scholarly journals AN APPROXIMATION OF THE WAVE RUN-UP FREQUENCY DISTRIBUTION

2011 ◽  
Vol 1 (8) ◽  
pp. 4
Author(s):  
Thorndike Saville
Keyword(s):  
Wave Height ◽  
Deep Water ◽  
Incident Wave ◽  
Laboratory Tests ◽  
Beach Erosion ◽  
Accurate Estimation ◽  
Small Scale ◽  
Wave Steepness ◽  
Technical Report ◽  
Run Up

The distribution of wave steepness (H/T ) for fully developed sea is obtained from Bretschneider's joint distribution of wave height and wave period. This steepness distribution is used with standard wave runup curves to develop a frequency curve of wave run-up. Use of this run-up distribution curve will permit more accurate estimation of the variability in wave run-up for design cases, and particularly the percent of time in which run-ups will exceed that predicted for the significant wave. The distribution may also be used with normal overtopping procedures to determine more accurate estimates of overtopping quantities. Wave run-up may be defined as the vertical height above mean water level to which water from a breaking wave will rise on a structure face. Accurate design data on the height of wave run-up is needed for determination of design crest elevations of protective structures subject to wave action such as seawalls, beach fills, surge barriers, and dams. Such structures are normally designed to prevent wave overtopping with consequent flooding on the landward side and, if of an earth type, possible failure by rearface erosion. Because of the importance of wave run-up elevations in determining structure heights and freeboards, a great deal of work has been done in the past six years in an attempt to relate wave run-up to incident wave characteristics, and slope or structure characteristics. Compilations based largely on laboratory experimental work have been made and have fe-?* suited in curves similar to those shown in Figure 1 which is reprinted from the U. S. Beach Erosion Board Technical Report No. 4. Such curves most frequently have related the dimensionless ratio of relative run-up (R/H ) to incident wave steepness in deep water (H /T ), as a function of structure type or slope. (H is the equivalent deep water wave height.) The curves shown in Figure 1 are of this type, and pertain to structures having a depth of water greater than three wave heights at the toe of the structure; this depth limitation in effect means that the wave breaks directly on the structure. The curves shown in Figure 1 are a portion of a set of five separate figures, covering different structure depths (d/H ). All are published in Beach Erosion Board Technical Report Number 4. These curves were derived primarily from small scale laboratory tests. Further laboratory tests with much larger waves (heights two to five feet) have shown that a scale effect exists for some conditions.

Bivariate Distributions of Significant Wave Height With Characteristic Wave Steepness and Characteristic Surf Parameter

2008 ◽  
Author(s):  
Dag Myrhaug ◽  
Se´bastien Fouques
Keyword(s):  
Wave Height ◽  
Deep Water ◽  
Significant Wave Height ◽  
Surf Zone ◽  
Bivariate Distribution ◽  
Wave Steepness ◽  
Peak Period ◽  
Characteristic Wave ◽  
Significant Wave ◽  
Run Up

The paper provides a bivariate distribution of significant wave height and characteristic wave steepness, as well as a bivariate distribution of significant wave height and characteristic surf parameter. The characteristic wave steepness in deep water is defined in terms of the significant wave height and the spectral peak period, and is relevant for e.g. the design of ships and marine structures. The characteristic surf parameter is given by the ratio between the slope of a beach or a structure and the square root of the characteristic wave steepness in deep water. The characteristic surf parameter is used to characterize surf zone processes and is relevant for e.g. wave run-up on beaches and coastal structures. The paper presents statistical properties of the wave parameters as well as examples of results typical for field conditions.

scholarly journals SURF SIMILARITY

1974 ◽  
Vol 1 (14) ◽  
pp. 26 ◽  
Author(s):  
J.A. Battjes
Keyword(s):  
Phase Difference ◽  
Incident Wave ◽  
Water Waves ◽  
Slope Angle ◽  
Wave Steepness ◽  
Similarity Parameter ◽  
General Terms ◽  
Depth Ratio ◽  
Run Up ◽  
Set Up

This paper deals with the following aspects of periodic water waves breaking on a plane slope breaking criterion, breaker type, phase difference across the surfzone, breaker height-to-depth ratio, run-up and set-up, and reflection. It is shown that these are approximately governed by a single similarity parameter only, embodying both the effects of slope angle and incident wave steepness. Various physical interpretations of this similarity parameter are given, while its role is discussed m general terms from the viewpoint of model prototype similarity.

