely Incident Sea Waves .2, Journal of Geophysical Research, 75 (33), 6790-&, 1970.


Longueth.Ms, Longshore Currents Generated By Obliquely Incident Sea Waves .1, Journal of Geophysical Research, 75 (33), 6778-&, 1970.


Maresca, J.W., and C.T. Carlson, Comment On Longshore Currents On the Fringe of Hurricane Anita, Journal of Geophysical Research-Oceans and Atmospheres, 85 (C3), 1640-1641, 1980.


Masselink, G., Longshore Variation of Grain-Size Distribution Along the Coast of the Rhone Delta, Southern France - a Test of the Mclaren Model, Journal of Coastal Research, 8 (2), 286-291, 1992.

Twenty nine beachface samples from the Rhone delta were collected and analysed to assess the application of the sediment transport model devised by MCLAREN and BOWLES (1985). According to this model, in the direction of longshore transport, successive sediment samples should become either coarser, better sorted, and more positively skewed, or finer, better sorted, and more negatively skewed. However, the Rhone delta beachface sediments tend to get finer and more poorly sorted in the longshore transport direction, and skewness exhibits no significant trend. The main reasons for the disagreement between the actual transport path along the Rhone delta coast, and that predicted by the model of MCLAREN and BOWLES is the fact that several assumptions underlying the model are not valid in the nearshore environment. Therefore, the use of the model in determining transport paths in the nearshore zone is limited.

Masselink, G., Longshore Variation of Grain-Size Distribution Along the Coast of the Rhone Delta, Southern France - a Test of the Mclaren Model - Reply, Journal of Coastal Research, 9 (4), 1142-1145, 1993.


McDougal, W.G., and R.T. Hudspeth, Longshore-Current and Sediment Transport On Composite Beach Profiles, Coastal Engineering, 12 (4), 315-337, 1989.


McDougal, W.G., and R.T. Hudspeth, Longshore Sediment Transport On Non-Planar Beaches, Coastal Engineering, 7 (2), 119-131, 1983.


McDougal, W.G., and R.T. Hudspeth, Wave Setup Setdown and Longshore-Current On Non-Planar Beaches, Coastal Engineering, 7 (2), 103-117, 1983.


McDougal, W.G., and R.T. Hudspeth, Influence of Lateral Mixing On Longshore Currents, Ocean Engineering, 13 (5), 419-433, 1986.


McLaren, P., Longshore Variation of Grain-Size Distributions Along the Coast of the Rhone Delta, Southern France - a Test of the Mclaren Model - Discussion, Journal of Coastal Research, 9 (4), 1136-1141, 1993.


Meadows, G., and W. Wood, Unsteady Longshore Currents in a Uniform Wave Field, Transactions-American Geophysical Union, 56 (12), 1009-1009, 1975.


Meadows, G.A., Long Period Fluctuations in Longshore Currents, Transactions-American Geophysical Union, 57 (12), 940-940, 1976.


Meadows, G.A., Horizontal Distribution of Longshore Currents Orthoganal to Shoreline, Transactions-American Geophysical Union, 58 (12), 1173-1173, 1977.


Mei, C.C., and D. Angelides, Longshore Circulation Around a Conical Island, Coastal Engineering, 1 (1), 31-42, 1977.


Mergen, B., Encyclopedia of hurricanes, typhoons, and cyclones, Environmental History, 6 (2), 319-320, 2001.


Middleton, J.F., and D.G. Wright, Shelf Wave Scattering Due to a Longshore Jump in Topography, Journal of Physical Oceanography, 18 (2), 230-242, 1988.


Miller, H.C., Field measurements of longshore sediment transport during storms, Coastal Engineering, 36 (4), 301-321, 1999.

This paper presents an analysis of longshore sediment transport (LST) rates based on an accumulation of data obtained during five storms. Direct measurements of velocities and sus pended sediment concentration were conducted at a minimum of nine positions across a barred profile in waves up to Hm(0) = 3.5 m to provide a measure of the cross-shore distribution and total suspended-load sediment transport rates. The study was conducted at the US Army Engineer Waterways Experiment Station's Field Research Facility, located in Duck, NC. Measurements were made using the Sensor Insertion System (SIS) which provides an economical means to collect the required information. The largest LST rate computed from the measurements was 1780 m(3) h(-1). Although the cross-shore distribution of the LST varied, it most often had two peaks associated with wave shoaling and breaking at the bar and near the beach. Comparisons of measurement results with predictions using the 'CERC' LST formula show the predicted rates were sometimes higher and other times lower; suggesting that additional terms may be required for short term predictions during storms. Comparisons to a 'Bagnold' type formulation, which included a velocity term that could account for wind and other effects on LST, show better agreement for at least one of the storms. These results are intended to help fill a void of information documenting the cross-shore distribution and LST rates, particularly during storms. (C) 1999 Elsevier Science B.V. All rights reserved.

Morfett, J.C., Numerical-Model of Longshore Transport of Sand in Surf Zone, Proceedings of the Institution of Civil Engineers Part 2- Research and Theory, 91, 55-70, 1991.

An approach to the modelling of the distribution of longshore sediment transport in the surf zone is described. The method is based on the application of the rate of energy dissipation of breaking waves. A mathematical model is presented which produces estimates of the sediment transport rate at any point within the surf zone or estimates of the total transport rate. The model has been calibrated against field data.

Mothersi.Js, A Grain Size Analysis of Longshore-Bars and Troughs, Lake- Superior, Ontario, Journal of Sedimentary Petrology, 39 (4), 1317-&, 1969.


Nair, R.R., N.H. Hashimi, and V.P. Rao, On the Possibility of High-Velocity Tidal Streams As Dynamic Barriers to Longshore Sediment Transport - Evidence From the Continental-Shelf Off the Gulf of Kutch, India, Marine Geology, 47 (1-2), 77-86, 1982.


Nelson, G., Longshore Wind Variation On the West-Coast of Southern Africa and Its Influence On the Shelf Sea, South African Journal of Science, 88 (8), 418-423, 1992.

The longshore wind On the west coast of southern Africa not only causes upwelling but generates coastal-trapped waves. Large-velocitY components associated with these waves can interact with upwelling itself by imposing time-dependent boundary conditions, suppressing or enhancing that process. Secondary effects of the wind are the formation of frontal jets near upwelling zones, and the formation of filaments and eddies. On the largest spatial scale, the wind influences seasonal equatorward drift and generates Rossby waves. Both wind speed and the frequency of modulation, ranging from zero to half a cycle Per day, influence these various physical processes. of particular interest are variations in wind forcing of 2 to 5 days and the mechanisms generating a variable hemisperic pressure field in this frequency band, Rossby waves on the subtropical jet stream. A discussion is given of the stability of these waves and their relation to the surface pressure field, and consequently synoptic longshore winds.

