Surf zone transformation of wave height to water depth ratios

1992 ◽  
Vol 17 (1-2) ◽  
pp. 49-70 ◽  
Author(s):  
R.C. Nelson ◽  
J. Gonsalves
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Surf Zone

scholarly journals A NUMERICAL INVESTIGATION OF THE LONGSHORE CURRENT PROFILE FOR MULTIPLE BAR/TROUGH BEACHES

1986 ◽  
Vol 1 (20) ◽  
pp. 73 ◽  
Author(s):  
Steven K. Baum ◽  
David R. Basco
Keyword(s):  
Numerical Model ◽  
Wave Height ◽  
Water Depth ◽  
Balance Equation ◽  
Surf Zone ◽  
Momentum Balance ◽  
Longshore Current ◽  
Current Profile ◽  
Momentum Balance Equation ◽  
Wave Decay

A numerical model is developed which calculates the longshore current profile for an arbitrary bottom profile. The basis of the model is the use of radiation stress theory in a longshore momentum balance equation which includes a driving stress, a bottom stress, and a lateral mixing stress. Each of the stresses is derived from previously developed formulations, rederiving them to take into account separate cross shore variations in the wave height and the water depth, as well as the wave approach angle. This is done to dispense with the constant wave breaking index assumption used to model wave decay in the surf zone, which is rejected as unrealistic for natural beaches. A numerical model is used to calculate distributions of the wave height and water depth across the surf zone for arbitrary, yet realistic, bottom profiles. A numerical model of the theoretically derived longshore momentum balance equation is developed and solved using the distributions obtained from the wave decay model. The profiles calculated are compared to previous theoretical models and to laboratory and field measurements.

scholarly journals Environmental controls on surf zone injuries on high-energy beaches

2019 ◽  
Vol 19 (10) ◽  
pp. 2183-2205 ◽  
Author(s):  
Bruno Castelle ◽  
Tim Scott ◽  
Rob Brander ◽  
Jak McCarroll ◽  
Arthur Robinet ◽  
...  
Keyword(s):  
Wave Height ◽  
Surf Zone ◽  
High Tide ◽  
High Energy ◽  
Water Levels ◽  
Small Scale ◽  
Beach Morphology ◽  
Environmental Controls ◽  
Flow Activity ◽  
Incident Waves

Abstract. The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and bodyboarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso–macro-tidal surf beach coast of southwestern France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide, and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind, likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore-break- and rip-related SZIs and weakest for surfing-related SZIs, the latter being also unaffected by tidal stage or range. Therefore, the analysis focused on bathers. More shore-break-related SZIs occur during shore-normal incident waves with average to below-average wave height (significant wave height, Hs = 0.75–1.5 m) and around higher water levels and large tide ranges when waves break on the steepest section of the beach. In contrast, more rip-related drownings occur near neap low tide, coinciding with maximised channel rip flow activity, under shore-normal incident waves with Hs >1.25 m and mean wave periods longer than 5 s. Additional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is interannually highly variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break-related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip-related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks or months in advance is therefore of paramount importance for predicting the primary surf zone life risks along this coast.

Evolution of a nourished sand beach under low wave energy in Thailand

Shore & Beach ◽  
2021 ◽  
pp. 36-54
Author(s):  
Jirat Laksanalamai ◽  
Nobuhisa Kobayashi
Keyword(s):  
Water Depth ◽  
Wave Energy ◽  
Surf Zone ◽  
Tidal Range ◽  
Gulf Of Thailand ◽  
Medium Sand ◽  
Sand Beach ◽  
Profile Changes ◽  
One Year ◽  
Upper Gulf Of Thailand

Sand beaches are essential for coastal tourism in Thailand, but erosion narrowed some beaches significantly over the years. Pattaya is a famous resort near Bangkok in the upper Gulf of Thailand. The Pattaya beach is microtidal with the average tidal range of 1.5 m. The average significant wave height is 0.2 m and the wave energy is low. The beach was widened by placing 130 m3/m of medium sand along the shoreline length of 2.8 km between two terminal groins constructed in 2018. The bathymetry and topography were measured in 2015, 2019, and 2020. Approximately 14% of the placed sand in the water depth less than 2 m was lost after one year, as may be expected for nourished beaches. The bathymetry change in the water depth of 2-4 m varied alongshore. The sand volume change in this offshore zone beyond the surf zone was as large as that in the landward sand placement zone. The assumption of negligible profile changes seaward of a closure depth is not applicable to this beach during 2015-2020.

