Nearshore currents and beach topography, Martinique Beach, Nova Scotia

1977 ◽  
Vol 14 (8) ◽  
pp. 1906-1915 ◽  
Author(s):  
J. R. Keeley
Keyword(s):  
Nova Scotia ◽  
Theoretical Model ◽  
Sediment Transport ◽  
Wind Direction ◽  
Seasonal Changes ◽  
Late Spring ◽  
Beach Profile ◽  
Storm Waves ◽  
Longshore Sediment Transport ◽  
Subsequent Disappearance

A series of profiles across Martinique Beach, Nova Scotia, surveyed at monthly intervals between April and October, 1974, showed the formation and subsequent disappearance of large cuspate projections on the beach face. A theoretical model of the distribution of longshore currents on the beach was used to predict the expected positions of convergences and divergences in the longshore sediment transport. The observed projections were found to occur in positions of convergence of waves generated by the southeasterly winds, dominant in the late spring. The disappearance of the cusps was associaled with the seasonal veering of wind direction to the southwest as summer advanced.The size of the seasonal changes in beach profile suggests that the morphology of Martinique Beach is controlled primarily by storm waves.

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

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

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

scholarly journals FIELD INVESTIGATION OF BEACH PROFILE CHANGES AND THE ANALYSIS USING EMPIRICAL EIGENFUNCTIONS

1982 ◽  
Vol 1 (18) ◽  
pp. 84
Author(s):  
Hiroshi Hashimoto ◽  
Takaaki Uda
Keyword(s):  
Sediment Transport ◽  
Time Lag ◽  
Field Investigation ◽  
Sand Transport ◽  
Wave Direction ◽  
Beach Profile ◽  
Sand Waves ◽  
Longshore Sediment Transport ◽  
Profile Changes ◽  
Incident Waves

In order to investigate the response of beach profiles to incident waves, computations by the empirical eigenfunction analysis proposed by Winant et al. are performed. The analysis of the data obtained at Ajigaura Beach over three years from 1976 to 1979 indicates that beach profile changes due to longshore and onshore-offshore sediment transport are separable by the empirical eigenfunction method. The beach profile changes due to longshore sediment transport has a time lag of 12 weeks with respect to the change of wave direction at Ajigaura Beach. It was found theoretically that this time lag was due to the sand waves propagating in the longshore direction. Regarding as onshore-offshore sand transport, the second eigenfunction is associated with the beach changes due to onshore-offshore sand transport caused by the change of wave height.

scholarly journals LONGSHORE CURRENT AND TRANSPORT ACROSS NON-SINGULAR EQUILIBRIUM BEACH PROFILES

1988 ◽  
Vol 1 (21) ◽  
pp. 104
Author(s):  
Kevin R. Bodge
Keyword(s):  
Sediment Transport ◽  
Longshore Current ◽  
Beach Profile ◽  
Infinite Slope ◽  
Profile Shape ◽  
Equilibrium Beach Profile ◽  
Longshore Sediment Transport ◽  
Beach Processes ◽  
Mathematical Expressions ◽  
Equilibrium Profile

The longshore current and longshore sediment transport distributions are described across an equilibrium beach profile comprised of an intersecting planar foreshore and a concave-up profile. Such a profile shape avoids the singularity associated with the infinite-slope at the shoreline described by traditional equilibrium profile forms and allows prediction of beach processes at and above the shoreline. The mathematical expressions which describe the distributions are simplified and can be more readily applied relative to expressions previously presented in the literature. The findings are in general agreement with similar previous analytic studies and indicate that the current and transport maxima are generally located at about the intersection of the planar and concave-up portions of the profile.

STUDY ON LONGSHORE SEDIMENT TRANSPORT USING CIRCULAR WAVE BASIN

2019 ◽  
Vol 75 (2) ◽  
pp. I_625-I_630
Author(s):  
Naoki AKITA ◽  
Risa KATO ◽  
Hoang Hai DONG ◽  
Tomoaki NAKUMURA ◽  
Norimi MIZUTANI
Keyword(s):  
Sediment Transport ◽  
Longshore Sediment Transport ◽  
Wave Basin

Revisiting the derivation of bulk longshore sediment transport rates using meta-heuristic algorithms

2021 ◽  
Vol 69 ◽  
Author(s):  
Zahra Gholami ◽  
Kamran Lari ◽  
Abbasali Aliakbari Bidokhti ◽  
AmirHosein Javid
Keyword(s):  
Sediment Transport ◽  
Heuristic Algorithms ◽  
Longshore Sediment Transport

Longshore Sediment Transport Model against Field Tracer Data at Ancao Peninsula (Portugal) and Lubiatowo (Poland)

2001 ◽  
Author(s):  
Leszek M. Kaczmarek ◽  
Rafał Ostrowski ◽  
Yann Balouin ◽  
Hélène Howa
Keyword(s):  
Sediment Transport ◽  
Transport Model ◽  
Sediment Transport Model ◽  
Longshore Sediment Transport

scholarly journals LONGSHORE TRANSPORT AT A TOTAL LITTORAL BARRIER

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

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

scholarly journals Lidar arc scan uncertainty reduction through scanning geometry optimization

2016 ◽  
Vol 9 (4) ◽  
pp. 1653-1669 ◽  
Author(s):  
Hui Wang ◽  
Rebecca J. Barthelmie ◽  
Sara C. Pryor ◽  
Gareth. Brown
Keyword(s):  
Theoretical Model ◽  
Wind Speed ◽  
Wind Energy ◽  
Turbulence Intensity ◽  
Wind Direction ◽  
Energy Production ◽  
Elevation Angle ◽  
Relative Standard Error ◽  
Power Performance ◽  
Relative Standard

Abstract. Doppler lidars are frequently operated in a mode referred to as arc scans, wherein the lidar beam scans across a sector with a fixed elevation angle and the resulting measurements are used to derive an estimate of the n minute horizontal mean wind velocity (speed and direction). Previous studies have shown that the uncertainty in the measured wind speed originates from turbulent wind fluctuations and depends on the scan geometry (the arc span and the arc orientation). This paper is designed to provide guidance on optimal scan geometries for two key applications in the wind energy industry: wind turbine power performance analysis and annual energy production prediction. We present a quantitative analysis of the retrieved wind speed uncertainty derived using a theoretical model with the assumption of isotropic and frozen turbulence, and observations from three sites that are onshore with flat terrain, onshore with complex terrain and offshore, respectively. The results from both the theoretical model and observations show that the uncertainty is scaled with the turbulence intensity such that the relative standard error on the 10 min mean wind speed is about 30 % of the turbulence intensity. The uncertainty in both retrieved wind speeds and derived wind energy production estimates can be reduced by aligning lidar beams with the dominant wind direction, increasing the arc span and lowering the number of beams per arc scan. Large arc spans should be used at sites with high turbulence intensity and/or large wind direction variation.

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