Ngusaru, A.S., Longshore currents over a multi-barred beach: Field measurements and dissipation models, Indian Journal of Marine Sciences, 29 (3), 206-218, 2000.

Strong longshore currents were measured on a multi-barred beach at Stanhope Lane beach on the northern coast of Prince Edward Island in Canada. The long time scale variability of the measured currents suggested considerable time dependence. In the scales of several days, the currents variability were correlated with the corresponding mean wind vector. There was lack of coherence between the longshore currents over different bars. However, flow on the same bar as measured by various current meters was coherent. This suggested that flow over different bars were forced independently. There was no correlation between the estimated local radiation stress component and the longshore current response. This was interesting because longshore currents are clearly forced by radiation stress. The observed currents were compared to theoretical estimates based on a dissipation model. The results showed that longshore currents over a complex topography could be reasonably modeled using turbulent momentum exchange and non-linear bottom friction without surface wind stress. Both the observations and theory suggest that longshore currents are strongly tied to individual bar crests. However, the observations were consistently displaced landward relative to the theoretical estimates.

Nof, D., On the Interaction Between Thin Isolated Eddies and Longshore Currents, Journal of Physical Oceanography, 14 (1), 125-137, 1984.


Oltmanshay, J., P.A. Howd, and W.A. Birkemeier, Shear Instabilities of the Mean Longshore-Current .2. Field Observations, Journal of Geophysical Research-Oceans, 94 (C12), 18031-18042, 1989.


Orford, J.D., and R.W.G. Carter, Mechanisms to Account For the Longshore Spacing of Overwash Throats On a Coarse Clastic Barrier in Southeast Ireland, Marine Geology, 56 (1-4), 207-226, 1984.


Orme, A.R., The Behavior and Migration of Longshore Bars, Physical Geography, 6 (2), 142-164, 1985.


Orourke, J.C., and P.H. Leblond, Longshore Currents in a Semicircular Bay, Journal of Geophysical Research, 77 (3), 444-&, 1972.


Ostendorf, D.W., Longshore Dispersion Over a Flat Beach, Journal of Geophysical Research-Oceans and Atmospheres, 87 (C6), 4241-4248, 1982.


Ozkan-Haller, H.T., and J.T. Kirby, Nonlinear evolution of shear instabilities of the longshore current: A comparison of observations and computations, Journal of Geophysical Research-Oceans, 104 (C11), 25953-25984, 1999.

The time dependent nearshore circulation field during 3 days of the SUPERDUCK field experiment is simulated. We consider the generation of nearshore currents due to obliquely incident breaking waves: damping effects due to bottom friction, and diffusion effects due to lateral momentum mixing caused by turbulence and depth-varying current velocities. Because of uncertainties in the friction and lateral mixing: coefficients, numerical simulations are carried out for a realistic range of values for these coefficients. The resulting shear instabilities of the Longshore current exhibit unsteady longshore progressive vortices with timescales of O(100 s) and length scales of O(100 m) and longer. The time dependent flow involves the strengthening, weakening, and interaction of vortices. Vortex pairs are frequently shed offshore. During this process, locally strong offshore directed currents are generated, We find that a stronger mean current and faster and more energetic vortex structures result as the friction coefficient is decreased. However, the longshore length scales of the resulting: flow structures are not altered significantly. An increase in the mixing coefficient causes relatively small variations in the propagation speeds. However, the resulting flow structures are less energetic with larger longshore length scales. Sheer instabilities are found to induce significant horizontal momentum mixing in the surf zone and affect the cross-shore distribution of the mean longshore current. Mixing due to the presence of the instabilities is found to be dominant over mixing caused by more traditional mechanisms such as turbulence. For values of the free parameters that reproduce the propagation speed of the observed motions, the frequency range within which shear instabilities are observed as well as the mean longshore current profile are predicted well.

Pedlosky, J., Longshore Currents and Onset of Upwelling Over Bottom Slope, Journal of Physical Oceanography, 4 (3), 310-320, 1974.


Pedlosky, J., Longshore Currents, Upwelling and Bottom Topography, Journal of Physical Oceanography, 4 (2), 214-226, 1974.


Perlin, A., and E. Kit, Longshore sediment transport on Mediterranean coast of Israel, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 125 (2), 80-87, 1999.

A modified version of the CERC formula, which relates longshore sediment drift to deep water wave height and direction, has been used to define the equivalent wave height. The directional distribution of these wave heights and corresponding sediment transport rates and their analytical approximations are found using statistical analysis of high quality directional wave data measured simultaneously at two sites, Ashdod and Haifa. The directional distributions enable one to determine the directional shift between the average wave directions at both sites and to find the necessary corrections of wave directions at any location along the coast. The results emphasize the importance of accounting for wave directional shift in sediment transport calculations even when the locations are close. A detailed computation of directional shift for different ranges of wave heights is performed using correlation analysis of data sets. The corrections of wave directions at various locations along the coast are found by interpolation, and an excellent agreement between sediment fluxes at each location has been obtained when using the LITPACK package for littoral transport simulations with each data set.

Prasad, D.S., G.V.S. Sarma, and M.S. Rao, Longshore Grain-Size Trends in the Kakinada-Mulapeta Beach, East Coast of India, Proceedings of the Indian Academy of Sciences-Earth and Planetary Sciences, 96 (3), 267-278, 1987.


Putrevu, U., J. Oltmanshay, and I.A. Svendsen, Effect of Alongshore Nonuniformities On Longshore-Current Predictions, Journal of Geophysical Research-Oceans, 100 (C8), 16119-16130, 1995.

Longshore currents have been primarily modeled by assuming alongshore uniformity. In this paper we revisit the problem of nonuniform longshore currents to refocus attention on the importance of accounting for alongshore nonuniformity in longshore current predictions and to provide an analytical estimate of the importance of this nonuniformity. We derive a semianalytical solution for the longshore currents that allows for weak alongshore variations in the bottom topography. The solution shows that the alongshore pressure gradient induced by alongshore variations in the bottom topography could contribute substantially to the forcing for the longshore currents. An example calculation shows that the longshore current could deviate by up to +/-30% from the mean for a +/-10% deviation of the bottom topography. Thus we suggest that in many practical cases it is important to include the alongshore pressure gradient to accurately model longshore currents.

Putrevu, U., and I.A. Svendsen, Shear Instability of Longshore Currents - a Numerical Study, Journal of Geophysical Research-Oceans, 97 (C5), 7283-7303, 1992.