scholarly journals Studi Hindcasting Dalam Menentukan Karakteristik Gelombang dan Klasifikasi Zona Surf Di Pantai Uluwatu, Bali

2018 ◽  
Vol 5 (1) ◽  
pp. 119
Author(s):  
Karina Santoso ◽  
I Dewa Nyoman Nurweda Putra ◽  
I Gusti Bagus Sila Dharma
Keyword(s):  
Wave Height ◽  
Calculation Result ◽  
Significant Wave Height ◽  
Surf Zone ◽  
Wind Data ◽  
Wave Transformation ◽  
Breaking Wave ◽  
Significant Wave ◽  
The World

Bali is one of the islands where there are many surf zones with various characteristics. In addition, Bali is also a heaven with a classy wave for the surfers of the world. One of the most challenging places to surf in Bali is Uluwatu Beach. Uluwatu Beach is ranked the 3rd best surf spot in the world version of CNN Travel in 2012. Wind causes sea waves, therefore wind data can be used to estimate the height and direction of the waves. Wave Hindcasting with Sverdrup, Munk and Bretschneider (SMB) method is calculated based on wind data for 10 years (2001 - 2010) from BMKG Ngurah Rai Station - Denpasar to obtain a significant wave height and period. In this research, it is necessary to approach through Hindcasting procedure, wave transformation analysis and surfing Terminology in determining the type of breaking wave and classification of surf zone in Uluwatu Beach area. Wave calculation result in Uluwatu Beach dominated by wave that coming from west side with significant wave height (Hs) of 0.98 m and significant wave period (Ts) of 5.21 s. The wave height due to the influence of wave refraction and shoaling is 0.976 m. The breaking wave height obtained from the calculation is 1.04 m at a depth of 0.849 m. From the result in this research, it can be concluded that the breaking wave type that occurred at Uluwatu Beach is plunging type according to the calculation result from its Irribaren number (0.4 <Ni <2.3). The classification of the surf zone at Uluwatu Beach based on its breakup type of wave is thought to be a good zone for surfers on intermediate level.

Statistical Analysis of a Set of Basin Waves

2011 ◽  
Author(s):  
Jule Scharnke ◽  
Janou Hennig
Keyword(s):  
Statistical Analysis ◽  
Wave Height ◽  
Water Depth ◽  
Water Waves ◽  
Rayleigh Distribution ◽  
Second Order ◽  
Distribution Functions ◽  
Wave Crest ◽  
Intermediate Water ◽  
Wave Measurements

In a recent paper the effect of variations in calibrated wave parameters on wave crest and height distributions was analyzed (OMAE2010-20304, [1]). Theoretical distribution functions were compared to wave measurements with a variation in water depth, wave seed (group spectrum) and location of measurement for the same initial power spectrum. The wave crest distribution of the shallow water waves exceeded both second-order and Rayleigh distribution. Whereas, in intermediate water depth the measured crests followed the second order distribution. The distributions of the measured waves showed that different wave seeds result in the same wave height and crest distributions. Measured wave heights were lower closer to the wave maker. In this paper the results of the continued statistical analysis of basin waves are presented with focus on wave steepness and their influence on wave height and wave crest distributions. Furthermore, the sampling variability of the presented cases is assessed.

Experimental study on the wave height distribution of wind-induced waves in the growth stage under finite water depth

2019 ◽  
Vol 19 (8) ◽  
pp. 2270-2279
Author(s):  
Ang Gao ◽  
Shiqiang Wu ◽  
Li Chen ◽  
Sien Liu ◽  
Zhun Xu ◽  
...  
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Growth Stage ◽  
Wind Wave ◽  
Model Parameters ◽  
Height Distribution ◽  
Distribution Models ◽  
Wave Height Distribution ◽  
Comparison Results ◽  
Optimized Model

Abstract With the method of a wind tank experiment, the real scenario of lakes with horizontal and vertical circulation of wind-induced flows is considered, and the features of wind wave height and its distribution in the different conditions of wind blowing distance, wind speed and water depth are studied systematically. Afterwards, comparison of the wave height distributions derived directly from experiment and the typical wave height distribution models show that some defects exist in typical wave height distribution models when describing wind wave height distribution in the wave growth stage. On this basis, we propose a new distribution model which is suitable for the description of wind wave height during the growth stage, and the model parameters are acquired with the programming solution method. Finally, the model is further optimized by relating B to σa, and Hs to σa. Comparison results of the optimized model and the typical ones show that the optimized model has advantages in calculation accuracy and convenience of use.

