bluuebunny/crossref_metadata_2025 huggingface dataset:
TOPOGRAPHIC CHANGES IN THE SURF ZONE PROFILE
Authors: Sonu Choule J. , Russell Richard J.
Published: February 2019

The conventional method of dealing with relationships between wave action and topographic response on a beach is to reduce the problem to a two-dimensional scheme that regards basic processes as taking place in a vertical plane normal to the shoreline. This scheme is valid only if the waves arrive at right angles to the shore and the nearshore contours are reasonably straight and parallel the beach. As these conditions are not realized in many cases another analytical method is necessary - one that recognizes effects of other than normal wave arrival and systematic patterns of diversification in nearshore topography. This study, based on a long period of field investigation on the Outer Banks, North Carolina, examines a three-dimensional approach. Observations from a long pier were used to explain nearshore topographic diversification and resulted in conclusions that were confirmed by subsequent field observation.
EQUILIBRIUM FLOW AREAS OF TIDAL INLETS ON SANDY COASTS
Authors: O'Brien Morrough P.
Published: February 2019

The flow area of inlets on sandy coasts is a unique function of the tidal prism when equilibrium has been achieved. The size of material, the presence or absence of jetties, and the magnitude of general littoral drift does not appear to affect this equilibrium flow area within the accuracy of the data available. In the summer of 1929, the writer made a reconnaissance of the beaches and harbors of the Pacific Coast of the United States for the predecessor organization of the U. S. Beach Erosion Board. In tiie years preceding this study, many tidal inlets on the Worth Pacific Coast had been improved for navigation by constructing jetties, and the progress of these inlets towards stabilization was being followed through frequent hydrographic surveys, which were available for study. The obvious fact that large inlets were found at large bays and small inlets at small bays suggested the possibility that there might be a unique relationship between entrance area and tidal prism.
THE INCREASE OP BED SHEAR IN A CURRENT DUE TO WAVE MOTION
Authors: Bijker E.W.
Published: February 2019

As early as 1948 Exnstein [lj suggested that the approach to the calculation of the sand transportation by waves could be similar to that for uniform flow. Tests conducted by author proved that for a current, with waves being propagated m a direction perpendicular or almost perpendicular to this current, the sand transportation is a function of the intensity of bed shear in the direction of the current. Therefore, an attempt has been made to study the increase of the bed shear of a current due to wave motion. The results of this study are presented in this paper. This problem has also been studied by Jonsson and Lundgren !?l >L5] t>ut they have assumed that current and wave-propagation occurs m the same direction. As for normal beach conditions, the angle between current and wave crests is between 0° and 20°, tests have been executed in the Delft Hydraulics Laboratory for angles of 0° and 15°. For an angle of 0° between the wave crests and the direction of the current, results have been presented by Bijker in the proceedings of the seminars at the I.A.H.R. conference which was held m Leningrad in 1965. Because it is not feasible to measure the bed shear directly an indirect method had to be chosen. Determination of the bed shear by means of the velocity profile m the vicinity of the bed is not feasible m this case as the combined velocity profile is of a rather complicated nature. The bed shear is therefore determined by means of the energy slope.
HYDRAULIC RESEARCH ON THE CLOSELY SPACED PILE BREAKWATER
Authors: Hayashi Taizo , Kano Tokutaro
Published: February 2019

Hydraulic properties of a row of closely spaced circular piles as a breakwater have been studied both theoretically and experimentally. A theory is presented for the transmission of waves past the breakwater and also for the thrust and bending moment to be exerted by the waves upon each pile in the breakwater. Laboratory experiment has been made on a model structure. A pretty close agreement is shown in the comparison between the theory and the experiment with respect to the transmission coefficient and the bending moment distribution. Special emphasis is laid on the remarkable rate of decrease of the thrust and bending moment to be exerted on each pile in the breakwater with the increase of the space of the piles. In taking this economical aspect of this structure into consideration, the closely spaced pxle breakwater has been concluded as a promising type of breakwater of comparatively light structure.
ON THE HYDROGRAPHY OF THE RIVER CLYDE
Authors: Allen John H.
Published: February 2019

