bluuebunny/crossref_metadata_2025 huggingface dataset:
SEDIMENT ADVECTION AND DIFFUSION BY OBLIQUELY DESCENDING EDDIES
Authors: Saruwatari Ayumi , Otsuka Junichi , Watanabe Yasunori
Published: February 2019

Three-dimensional vortex structures involving obliquely descending eddies (ODE), produced by depth-induced breaking-waves, has been proved to be associated with local sediment suspension in the surf zone (Zhou et al., 2017); vertical velocity fluctuations around the ODEs induces sediment suspension near the bed. Otsuka et al. (2017) explained the mechanical contributions of the ODEs to enhance local sediment suspension under the breaking waves and modeled the vortex-induced suspension to predict the profile of the equilibrium sediment concentration in the surf zone. In order to predict local behaviors of sediment, however, sediment-turbulence interactions in the transitional turbulence under breaking waves need to be understood. The interaction may be described in terms of Schmidt number (Sc). Sc has been empirically determined for trivial steady flows such as open channel or pipe flows. In the surf zone where organized flows evolve into a turbulent bore, the interaction may vary with the transitional feature of turbulence during a wave-breaking process, and thus Sc may be variable in time and space. No appropriate Sc model has been proposed for the surf zone flow. A parametric study on the sediment motion with respect to the variation of Sc is required for better prediction of sediment transport in the surf zone. In this study, contributions of the sediment advection and diffusion in the vortex structure to the concentration are computationally investigated. Effects of Sc to the sediment suspension and diffusion process will be also discussed in this work.
THREE-DIMENSIONAL FLUID-STRUCTURE ANALYSIS ON SEAWALL FAILURE INDUCED BY 2011 GREAT TOHOKU EARTHQUAKE TSUNAMI
Authors: Kawasaki Koji , Nonaka Tetsuya
Published: February 2019

The Great Tohoku Earthquake with a magnitude of 9.0 occurred off the pacific coast of Japan on March 11th, 2011, which was the largest earthquake in the recorded history of Japan. Tohoku region, which is located on the northern part of the main island of Japan, has been devastated by some tsunamis in the past. It is of extreme importance from the perspectives of tsunami disaster prevention and mitigation to comprehend the failure mechanisms of coastal structures and nonlinear interaction between fluid and structure. In this study, a three-dimensional fluid-structure analysis model is proposed to discuss seawall failure mechanism caused by tsunami. The utility of the model is verified by applying it to the failure phenomenon of seawalls broken by the 2011 Great Tohoku Earthquake Tsunami.
DEVELOPMENT OF FRAGILITY CURVES FOR REINFORCED DUNES
Authors: Maggi Brian , Baxter Christopher , Bradshaw Aaron , Grilli Annette , Licht Stephen , Stegagno Paolo , Al Naser Naser
Published: February 2019

The objective of this paper is to present the results of on-going field studies to assess the performance of geotextile sand-filled container (GSC) reinforced dunes and to develop probabilistic fragility curves for a range of damage states to these structures. While numerous lab experiments and numerical models have been developed to predict the hydraulic stability of coastal revetments made of GSCs, there has been limited in situ validation of these systems, especially when they are used to reinforce the core of a natural system (Dassanayake and Oumeraci, 2012). Furthermore, the formulas and nomograms developed to characterize GSC systems are not intuitive for coastal community stakeholders to assess the level of resiliency provided by a beach and GSC dune system. The development of fragility curves offers a solution to assess the performance and understand the tradeoffs of reinforced dunes for coastal protection systems.
REVISITED HYDRAULIC FUNCTIONING OF PERMEABLE PILE GROINS
Authors: Zhang Rong , Stive Marcel J.F.
Published: February 2019

Since 1965, a new type of permeable groins (or â€˜pile screensâ€™ referred to Bakker et al.,(1984)), which consist of wooden pile rows with a high permeability, have been widely used to protect the coastline from recession in the Netherlands, especially at southwestern coastline. However, the hydraulic functioning of such structures has not been understood well compared to traditional impermeable pebble mound groins. As the wooden pile groins become older and the maintenance costs increase, the issue of their effectiveness has become of importance, while no serious research has been undertaken. This paper tries to tackle this issue. Based on experimental data which was obtained at Delft Hydraulics (Hulsbergen and Horst, 1973), the functioning of pile groins has been revisited and analyzed by an advanced numerical model. The simulations give deeper insights into the effectiveness of permeable pile groins under well controlled laboratory conditions.
NUMERICAL ANALYSIS OF INTERLOCKING CAISSON BREAKWATER USING MODULAR SYSTEM
Authors: Song Sunghoon , Park Minsu , You Youngjun , Jeong Younju , Hwang Yoonkoog
Published: February 2019

Breakwaters have been severely damaged quite often since they are directly exposed to large waves. And damage level of breakwaters has been scaled up because of abnormal global climate changes. In particular, according to the report of caisson breakwater damages in Japan(Takayama, 2002), it was found that damages caused by caisson sliding, account for more than 70% of breakwater failure modes. So, the design criteria for new breakwaters is being intensified to cope with abnormal global climate changes and unusual waves. In the case of a long structure, the wave force is reduced due to the phase difference in oblique waves. Therefore, if a caisson is made as long as possible, the stability of breakwaters could be ensured even if unusual high waves occur. Recently, interlocking caisson systems, which are to form a long caisson by interlocking individual caissons with each other, have been much attention to enhance the structural stability of conventional caisson breakwaters. In the present study, a modular caisson was proposed that can improve structural stability and workability by using the shear-key interlocking system; and the wave force reduction effects of the modular caisson breakwater were evaluated by numerical analysis method.
COMPARISON OF SILL AND REVETMENT IN REDUCING SHORE EROSION AND WAVE OVERTOPPING
Authors: Yuksel Z. Tugce , Kobayashi Nobuhisa
Published: February 2019

