scholarly journals OBSERVATIONS OF SEDIMENT PARTICLE MOVEMENTS UNDER ACCRETIVE WAVE CONDITIONS

2018 ◽  
pp. 68
Author(s):  
Takayuki Suzuki ◽  
Yu Inami ◽  
Shinichi Yanagishima ◽  
Shuhei Sakihama ◽  
Daniel Cox
Keyword(s):  
Surf Zone ◽  
Outer Side ◽  
Field Observations ◽  
Swash Zone ◽  
Sediment Particle ◽  
Beach Management ◽  
Sediment Movement ◽  
Recovery Duration ◽  
Wave Conditions

From the aspect of beach management, understanding of sediment movement from the outer-surf zone to the swash zone during recovery duration is important. In this study, field observations were conducted during accretive wave conditions to investigate the sediment movement from the outer side of the bar to the swash zone using fluorescent sand tracers.

scholarly journals SWASH ZONE MORPHODYNAMICS OF COARSE-GRAINED BEACHES DURING ENERGETIC WAVE CONDITIONS

2014 ◽  
Vol 1 (34) ◽  
pp. 35 ◽  
Author(s):  
Luis Pedro Almeida ◽  
Gerd Masselink ◽  
Paul Russell ◽  
Mark Davidson ◽  
Robert McCall ◽  
...  
Keyword(s):  
Coarse Grained ◽  
Swash Zone ◽  
Wave Conditions

scholarly journals FIELD MEASUREMENTS AND MODELLING OF NEARSHORE CURRENTS AT A HIGH-ENERGY GEOLOGICALLY-CONSTRAINED BEACH

2020 ◽  
pp. 18
Author(s):  
Arthur Mouragues ◽  
Philippe Bonneton ◽  
Bruno Castelle ◽  
Vincent Marieu
Keyword(s):  
Surf Zone ◽  
Low Frequency ◽  
Field Measurements ◽  
High Energy ◽  
Oblique Wave ◽  
Wave Forcing ◽  
Circulation Patterns ◽  
Wave Conditions ◽  
Nearshore Currents ◽  
Set Up

We present field measurements of nearshore currents at a high-energy mesotidal beach with the presence of a 500-m headland and a submerged reef. Small changes in wave forcing and tide elevation were found to largely impact circulation patterns. In particular, under 4-m oblique wave conditions, our measurements indicate the presence of an intense low-frequency fluctuating deflection rip flowing against the headland and extending well beyond the surf zone. An XBeach model is further set up to hindcast such flow patterns.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/EiqnjBIkWJE

scholarly journals STORM INDUCED PERIODICITIES OF SUSPENDED SAND MOVEMENT

1978 ◽  
Vol 1 (16) ◽  
pp. 105 ◽  
Author(s):  
Jay E. Leonard ◽  
Benno M. Brenninkmeyer
Keyword(s):  
Surf Zone ◽  
Normal Wave ◽  
Low Frequency ◽  
Sediment Concentration ◽  
Frequency Component ◽  
High Frequency Component ◽  
Computational Technique ◽  
Electromagnetic Current ◽  
Discrete Fourier Analysis ◽  
Sediment Movement

An array of electronic sensors was installed on Nauset Light Beach, Cape Cod, Massachusetts, U.S.A., in order to provide a description of the sediment movement during storm conditions. These sensors included two sediment concentration indicators (almometers) which monitor sediment movement as a function of elevation and time, one bidirectional electromagnetic current meter, and a resistive wave staff. Prior field studies performed during "normal" conditions have indicated that surf-zone suspended sediment movement is a low-frequency phenomenon, with the relatively high-frequency component (normal wave period) contributing little to the amount of total sediment transported. Development of a computational technique based upon discrete Fourier analysis and digital filtering called Spectrally Filtered Integration (SFI) provides the calculation and filtering of true units of sediment change in grams-per-liter. Moreover, the SFI technique eliminates the possibility spurious sediment information created by the presence of air bubbles in the water column. Generally, higher-frequency sediment movement is more common during storm conditions than during normal non-storm conditions. This movement is controlled not by the prevailing wave and swell periods, but by a longer period which may be due to water interactions below the surface.

Aeolian transport on a wet beach: Field observations from the swash zone

2020 ◽  
Author(s):  
Christy Swann ◽  
sarah trimble
Keyword(s):  
Moisture Content ◽  
Sediment Supply ◽  
Strong Wind ◽  
Field Observations ◽  
Swash Zone ◽  
Aeolian Transport ◽  
Near Surface ◽  
Moisture Contents ◽  
Wind Velocities ◽  
Wind Events