The River Clyde is one of the major industrial rivers of Scotland and the shipbuilding on the banks of its estuary has been famous for centuries. With the increase in the size of the ships being constructed and using the Clyde as a port, steps must be taken to ensure that the Clyde maintains its relative position. In order to study the effect of various proposals for improvements, a large scale hydraulic model involving the simulation of saline stratification and sediment movement has been commissioned by the Clyde Port Authority and is now being constructed and operated under the direction of Professor Frazer and Dr. Barr of the University of Strathclyde. This paper describes some of the field work carried out in conjunction with this model study in order that water and sediment transport may be correctly simulated.
STUDY ON SCOURING AT THE FOOT OF COASTAL STRUCTURES
Authors: Sato Shoji , Tanaka Norio , Irie Isao
Published: February 2019

This paper presents the results of two-dimensional model experiments conducted in order to clarify the basic characteristics and to find out some preventive measures against scouring around coastal structures. The applicability of these results to the field are discussed on the basis of some results of field investigations. The results of two-dimensional experiments presented herein show that the characteristics of waves just in front of structures and their reflection by structures are most important factors of scouring. The results of field investigations, however, indicate that in addition to those two factors, the currents caused due to waves around structures play important roles m scouring.
FURTHER RESULTS ON THE DEPOSITION OF COHESIVE SEDIMENTS
Authors: Partheniades Emmanuel , Cross Ralph H. , Ayora Alfredo
Published: February 2019

Experimental investigations on the depositional behavior of suspensions of fine cohesive sediments in turbulent flows have been conducted in a special laboratory apparatus. This apparatus consists essentially of an annular channel containing the water-sediment mixture, and an annular ring positioned within the channel and in contact with the water surface. A turbulent shear flow is generated by a simultaneous rotation of the channel and ring in opposite directions at the proper relative speeds to minimize secondary currents in the bottom of the channel, so that the sediment deposits uniformly.
THE THEORY AND DESIGN OF BUBBLE BREAKWATERS
Authors: Bulson P.S.
Published: February 2019

This paper sets down basic information on the behaviour of bubble breakwaters, drawn from analytical and experimental studies carried out by the author and others in recent years. Design formulae are given for surface velocity and thickness of the horizontal current produced by a bubble curtain, and for the quantity of free air required to suppress waves of known length and height. The effect of an intermittent air supply is examined. It is concluded that the quantity of air required is astronomical and the practical difficulties immense.
ANALYSIS OF THE FLOW INDUCED BY AIR-BUBBLE SYSTEMS
Authors: Kobus Helmut E.
Published: February 2019

The pattern of vertical velocities induced by an orifice discharging air into water can be represented by Gaussian distribution curves with a linear spread in the vertical except for the regions near the orifice and close to the free surface. An analytical treatment considering the momentum-flux increase due to the buoyancy of the air together with experimental information about the spread of the velocity profiles and the mean rising speed of the air bubble stream, which has been obtained from velocity and density measurements over a wide range of conditions, leads to a complete description of the flow field. The ratio of the water volume flux to the air discharge rate, which has been proposed as an efficiency criterion, is now at hand as a function of depth and air supply for both single orifices and rows. The experimental evidence supports the analysis well and suggests that extrapolation to larger water depths and air supplies should be permissible, which would allow approximate predictions of the volume flux for any air-bubble system.
THE ATLANTIC COAST OF LONG ISLAND
Authors: Panuzio Frank L.
Published: February 2019

The south shore of Long Island, located on the northeast coast of the United States, consists of 120 miles of headlands and harrier beach which is breached by inlets that interconnect the coastal bays with the Atlantic Ocean. The shore is subject to severe changes due to constant attack of the ocean, rising level of the ocean and severe storms. The predominant, east to west littoral drift moves from 300,000 to 600,000 cubic yards of sand along the shore annually. The affected area encompasses a million people and is valued at $2.5 billions. Improvements have been authorized for 110 miles of shore, and involve sandfill, feeder beaches, groins, jetties, sand bypassing, and inlet barriers The estimated cost for the entire shore improvement is $188 million. The annual charges are about $10 million. The annual benefits are $16 million. The implementation of the authorized work includes the design and model testing of several sections and the completed work m several sections, such as sandfill, feeder beaches, and groins. The completed work shows considerable effect on shore processes. Overall evaluation must await completion of the total improvement in an integral section of the shore.
WAVES GENERATED BY LARGE SHIPS AND SMALL BOATS
Authors: Das M.M. , Johnson J.W.
Published: February 2019

The peak wave energy in a system of waves resulting from the passage of a ship is of importance in such problems as bank erosion, the motion of moored vessels, forces on fixed and floating docks, etc With respect to the bank erosion problem, the question often asked is whether the single passage of a large ship during a day, for example, is more damaging than numerous passages of small pleasure craft during the day With this in mind this study was conducted to determine the relative importance of the peak energy resulting from the passage of a Mariner class cargo ship and a pleasure cruiser.
WAVE REFRACTION THEORY IN CONVERGENCE ZONE
Authors: Whalin Robert W.
Published: February 2019