Sills (lowâ€“crested rubble mounds) are constructed to protect eroding bluffs and planted marshes in living shoreline projects (http://mycopri.org). Revetments are conventionally used to protect eroding shores and reduce wave overtopping and damage to backshore areas. However, revetment construction may result in loss of buffering wetlands. On the other hand, no established method exists to design the sill geometry (crest height, width and side slopes) and its distance from the eroding shore. This study compares the efficacies of the two different rubble structures with the same number of stones in order to clarify their similarity and difference for the purpose in reducing shore erosion and wave overtopping.
DYNAMIC NOURISHMENT AND MULTI-PURPOSE ARTIFICIAL REEF AS A BEACH EROSION COUNTERMEASURE
Authors: Shim Kyu-Tae , Kim Kyu-Han , Kobayashi Nobuhisha
Published: February 2019

Presently, various energy power plant facilities are being constructed along the coast of the East Sea of Korea. Large-scale breakwaters are also being constructed seaward of these facilities in order to create a tranquil area for the docking facilities of ships as well as to minimize the damaging effects of tsunamis and storm surge. The construction of such large-scale coastal infrastructures has changed the wave-induced current and sediment transport patterns and caused severe erosion and deposition on the beach.
AN EXPERIMENTAL STUDY OF HYDRODYNAMICS OF OWC DEVICE EMBODYING IN CAISSON BREAKWATER
Authors: Tsai Ching-Piao , Huang Ching-En , Ko Chun-Han , Chen Ying-Chi
Published: February 2019

It has currently become an important issue in searching for clean and sustainable renewable energy. Wave power is one of substantial renewable energies. The oscillating water column (OWC) device is the most extensively studies of wave energy converter and the largest number of prototypes so far deployed into the sea. The breakwater-integrated OWC has been constructed successfully in Sakata harbor in Japan, Mutriku port in Spain, and Civitavecchia harbor in Italy etc. The breakwater-integrated OWC has several advantages, especially much easier maintenance of the wave energy plant (FalcÃ£o and Henriques, 2016). However, the front wall of typical OWC device may be received large wave force when the storm waves impacted on it. This study proposed an improvement of a caisson type breakwater-integrated OWC device by installing a perforated front wall to reduce the wave impacting on the structure but also to promote the capture efficiency of the wave energy. This study reports the experimental results of both water and air flow characteristics inside the OWC chamber to demonstrate the hydrodynamic performance of the improved OWC device.
RECONSTRUCTION OF SEAWALL ABUTTING A HEAVILY TRAVELED COASTAL HIGHWAY WITHOUT SUSPENSION OF TRAFFIC WITH PRESSED-IN PIPE PILE WALLS
Authors: Takuma Takefumi
Published: February 2019

National Route 134 of Japan is a scenic coastal highway about 30 miles southwest of downtown Tokyo. Its highly traveled two lane section in the ancient capital city of Kamakura (1.4 km, i.e., 0.85 miles long) is sandwiched by a sandy ocean beach on the south side and a narrow gauge railroad or rock outcrop on the north side. The 50- year old concrete seawall abutting the highway above suffered scour and settlement from a typhoon-caused storm surge in the past with the rest of the seawall also showing heavy deterioration.
WAVE PRESSURE FORMULA FOR PERFORATED CAISSON WITH DOUBLE CHAMBERS
Authors: Oh Sang-Ho , Ji Chang-Hwan
Published: February 2019

Some of perforated caisson breakwaters have double wave chambers, for which no clear guideline for estimating design load is available. The well-known Takahashi's formula (Takahashi and Shimosako, 1994) is basically applicable to single-chamber perforated caisson. Considering this, we conducted physical experiment to develop a wave pressure formula for double-chamber perforated caisson.
TSUNAMI-SEABED-STRUCTURE INTERACTION FROM GEOTECHNICAL AND HYDRODYNAMIC PERSPECTIVES: ROLE OF OVERFLOW/SEEPAGE COUPLING
Authors: Sassa Shinji
Published: February 2019

This paper presents some recent research advances in tsunami-seabed-structure interaction following the 2011 Tohoku Earthquake Tsunami, Japan. Role of overflow and seepage coupling is highlighted, based on the effect of tsunami-induced seepage on piping/boiling, erosion and bearing capacity decrease and failure of the rubble/seabed foundation (Takahashi et al., 2014; Sassa, 2014; Sassa et al., 2016).
STABILITY ANALYSIS OF RUBBLE-MOUND BREAKWATERS UNDER TSUNAMI FIRST IMPACT AND OVERFLOW
Authors: Aniel-Quiroga ÃÃ±igo , Vidal César , GonzÃ¡lez Mauricio , Lara Javier L.
Published: February 2019