Wave Steepness and Relative Width: Influence on Transmission Coefficient of Horizontal Interlaced, Multilayered, Moored Floating Pipe Breakwater With Five Layers

2011 ◽  
Vol 45 (5) ◽  
pp. 20-27
Author(s):  
Sacchi Rajappa ◽  
Arkal Vittal Hegde ◽  
Subba Rao ◽  
Veena Channegowda
Keyword(s):  
Physical Model ◽  
Transmission Coefficient ◽  
Wave Height ◽  
Incident Wave ◽  
Wave Attenuation ◽  
Transmitted Wave ◽  
Relative Width ◽  
Wave Steepness ◽  
Transmission Characteristics ◽  
Time Period

AbstractThis paper presents the results of a series of physical model scale experiments conducted to determine the transmission characteristics of a horizontal interlaced, multilayered, moored floating pipe breakwater. The studies are conducted on physical breakwater models having five layers of PVC pipes. The wave steepness (Hi/gT2, where Hi is incident wave height, g is acceleration due to gravity, and T is time period) was varied between 0.063 and 0.849, relative width (W/L, where W is width of breakwater and L is the wavelength) was varied between 0.4 and 2.65, and relative spacing (S/D, where S is horizontal centre to centre spacing of pipes and D is the diameter of pipes) was set equal to 2. The transmitted wave height is measured, and the gathered data are analyzed by plotting nondimensional graphs depicting the variation of Kt (transmission coefficient) with Hi/gT2 for values of d/W (d is depth of water) and of Kt with W/L for values of Hi/d. It is observed that Kt decreases as Hi/gT2 increases for the range of d/W between 0.082 and 0.139. It is also observed that Kt decreases with an increase in W/L values for the range of Hi/d from 0.06 to 0.40. The maximum wave attenuation achieved with the present breakwater configuration is 78%.

scholarly journals Laboratory Investigation on Hydrodynamic Performance of an Innovative Aeration Device with a Wave-Driven Heaving Buoy

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3262 ◽  
Author(s):  
Zegao Yin ◽  
Yanxu Wang ◽  
Yong Liu ◽  
Chengyan Gao ◽  
Huan Zhang
Keyword(s):  
Wave Height ◽  
Flow Rate ◽  
Incident Wave ◽  
Air Flow ◽  
Wave Period ◽  
Hydrodynamic Performance ◽  
Wave Steepness ◽  
Air Flow Rate ◽  
Rate Decrease ◽  
Relative Value

Coastal seawater quality is of significance for the environment, ecology and fisheries. In recent years, the hypoxia or anoxia problems of bottom seawater aggravated due mainly to the seawater stratification and eutrophication. This paper addresses an innovative aeration device with a wave-driven heaving buoy to enhance the dissolved oxygen concentration for bottom water. A series of physical experiments was conducted to investigate its hydrodynamic performance and air flow rate. The response amplitude of heaving components and the average value of air flow rate were examined with the related parameters, including incident wave height, incident wave steepness and aeration depth. It was found that with increasing incident wave height, the average heaving displacement and the average air flow rate increase respectively. With the increase of incident wave steepness, the relative value of average heaving displacement increases obviously for high wave period scenarios, it increases slightly for small wave period scenarios in comparison and the relative value of air flow rate increases evidently. With the increase of aeration depth, the average heaving displacement and the average air flow rate decrease respectively. With the increase of relative aeration depth, the relative value of average heaving displacement and the relative value of air flow rate decrease respectively. In addition, the dimensional analysis and the least squares methods were used to obtain the prediction formulas for the average heaving displacement and the average air flow rate, and they agreed well with the related experimental data.

scholarly journals Predicting site-specific storm wave run-up

2020 ◽  
Vol 104 (1) ◽  
pp. 493-517 ◽  
Author(s):  
Julia W. Fiedler ◽  
Adam P. Young ◽  
Bonnie C. Ludka ◽  
William C. O’Reilly ◽  
Cassandra Henderson ◽  
...  
Keyword(s):  
Deep Water ◽  
Warning System ◽  
Wave Model ◽  
Water Levels ◽  
Beach Erosion ◽  
Integral Approach ◽  
Incoming Wave ◽  
Flood Warning ◽  
Storm Wave ◽  
Run Up