An experimental investigation utilizing nonbreaking waves and one bottom topography with parallel circular contours symmetric about the center of the basin was performed to assess the limits of applicability of linear wave refraction theory in a convergence zone. Analytical computations of reflections from underwater topographic variations and of viscous dissipation of energy at the bottom agreed with experimental measurements. It was vividly illustrated that a significant amount of energy was involved in diffraction along the wave crest, thus the necessity of developing a theory to include the stepwise computation of diffraction processes simultaneously with the computation .of wave refraction is now evident. Nonlinear transfer of energy from lower to higher frequency components was investigated by performing a harmonic analysis over one wave period. As expected, nonlinear effects increased with both wave period and wave height (for a given wave period). Only 20 percent of the energy remained in the fundamental component for the longest period largest amplitude wave tested. Higher frequency components ranged from being completely coupled to the fundamental frequency to almost completely uncoupled. It was clearly demonstrated that in some circumstances the consideration of nonlinear effects becomes extremely important.
IMPULSE WAVES GENERATED BY LANDSLIDES
Authors: Kamphuis J.W. , Bowering R.J.
Published: February 2019

A study programme has been initiated to investigate the impulse waves generated by landslides originating entirely above the water surface It may be seen that the characteristics of this wave depend mainly on the slide volume and the Froude number of the slide upon impact with the water The resulting wave goes through a transition period For the highest wave (usually the first), the wave height becomes stable relatively quickly and decays exponentially during the period of transition, the wave period continues to increase for a long time, the velocity of propagation may be approximated very closely by solitary wave theory.
PROPERTIES OF LONGSHORE BARS IN THE GREAT LAKES
Authors: Saylor James H. , Hands Edward B.
Published: February 2019

Longshore bars are permanent features of nearshore bathymetry along the windward coasts of the Great Lakes The stability and permanency of these features have been noted by numerous investigators, but movements of the bars and troughs vn relation to varying lake levels and incident wave energies are not fully understood Studies of nearshore bathymetry and sediment properties were conducted during 1967 and 1969 along a forty-five kilometer reach of the eastern coast of Lake Michigan Results show that the offshore bars migrate significantly due to changes in lake level, a rise of one-half meter in the surface of Lake Michigan between 1967 and 1969 was accompanied by a shoreward movement of bar crests and troughs over a distance averaging SO meters Elevations of the crests and troughs are also built upward toward new equiblibrium levels during rising water levels, but elevating of the crests lags the increase in stage Extensive shore erosion occurs because of the reduced effectiveness of longshore bars in dissipating incident wave energy The average crest depth was found to increase linearly in the offshore direction Average distances between crests increase exponentially These relationships are preserved during the bar growth and shifting that accompanies long term changes in lake level Bar troughs are characteristically crescent shaped, with no abrupt changes in slope Fathograms from several ranges show atypical trough configurations consisting of flat bottoms with discontinuities in slope on ascent to adoacent crests This unusual trough shape is indicative of an immobile stratum exposed along the bottom of the trough.
UNDERWATER MOUND FOR THE PROTECTION OF DURBAN'S BEACHES
Authors: Zwaborn J.A. , Fromme G.A.W. , FitzPatrick J.B.
Published: February 2019

The construction of an underwater mound of sand for the protection and improvement of Durban's beaches has been recommended on the basis of intensive investigations These investigations included prototype measurements of beach changes as related to recorded sea conditions, basic scaling tests in which these beach changes were reproduced to scale in movable bed models and tests of the proposed underwater mound in models, using different scales in order to eliminate possible scale effects The test results showed that, provided the shear-settling velocity similarity criterion is satisfied, beach changes can be reproduced in a movable bed model to a reasonable degree of accuracy Optimum dimensions for the cross section of the mound were determined on the basis of the criterion for erosive and non-erosive wave conditions which was derived from the prototype beach profile changes and confirmed by model tests The resulting dimensions are a mound of sand about 4 5 km long, about 1 200 m offshore, reaching to 7 3 m below LWOST, with side slopes of 1 in 25 and a crest width of 61 m 3 3 Of the total quantity required (8 000 000 m ) some 2 500 000 m of sand, available from harbour dredging works in Durban Bay, had been dumped by May, 1970 Model predictions on mound stability and beach improvements were confirmed to a high degree of accuracy by the full scale events.
COMPARISON OF PRESSURE AND STAFF WAVE GAGE RECORDS
Authors: Esteva D. , Harris D. Lee
Published: February 2019