Temporal variations of longshore currents have recently been identified on natural beaches (Oltman-Shay et al., 1989). Termed shear waves, these variations appear to be strongly linked to the strength of the mean longshore current. Bowen and Holman (1989) proposed a simple model based on the shear instability of a steady bilinear longshore current profile over a constant depth to explain these observations. In this work we generalize Bowen and Holman's model. A numerical solution technique is employed to study the characteristics of shear waves generated by instabilities of smooth longshore current profiles on general bottom topographies. We find that the stability characteristics are extremely sensitive to variations in the bottom topography. The "dispersion" relationship of the shear waves is almost linear and does not seem to be very sensitive to the topography. We find that the presence of a nearshore bar greatly enhances the strength of the instability and, in certain situations, tends to trap the shear wave shoreward of the bar crest. The results also suggest that the shear on the seaward face of the longshore current profile is an important parameter in the stability problem. A Fjortoft condition is established for the instability equation. Estimates of length and time scales indicate that shear waves should be detectable in laboratory experiments. An order of magnitude analysis indicates that shear waves may be a plausible mixing mechanism in the nearshore region.

Pyokari, M., Longshore Movement of Pebbles and Cobbles in the Southwestern Finnish Archipelago, Geografiska Annaler Series a-Physical Geography, 66 (1-2), 151-163, 1984.


Reddering, J.S.V., An Inlet Sequence Produced By Migration of a Small Microtidal Inlet Against Longshore-Drift - the Keurbooms Inlet, South- Africa, Sedimentology, 30 (2), 201-218, 1983.


Reniers, A., and J.A. Battjes, A laboratory study of longshore currents over barred and non- barred beaches, Coastal Engineering, 30 (1-2), 1-21, 1997.

A detailed description is given of the results of laboratory experiments on wave-driven longshore currents on both barred and non-barred beaches. The objective is to examine the cross- shore distribution of the longshore current velocities for purely wave-driven currents, with emphasis on the position of maximum current velocity with respect to areas where wave energy is dissipated. Unidirectional obliquely incident waves, both regular and random, were used. The measurements were performed in a large wave basin with a pump recirculation system to create spatially homogeneous longshore currents. The experiments yielded information on wave transformation, set-up of the mean water level and the cross-shore distribution of wave-driven longshore current velocity. A number of cases are presented and compared with each other. The measurements show that in the case of purely wave-driven longshore currents, the maximum current velocities occur close to areas where wave breaking is most intense. The effect of mixing, bottom friction and wave rollers on the longshore current velocity profile are examined in more detail with help of numerical modelling. Existing model equations, based on the assumption of alongshore uniformity, are used. The results for the mean longshore current profile on a barred beach are in close agreement with the measurements.

Reniers, A., and J.A. Battjes, A laboratory study of longshore currents over barred and non- barred beaches (vol 30, pg 1, 1997), Coastal Engineering, 31 (1-4), 339-340, 1997.


Reniers, A., J.A. Battjes, A. Falques, and D.A. Huntley, A laboratory study on the shear instability of longshore currents, Journal of Geophysical Research-Oceans, 102 (C4), 8597-8609, 1997.

Low-frequency oscillations in the nearshore velocity field due to the instability of the shear of a longshore current are termed shear waves. Laboratory experiments have been performed to test theoretical predictions of the dispersion relation and growth rates for shear instabilities under controlled conditions and to provide empirical data for model calibration. The results, obtained with a high-resolution spectral analysis technique (Maximum Entropy Method), show that it is possible to generate instabilities of significant amplitude in a wave basin of limited length. The measurements demonstrate that these instabilities can be attributed to the shear instability of the longshore current. Quantitative comparison showing good correspondence with model predictions has been performed.

Restrepo, J.M., and J.L. Bona, 3-Dimensional Model For the Formation of Longshore Sand Structures On the Continental-Shelf, Nonlinearity, 8 (5), 781-820, 1995.

A model is proposed for the formation and evolution of three- dimensional sedimentary structures such as longshore sand ridges on the continental shelf in water deeper than that of the shoaling region. Owing to the striking similarity between the bar spacing and the length scales in which interactions among the most energetic modes of shallow water waves take place, we argue that these bars are formed slowly by Rows in the turbulent boundary layer generated by weakly nonlinear, dispersive waves. The model is based on the interaction between surficial or internal, weakly nonlinear shallow water waves, having weak spanwise spatial dependence, and the bottom topography. while such underwater structures are not the result of a single formative agent, it is argued that the mechanism proposed in this study does contribute significantly to their generation and evolution.

Restrepo, J.M., and J.L. Bona, Discretization of a Model For the Formation of Longshore Sand Ridges, Journal of Computational Physics, 122 (1), 129-142, 1995.

This paper presents and evaluates the numerical solution of a coupled system of equations that arises in a model for the formation and evolution of three-dimensional longshore sand ridges. The model is based on the interaction between surficial or internal weakly nonlinear shallow-water waves, having weak spanwise spatial dependence, and the deformable bottom topography. The presentation of the details concerning the discretization of the model is primarily motivated by: (1) the model involves equations for which little is known regarding its solutions; (2) we believe th at the methodology used in simplifying the solution to the coupled sand ridge model may be of interest to other researchers in the geophysical community; and (3) the predictor-corrector scheme presented here, which combines finite difference techniques and fixed-point methods, is simple, fast, and general enough to be used in the discretization of other partial differential equations with local nonlinearities whose solutions are smooth and bounded, (C) 1995 Academic Press, Inc.

Rodriguez, H.N., and A.J. Mehta, Longshore transport of fine-grained sediment, Continental Shelf Research, 20 (12-13), 1419-1432, 2000.

An approximate formula is derived for the longshore transport of tine-grained sediment due to waves, This formula yields the cross-shore distribution of the unit discharge of suspended sediment mass as a function of wave and sediment properties, and bottom slope. The derivation is conveniently divided into two parts, one for the surf zone from the shoreline to the breakerline, and the other for the zone seaward of the breakerline, nominally up to the depth of closure. Suspended sediment concentration at any position is assumed to be determined exclusively by a local balance between erosion or entrainment of bottom sediment and settling of the eroded material. The formula has been applied to limited laboratory basin data on longshore current and suspended sediment concentration, as well as some suspended sediment measurements off Lian Island bordering the Yellow Sea in China, Improvements to the approach are contingent upon a better physical understanding of the way in which bottom mud is eroded and transported over the profile. (C) 2000 Elsevier Science Ltd. All rights reserved.

Ryrie, S.C., Longshore Motion Generated On Beaches By Obliquely Incident Bores, Journal of Fluid Mechanics, 129 (APR), 193-212, 1983.


Ryrie, S.C., Longshore Motion Due to an Obliquely Incident Wave Group, Journal of Fluid Mechanics, 137 (DEC), 273-284, 1983.