Tsunamis are relatively infrequent but very destructive phenomena that can cause devastating consequences on coastal areas. In view of recent tragic episodes, the scientific community is strengthening their efforts to develop strategies to mitigate the risk of tsunami consequences, specially focused on the potentially affected areas. One of the strategies in this direction is the design and construction of more efficient coastal structures. In this way, in the frame of the EU FP7 project ASTARTE physical experiments on rubble-mound breakwaters (RMB) under tsunami wave attack have been carried out in the IH Cantabria facilities in Santander, Spain. These experiments focused on gaining a better understanding of tsunami impacts on this kind of structures. Improving the knowledge about their stability and hydrodynamics will contribute to a better design of coastal protection marine structures.
XBLOC-PLUS â€“ DEVELOPMENT OF A REGULAR PLACED INTERLOCKING ARMOUR UNIT
Authors: Jacobs Robert , Bakker Pieter , Vos-Rovers Ineke , Reedijk Bas
Published: February 2019

Randomly placed single layer interlocking concrete armor units are currently the most advanced and cost-efficient option for the protection of breakwaters. The key feature of these units is the random orientation of the units, which requires the crane operator to assess the orientation of each individual unit during block placement. DMC noticed the desire for a block which can be placed in a regular pattern as this will increase the placement rates. Apart of this, regular placement of armor units can also be preferred for aesthetical reasons. Fifteen years after the introduction of Xbloc, DMC therefore introduces a new breakwater armour unit called XblocPlus which is placed with uniform block orientations.
SURVIVABILITY ASSESSMENT OF FASTNET LIGHTHOUSE
Authors: Antonini Alessandro , Raby Alison , Caputo Piermodesto , Brownjohn James , Papas Athanasios , D'Ayala Dina
Published: February 2019

Historic rock-mounted lighthouses play a vital role in the

safe navigation around perilous reefs. However their

longevity is threatened by the battering of waves. Virtual

navigational aids such as GPS are fallible, and reliance

on them can be disastrous. Mariners will therefore

continue to need the physical visual aids of these

strategic structures. After a site-specific extreme wave

characterisation, the study evaluates the dynamic

response of Fastnet Lighthouse under the

action of different wave loadings through a validated FEM

numerical model. The aim of the study is to provide a

comprehensive survivability assessment methodology for

this type of structures.
PROBABILISTIC INVESTIGATION OF DEBRIS IMPACT VELOCITIES DURING EXTREME FLOODING EVENTS
Authors: Stolle Jacob , Nistor Ioan , Goseberg Nils , Petriu Emil
Published: February 2019

Forensic engineering surveys of extreme flooding events, such as the 2011 Tohoku Tsunami and the 2012 Hurricane Katrina, demonstrated the importance of debris in estimating loading on structures. Debris are any solid objects entrained within the inundating flow. The resulting loads from these objects can be the result of debris damming, where debris accumulate at the front face of a structure, or of individual debris impact, where the debris exerts an impulse load as the it rapidly impacts the structure.
ORPHAN BREAKWATERS: COLLAPSE AND TRANSMISSION REDUCTION
Authors: Allsop William , Bruce Tom , Pearson Adrian
Published: February 2019

In the past, many coastal towns or villages constructed harbours for trade and/or fishing. These were protected by breakwaters, commonly rubble mounds to low-water, surmounted by vertical walls of dressed stone blocks (later concrete) with rubble core. Now, 100-150 years later, many such harbours have little or no income to maintain or repair their breakwaters, but meantime, the areas protected have been adopted for commercial and residential purposes, at increased risk of flooding if the 'orphan' breakwater were to collapse, Hampshire et al. (2013). Even after collapse, some wave reduction will however still be afforded by the relict structure. Tests by Allsop et al (2017) have modelled the collapse of several simplified breakwaters, and measured levels of wave transmission over the collapsed structures. This paper extends that work with more analysis of collapsed crest levels, and hence of likely wave transmission.
MODELING TIDEâ€™S INFLUENCE ON SEAWALLâ€™S SURFACE TEMPERATURE IN TROPICAL REGIONS
Authors: ZHAO Kuifeng , YUAN Jing , LIU Philip L-F
Published: February 2019

In tropical regions, intense solar radiation on seawall can lead to a high surface temperature, which far exceeds common marine speciesâ€™ tolerable limits. This is a primary reason for low biodiversity on Singaporeâ€™s seawalls and therefore must be considered in eco-engineering practices. The intertidal zone of a seawall is periodically submerged and cooled by the tidal motion, and therefore can support a local ecosystem. The objective of this research is to establish a predictive model for surface temperature of seawallâ€™s intertidal zone and use this model to study how local biodiversity is affected by the occurrence of high temperature.
FLOATING BREAKWATERS AS PUBLIC PLATFORMS â€“ IMPACT ON POSTURAL STABILITY
Authors: Freeman Elizabeth , Splinter Kristen , Cox Ron
Published: February 2019

Floating Breakwaters are used extensively to provide cost effective protection from wind and vessel waves. Floating breakwaters are commonly multitasked, being used as a point of mooring for vessels or simply an access way to other pontoons in a small boat harbour, as well as their main function as wave dissipators. A floating breakwater does not completely stop the incident wave; rather it partially transmits, partially reflects and partially dissipates the wave energy. Cox et al (2007) completed wave flume testing of a number of floating breakwaters and reported on performance in irregular waves with particular emphasis on wave transmission and reflection, energy dissipation and restraining forces. Motion measurements were limited by the instrumentation. This paper discusses the results from a further series of laboratory experiments on the dynamic motions of an active floating breakwater system. The performance is related to wave attenuation, wave reflection and energy dissipation as well as safety considerations for standing persons based on high resolution measurements of accelerations in all six degrees of freedom.
OBLIQUE BREAKWATERS FOR MULTI-PURPOSE BEACH RECREATION AND SHORE PROTECTION
Authors: Dally William
Published: February 2019