Simultaneous records from two pressure gages located at different depths, a step-resistance relay gage, and a continuous-wire staff gage have been collected at Atlantic City, N J Spectra and cross-spectra are computed using the Fast Fourier Transform Algorithm (FFT) method proposed by Cooley and Tukey Individual harmonics of the pressure energy spectra are compensated for pressure attenuation according to classical theory Results indicate better agreement is obtained between the wave height and the spectra computed from the compensated pressure gages and those computed from the continuous-wire staff gage than between the two surface gages Values of coherences are near 98 in the energy-containing part of the spectrum, and are always larger for the pressure-continuous wire staff cases than for the two surface gages which are displaced from each other only 12 feet m the horizontal.
EQUILIBRIUM PROFILES OF MODEL BEACHES
Authors: Nayak Irvathur Vasudeva
Published: February 2019

The investigation reported herein covers two aspects of equilibrium beach profiles, namely, (a) the criterion governing their type and (b) their reflection characteristics The problems are first analysed from dimensional considerations and then studied experimentally in laboratory wave flumes using different sizes of quartz, ground walnut shell and ground plastic as movable bed material. Empirical relations between pertinent parameters governing the beach process are given.
SUCCESSIVE SALTATION OF A SAND GRAIN BY WIND
Authors: Tsuchiya Yoshito
Published: February 2019

In order to establish the mechanics of sand transport in an air or water stream, the mechanics of saltation of sand grains should first be considered In sand storms, most of the saltating sand grains on a granular bed have successively continued the saltation motion In this paper, such a saltation motion is defined as successive saltation A theoretical approach to the saltation of a single sand grain on a fixed granular bed is proposed on the basis of the equations of motion for the saltation and the dynamic characteristics of collision between a saltating sand grain and bed sand grains Some experiments of the successive saltation of a single sand gram on a fixed granular bed were carried out to compare with the theoretical relationships It was verified from the comparison that the theoretical relationships of the height and distance of saltation of a sand gram are in fairly good agreement m substance with the results of experiment.
BREAKWATER AND QUAY WELL BY HORIZONTAL PLATES
Authors: Ijima Takeshi , Ozaki Shigeo , Eguchi Yasuhiko , Kobayashi Akire
Published: February 2019

Wave action to breakwater and quay wall by fixed horizontal plates as shown in iig 4 and 5 are studied theoretically and experimentally Transmission and reflection coefficients for breakwater are calculated as shown m Fig 6(a)(b), which suggest that only fixing the water surface by rigid plate is effective to reduce the transmitted waves for appropriate wave conditions Pressure distributions to plates are calculated as shown in Fig 7 and total pressures are in Fig 8 Pressure distributions to norizontal plate and vertical wall of quay wall are shown in Fig 9 and 10, which show that the plate* makes the pressure distribution to vertical wall more uniform than the one without plate and also submerged plates of breakwater and quay wall make the pressure distributions smooth Wave action m case when the region under plates is filled by permeable material are also calculated The results suggest that the void of the material has the effect to elongate the plate and the fluid resistance acts as wave energy absorber.
NUMERICAL AND HYDRAULIC EXPERIMENTS ON BORE PRESSURE DUE TO TSUNAMI
Authors: Kimura Tatsuto , Masuko Masahiro , Fujii Naoki , Kaida Hideki , Kihara Naoto
Published: February 2019

The 2011 Tohoku earthquake tsunami struck a wide area of the northeastern coast of Japan, and many coastal structures and buildings were damaged by the tsunami. Most of the buildings were damaged by the tsunami wave pressure. After the tsunami, characteristics of tsunami waive pressures have been investigated by many researcher, and are being clarified. As shown in previous studies, there are three regimes charactering the vertical pressure profiles. The first one is the impulsive pressure, which is observed just after the tsunami-bore impacted structures. In this regime, strong hydrodynamic pressures are generated by the fluid-solid impact process. After that, the bore pressure is observed, and both the hydrodynamic and hydrostatic pressures contribute the pressure profile. After that, the flow near the structures reaches a quasi-steady state, and the pressure profile becomes hydrostatic. Most of the evaluation equations of tsunami wave pressure proposed by the previous studies can be used against the impulsive pressures and the pressures in the quasi-steady-state regime. On the other hand, the characteristics and quantitative evaluations of the bore pressure remain immature. In this study, in order to clarify the characteristics of the bore pressure, experiments on the bore pressure are carried out, and furthermore, three-dimensional numerical simulations are also carried out.
GEOCENTRIC MEAN SEA LEVEL FIELDS AT THE GERMAN NORTH SEA AND BALTIC COAST
Authors: Kelln Jessica , Dangendorf SÃ¶nke , Jensen JÃ¼rgen , Patzke Justus , Niemeier Wolfgang , GrÃ¤we Ulf , Santos Victor Malagon
Published: February 2019