Samsuddin, M., and G.K. Suchindan, Beach Erosion and Accretion in Relation to Seasonal Longshore- Current Variation in the Northern Kerala Coast, India, Journal of Coastal Research, 3 (1), 55-62, 1987.


Sarrikostis, E., and J. McManus, Potential Longshore Transports On the Coasts North and South of the Tay Estuary, Proceedings of the Royal Society of Edinburgh Section B- Biological Sciences, 92, 297-310, 1987.


Schonfeldt, H.J., On the Modification of Edge Waves By Longshore Currents, Continental Shelf Research, 15 (10), 1213-1220, 1995.

On natural, barred beaches edge waves with frequencies within the range of the wind-wave frequencies are found to be trapped on the bar. For edge waves travelling in the direction of a longshore current, the onset of trapping is shifted to lower frequencies. The frequency range where the waves are trapped on the bar becomes greater and the waves in this range exhibit larger amplitudes offshore than at the shoreline. Furthermore, the most distant offshore antinode trapped on a bar increases its amplitude under the influence of longshore currents for edge waves travelling with the current. The objective of this note is to elucidate some new aspects of the impact of a natural seabed profile in the presence of longshore current.

Schoonees, J.S., Annual variation in the net longshore sediment transport rate, Coastal Engineering, 40 (2), 141-160, 2000.

The annual variation in the net longshore sediment transport rates at three South African and at one North African site is investigated. The net rates at these sites, given in the first table, show large variations. It was found that measurements of longshore transport rates should be conducted continuously for 5-8 years in order to obtain an accurate value (within 10%) of the true long-term mean net longshore transport rate. A second table was drawn up, which can be applied to determine the range in which the true mean rate will fall if measurements were done over a shorter period than the recommended 5-8 years. It is reasonable to expect that the conclusions are widely applicable, especially for exposed sites. It is recommended that an accurate assessment of the long-term mean net longshore transport rate at a site can best be made cost-effectively by doing limited site-specific measurements, calibrating the best longshore transport formula for the particular site, and predicting the transport rates using a representative wave climate. (C) 2000 Elsevier Science B.V. All rights reserved.

Schoonees, J.S., and A.K. Theron, Review of the Field-Data Base For Longshore Sediment Transport, Coastal Engineering, 19 (1-2), 1-25, 1993.

A literature search was undertaken to collect field data on longshore sediment transport. This yielded a large number of data sets (273 points for bulk transport rates) from a variety of sites around the world. Data are especially lacking for transport rates exceeding 0.2 x 10(6) m3/year, significant wave heights higher than 1.8 m, sediment grain sizes coarser than 0.6 mm and beach slopes steeper than 0.06 (= 1/14). A point rating system was devised whereby the quality of the data could be assessed. The recording method and the accuracy thereof as well as the representativeness of the data were taken into account. It was found that the evaluation was done reasonably objectively and consistently. The data were divided into three categories. The highest score achieved in the evaluation was only 71% thus reflecting the difficulty of measuring longshore transport accurately. It is recommended that longshore transport formulae be calibrated against the data in the higher category (60% and better) and then be tested against all the other data. This will ensure that the formulae will be tested in as many different conditions and sites as possible without the lower quality data contributing to the calibration constants.

Schwartz, R.K., Study of Longshore Sediment Transport Near Breaker Zone, Transactions-American Geophysical Union, 58 (12), 1161-1161, 1977.


Self, R.P., Longshore Variation in Beach Sands Nautla Area, Veracruz, Mexico, Journal of Sedimentary Petrology, 47 (4), 1437-1443, 1977.


Seymour, R.J., Longshore Sediment Transport By Tidal Currents, Journal of Geophysical Research-Oceans and Atmospheres, 85 (C4), 1899-1904, 1980.


Seymour, R.J., and D. Castel, Episodicity in Longshore Sediment Transport, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 111 (3), 542-551, 1985.


Shanks, A.L., and W.G. Wright, Internal-Wave-Mediated Shoreward Transport of Cyprids, Megalopae, and Gammarids and Correlated Longshore Differences in the Settling Rate of Intertidal Barnacles, Journal of Experimental Marine Biology and Ecology, 114 (1), 1-13, 1987.


Sharafel.Sh, Longshore Sand Transport in Surf Zone Along Mediterranean Egyptian Coast, Limnology and Oceanography, 19 (2), 182-189, 1974.


Shemer, L., N. Dodd, and E.B. Thornton, Slow-Time Modulation of Finite-Depth Nonlinear Water-Waves - Relation to Longshore-Current Oscillations, Journal of Geophysical Research-Oceans, 96 (C4), 7105-7113, 1991.

Nonlinear dynamics of steep waves in water of finite depth are analyzed. The most unstable Benjamin-Feir sidebands are found for a number of values of carrier wave steepness and water depth. The long-time evolution of a three-wave system, consisting of the carrier and the two most unstable sidebands, is then studied. Such a wave system undergoes periodic recurrence. It is shown that the slow-time modulation leads to a corresponding periodic variation in the radiation stress when the propagation directions of the sidebands differ from that of the carrier. The variation of the radiation stress, in turn, results in slow-time modulation of longshore current.

Sherman, D.J., Empirical-Evaluation of Longshore-Current Models, Geographical Review, 78 (2), 158-168, 1988.


Smith, A.W., and L.A. Jackson, Discussion of Wang, P., N. C. Kraus, and R. A. Davis, 1998. Total longshore sediment transport rate in the surf zone: Field measurements and empirical predictions. Journal of Coastal Research, 14(1), 269-282, Journal of Coastal Research, 15 (1), 275-276, 1999.


Smith, J.M., M. Larson, and N.C. Kraus, Longshore-Current On a Barred Beach - Field-Measurements and Calculation, Journal of Geophysical Research-Oceans, 98 (C12), 22717-22731, 1993.

Measurements of the longshore current on a barred beach made during the 1990 Duck Experiment on Low-Frequency and Incident- Band Longshore and Across-Shore Hydrodynamics (DELILAH) field data collection project conducted at Duck, North Carolina, revealed an unexpected and persistent broad peak in the current velocity in the trough between the nearshore bar and the shore. This paper introduces longshore current and associated wave measurements from DELILAH together with a numerical model capable of describing the field observations. An existing numerical model of the mean current is modified to include a general transport equation for the mean turbulent kinetic energy created by wave breaking, and Reynolds stress components needed to calculate the longshore current and mean water level are reexpressed to include the turbulent momentum transport. In comparison to predictions from the original model, the modified model produces much improved agreement with the measured current velocity on the barred profiles in the field measurements and with the velocity profile and mean water level generated on a uniformly sloping laboratory beach by monochromatic waves. Three forms of a bottom friction coefficient are examined, and the open-channel-flow Manning friction coefficient is selected because of best agreement and consistency. Values of the Manning friction coefficient required to calibrate the model agree with values normally assigned to the related bottom roughness in open-channel flow.