<p>Quantifying aeolian transport within the swash zone is critical to understanding feedbacks between aeolian and nearshore processes in coastal environments. In the swash zone, high moisture contents are thought to significantly limit the amount of sediment available for transport by wind. These assertions are supported by empirical relationships between the threshold for aeolian transport and moisture content that show gravimetric moisture contents greater than ~5% severely restrict the transport of windblown sand. Yet, during strong wind events aeolian transport can occur in the swash zone where moisture content is significantly higher. Here, we present field observations of fully-saturated aeolian transport on a wet beach and highlight the proficiency of winds to sustain aeolian transport in the swash zone.  </p><p>Field observations were collected during the passing of Tropical Storm Nester on a dissipative beach north of Corolla, North Carolina, USA in the early morning hours of October 19. 2019. Beach width ranged between ~50 and 100 meters and observations were made during a falling tide. Alignment of predominate winds and beach orientation provided a nearly unlimited fetch with an abundant sediment supply from the drier upper beach. Mean grain sizes of surface grab samples in the swash zone were 0.17 to 0.19 mm and moisture content in the swash zone ranged from 8 to 13% during the observational period.</p><p>Videos of fully developed, saturated transport in the form of nested streamers, approximately 5-20 cm wide, were recorded. A vertical array of cup and sonic anemometers measured near surface fluid flow. Cup anemometers were sampled at 1 Hz and observed wind velocities at 7, 18, 44, 68 and 93 cm above the surface. Ultrasonic anemometers sampled 3 dimensional velocity components at 32 Hz via at 53 and ~100 cm.  Sustained wind velocities were 9.5 m/s at 93 cm above the surface with gusts reaching 14 m/s. A series of vertically-segregating saltation traps captured particles in transport and showed minimal size-segregation with height. Gravimetric moisture content of captured saltation ranged from 0 to 4%.</p><p>Pulses of abundant aeolian transport during the storm were largely driven by largescale coherent eddies initiating transport from the drier upper beach. These upper beach sediments sustained transport on the lower, wet beach. The spatial and temporal variability of the exceedance of both fluid and impact thresholds strongly controls transport. These field observations demonstrate the proficiency of wind to transport of large volumes sand in the swash zone during strong alongshore wind events.</p>

scholarly journals LiDAR Observations of Multi-modal Swash Probability Distributions on a Dissipative Beach

2020 ◽  
Author(s):  
Caio Eadi Stringari ◽  
Hannah E. Power
Keyword(s):  
Coastal Management ◽  
Surf Zone ◽  
Probability Distributions ◽  
Statistical Modelling ◽  
High Energy ◽  
Swash Zone ◽  
The Novel ◽  
Transport Models ◽  
Management Tools ◽  
Data Collection And Analysis

Understanding swash zone dynamics is of crucial importance for coastal management as the swash motion, consisting of the uprush of the wave on the beach face and the subsequent downrush, is responsible for driving changes the beach morphology trough sediment exchanges between the sub-aerial and sub-aqueous beach. Improved understanding of the probabilistic characteristics of these motions has the potential to allow coastal engineers to develop improved sediment transport models which, in turn, can be further developed into coastal management tools. In this paper, novel descriptors of swash motions are obtained by combining field data and statistical modelling. Our results indicate that the probability distribution function (PDF) of shoreline height (p(ζ)) and trough-to-peak swash heights (p(ρ)) measured at a high energy, sandy beach were both inherently multimodal. Based on the observed multimodality of these PDFs, Gaussian Mixtures are shown to be the best method to statistically model them. Further, our results show that both offshore and surf zone dynamics are responsible for driving swash zone dynamics, which indicates unsaturated swash. The novel methods and results developed in this paper, both data collection and analysis, could aid coastal managers to develop improved swash zone models in the future.

scholarly journals NEARSHORE CIRCULATION

2010 ◽  
Vol 1 (1) ◽  
pp. 5
Author(s):  
F. P. Shepard ◽  
D. L. Inman
Keyword(s):  
World War Ii ◽  
University Of California ◽  
Field Observations ◽  
Laboratory Measurements ◽  
World War ◽  
Scripps Institution ◽  
Nearshore Circulation ◽  
Longshore Currents ◽  
Wave Conditions ◽  
Energy And Momentum

Studies of nearshore circulation were initiated at Scripps Institution during World War II. A method of estimating the velocity of longshore currents from known wave conditions on straight beaches with parallel contours was devised by Munk and Traylor (1945) and later revised by Putnam, Munk and Traylor (1949). Their methods were based on energy and momentum considerations which were applied to the following two types of observations: (1) field observations of longshore currents along the straight beach at Oceanside, California made by Munk and Traylor (1945), and (2) laboratory measurements conducted at the Department of Engineering, University of California.

scholarly journals LONGSHORE TRANSPORT OF SAND

1968 ◽  
Vol 1 (11) ◽  
pp. 18 ◽  
Author(s):  
Douglas L. Inman ◽  
Paul D. Komar ◽  
Anthony J. Bowen
Keyword(s):  
Energy Flux ◽  
Surf Zone ◽  
Field Measurements ◽  
Breaking Waves ◽  
Transport Rate ◽  
Wave Power ◽  
Longshore Transport ◽  
Wave Conditions

Simultaneous field measurements of the energy flux of breaking waves and the resulting longshore transport of sand in the surf zone have been made along three beaches and for a variety of wave conditions. The measurements indicate that the longshore transport rate of sand is directly proportional to the longshore component of wave power.

FORECASTING WAVE CONDITIONS IN BEACHES: FROM NESTED SIMULATIOS TO FIELD OBSERVATIONS

2005 ◽  
Author(s):  
DANIEL GONZALEZ-MARCO ◽  
AGUSTIN SANCHEZ-ARCILLA ◽  
RODOLFO BOLAÑOS ◽  
JOAQUIM SOSPEDRA ◽  
JOAN PAU SIERRA ◽  
...  
Keyword(s):  
Field Observations ◽  
Wave Conditions
Sign in / Sign up

Export Citation Format

Share Document