Breakwaters, jetties, and groins have long been used in the littoral environment as port, navigation, shoreline stabilization and beach protection structures. Customarily however, the recreational benefits of structures such as these have been realized only incidentally. For example, jetties built solely to stabilize an inlet almost immediately attract surfers who exploit the break created by waves reflecting from the structure. This is the case at Sebastian Inlet, Florida, where the world renowned â€˜First Peakâ€™ was created when the north jetty was lengthened in the early 1970â€™s. Often when the waves elsewhere are too small to surf, one can rely on First Peak to be surfable. Also, under conditions of large, long-period swell, although the normally incident surfbreak elsewhere tends to â€˜close-outâ€™, not only is First Peak an excellent break, but sometimes a second and third surfable peak appear.
SIMULATION OF TSUNAMI FORCE IN THE PRESENCE OF BEACHSIDE STRUCTURES
Authors: Nakamura Tomoaki , Yamashima Aya , Mizutani Norimi , Cho Yonghwan
Published: February 2019

The 2011 Tohoku earthquake tsunami caused a catastrophic disaster along the northeast coast of the Honshu Island, Japan. To deal with such massive tsunamis (identified as â€œlevel 2â€ tsunamis in Japan), the concept of disaster mitigation using multifaceted countermeasures is essential in addition to the construction of shore protection facilities for tsunamis at relatively high frequencies (â€œlevel 1â€ tsunamis). This study focused on one of such countermeasures, which involved beachside rigid structures. Such structures are expected to be effective for disaster mitigation because of the complementation of shore protection facilities by reducing tsunami force on rear buildings. To quantitatively evaluate the influence of beachside rigid structures on tsunami force, a three-dimensional (3-D) numerical analysis was performed using a 3-D coupled fluid-structure-sediment-seabed interaction model (FS3M; Nakamura and Mizutani, 2014).
EXPERIMENTAL TEST OF A CYLINDERICAL WAVE ENERGY SYSTEM WITH HORIZONTAL ROTATION FOR SHALLOW WATER
Authors: Park Min-Su , Jeong Youn-Ju
Published: February 2019

In the present study a cylindrical wave energy system with horizontal rotation for shallow water is newly suggested. The horizontal cylinder is floated at the free surface, and rotated by the water particle velocity and the current flow. The electric generator is located in the horizontal cylinder. Thus, the generator is not affected by sea waters. The swing plate is submerged at the bottom of horizontal cylinder and has the pendulum motion according to incident wave motion. In real ocean environments, the propagation direction of wave may change from day to day. Therefore, the yaw system is adopted in this design. To evaluate the characteristic of cylindrical wave energy system the experimental test is carried out for the various parameters.
A NEW APPROACH TO NEARSHORE BREAKWATERS: A CASE STUDY FOR UNDULATING CRESTS
Authors: Nordstrom Taylor , Levitz Chris
Published: February 2019

Traditionally, stone nearshore breakwaters are designed and constructed using standard parameters based on a series of existing equations and calculations (frequently those specified in the Coastal Engineering Manual for the U.S.). These include a calculated crest elevation based on design wave heights, along with computationally derived side slopes and crest widths chosen to either eliminate or reduce wave energy transmission by a desired amount. Another design decision is how frequent and how large to make gaps between the breakwaters, which is more standard for sandy scenarios, but less so when dealing with marsh and bluff shorelines. Additionally, the breakwaters are designed to be constructed within a range of design distances from the shoreline, with parameters chosen to define desired post-construction scenarios such as tombolo or spit formation. There are significant data and existing research allowing for these calculations in sandy environments. For marsh or bluff based shorelines, the offshore distance is often developed based on constructability or a desired marsh restoration template.
ON PREVENTIVE MAINTENANCE POLICY FOR WAVE DISSIPATING BLOCKS COVERING CAISSON BREAKWATER
Authors: Ota Takao , Kawamura Hiroyuki , Matsumi Yoshiharu , Koyanagi Junji , Satow Takashi
Published: February 2019

The infrastructures are required to keep a certain level of performance during the duration of service. Because the performance of the infrastructures including harbor and coastal structures deteriorates due to aging and damage that is caused by the action of external forces, it is necessary to perform appropriate maintenance. Satow et al. (2009) proposed a mathematical model for the preventive maintenance of wave dissipating blocks based on the method of the reliability engineering. They also derived the expected maintenance cost over the in service period and the optimal preventive maintenance policy. In this study, the optimal threshold for preventive maintenance to minimize the expected maintenance cost is determined for the wave dissipating blocks covering caisson breakwater by using the above model.
ACCUMULATED DAMAGE EVOLUTION AND INVESTMENT COSTS OF BREAKWATERS
Authors: Folgueras P. , Del-Rosal-Salido J. , Moragues M. V. , Lopez J.D. , Losada M.A.
Published: February 2019