Smith, N.P., Longshore Currents On the Fringe of Hurricane Anita, Journal of Geophysical Research-Oceans and Atmospheres, 83 (C12), 6047-6051, 1978.


Smith, N.P., Longshore Currents On the Fringe of Hurricane Anita - Reply, Journal of Geophysical Research-Oceans and Atmospheres, 85 (C3), 1642-1642, 1980.


Smith, N.P., Temporal and Spatial Variability in Longshore Motion Along the Texas Gulf-Coast, Journal of Geophysical Research-Oceans and Atmospheres, 85 (C3), 1531-1536, 1980.


Stewart, C.J., and R.G.D. Davidsonarnott, Morphology, Formation and Migration of Longshore Sandwaves - Long Point, Lake Erie, Canada, Marine Geology, 81 (1-4), 63-77, 1988.


Stiassnie, M., and U. Kroszynski, Extreme Values of Breaker Direction and Longshore Current, Journal of the Waterway Port Coastal and Ocean Division-Asce, 105 (3), 331-334, 1979.


Stone, G.W., F.W. Stapor, J.P. May, and J.P. Morgan, Multiple Sediment Sources and a Cellular, Non-Integrated, Longshore-Drift System - Northwest Florida and Southeast Alabama Coast, Usa, Marine Geology, 105 (1-4), 141-154, 1992.

The morphosedimentary maintenance of a 225 km stretch of coast along the northeast Gulf of Mexico, from Grayton Beach, Florida, to Morgan Point, Alabama, has been interpreted previously within the framework of a unidirectional, integrated, monotonic longshore drift model, with a single headland source of sediment located east of Grayton Beach. Net longshore transport and the granulometry and composition of some 2000 foredune, beach and step samples indicate a cellular net drift system, supplied by three independent sources of sediment. One source is provided by the Pleistocene barrier island complex along Grayton-Mirimar Beach, the second at Pensacola Beach on Santa Rosa Island, and the third is onshore transport across the inner shelf between Pensacola, Florida, and Morgan Point, Alabama. The Pleistocene "headland" and Pensacola Beach supply two cells along Santa Rosa Island. whereas onshore transport from the low gradient inner shelf supplies sediment to three cells along the largely accretional beach-ridge-dominated coast from Pensacola Pass to Morgan Point. Drift cells along this coast experience negligible net sediment exchange. These findings have significant implications for both the late Holocene evolution and the morphodynamic maintenance of this coast.

Sturges, W., Small Longshore Slopes Induced By Tidal Interactions, Deep-Sea Research, 21 (12), 1035-1038, 1974.


Stutz, M.L., and O.H. Pilkey, Discussion of: Wang, P.; N.C. Kraus, and R.A. Davis. 1998. Total longshore sediment transport rate in the surf zone: Field measurements and empirical predictions. Journal of Coastal Research, 14(1), 269-282, Journal of Coastal Research, 15 (1), 272-274, 1999.


Svendsen, I.A., and R.S. Lorenz, Velocities in Combined Undertow and Longshore Currents, Coastal Engineering, 13 (1), 55-79, 1989.


Swain, A., Longshore Currents With Wave Current Interaction - Discussion, Journal of the Waterway Port Coastal and Ocean Division-Asce, 107 (3), 213-216, 1981.


Tessler, M.G., and M.M. Demahiques, Utilization of Coastal Geomorphic Features As Indicators of Longshore Transport - Examples of the Southern Coastal Region of the State of Sao-Paulo, Brazil, Journal of Coastal Research, 9 (3), 823-830, 1993.

On the Brazilian coast, where sandy shores predominate, not only the form of the coastline but depositional features associated therewith (spits, sandbanks, etc.) have also been frequently used as geomorphic indicators of the predominant direction of the longshore transport of sediments. On the southern coastal region of State Sao Paulo, the growth of prominent features is related not only to the longshore drift but also to the interaction between these processes and internal dynamics strongly conditioned by the action of tides. This intense interaction takes place especially in the proximities of lagoonal mouths. In the lagoonal mouth of Ararapira (on the boundary of the states of Sao Paulo and Parana) the growth of the sandy spit occurs in the opposite direction to that of the drift of the current responsible for the transport of sediments along the coastline. On the other hand, on the lagoonal mouth of Icapara, to the northeast of Iguape (SP) the growth of the sandy feature occurs in the same direction as that of the drift current most effective in the transport of sediments, inasmuch as there is conformity between this and the vector resulting from the currents of the lagoonal region. Therefore, the simple observation of the direction of the growth of coastal features, when associated with lagoonal or estuarine systems, strongly controlled by tidal conditions, cannot be used without reservations as indicative of the predominant direction of the transport of sediments along the coastlines.

Thevenot, M.M., and N.C. Kraus, Longshore Sand Waves At Southampton Beach, New-York - Observation and Numerical-Simulation of Their Movement, Marine Geology, 126 (1-4), 249-269, 1995.

This paper describes measurements and numerical simulations of the movement of longshore sand waves observed at Southampton Beach, Long Island, New York. These large morphologic features are created by periodic opening of a small inlet and subsequent welding of its ebb shoal to the beach. Longshore sand waves are wave-like forms that maintain identity while moving along the shore and represent a simple type of collective sediment movement or large-scale coastal behavior. Despite being described as early as 1939, few measurements of longshore sand waves have been made, and their dynamic behavior is not well understood. Eleven longshore sand waves were identified along Southampton Beach and have an average length of 0.75 km and an amplitude of 40 m. Migration speed was greatest under winter wave action and reached an average 1.09 km year(-1) and yearly average speed including summer calms was a much lower 0.35 km year(-1). During a 16-month observation period, the longshore sand waves did not disperse during their steady migration westward in the direction of predominant wave incidence, and longer waves moved faster than those with smaller wavelengths. A numerical model of shoreline change including both standard particulate longshore sand transport and a component describing migration of a longshore sand wave is developed in which the velocity of the wave is related to the calculated longshore discharge of water. The model shows wave refraction to be an important mechanism contributing to the longevity of longshore sand waves, acting to retard the otherwise expected diffusion. Model calculations of the migration of a single longshore sand wave agree quantitatively with the observations.

Thomson, R.E., Longshore Current Generation By Internal Waves in Strait of Georgia, Canadian Journal of Earth Sciences, 12 (3), 472-488, 1975.


Thornton, E.B., and R.T. Guza, Surf Zone Longshore Currents and Random Waves - Field Data and Models, Journal of Physical Oceanography, 16 (7), 1165-1178, 1986.


Thornton, E.B., and C.S. Kim, Longshore-Current and Wave Height Modulation At Tidal Frequency Inside the Surf Zone, Journal of Geophysical Research-Oceans, 98 (C9), 16509-16519, 1993.