Global mean sea level has risen over the 20th century (Hay et al. 2015; Dangendorf et al. 2017) and under sustained greenhouse gas emissions it is projected to further accelerate throughout the 21st century (Church et al. 2013) with large spatial variations, significantly threatening coastal communities. Locally the effects of geocentric (sometimes also referred to absolute) sea level rise can further be amplified by vertical land motion (VLM) due to natural adjustments of the solid earth to the melting of the large ice-sheets during the last deglaciation (GIA) or local anthropogenic interventions such as groundwater or gas withdrawal (e.g. SantamarÃ­a-GÃ³mez et al. 2017). Both, the observed and projected geocentric sea level rise as well as VLM are critically important for coastal planning and engineering, since only their combined effect determines the total threat of coastal flooding at specific locations. Furthermore, due large spatial variability of sea level, information is required not only at isolated tide gauge (TG) locations but also along the coastline stretches in between.
COASTAL HYDRODYNAMIC MODELING TO SUPPORT THE RECONSTRUCTION OF BREAKWATERS AT CAP-DES-ROSIERS
Authors: Roy Mathieu , Ruest Benoit , Métivier Vincent , Guillemette Nicolas , Renaud Steve , Drouin Alain
Published: February 2019

The fishing harbor of Cap-des-Rosiers is located at the northeast end of the GaspÃ© Peninsula and is owned by Parks Canada. It is located within the Forillon National Park, at the mouth of the Whalen River. Two jetties, composed of Berlin walls, delineate the inner channel of the harbor and act as breakwaters. Despite the presence of these breakwaters, significant problems of agitation have been observed in the past within the harbor during storms.
UNDULAR BORE DEVELOPMENT OVER A LABORATORY FRINGING REEF
Authors: Tissier Marion , Dekkers Jochem , Reniers Ad , Pearson Stuart , Van Dongeren Ap
Published: February 2019

Several studies have reported the development of

undular bores over fringing coral reefs (e.g, Gallagher,

1976; Nwogu and Demirbilek, 2010) but the importance

of this phenomenon for reef hydrodynamics has never

been studied. Yet, the transformation of a long wave

(e.g., swell or infragravity wave) into an undular bore

leads to significant modifications of the wave field. The

formation of undulations is for example associated to a

significant increase of the leading bore height. Moreover,

if the undulations have enough time to develop (i.e. if the

reef flat is wide enough), the initial long wave will

ultimately split into a series of solitons (e.g., Grue et al.,

2008). All this is likely to affect wave run-up. As reeffronted

coastlines are particularly vulnerable to flooding,

a good understanding of long wave transformation over

the reef flat, including their possible transformation into

undular bores, is crucial.

In this study, we investigate undular bore development

over reef-type profiles based on a series of laboratory

experiments. More specifically, we aim to characterize

the conditions under which undular bores develop, and

analyse how their development affect the hydrodynamics

at the toe of the reef-lined beach and the resulting wave

run-up.
HURRICANE WATER LEVEL PREDICTION USING SURROGATE MODELING
Authors: Melby Jeffrey A. , Diop Fatima , Nadal-Caraballo Norberto , Taflanidis Alex , Gonzalez Victor
Published: February 2019

For this study, the surrogate was constructed using kriging (Jia et al. 2015). The high fidelity coupled surge and wave numerical modelling for the Gulf of Mexico was used as the training set. The numerical model was either ADCIRC and STWAVE or ADCIRC and SWAN in the nearshore. The surrogate models were trained using tropical storm parameters (latitude, longitude, central pressure, radius to maximum wind speed, storm heading, and forward speed) at a specific location as inputs and individual responses (e.g. surge) as outputs. Tide was computed separately using ADCIRC and linearly superimposed with surge to get total water level. The regional surrogates accurately reproduced both peaks and time series of water levels for historical storms. An extensive validation was conducted to determine the optimal application of the kriging approach. In this paper we will report the efficient design-of-experiments approach, surrogate training and validation.
TSUNAMI INUNDATION SIMULATIONS IN URBAN TOPOGRAPHY
Authors: Miyashita Takuya , Mori Nobuhito
Published: February 2019