Since the pioneering work by Borgman, (for vertical walls), and Paape, (for rubble mound breakwaters) in the 50Â´s of the last century, the design of new breakwaters and rehabilitation of existing breakwaters can be based on lifecycle analysis targeting the optimum investment costs, including the construction costs, maintenance, repairs and demolition, costs, and downtime costs. The estimation of these costs is based on the performance criteria of each failure mode for the structural and hydraulic responses related to the design limit stages SLS and ULS, including both a physical measure and a probability of occurrence, ROM 0.0 and 1.0 (2000 and 2007) and PIANC 2017. To evaluate these costs including their uncertainty it is necessary to apply, (1) a spatial and temporal damage evolution model of each failure mode, (2) to define the interdependence between modes including the decision criteria when start to repair, and (3) to compute the costs depending on the real sea conditions, the strategy of construction and the available construction power. The main objective of this work is to present a methodology to estimate the probability distribution function of the investment costs in the useful life of the structure.
APPLICATION OF COMPOSITE GROYNES IN STABILIZING DUBAI BEACHES
Authors: Juma Ibrahim Mohammad , Karanam Sankarbabu , Al Harmoudi Alya Abdulrahim
Published: February 2019

The increase in demand for waterfront living has led to the development of large-scale offshore reclamation projects - The Palm Jumeirah, The World etc., rapidly transforming the coastal zone of Dubai. Development of such offshore islands have interfered with the coastal processes causing reorientation of shorelines at several stretches of Dubai coast (Mangor et al 2008). Regular beach nourishment programs to maintain the required minimum beach width for recreational activities was found to be ineffective due to non-availability of beach quality sand and environmental impacts of dredging and sand shifting operations.
RECONSTRUCTION OF THE NEARSHORE SURFACE WAVE FIELD VIA ASSIMILATION OF REMOTE SENSING DATA
Authors: Simpson Alexandra , Haller Merrick
Published: February 2019

Typically, phase-resolved observations of the surface wave field are limited to in situ single-point time series. Select locations and field projects may have a handful or more single-point time series, such as for example the USACE FRF â€œ8 meter arrayâ€. Recently, phase-resolved wave field observations with more spatial coverage have become available using LIDARs; however, LIDAR scan rates are only fast enough to encompass one horizontal dimension at the necessary phase-resolving sampling rates. Imaging remote sensors, such as optical cameras and marine radars, offer the possibility of full 2D reconstruction of the phase-resolved wave field. Accurate reconstructions from these sensors would essentially be equivalent to having thousands of wave gauges. Applications include short-term wave forecasting for maritime operations (e.g., cargo unloading) and highspeed navigation, as well as control schemes for wave energy converters. Moreover, realistic wave field reconstruction of nearshore wave fields would offer a very valuable new tool for investigating the time and space varying wave forcing in the nearshore.
A NUMERICAL STUDY OF FREAK WAVE GENERATION IN RANDOM SEAS OVER A SUBMERGED BAR
Authors: Ma Yuxiang , Fu Ruili , Dong Guohai , Du Qiannan
Published: February 2019

Freak waves, also called rogue waves and giant waves, are much larger and steeper than the surrounding waves, can cause severe accidents, and can be formed in both coastal and offshore regions. The past researchers on freak waves in coastal regions are mainly focused on the statistical properties, and the generation mechanism of such large waves are not yet discussed intensively. The aim of the present study is to examine the generation process of freak waves in unidirectional propagating random waves over a submerged bar using a fully nonlinear numerical wave model, SWASH. It was found that freak waves are readily formed at the seaward part of the crest of the bar and gradually emerged from an intense wave group. The enhancement of the bound higher harmonics in the shoaling process is the main reason to form such large waves in shallow water. On the crest bar of the bathymetry, the extreme wave gradually vanished, mainly due to the releasing of bound higher-harmonics to free wave components.
OPERATIONAL FORECASTING SYSTEM FOR DUBAI COASTAL WATERS
Authors: Juma Ibrahim Mohammad , Hokal Noora Mohammed , Jena Gagan Kumar
Published: February 2019

The abstract is based on decision support system for Dubai Coastal Zone and Waterway Operations. This is a sophisticated project to couple a suite of meteorology and ocean models with data management infrastructure and web-based tools to deliver data and decision support information to Dubai Municipality as well as public users. The latest open-source modeling technology available from the research and academic communities to build an operational forecast system that is a suite of interconnected components that allows for seamless interaction of different models, real-time data, and custom web-based reports and tools that access model forecasts and real-time observations. This included measurements taken in the Dubai coastal zone, satellite and atmospheric measurements across the Arabian Gulf, and from a variety of online global environmental models. The data specifically used to create each of the meteorological, hydrodynamic, spectral wave, inundation and oil-spill models. The circulation modeling studies of the Arabian Gulf were carried out by Kampf (2006), Thoppil (2010) and Xue and Eltahir (2015).
WAVE OVERWASH ON A ROCK PLATFORM: REMOTE SENSING AND PRESSURE SENSOR OBSERVATIONS
Authors: Power Hannah E. , Kinsela Michael A. , Stringari Caio E. , Kendall Murray J. , Hanslow David J.
Published: February 2019