Data were acquired continuously during the 19-day DELILAH nearshore experiment with a specific objective of examining variability of the longshore current at tidal frequencies. It is hypothesized that breaking wave heights inside the surf zone are strong functions of the depth which are modulated by the tidal variations, and since radiation stress is a function of the wave height, longshore currents are forced at the tidal frequency inside the surf zone. The measured longshore current variations at tidal frequency are the same order of magnitude as the mean longshore current variations for moderate wave height conditions, indicating that the tide is a dominant mechanism associated with longshore current variability. Simulations of the magnitude and phase of the longshore current variability with tide elevation using the model by Thornton and Guza (1986) are used to explain observations. The measured tidal elevation and longshore current are in phase in the inner surf zone and out of phase in the outer surf zone as predicted by the model, verifying the hypothesis.

Todd, T.W., Dynamic Diversion - Influence of Longshore Current-Tidal Flow Interaction On Chenier and Barrier Island Plains, Journal of Sedimentary Petrology, 38 (3), 734-&, 1968.


Tomczak, M., Longshore Advection During an Upwelling Event in the Canary Current Area As Detected By Airborne Radiometer, Oceanologica Acta, 4 (2), 161-169, 1981.


Torresnavarrete, C.R., and A.M. Deleon, Longshore Sand Transport Southeast of Bahia-De-Todos-Santos, Bc Mexico, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 119 (5), 580-586, 1993.


Van Wellen, E., A.J. Chadwick, and T. Mason, A review and assessment of longshore sediment transport equations for coarse-grained beaches, Coastal Engineering, 40 (3), 243-275, 2000.

Previous assessments of analytical longshore sediment transport formulae have been heavily biased towards sand-sized sediment. All have noted the shortage of high quality field data from coarse-grained beaches against which to test predictions of longshore transport rates. In this paper, 12 existing formulae were identified as being potentially applicable for coarse- grained sediments and predictions from these formulae are compared using a measured annual transport rate from a shingle beach and a concurrent hindcast wave climate. Two new empirical equations are also derived, one from a numerical model calibrated against the same data set, the other derived from field experiments on coarse grained beaches. Energetics-based equations are found to give reasonable predictions of the shingle transport, despite being derived for sand beaches. In contrast, those dimensional analysis type equations which had been validated using laboratory data, grossly over-predicted the measured transport rates. The most accurate predictions were from formulae previously validated at sites similar to that used for this comparison and therefore require further testing against field data from dissimilar sites. (C) 2000 Elsevier Science B.V. All rights reserved.

Vandermeer, J.W., and J.J. Veldman, Singular Points At Berm Breakwaters - Scale Effects, Rear, Round Head and Longshore Transport, Coastal Engineering, 17 (3-4), 153-171, 1992.

Design aspects other than the profile development of the seaward side have been investigated in this paper. Aspects such as scale effects, rear stability, round head design and longshore transport have been treated here, based on extensive test series on two different berm breakwater designs. A first conclusion is that scale effects were not present in a 1:35 scale model compared with a 1:7 large scale model with wave heights up to 1.7 m. A first design rule was assessed on the relationship between damage at the rear of a berm breakwater and the crest height, wave height, wave steepness and rock size. Tests on a berm breakwater head showed that enlarging the berm height at the crest and therefore the amount of rock in the berm was effective with regard to stability. Finally the onset of longshore transport due to oblique wave attack was studied and compared with literature. Formulae were derived for this onset of transport and also for the range of more serious transport up to longshore transport of coarse gravel.

vanRijn, L.C., and K.M. Wijnberg, One-dimensional modelling of individual waves and wave-induced longshore currents in the surf zone, Coastal Engineering, 28 (1-4), 121-145, 1996.

A probabilistic model (WAVIS-model) was developed to describe the propagation and transformation of individual waves (wave by wave approach). The individual waves shoal until an empirical criterion for breaking is satisfied, Wave height decay after breaking is modelled by using an energy dissipation method, Wave-induced set-up and set-down and breaking-associated longshore currents are also modelled, Laboratory and field data were used to calibrate and verify the model. The model was calibrated by adjusting the wave breaking coefficient (as a function of local wave steepness and bottom slope) to obtain optimum agreement between measured and computed wave height. Four tests carried out in the large Delta flume of Delft Hydraulics were considered, Generally, the measured H-1/3-wave heights are reasonably well represented by the model in all zones from deep water to the shallow surf zone. The fraction of breaking waves was reasonably well represented by the model in the upsloping zones of the bottom profile. Verification of the model results with respect to wave-induced longshore current velocities was not extensive, because of a lack of data. In case of a barred profile the measured longshore velocities showed a relatively uniform distribution in the (trough) zone between the bar crest and the shoreline, which could to some extent be modelled by including space-averaging of the radiation force gradient, horizontal mixing and longshore water surface gradients related to variations in set-up. In case of a monotonically upsloping profile the cross-shore distribution of the longshore current velocities is reasonably well represented.

Vincent, C.E., Longshore Sand Transport Rates - Simple-Model For the East Anglian Coastline, Coastal Engineering, 3 (2), 113-136, 1979.


Visser, P.J., Laboratory Measurements of Uniform Longshore Currents, Coastal Engineering, 15 (5-6), 563-593, 1991.

Experiments on uniform longshore currents in a wave basin are described. The measurements were performed in a basin with a pumped recirculation through openings in the wave guides. Minimal return flows in the offshore region of the basin are found to be accompanied with longshore currents which are virtually uniform alongshore. Three-dimensional longshore current velocity distributions were measured with much attention to quality control. Detailed experimental results are presented for different wave fields, two beach slopes and two beach roughnesses.

Visser, P.J., Laboratory Measurements of Uniform Longshore Currents - Reply, Coastal Engineering, 18 (3-4), 341-345, 1992.


Walton, T.E., Littoral Sand Transport From Longshore Currents, Journal of the Waterway Port Coastal and Ocean Division-Asce, 106 (4), 483-487, 1980.


Walton, T.L., Sand-Bypassing Simulation Using Synthetic Longshore Transport Data, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 115 (4), 576-577, 1989.


Walton, T.L., and R.O. Bruno, Longshore Transport At a Detached Breakwater, Phase-Ii, Journal of Coastal Research, 5 (4), 679-691, 1989.


Wang, P., Longshore sediment flux in water column and across surf zone, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 124 (3), 108-117, 1998.

