scholarly journals WAVE SET-UP IN THE SURF ZONE

1978 ◽  
Vol 1 (16) ◽  
pp. 62
Author(s):  
Uwe A. Hansen
Keyword(s):  
Water Level ◽  
Dynamic Load ◽  
Static Load ◽  
Surf Zone ◽  
Wave Heights ◽  
Level Elevation ◽  
Set Up ◽  
Protective Structures ◽  
The Waves ◽  
Design Water Level

In designing coastal protective structures the knowledge of the static load due to the water level elevation is as important as that of the dynamic load due to the waves. The structure, designed at sandy coasts with well formed surf zones on the beach - these areas are the basis of this examination - has to stand against both, the superposition of the static and dynamic load, which are dependent on each other. Undoubtedly a rise in the design water level (a summation of different influences - see figure 1) will cause an increase in the wave heights and the reverse will happen, when the design water level decreases.

scholarly journals WAVE ATTENUATION AND SET-UP ON A BEACH

1984 ◽  
Vol 1 (19) ◽  
pp. 4 ◽  
Author(s):  
I.A. Svendsen
Keyword(s):  
Surf Zone ◽  
Wave Attenuation ◽  
Outer Region ◽  
Dimensional Model ◽  
Radiation Stress ◽  
Wave Heights ◽  
Actual Flow ◽  
Set Up ◽  
The Waves ◽  
Wave Properties

A theoretical two-dimensional model for wave heights and set-up in a surf zone is described and compared to measurements. The integral wave properties energy flux Ef, and radiation stress Sxx are determined from crude approximations of the actual flow in surf zone waves. Some physical aspects of the outer region are discussed and found to agree with our knowledge of the waves seawards and shorewards of this region.

scholarly journals Wave heights and set-up in a surf zone

1984 ◽  
Vol 8 (4) ◽  
pp. 303-329 ◽  
Author(s):  
I.A. Svendsen
Keyword(s):  
Surf Zone ◽  
Wave Heights ◽  
Set Up

scholarly journals THE INTERACTION OF WAVES AND CURRENTS OVER A LONGSHORE BAR

1986 ◽  
Vol 1 (20) ◽  
pp. 116 ◽  
Author(s):  
I.A. Svendsen ◽  
J. Buhr Hansen
Keyword(s):  
Wave Height ◽  
Wave Motion ◽  
Surf Zone ◽  
Wave Theory ◽  
Runge Kutta Method ◽  
Waves And Currents ◽  
Set Up ◽  
The Waves ◽  
Wave Properties ◽  
A Current

A two-dimensional model for waves and steady currents in the surf zone is developed. It is based on a depth integrated and time averaged version of the equations for the conservation of mass, momentum, and wave energy. A numerical solution is described based on a fourth order Runge-Kutta method. The solution yields the variation of wave height, set-up, and current in the surf zone, taking into account the mass flux in the waves. In its general form any wave theory can be used for the wave properties. Specific results are given using the description for surf zone waves suggested by Svendsen (1984a), and in this form the model is used for the wave motion with a current on a beach with a longshore bar. Results for wave height and set-up are compared with measurements by Hansen & Svendsen (1986).

scholarly journals FIELD INVESTIGATIONS IN THE TOW STUDY PROGRAMME FOR COASTAL SEDIMENT TRANSPORT IN THE NETHERLANDS

1984 ◽  
Vol 1 (19) ◽  
pp. 123 ◽  
Author(s):  
H. Derks ◽  
M.J.F. Stive
Keyword(s):  
Surf Zone ◽  
Weather Conditions ◽  
Measurement Systems ◽  
Field Investigations ◽  
Study Programme ◽  
Wave Heights ◽  
Coastal Sediment Transport ◽  
Set Up ◽  
Offshore Wave

Field campaigns were conducted in 1981 and 1982/83 on the Dutch coast near Egmond. Measurements were made of surface elevations, water velocities and sediment concentrations in 3 to 8 surf zone locations and 2 to 5 offshore locations simultaneously. A total of 50 measurement series was obtained under a variety of weather conditions, resulting in offshore wave heights of 0.2 to 4.6 m. A description is given of the field set-up, the instruments and measurements, and the collected data. The quality of the various measurement systems and the data produced has been investigated extensively by intercomparison of instruments and devices in the field. The results are reported here.

Set-up of Sydney Harbour by waves, wind and atmospheric pressure

1983 ◽  
Vol 34 (1) ◽  
pp. 97 ◽  
Author(s):  
RORY Thomson
Keyword(s):  
Water Level ◽  
Atmospheric Pressure ◽  
Tide Gauge ◽  
Confounding Factors ◽  
Average Depth ◽  
Tide Gauge Data ◽  
Sydney Harbour ◽  
Gauge Data ◽  
Set Up ◽  
The Waves

Nine years of hourly tide-gauge data from inside Sydney Harbour were detided and combined with wave- rider observations from outside, to test the effect of the waves on water level in the Harbour. Weather records were appended, to account for the confounding factors of wind and atmospheric pressure via a multiple regression analysis. The regression of water level on wave variance was found to be 2.88 cm m-2, in satisfactory agreement with the theoretical value of 3/4H, where H is the average depth of the Harbour entrance. Wind set up the Harbour most efficiently (0.48 cm perm s-1) when blowing toward 18� west of north. The regression of water level on atmospheric pressure was 0.74 cm mb-1, definitely less than 1.01 cm mb-1, the value of isostasy.