Open ocean rocky shore platforms are typically exposed to high wave energy and are often the location of recreational activities from sightseeing and walking to fishing (Kennedy et al. 2017). The exposure of these environments, combined with the use for recreation, results in a high level of risk for those who use the rock platform. In Australia, for example, 19% of coastal fatalities occur on rock coasts, most commonly when individuals fall from microtidal semi-horizontal platforms into the ocean (SLSA, 2014a,b). Managing the hazards and resultant risk on rocky shore platforms requires a different approach to that taken for sandy beaches as the sites are typically remote. Here we explore the wave overwash hazards on a remote but high visitation rocky shore platform 40 km south of Sydney, Australia.
DEVELOPMENT OF WAVE OVERTOPPING MODEL INCORPORATING WATER OVERFLOW FOR VERTICAL WALLS
Authors: Tanaka Yoji , Suzuyama Katsuyuki , Higuchi Naoto , Shibaki Hidenori
Published: February 2019

In a situation where water overflow occurs on the seawalls due to a storm surge, generally it is high waves that cause wave overtopping. However, it is common that overflow and overtopping are modeled as separate phenomena, in a situation where both phenomena occur at the same time, the amount of water exceeding the seawalls may not be evaluated correctly. The purpose of this research is to develop a new wave overtopping model including the water overflow for vertical seawalls. The new overtopping model improved the overtopping model of Goda (Goda, 2008: Goda08 model). Goda08 model was developed to adapt for various seawall forms. Goda (2008) insisted it was more accurate than EurOtop model. Nonetheless, Goda08 model has a problem of overestimation in shallow area. Therefore, we tuned the parameters again. It is difficult to reproduce the situation where the overtopping and overflow occur at the same time in a hydraulic experiment. Consequently, CADMAS-SURF which is based on the 2-dimensional non-compressive fluid using the VOF method was used as an experimental data provider for comparative verification of the model.
RECENT ADVANCES IN MODELING WAVE ATTENUATION BY VEGETATION
Authors: Chen Qin , Zhu Ling , Chakrabarti Agnimitro
Published: February 2019

In the past decade, interest in wave attenuation by vegetation has increased considerably as coastal engineers and scientists search for sustainable solutions to mitigate the impacts of climate change and natural hazards. The interactions of surface weaves and natural vegetation span over a large range of scales, from turbulence and eddies at the vegetation stem scale to wave generation in vast inundated wetlands of hundreds of square miles under hurricane conditions. Restoring coastal wetlands and reducing flood risks of coastal communities require improved understanding and better predictive capability for wave attenuation over inundated coastal landscapes with vegetation. The objective of this paper is to present recent advances in multi-scale modeling of wave attenuation by wetland vegetation. Numerical modeling results ranging from vegetation-resolved large eddy simulation under idealized conditions to incorporating vegetation-induced drag forces into conservation laws of momentum and energy for engineering applications will be shown. Effects of vegetation flexibility and various wave theories on the prediction of wave attenuation and the choice of vegetation drag coefficients will be discussed.
STUDY ON THE PROUDMAN RESONANCE OF WAVES INDUCED BY A MOVING ATMOSPHERIC PRESSURE DISTURBANCE
Authors: Niu Xiaojing , Chen Yixiang , Zhou Haojie
Published: February 2019

A moving atmospheric pressure disturbance can induce a system of forced water waves. As predicted by the linear theory, an infinite wave height will be induced when the Froude number Fr=1, which is known as the Proudman resonance. Fr is defined as the ratio between the moving speed of an atmospheric pressure disturbance and the phase velocity of shallow water wave. The Proudman resonance is thought to be one of main mechanisms for the destructive meteotsunami (Monserrat et al., 2006). In this study, the nonlinear shallow water equations are used to describe the waves induced by a moving pressure disturbance, and the impact factors to the maximum water elevation in the case of Fr=1 are discussed.
HIGHLY RESOLVED DIRECTIONAL PROPERTIES OF WIND WAVES AND SWELL WITH VARIOUS SCALES
Authors: Fujiki Takashi , Kawaguchi Koji , Suehiro Fumikazu , Hashimoto Noriaki
Published: February 2019

Wave directional spectrum is basic information as the forcing on the coastal process. The directional properties of coastal waves have been widely investigated through observations and the results are applied for design use of coastal structures and implementation of numerical wave model. But these studies focused only on wind waves under moderate sea conditions because the limitations of instruments such as buoys and wave staffs make them unsuitable for observing under various sea conditions including the severe sea. Thus there are few systematic studies for coastal engineering application which needs treatment for various sea state, from modest to severe sea. In this study, we observed the wave directional spectrum with the bottom mounted ADCP (Acoustic Doppler Current Profiler) which can record even under severe conditions. We investigated the directional properties of wind waves and swell with various scales.
AN EXPERIMENTAL STUDY OF EXTREME WAVE KINEMATICS ON OPPOSING DEPTH-VARYING CURRENTS
Authors: Niu Xuyang , Ma Yuxiang , Ma Xiaozhou , Dong Guohai , Song Yongbo
Published: February 2019