The inundation of the 2011 Tohoku Earthquake Tsunami showed complex behavior over the land. According to the surveys of the Tohoku Earthquake Tsunami in 2011, the behavior of tsunami in urban areas was different from that in rural areas and the damage was not only dependent on the inundation heights but also the local momentum. The buildings are commonly excluded and smoothed off in the topography in the conventional inundation simulation but itâ€™s important to understand the local characteristics of tsunami run-up in urban areas. The purpose of this study is to understand and validate numerical models of tsunami in the urban area.
PROBABILISTIC EVALUATION OF STORM SURGES IN SURUGA BAY EMPLOYING STOCHASTIC TYPHOON MODEL
Authors: Yasuda Tomohiro , Iwahara Katsuhito , Hirai Shota
Published: February 2019

Design procedure of coastal embankment in Japan compares tsunami height and storm surge height and employs higher value as a crown level. Estimation of tsunami or storm surge height is usually based on the historical maximum record or an assumed maximum value. Estimation of storm surge needs not only typhoon intensity but also its characteristics e.g. tracks and travel speed. It is difficult to estimate the probability of storm surges using only observed data since typhoon rarely attacks particular area and storm surges are seldom generated. This study proposes probabilistic evaluation procedure of storm surges employing stochastic typhoon model and applies to Suruga Bay, Japan.
ESTIMATING METEO-TSUNAMI OCCURRENCES FOR THE US EAST COAST
Authors: Woodruff India , Kirby James , Shi Fengyan , Grilli Stephan
Published: February 2019

Meteorological tsunamis, also called meteo-tsunamis, are significant ocean surface waves generated by atmospheric forcing. The waves typically result from energy transfer from atmosphere to ocean through the Proudman resonance phenomena, where translation speed of the storm system in the atmosphere coincides with the free wave speed of long surface waves. These tsunami-like waves can be hazardous, either through direct inundation of shorelines or through generation of harbor oscillations and other disruptions to maritime activities. The wide continental shelf bathymetry of the United States (US) East Coast provides a long potential fetch length for the resonant generation process, making the region particularly susceptible to meteo-tsunamis. In this study, we carry out a probabilistic analysis of potential meteo-tsunami hazard on the US East Coast, extending the earlier work of Geist et al. (2014) to include a wider range of storm conditions and additional response types including coastally-trapped edge waves. The work, carried out under the auspices of the National Tsunami Hazard Mitigation Program (NTHMP), extends the previous efforts of Geist et al. to include a representation of inundation and maritime hazards in at-risk areas. The work is conducted using the fully nonlinear Boussinesq wave model FUNWAVE-TVD (Shi et al., 2012), extended to include atmospheric pressure and wind forcing.
INTER-COMPARISON OF COASTAL MODELS: CASE STUDY OF STORM SURGE AT NEMURO IN JAPAN
Authors: Nakamura Ryota , MÃ¤ll Martin , Shibayama Tomoya , Kato Shigeru
Published: February 2019

The numerical coastal circulation models play an essential role in predicting storm surges. Several models (e.g. ADCIRC: Dietrich et al., 2004, FVCOM: Chen et al., 2003) have been previously inter-compared (Kerr et al., 2013; Chen et al., 2013). In these studies, storm surges were reproduced in locations where the bathymetry has a gradual increase from offshore to coast, within a closed gulf. On the other hand, there are few studies in regards to modelling storm surge where the near coast bathymetry is steep and connected to open ocean. Considering the storm surge dependence on local bathymetry, it can be important to conduct an inter-comparison of ocean circulation models in such a region. In this study, numerical coastal circulation models (2D-ADCIRC and 3D-FVCOM) are compared by using a 2014 Dec. storm surge event at Nemuro city in Hokkaido (Japan), which was caused by a rapidly intensified extra-tropical cyclone approaching the area. In this region, local bathymetry is steep due to Japan Trench. The cyclone caused a storm surge of nearly up to 1.8 m within the Nemuro city between 00:00 UTC 16th and 17th Dec. 2014. The aim of this study is to evaluate the performance of ocean circulation models using several air-sea drag coefficients and contribute to inter-comparison studies using ADCIRC and FVCOM.
MODELING EFFECTS OF VEGETATION ON SETUP AND RUNUP OF RANDOM WAVES
Authors: Zhu Ling , Chen Qin J. , Jafari Navid , Rosati Julie D. , Ding Yan
Published: February 2019