Streamer sediment traps were used to measure the distribution of longshore sediment flux in the surf zone at 29 locations along the southeast coast of the United States and the Gulf coast of Florida. Measurements were conducted on both barred and nonbarred coasts under low-wave energy conditions. Results indicate that longshore sediment flux decreases logarithmically upward in the water column throughout the surf zone, and the rate of upward decrease is largest in the trough and smallest in the swash due to stronger mixing energy in the swash. Six types of cross-shore distribution patterns of longshore sediment transport (LST) were found. These six distribution patterns are controlled by nearshore morphology, breaker type, and energy dissipation pattern. For low-wave energy coasts, the swash (nonbarred coast) and inner surf (barred coast) zones contain significant contributions to the longshore sediment transport rate. The cross-shore distribution pattern of the longshore sediment transport rate along nonbarred coasts was well reproduced using energy-dissipation and shear-stress approaches developed mainly from laboratory studies.

Wang, P., and N.C. Kraus, Longshore sediment transport rate measured by short-term impoundment, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 125 (3), 118-126, 1999.

The total longshore sediment transport rate in the surf zone was measured at a temporary groin installed at Indian Rocks Beach, west central Florida. Approximate mass balance between updrift accumulation and downdrift erosion, which served as an indicator of reliability, was obtained in four of the six runs, which were subjected to further analysis. Magnitudes of three of the four transport rates were considerably lower than predictions by the Coastal Engineering Research Center formula calculated based on contemporaneous measurements of the breaking waves. Error analysis indicated that the determination of the longshore wave-energy flux factor carried a 22-48% maximum uncertainty, and the measured volume-change rate carried a 22-43% uncertainty. The combined uncertainties produce a 40-90% maximum uncertainty in determination of the empirical transport coefficient K appearing in the Coastal Engineering Research Center formula. Comparable or greater uncertainty in K-values probably exists in the total database available for calibrating predictive formulas. The range in values of K in these measurements cannot be explained by measurement error or uncertainty. Therefore, it is concluded that K is not a constant and that other factors may enter, such as breaker type, turbulence intensity, and threshold for sediment transport.

Wang, P., N.C. Kraus, and R.A. Davis, Total longshore sediment transport rate in the surf zone: Field measurements and empirical predictions, Journal of Coastal Research, 14 (1), 269-282, 1998.

The total rate of longshore sediment transport was measured by streamer traps at 29 locations along the southeast coast of the United States and the Gulf Coast of Florida. The rate was also measured concurrently by traps and by short-term impoundment at Indian Rocks Beach, west-central Florida. Data on beach profiles, breaking wave conditions, and sediment properties were taken together with the transport rate. The measured total rates of longshore sediment transport were compared to predictions obtained with published empirical formulas, most of which have been calibrated mainly by sediment tracer measurements made on the (high-wave energy) Pacific coast. Transport rates measured in this study by the streamer sediment traps and the short-term impoundment along low-wave energy coasts were considerably lower than the rates predicted by empirical formulas. The empirical predictions appear to be unrealistically high for the low-wave energy settings investigated in this study. The linear relationship between wave energy flux factor and the total rate of longshore sediment transport contained in the commonly used CERC predictive formula is supported by the streamer trap measurements. However, a lower value of the empirical coefficient, 0.08 instead of the 0.78 recommended by the Shore Protection Manual, was determined by the trap data for low- energy coasts. The total rates of longshore sediment transport predicted by the KAMPHUIS (1991) formula which includes the influences of wave period, beach slope, and sediment grain size were about 3 times lower than the CERC predictions and closer to the measured values.

Weggel, J.R., S.L. Douglass, and J.E. Tunnell, Sand-Bypassing Simulation Using Synthetic Longshore Transport Data, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 114 (2), 146-160, 1988.


Weggel, J.R., and M. Perlin, Statistical Description of Longshore Transport Environment - Closure, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 115 (5), 712-713, 1989.


Weggel, J.R., and M. Perlin, Statistical Description of Longshore Transport Environment, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 114 (2), 125-145, 1988.


Werner, F.E., and B.M. Hickey, The Role of a Longshore Pressure-Gradient in Pacific Northwest Coastal Dynamics, Journal of Physical Oceanography, 13 (3), 395-410, 1983.


Whitford, D.J., and E.B. Thornton, Bed shear stress coefficients for longshore currents over a barred profile, Coastal Engineering, 27 (3-4), 243-262, 1996.

Quantitative estimates are obtained of various terms in the momentum equation governing the mean alongshore flow in the surf zone on a barred beach. A movable sled was instrumented with pressure, current, and wind sensors to measure wave and wind forcing during the SUPERDUCK experiment. Mean currents and bottom shear stress at various locations across the surf zone were determined. Particular attention is devoted to precise estimation of the cross-shore gradient of the radiation stress. Wind forcing is found to be a first-order term, along with wave forcing, under certain conditions. Time dependence of the mean longshore current is due to variable wave forcing inside the surf zone as the tide modulates the depth of waves breaking on the bar. Bed shear stress coefficients, determined as a residual of the local alongshore momentum balance, tended to decrease in magnitude shoreward. Mean bed shear stress coefficients and estimated error are 0.004 +/- 0.0013, 0.003 +/- 0.0006, and 0.001 +/- 0.0003 for offshore the bar, on top and immediately in front of the bar, and in the trough.

Whitford, D.J., and E.B. Thornton, Comparison of Wind and Wave Forcing of Longshore Currents, Continental Shelf Research, 13 (11), 1205-1218, 1993.

Wind and wave forcing of longshore currents for varying wind conditions and beach slopes are compared using a numerical model. Waves are assumed to be locally generated by the same winds and fully arisen, The finite-depth TMA wind-wave spectrum is used to describe the radiation stress spectrum. Total wind force acting across the surf zone is proportional to surf zone width and therefore inversely proportional to beach slope. Wind force is not important for steep beaches. Total wave force is dependent of wave energy flux and wave direction at breaking, which are functions of the wind speed and direction. Wind force becomes increasingly significant relative to wave force, as wind speed and incident wind direction approaches parallel to shore. For obliquely onshore winds and a gentle beach slope (tan beta = 0.01), wind force can be significant, with wind to wave force ratios ranging from 10 to 100% for winds between 10 and 30 m s-1 and wind and wave directions from 10 to 80- degrees. Thus, under certain wind and wave conditions, wind force can be a first order term in the alongshore momentum balance.

Williams, H.F.L., Sand-spit erosion following interruption of longshore sediment transport: Shamrock Island, Texas, Environmental Geology, 37 (1-2), 153-161, 1999.