In the past decades, there are numerous reports on the accidents caused by extremely large waves. A large number of papers have contributed to the study on the physical properties and the generation mechanisms of such large waves. However, most of the research has been carried out without presence of currents. In the real ocean, the waves most likely coexist with currents. In many circumstances, owing to wind force and oceanic circulation, the currents are commonly not uniform and vary with depth, which plays an important role in the evolution of gravity waves (Swan et al., 2001). Wave kinematics is a key factor in designing structures. However, experimental studies of the influence of depth-varying currents on extreme waves are mainly considered for the changing of spatial and temporal geometric characteristics (Yao and Wu, 2006). In the present study, the kinematics of extreme waves on opposing depth-varying currents will be investigated using the PIV technology.
NUMERICAL STUDY OF WAVE INTERACTION WITH A SUBMERGED POROUS BREAKWATER IN COMBINATION WITH A FLOATING BREAKWATER
Authors: Kamath Arun , Sasikumar Athul , Bihs Hans
Published: February 2019

Conventional emerged rubble mound breakwaters are commonly built to protect ports and marinas from direct wave action. With increased high-valued developments in the coastal region, engineers have to design innovative coastal protection structures that can provide adequate harbor tranquility with minimum visual impact. One such solution is the combination of a submerged breakwater with a floating breakwater. In this paper, the open-source CFD model REEF3D (Bihs et al. 2016) is used to simulate wave interaction with a submerged porous breakwater with a floating breakwater on the lee side. The wave interaction with the submerged porous breakwater is validated by comparison with experimental data from Hieu and Tanimoto (2006). The validated model is then used to simulate the wave interaction with a combination of the submerged breakwater and the floating breakwater. The transmission coefficient across the combination is calculated to be about 12.5%, demonstrating the possibility to provide harbor tranquility with minimum visual impact.
A SIMPLE AND ACCURATE NONLINEAR METHOD FOR RECOVERING THE SURFACE WAVE ELEVATION FROM PRESSURE MEASUREMENTS
Authors: Bonneton Philippe , Mouragues Arthur , Lannes David , Martins Kevin , Michallet Hervé
Published: February 2019

Near-bottom-mounted pressure sensors have long been used for measuring surface wave in the nearshore. The commonly used practice is to recover the wave field by means of a transfer function based on linear wave theory (e.g. Guza and Thornton, 1980; Bishop and Donelan, 1987). However, wave nonlinearities can be strong in the shoaling zone, especially in the region close to the onset of breaking, and thus the use of a linear theory can be questioned. Martins et al. (2017) and Bonneton (2017, 2018) have shown that the linear reconstruction fails to describe the peaky and skewed shape of nonlinear waves prior to breaking, with wave height errors up to 30%. Such measurement errors are problematic for many coastal applications. For instance, studies on wave overtopping and submersion require accurate measurements of the highest wave crests. Furthermore, a correct description of wave asymmetry and skewness is of paramount importance for understanding sediment dynamics. Finally, an accurate description of the wave elevation field is also crucial for the validation of the new generation of fully-nonlinear phase-resolving wave models.
HARMONICS GENERATION BY COASTAL FORESTS
Authors: Chang Che-Wei , Liu Philip L.-F.
Published: February 2019

The linear model on shallow-water wave propagations through a coastal forest has been developed by Mei et al. (2011). In this study, we extend the linear model and consider weakly nonlinear effects. Because of the weakly nonlinear effects, higher harmonics will be generated inside the forest. Wave attenuation is investigated and the new results are compared with those of the linear model. The effects of different physical parameters are also discussed.
EXPERIMENTAL STUDY OF GUIDED WAVES OVER THE OCEAN RIDGE
Authors: Wang Gang , Yu Hong-Quan , Zheng Jin-Hai
Published: February 2019

Long waves can be trapped by oceanic ridges due to refraction effect, and such guided waves travel along the ridge and transfer their energy to rather long distance. The guided wave is constrained over the top of the ridge and propagates slower than the free long wave, which leads to the largest amplitude waves arriving later and duration of tsunami activity longer. The existence of trapping effect of ocean ridges has not only been demonstrated mathematically (Buchwald 1969; Zheng et al. 2016), but also been verified by the interpretation of tide-gauge data and numerical models on global tsunami events (Koshimura et al. 2001; Titov et al. 2005).
REAL-TIME ASSIMILATION USING A DENSE ARRAY OF DIRECTIONAL WAVE OBSERVATIONS
Authors: Smit Pieter Bart , Janssen Tim , Gans Wheeler , Dunning Cameron
Published: February 2019

Wave conditions along our coastlines are monitored using networks of wave buoys. Augmented with regional wave now- and hind-casts from operational wave models, these data networks provide detailed regional information of wave conditions providing vital updates of wave conditions for maritime, engineering, recreational and scientific purposes. Currently, the observational networks are mostly used to initiate models and assess model performance, but are usually not directly integrated into the modeling system. Recent work by Crosby et al. (2017) explores the integration of buoy data into models and shows that data assimilation of buoy observations into models can improve predictions and wave hindcasts. The results suggest that assimilation of dense observational networks results in significant and important improvements in model performance. In the current work we leverage these modeling advances with the recent development of low-cost directional wave buoys (such as the Spoondrift Spotter, www.spoondrift.co). The use of low-cost and solar powered instruments allows for much denser long-term arrays of instruments than was previously possible. The availability of large numbers of independent observations, in turn, can provide excellent constrains on models and model boundary conditions.
A NUMERICAL STUDY ON SURFACE WAVE EVOLUTION OVER VISCOELASTIC MUD
Authors: Sharifineyestani Elham , Tahvildari Navid
Published: February 2019