The effects of coastal vegetation on wave attenuation have been well acknowledged and quantified. However, the studies on the effects of vegetation on wave setup and runup are still limited. Wave setup contributes to the elevated water level during a storm event. Flume tests (Wu et al. 2011) show that vegetation reduces the wave setup and neglecting vegetation will overestimate the mean water level (MWL). Dean and Bender (2006) theoretically examined the MWL change in vegetation. van Rooijen et al. (2016) numerically studied the effects of vegetation on wave setup using a storm impact model, XBeach. The wave-averaged drag force (ð‘“ð‘£Ì…) in XBeach was obtained through a wave shape model based on stream function wave theory. This wave shape model was calibrated with field data collected at barred beaches without vegetation, and thus may not be applicable to vegetated shorelines. The objective of this study is to model the effects of vegetation on the setup and runup of random waves using a cross-shore numerical model (CSHORE; Kobayashi et al. 1998). A new parametric model is proposed to compute ð‘“ð‘£Ì… in CSHORE. Effects of vegetation on wave setup and runup are examined through numerical experiments.
RELIABILITY OF PRESSURE SENSORS TO MEASURE WAVE HEIGHT IN THE SHOALING REGION
Authors: Marino Massimiliano , Rabionet IvÃ¡n CÃ¡ceres , Musumeci Rosaria Ester , Foti Enrico
Published: February 2019

A comparison between a range of transfer functions to recover wave height from pressure sensors data is presented. The analysis is carried out by means of a large-scale wave flume experimental dataset, in which resistive, acoustic and pressure gauges recovered wave height are compared as the waves travel from intermediate waters, to the shoaling region and finally into the surf zone. All the considered transfer functions result adequate in recovering wave height in intermediate waters, becoming gradually less accurate as the steepness of the wave increases in the shoaling region and in the surf zone. The accuracy of the compared transfer functions is assessed by means of an ensemble wave height based deviation.
AN ENGINEERING BASED ANALYSIS OF THE COAST OF CAMPECHE AS THE PATH TO SUSTAINABLE MANAGEMENT DECISIONS
Authors: Turriza RomÃ¡n Canul , Mendoza Edgar , Posada Gregorio , Silva Rodolfo
Published: February 2019

Chronic coastal erosion problems have been reported in Campeche State; however, beaches and ecosystems have not yet been degraded to the point of being at high risk. A proposal for coastal segmentation is presented here, in order to rank the coastal sectors according to the urgency required for intervention; given that this approach applies a large â€“ scale perspective; the analysis is suited to any other coastal zone. The proposed methodology hierarchically identifies littoral segments in three steps: 1) dividing the study area into littoral cells, 2) assessing coastal vulnerability and 3) identifying the immediacy of intervention needed for each coastal sector.
COASTAL STORM INDUCED EROSION PREDICTIONS FOR FEMA FIS COASTAL HAZARD RISK MAPPING
Authors: Lindemer Christina , Gangai Jeffrey , Mack Christopher , Drei-Horgan Elena , Hatheway Darryl
Published: February 2019

Flood Insurance Studies (FISs) produced by the Federal Emergency Management Agency (FEMA) per the National Flood Insurance Program (NFIP) regulations and guidelines adopt storm-induced erosion criteria often called the â€œ540 ruleâ€. The methods used in the erosion analysis have been in place since the 1980s. The method requires dunes to be classified as fully eroded, or â€œremovedâ€, when their cross-sectional reservoir is smaller than 540 square feet. Since the ruleâ€™s first application, additional data and recent evidence have become available leading FEMA to identify this approach as an area of the program in need of updating and improvement. Experts involved in conducting coastal hazard analyses for FEMA studies recommend exploring opportunities to improve FEMA guidelines for erosion criterion and revise NFIP regulations and guidance, as needed, to ensure that storm-related erosion hazards are appropriately evaluated and mapped along US coastlines.
A MODIFIED HYPERBOLIC TANGENT EQUATION TO DETERMINE EQUILIBRIUM SHAPE OF HEADLAND BAY BEACHES
Authors: Kemp Jonathan , Vandeputte Benoit , Eccleshall Thomas , Simons Richard , Troch Peter
Published: February 2019