LARGE SCALE EXPERIMENTS ON EVOLUTION AND RUN-UP OF BREAKING SOLITARY WAVES

2007 ◽  
Vol 01 (03) ◽  
pp. 257-272 ◽  
Author(s):  
KAO-SHU HWANG ◽  
YU-HSUAN CHANG ◽  
HWUNG-HWENG HWUNG ◽  
YI-SYUAN LI
Keyword(s):  
Solitary Wave ◽  
Wave Height ◽  
Solitary Waves ◽  
Water Depth ◽  
Large Scale ◽  
Scale Effects ◽  
Wave Heights ◽  
Run Up ◽  
Hydraulics Laboratory ◽  
The Waves

The evolution and run-up of breaking solitary waves on plane beaches are investigated in this paper. A series of large-scale experiments were conducted in the SUPER TANK of Tainan Hydraulics Laboratory with three plane beaches of slope 0.05, 0.025 and 0.017 (1:20, 1:40 and 1:60). Solitary waves of which relative wave heights, H/h0, ranged from 0.03 to 0.31 were generated by two types of wave-board displacement trajectory: the ramp-trajectory and the solitary-wave trajectory proposed by Goring (1979). Experimental results show that under the same relative wave height, the waveforms produced by the two generation procedures becomes noticeably different as the waves propagate prior to the breaking point. Meanwhile, under the same relative wave height, the larger the constant water depth is, the larger the dimensionless run-up heights would be. Scale effects associated with the breaking process are discussed.

Assessment of the wave attenuation capacity of a mangrove forest based on its age and the incident wave conditions

2020 ◽  
Author(s):  
Maria Maza ◽  
Javier L. Lara ◽  
Iñigo J. Losada
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Mangrove Forest ◽  
Wave Attenuation ◽  
Volume Fraction ◽  
Coastal Protection ◽  
Local Flow ◽  
Ecosystem Properties ◽  
Wave Decay ◽  
Wave Conditions

&lt;p&gt;Although mangroves reduce annual flooding to millions of people there is not a methodology to implement these solutions and it is still difficult to estimate the protection provided by them under different environmental conditions and ecosystem properties. To move forward in the consecution of an engineering approach when implementing these solutions for coastal defense, the first step to make is to better understand and parameterize the basic physical processes involved in flow-mangroves interaction. With the aim of getting a new formulation for wave decay provided by Rhizophora mangrove forests based on flow and ecosystem properties, an experimental campaign was carried out where both wave attenuation and forces on mangrove individuals were measured under different wave conditions. Both, the hydrodynamic conditions and the mangrove forest, were scaled according to field conditions for short waves. The detailed wave attenuation and drag force measurements obtained in these experiments allowed to obtain new formulations of wave decay produced by the forest depending on the flow, i.e.: water depth, wave height and period, and on the forest characteristics, i.e.: individuals submerged solid volume fraction and density. These formulations are used to get attenuation rates under different flow and ecosystem conditions. The resultant curves provide with the wave decay produced by a specific Rhizophora forest subjected to the defined wave conditions. The forest is defined on the basis of its age, considering the differences in individual trees depending on their maturity and the density of the forest as the number of trees per unit area. Wave conditions are defined by the root mean square wave height and the peak period and water depth is also considered. The obtained curves allow to estimate the width of the forest necessary to reach a certain level of protection considering the local flow conditions and the forest age. This can assist in the inclusion of nature-based solutions in the portfolio of coastal protection measures.&lt;/p&gt;

Prediction of Water Wave Breaking Height and Depth Using ANFIS

2011 ◽  
Author(s):  
Ehsan Delavari ◽  
Ahmad Reza Mostafa Gharabaghi ◽  
Mohammad Reza Chenaghlou
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Fuzzy Inference System ◽  
Wave Breaking ◽  
Fuzzy Inference ◽  
Breaking Point ◽  
Empirical Equations ◽  
Anfis Model ◽  
Inference System ◽  
Semi Empirical

Wave height as well as water depth at the breaking point are two basic parameters which are necessary for studying coastal processes. In this paper, the application of Fuzzy Inference System (FIS) and Adaptive Neuro-Fuzzy Inference System (ANFIS) and semi-empirical models are investigated. The data sets used in this study are published laboratory data obtained from regular wave breaking on plane, impermeable slopes collected from 22 sources. Results indicate that the developed ANFIS model provides more accurate and reliable estimation of breaking wave height, compared to semi-empirical equations. However, some of semi-empirical equations provide better predictions of water depth at the breaking point compared to the ANFIS model.

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