Wave set-up, percolation and undertow in the surf zone

1983 ◽  
Vol 390 (1799) ◽  
pp. 283-291 ◽  
Keyword(s):  
Surf Zone ◽  
Bottom Current ◽  
Straight Tube ◽  
Mean Flow ◽  
Mean Water Level ◽  
The Mean ◽  
Run Up ◽  
Set Up ◽  
Sloping Beach ◽  
The Waves

Waves approaching a sloping beach induce a tilt in the mean water level within the surf zone. The existence of this ‘set-up’ is here demonstrated by observing the mean flow in a straight tube laid parallel to the incoming waves; also by showing that the waves induce a siphon in a U-tube laid on the sloping bottom. It is argued theoretically, and confirmed by experiment, that the set-up should help to drive an offshore bottom current (the undertow) between the shoreline and the breaker line. Seawards from the breaker line the bottom current is reversed. The consequent convergence of the bottom currents may contribute to building up the ‘breaker bar’. Further experiments show that the mean onshore pressure gradient drives a circulation of water within a porous beach. The associated pattern of streamlines also extends into the land, inshore from the run-up line. Theoretically, the injection of dye at the sediment-water interface might be used to probe the porosity of the beach material.

scholarly journals A Model-Derived Empirical Formulation for Wave Run-Up on Naturally Sloping Beaches

2021 ◽  
Vol 9 (11) ◽  
pp. 1185
Author(s):  
Maarten van Ormondt ◽  
Dano Roelvink ◽  
Ap van Dongeren
Keyword(s):  
Surf Zone ◽  
Sandy Beaches ◽  
Wide Range ◽  
Wave Heights ◽  
Incident Wave Angle ◽  
Wave Angle ◽  
Run Up ◽  
Set Up ◽  
Offshore Wave ◽  
Infragravity Wave

A new set of empirical formulations has been derived to predict wave run-up at naturally sloping sandy beaches. They are obtained by fitting the results of hundreds of XBeach-NH+ model simulations. The simulations are carried out over a wide range of offshore wave conditions (wave heights ranging from 1 to 12 m and periods from 6 to 16 s), and surf zone (Dean parameters aD ranging from 0.05 to 0.30) and beach geometries (slopes ranging from 1:100 to 1:5). The empirical formulations provide estimates of wave set-up, incident and infragravity wave run-up, and total run-up R2%. Reduction coefficients are included to account for the effects of incident wave angle and directional spreading. The formulations have been validated against the Stockdon dataset and show better skill at predicting R2% run-up than the widely used Stockdon relationships. Unlike most existing run-up predictors, the relations presented here include the effect of the surf zone slope, which is shown to be an important parameter for predicting wave run-up. Additionally, this study shows a clear relationship between infragravity run-up and beach slope, unlike most existing predictors.

scholarly journals VARIATION OP LONGSHORE CURRENT ACROSS THE SURF ZONE

1970 ◽  
Vol 1 (12) ◽  
pp. 18 ◽  
Author(s):  
Edward B. Thornton
Keyword(s):  
Surf Zone ◽  
Engineering Practice ◽  
Longshore Current ◽  
Current Variation ◽  
Excess Momentum ◽  
Shoaling Waves ◽  
Set Up ◽  
Spilling Breakers ◽  
Wave Induced ◽  
The Waves

The wave-induced longshore current variation across the surf zone is described for a simplified model The basic assumptions are that the conditions are steady, the bottom contours are straight and parallel but allow for an arbitrary bottom profile, the waves are adequately described by linear theory, and that spilling breakers exist across the surf zone Conservation equations of mass, momentum, and energy, separated into the steady and unsteady components, are used to describe second order-wave-induced phenomena of shoaling waves approaching at an angle to the beach An expression for the longshore current is developed, based on the alongshore component of excess momentum flux due to the presence of unsteady wave motion Wave set-down and set-up have been included in the formulation Emphasis in the analysis is placed on formulating usable predictive equations for engineering practice Comparison with experimental results from the laboratory and field show that if the assumed conditions are approximately fulfilled, the predicted results compare quite favorably.

scholarly journals SHORT WAVE BREAKING EFFECTS ON LOW FREQUENCY WAVES

2011 ◽  
Vol 1 (32) ◽  
pp. 20 ◽  
Author(s):  
Christopher Daly ◽  
Dano Roelvink ◽  
Ap Van Dongeren ◽  
Jaap Van Thiel de Vries ◽  
Robert McCall
Keyword(s):  
Wave Breaking ◽  
Surf Zone ◽  
Low Frequency ◽  
Breaking Waves ◽  
Short Wave ◽  
Frequency Wave ◽  
Wave Heights ◽  
Wave Groupiness ◽  
Set Up ◽  
Low Frequency Waves

The effect of short wave breaking on low frequency waves is investigated using two breaker formulations implemented in a time-dependent numerical model (XBeach): (1) an advective-deterministic approach (ADA) and (2) the probabilistic breaker formulation of Roelvink (1993). Previous research has shown that the ADA breaker model gives different results for the cross-shore pattern of the fraction of breaking waves, which is now shown to affect not only the short wave height but also the short wave groupiness. While RMS short wave heights are comparable to measurements using both breaker models, the ADA breaker model allows higher levels of short wave groupiness into the surf zone. It is shown that this acts as an additional forcing mechanism for low frequency waves in the shoaling and nearshore zone, which, in addition to greater levels of breaking, leads to higher values of wave set-up. These findings are dependent on the complexity of the local bathymetry. For a plane slope, the differences in the low frequency wave heights and set-up predicted by both breaker models are negligible. Where arbitrary breakpoints are present in the field of wave propagation, such as nearshore bars or reefs, the ADA model predicts higher localized set-up, indicative of greater flow over such features. Differences are even more pronounced when the incident wave regime is highly energetic.

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