Abstract Storm wave run-up causes beach erosion, wave overtopping, and street flooding. Extreme runup estimates may be improved, relative to predictions from general empirical formulae with default parameter values, by using historical storm waves and eroded profiles in numerical runup simulations. A climatology of storm wave run-up at Imperial Beach, California is developed using the numerical model SWASH, and over a decade of hindcast spectral waves and observed depth profiles. For use in a local flood warning system, the relationship between incident wave energy spectra E(f) and SWASH-modeled shoreline water levels is approximated with the numerically simple integrated power law approximation (IPA). Broad and multi-peaked E(f) are accommodated by characterizing wave forcing with frequency-weighted integrals of E(f). This integral approach improves runup estimates compared to the more commonly used bulk parameterization using deep water wave height $$H_0$$ H 0 and deep water wavelength $$L_0$$ L 0 Hunt (Trans Am Soc Civ Eng 126(4):542–570, 1961) and Stockdon et al. (Coast Eng 53(7):573–588, 2006. 10.1016/j.coastaleng.2005.12.005). Scaling of energy and frequency contributions in IPA, determined by searching parameter space for the best fit to SWASH, show an $$H_0L_0$$ H 0 L 0 scaling is near optimal. IPA performance is tested with LiDAR observations of storm run-up, which reached 2.5 m above the offshore water level, overtopped backshore riprap, and eroded the foreshore beach slope. Driven with estimates from a regional wave model and observed $$\beta _f$$ β f , the IPA reproduced observed run-up with $$<30\%$$ < 30 % error. However, errors in model physics, depth profile, and incoming wave predictions partially cancelled. IPA (or alternative empirical forms) can be calibrated (using SWASH or similar) for sites where historical waves and eroded bathymetry are available.

scholarly journals NUMERICAL SIMULATION OF SEAWALL- BEACH PROFILE INTERACTION IN RUNUP ZONE

2017 ◽  
pp. 21
Author(s):  
Berna Ayat Aydogan ◽  
Nobuhisa Kobayashi ◽  
Yalçın Yüksel ◽  
Burak AydoÄŸan
Keyword(s):  
Numerical Model ◽  
Laboratory Tests ◽  
Surf Zone ◽  
Vertical Wall ◽  
Small Scale ◽  
Scour Depth ◽  
Beach Profile ◽  
The Cross ◽  
Run Up ◽  
Offshore Transport

This study aimed to determine beach response in the presence of a vertical wall placed in the run-up zone. The responses of natural beach and the beach with a seawall with two different configurations were studied numerically. The capability and limitation of the cross-shore numerical model CSHORE in simulating the cross-shore transformation and the beach evolution in front of a seawall situated inside the surf zone was examined. Numerical model results were compared with small scale laboratory tests (Yüksel et. al, 2014). Offshore transport was observed in all three tests and the model was shown to predict the same trends in profile evolution. Scour depth in front of the vertical wall was correctly captured by the numerical model.

scholarly journals DETERMINATION OF THE WAVE HEIGHT IN NATURE FROM MODEL TESTS SUPPLEMENTED BY CALCULATION

2011 ◽  
Vol 1 (6) ◽  
pp. 12
Author(s):  
J. G.H.R. Diephuis ◽  
J. G. Gerritze
Keyword(s):  
Shallow Water ◽  
Wave Height ◽  
Deep Water ◽  
Bottom Topography ◽  
Model Tests ◽  
Small Scale ◽  
Wave Characteristics ◽  
Sea Bottom ◽  
The Waves

This paper deals with the problem of determining the wave characteristics in shallow water from those in deep water. In general this can be done by means of a refraction calculation. If the sea bottom topography is too irregular the height of the waves can be determined by means of a small-scale refraction model. In both cases, however, some additional effects have to be taken into account, viz. the influence of the bottom friction and the influence of the wind.

Extreme run-up events on a vertical wall due to nonlinear evolution of incident wave groups

2016 ◽  
Vol 797 ◽  
pp. 644-664 ◽  
Author(s):  
Gal Akrish ◽  
Oded Rabinovitch ◽  
Yehuda Agnon
Keyword(s):  
Nonlinear Wave ◽  
Deep Water ◽  
Incident Wave ◽  
Water Waves ◽  
Nonlinear Evolution ◽  
Vertical Wall ◽  
Computational Domain ◽  
Wave Groups ◽  
Wide Range ◽  
Run Up