Shamrock Island, located in Corpus Christi Bay, Texas, is a former sand spit that was detached from Mustang Island by navigation channels constructed in the early 1950s. The navigation channels effectively eliminated longshore sediment transport to the island, resulting in severe and ongoing erosion of the island's north shore. This study documents long- term shoreline change, based on analysis of aerial photographs from 1938, 1948, 1950, 1952, 1956, 1967, 1975, 1979, 1985, 1990, and 1995. Shamrock Island grew steadily to the south prior to 1956, while the north shore of the island was relatively stable. After 1956, the north shore eroded rapidly, while the south shore continued to grow, probably because sand eroded from the north was redistributed to the south. By 1995, up to 156 m of retreat had occurred on the north shore. The island was recently acquired by the Nature Conservancy of Texas for use as a nature preserve. Erosion now threatens to breach the island, which may result in degradation of an interior lagoon and loss of valuable wildlife habitats. Therefore, in addition to documenting long-term erosion following interruption of longshore sediment transport, this study also illustrates how human modification of the coastal zone can have important and unforseen ramifications affecting future shoreline uses for many decades.

Winant, C.D., Longshore Coherence of Currents On the Southern-California Shelf During the Summer, Journal of Physical Oceanography, 13 (1), 54-64, 1983.


Wing, S.R., J.L. Largier, and L.W. Botsford, Coastal retention and longshore displacement of meroplankton near capes in eastern boundary currents: Examples from the California Current, South African Journal of Marine Science-Suid-Afrikaanse Tydskrif Vir Seewetenskap, 19, 119-127, 1998.

Nearshore larval retention mechanisms influence the dispersal and recruitment patterns for a wide variety of meroplanktonic species in eastern boundary regions. Areas of coastal larval retention associated with capes in eastern boundary currents provide important spatial structure to coastal populations of fish and invertebrates through their influence on longshore settlement variability. Some patterns observed in the northern California Current for three meroplanktonic species groups (crabs, sea urchins and rockfish) relative to two such apparent retention features are synthesized. It is found that spatial variability in settlement of crabs is predictable at the scale of headlands. Apparent timing of upwelling intermittency and variability on weekly One-scales, as indicated by temperature change, is critical to interannual settlement variability. The average magnitude of upwelling, measured by an upwelling index, is by comparison a poor predictor of interannual settlement variability. Distribution of planktonic larvae relative to a nearshore retention feature is dependent on taxon. These nearshore retention features may act as reservoirs for some taxa or as conduits to the coast for others, likely depending on larval behaviour, timing and cross-shelf location of release relative to upwelling features. The longshore variability in recruitment created by the above patterns can result in differences in subpopulation productivity. For example, strength of a cohort of yea urchins varies longshore in accordance with proximity to retention features.

Wiuff, R., Buoyant Surface Jet in Tidal Longshore Current, Journal of the Hydraulics Division-Asce, 105 (10), 1340-1341, 1979.


Wolanski, E.J., and M.L. Banner, Buoyant Surface Jet in Tidal Longshore Current, Journal of the Hydraulics Division-Asce, 104 (11), 1505-1519, 1978.


Wolanski, E.J., and M.L. Banner, Bouyant Surface Jet in Tidal Longshore-Current - Discussion, Journal of the Hydraulics Division-Asce, 106 (8), 1407-1407, 1980.


Wood, W., and G. Meadows, Unsteady Longshore Currents in a Nonuniform Wave Field, Transactions-American Geophysical Union, 56 (12), 1010-1010, 1975.


Wood, W.L., Dependency of Surf Zone Motions On Longshore Bottom and Wave Variability, Transactions-American Geophysical Union, 57 (12), 934-934, 1976.


Wood, W.L., and G.A. Meadows, Unsteadiness in Longshore Currents, Geophysical Research Letters, 2 (11), 503-505, 1975.


Wu, C.S., E.B. Thornton, and R.T. Guza, Waves and Longshore Currents - Comparison of a Numerical-Model With Field Data, Journal of Geophysical Research-Oceans, 90 (C3), 4951-4958, 1985.


Xie, S.L., Statistical Description of Longshore Transport Environment, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 115 (5), 711-712, 1989.


Xie, S.L., and T.F. Liu, Long-Term Variation of Longshore Sediment Transport, Coastal Engineering, 11 (2), 131-140, 1987.


Yoo, D.H., Wave-Induced Longshore Currents in Surf Zone, Journal of Waterway Port Coastal and Ocean Engineering-Asce, 120 (6), 557-575, 1994.

This paper presents the numerical model of longshore currents driven by irregular waves in the surf zone. The wave field is described using the wave number vector equations and the energy-conservation equation with a superposition technique for the description of irregular waves, while the current field is described using the momentum-conservation equations and the continuity equation. Particular care has been given to the bed friction on a movable bed and the mixing processes possibly caused by both turbulence and shear flow dispersion. The model was applied to a field situation of irregular waves on a uniform beach.

Yu, J., and C.C. Mei, Do longshore bars shelter the shore?, Journal of Fluid Mechanics, 404, 251-268, 2000.

In most past theories on Bragg reflection of waves by a finite patch of rigid bars, only outgoing waves are allowed on the transmission side, simulating the effect of an idealized shoreline where all the incident wave energy is consumed by breaking. In these theories the amplitudes of both the incident and reflected waves are found to decrease monotonically over the bar patch in the shoreward direction. This result has motivated the idea of artificially constructing bars to protect a beach from incident waves. However, some numerical calculations have suggested that this tendency does not always hold when there is some reflection from the shore. We show here that with finite reflection by the shoreline the spatial distribution of wave energy over the patch can indeed be reversed, indicating that the mechanism can increase the hazards to the beach. The phase relation between the bars and the shoreline reflection is found to be the key to this qualitative change of wave response.

Yurkevic.Mg, and Yurkevic.Li, Determination of Amount of Longshore Drift, Oceanology-Ussr, 7 (6), 877-&, 1967.


Zhang, J.E., and T.Y. Wu, Oblique long waves on beach and induced longshore current, Journal of Engineering Mechanics-Asce, 125 (7), 812-826, 1999.

This study considers the 3D runup of long waves on a uniform beach of constant or variable downward slope that is connected to an open ocean of uniform depth. An inviscid linear long-wave theory is applied to obtain the fundamental solution for a uniform train of sinusoidal waves obliquely incident upon a uniform beach of variable downward slope without wave breaking. For waves at nearly grazing incidence, runup is significant only for the waves in a set of eigenmodes being trapped within the beach at resonance with the exterior ocean waves. Fourier synthesis is employed to analyze a solitary wave and a train of cnoidal waves obliquely incident upon a sloping beach, with the nonlinear and dispersive effects neglected at this stage. Comparison is made between the present theory and the ray theory to ascertain a criterion of validity. The wave induced longshore current is evaluated by finding the Stokes drift of the fluid particles carried by the momentum of the waves obliquely incident upon a sloping beach. Currents of significant velocities are produced by waves at incidence angels about 45 degrees and by grazing waves trapped on the beach. Also explored are the effects of the variable downward slope and curvature of a uniform beach on 3D runup and reflection of long waves.