A numerical modeling approach is applied to investigate the combined effect of wave-current-mud on the evolution of nonlinear waves. A frequency-domain phase-resolving wave-current model that solves nonlinear wave-wave interactions is used to solve wave evolution. A comparison between the results of numerical wave model and the laboratory experiments confirms the accuracy of the numerical model. The model is then applied to consider the effect of mud properties on nonlinear surface wave evolution. It is shown that resonance effect in viscoelastic mud creates a complex frequency-dependent dissipation pattern. In fact, due to the resonance effect, higher surface wave frequencies can experience higher damping rates over viscoelastic mud compared to viscous mud in both permanent form solution and random wave scenarios. Thus, neglecting mud elasticity can result in inaccuracies in estimating total wave energy and wave shape.
WAVE OVERTOPPING WITH A CHANGING STEEP SANDY FORESHORE, CONVENTIONAL AND NUMERICAL ANALYSIS OF RESULTS
Authors: Van der Meer Jentsje , Akbar Rizki , Mukhdiar Ryard , Briganti Riccardo , Musumeci Rosaria Ester , Romano Alessandro , Suzuki Tomohiro , Altomare Corrado
Published: February 2019

Large scale tests were performed in the large scale facility GWK at Hannover, Germany, within the HYDRALAB+ project ICODEP: Impact of Changing fOreshore on flood DEfence Performance. The test set-up consisted of a relatively steep 1:15 sandy beach profile in front of a battered seawall with 10:1 slope (almost vertical). Two storms were generated, S1 and S2 with for each storm a specific combined surge and tide profile with varying wave conditions (sea states) depending on water level. These two types of storms have been modelled in varying order, giving three types of storm clusters (C1, C2, and C3). After each sea state the foreshore profile was measured and during each sea state wave conditions as well as wave overtopping have been measured. The changing foreshore showed a breaker bar formation as well as scour or accretion directly in front of the battered wall, depending on water level.
VERIFICATION OF WEATHER CONDITION FOR HIGH WAVE AND STORM SURGE ESTIMATION DUE TO EXPLOSIVE CYCLONE
Authors: Haga Takuto , Fujiwara Kazuhiro , Seki Katsumi , Arikawa Taro
Published: February 2019

There is concern that the disaster risk of high wave and storm surge due to explosive cyclone is increasing around Japan with the global warming as a cause. When studying the disaster prevention of high wave and storm surge, high wave and storm surge estimation is a cogent means. In order to maintain higher estimation accuracy, reproducibility of weather field as external force condition is important. Even among them, the accuracy of empirical weather model is important for probabilistic risk assessment for waves and storm surges. However, there are few examples to apply empirical weather model to explosive cyclone. Therefore, we applied empirical typhoon model to explosive cyclones and the applicability to wave and storm surge estimations is verified.
SIMULATIONS OF HURRICANE MATTHEW SURGE AND WAVES; COMPARISONS TO MEASUREMENTS
Authors: Bender Christopher , Kauppila Ashley , Bredesen Hunter
Published: February 2019

Hurricane Matthew formed into a hurricane in the eastern Caribbean and rapidly intensified with peak intensity occurring in late September 2016 when the storm reached Saffir-Simpson Category 5 strength with 160 mph winds (Stewart, 2017). After leaving the Caribbean, Hurricane Matthew moved northward and remained close to the coasts of Florida, Georgia, South Carolina, and North Carolina and caused elevated water levels, large waves, and extensive coastal erosion.
ANALYSIS OF WAVE CHARACTERISTICS FOR DESIGN AND CONSTRUCTION OF OFFSHORE WIND POWER PLANT
Authors: Fukuyama Takako , Ikeya Tsuyoshi , Fukumoto Yukinari
Published: February 2019

The potential of offshore wind power in Japan is high, because Japan is surrounded by the sea on all sides. For this reason, proving research and planning of wind farms have been conducted in various locations. However the introduction is delayed compared with Europe due to severe natural conditions such as typhoons and swells unique to Japan. Offshore Choshi is one of the suitable sites for wind power generation on the Pacific side, but there is no data about characteristics of high waves required for setting the design conditions and characteristics of low waves required for the construction onsite. Therefore in this research, we aim to establish the design and construction of offshore wind farm adapted to Japan, using wave data obtained by proving research offshore Choshi, to investigate the wave characteristics for wind farm design and construction.
LABORATORY OBSERVATIONS OF DISSOLVED CARBON DIOXIDE TRANSPORT UNDER REGULAR BREAKING WAVES
Authors: Otsuka Junichi , Watanabe Yasunori
Published: February 2019

Air bubbles and strong turbulence that form in water from breaking waves play important roles in gas transfer across the air-sea interface (Melville, 1996). The entrained bubbles increase the total area of air-water interface per unit volume and enhance local gas dissolution into water. The dissolved gases mix in the water mass diffuse by the strong turbulence. These gas transfer-enhancing factors have been parameterized by only wind speed in models of gas transfer velocity in the deep ocean. Bulk parameters based on wind speed cannot be used for a surf zone, where waves break due to shoaling. In a surf zone, the cross-shore distributions of entrained bubbles and the turbulent intensity vary as waves propagate. The physical process of gas transfer under the complex air-water turbulent flows in breaking waves has not been clarified. Thus, breaking-wave factors that enhance gas transfer in a surf zone cannot be parameterized. In this study, we observed the transport process of dissolved carbon dioxide (DCO2) under air-water turbulent flows in a laboratory surf zone using image measurement systems.