Nonlinear evolution of long-crested wave groups can lead to extreme interactions with coastal and marine structures. In the present study the role of nonlinear evolution in the formation of extreme run-up events on a vertical wall is investigated. To this end, the fundamental problem of interaction between non-breaking water waves and a vertical wall over constant water depth is considered. In order to simulate nonlinear wave–wall interactions, the high-order spectral method is applied to a computational domain which aims to represent a two-dimensional wave flume. Wave generation is simulated at the flume entrance by means of the additional potential concept. Through this concept, the implementation of a numerical wavemaker is applicable. In addition to computational efficiency, the adopted numerical approach enables one to consider the evolution of nonlinear waves while preserving full dispersivity. Utilizing these properties, the influence of the nonlinear wave evolution on the wave run-up can be examined for a wide range of water depths. In shallow water, it is known that nonlinear evolution of incident waves may result in extreme run-up events due to the formation of an undular bore. The present study reveals the influence of the nonlinear evolution on the wave run-up in deep-water conditions. The results suggest that extreme run-up events in deep water may occur as a result of the disintegration of incident wave groups into envelope solitons.

scholarly journals A NEW PARAMETER FOR WAVE BREAKING WITH OPPOSING CURRENT ON SLOPING SEA BED

1988 ◽  
Vol 1 (21) ◽  
pp. 77
Author(s):  
Shigeki Sakai ◽  
Ken-ichi Hirayama ◽  
Hiroshi Saeki
Keyword(s):  
Shallow Water ◽  
General Expression ◽  
Deep Water ◽  
Incident Wave ◽  
Wave Breaking ◽  
Gravitational Acceleration ◽  
Wave Steepness ◽  
Unit Width ◽  
Sea Bed ◽  
Wave Celerity

Opposing currents affect the wave breaking processes. The condition of wave breaking caused by opposing currents in deep water is described by the ratio of the wave celerity to the velocity of the opposing current(Yu(1952)). For the wave breaking caused by the opposing currents in shallow water on a flat bed, the equation given by Miche(1951) for the breaking criteria without current remains available (Iwagaki et al.(1980)). However, it is the breaking of shoaling wave in the presence of opposing current on a uniform slope, which is of concern in this paper. Sakai et al.(1981) showed that the wave breaking affected by opposing currents on a sloping sea bed is characterized by a normalized unit width discharge q*, as well as an incident wave steepness Ho/Lo and a slope of sea bed S, where q* is defined as q*= q/g2T3; q: a unit width discharge, g; the gravitational acceleration, T: a wave period. They proposed diagrams for the breaker height and the breaking depth as a function of these three parameters. The breaker index curves in their diagrams show the relationships between the breaker height (or the breaking depth) and q* for waves with particular values of Ho/Lo and S, and it is much more convenient to give a general expression for the breaker indices for arbitrary conditions of q*, Ho/Lo and S. The purpose of this study is to formulate the effects of these parameters on wave breaking, based on the results of systematic experiments performed by the authors, and to derive an empirical and simplified expression for the breaker height and depth in the presence of opposing currents.

Experimental Study of Reduction of Solitary Wave Run-Up by Emergent Rigid Vegetation on a Beach

2015 ◽  
Vol 09 (05) ◽  
pp. 1540003 ◽  
Author(s):  
Yu Yao ◽  
Ruichao Du ◽  
Changbo Jiang ◽  
Zhengjiang Tang ◽  
Wancheng Yuan
Keyword(s):  
Wave Height ◽  
Incident Wave ◽  
High Speed ◽  
Wave Reflection ◽  
Ccd Camera ◽  
Mangrove Forests ◽  
Tsunami Waves ◽  
Forest Density ◽  
Run Up ◽  
Sloping Beach

Extensive studies have been carried out to study the performance of mangrove forests in wave height reduction. In this study, the reduction of the inundation and run-up of leading tsunami waves by mangrove forests was investigated through a series of laboratory experiments conducted in a long wave tank. The inundation and run-up were measured using a high speed CCD camera. Solitary waves were used to model the leading tsunami waves. Five vegetation models representing three forest densities and two tree distributions were examined on an impermeable sloping beach, and they were compared with the non-vegetated slope in view of wave reflection, transmission, and run-up. Results show that both incident wave height and run-up could be reduced by up to 50% when the vegetation was present on the slope. Dense vegetation reduced the wave transmission because of the increased wave reflection and energy dissipation into turbulence in vegetation. Normalized wave run-up on the beach decreased with the increase of both normalized incident wave height and forest density. Effect of forest density on the wave run-up on the sloping beach was further examined, and an empirical formula with the density incorporated was proposed. The study also highlighted the importance of tree distribution to wave interaction with vegetation on the slope when the forest density was unaltered, and run-up reduction difference between tandem and staggered arrangements of the trees could reach up to 20%.

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