When designing any artificial beach, itâ€™s desirable to avoid (or minimise) future maintenance commitments by arranging the initial beach planshape so that it remains in equilibrium given the incident wave climate. Headlands bays, or embayments, where a sandy beach is held between two erosion resistant headlands, tend to evolve to a stable beach planshape with little movement of the beach contours over time. Several empirical bay shape equations have been derived to fit curves to the shoreline of headland bay beaches. One of the most widely adopted empirical equations is the parabolic bay shape equation, as it is the only equation that directly links the shoreline positions to the predominant wave direction and the point of diffraction. However, the main limitation with the application of the parabolic bay shape equation is locating the downcoast control point. As a result of research presented in this paper a new equation, based on the hyperbolic tangent shape equation was developed, which eliminates the requirement of placing the down coast control point and relies on defining a minimum beach width instead. This modified equation was incorporated into a new ArcGIS tool.
WAVE PRESSURE DISTRIBUTIONS ON A U-OWC BREAKWATER: EXPERIMENTAL DATA VS CFD MODEL
Authors: Filianoti Pasquale G. Fabio , Gurnari Luana
Published: February 2019

U-OWCs are Wave Energy Converters belong in to the family of Oscillating Water Column. The interaction between waves and a U-OWC breakwater produces an unknown pressure distribution on the breakwater wall, due to the motion inside the plant. In order to evaluate the force acting on a U-OWC breakwater produced by regular waves, we carried out an experiment in a 2D numerical flume. The computational domain is equipped by a piston-type wavemaker, in the left extremity side and a U-OWC breakwater on the opposite side. The water-air interaction is taken into account by means of the Volume Of Fluid (VOF) model implemented in the commercial CFD code Ansys Fluent. Both air and water flow fields are assumed to be unsteady and are computed by solving the Reynolds-Averaged Navier-Stokes (RANS) equations. In the numerical model, air is considered as an ideal gas, in order to take into account the compressibility inside the plenum chamber. Results were compared with a theoretical model on a traditional vertical breakwater and experimental results obtained through an experiment directly at sea, off the beach of Reggio Calabria, in the eastern coast of the Straits of Messina (Southern Italy). As observed in the physical experiment at sea, the pressure distribution are strongly influenced by the absorption of the plant. Indeed, in case of high performance of the U-OWC, we found a deformation of the pressure distribution in respect to the theoretical one, especially near the outer opening of the plant. This deformation produces a lower in line force on the structure.
OVERTOPPING ON BREAKWATERS WITH A PERMEABLE CREST
Authors: Eldrup Mads RÃ¸ge , Andersen Thomas Lykke , Thomsen Jonas Bjerg , Burcharth Hans Falk
Published: February 2019

In model tests, the wave overtopping discharge is typically measured at the rear corner of the armour crest. So far, all overtopping formulae have been calibrated to predict this specific overtopping discharge. The EurOtop Manual however proposed a formula to include also the discharge trough the permeable armour crests. The total overtopping including the discharge trough the crest armour is relevant in relation to rear armour stability. The discharge trough the armour depends also on the permeability of the core material. In order to study this effect, new model tests were performed with a permeable and an impermeable core. A method for the prediction of the total overtopping discharge is given.
STUDY ON MECHANISM OF BACK-SILTATION IN THE DEEP-DRAFT WATERWAY OF THE YANGTZE ESTUARY, AND EVALUATION OF ENGINEERING MEASURES
Authors: Gao Min , Wan Yuanyang
Published: February 2019

Since the 92.2km-long , 350m-wide and -12.5m-deep draft channel was successfully achieved in the South Channel and the North Passage in the year 2010 , high siltation was found to temporally take place in the wet seasons , and spatially concentrate in the middle reach of the North Passage, where is consistent with the location of the traditional turbidity maximum zone (TMZ) of the Yangtze Estuary. The data from 2011 to 2015 show that the average annual siltation in the draft channel reached 80 Million m3 per year. With systematic analysis of the sediment source and comprehensive investigation on the mechanism of the flow and sediment transportation and siltation in the North Passage, this paper reveals a major cause of the back-siltation in the middle reach and subsequently discusses several engineering measures proposed to reduce the siltation . The final-selected engineering measure has been implemented quite recently , and the preliminary study shows that desired effect has been produced by the engineering measure.
QUANTIFYING BEACH AND DUNE RESILIENCE USING THE COASTAL RESILIENCE INDEX
Authors: Dong Zhifei , Elko Nicole , Robertson Quin , Rosati Julie
Published: February 2019

US Army Corps of Engineers Coastal Storm Risk Management (CSRM) projects have reduced coastal vulnerability and helped communities anticipate and mitigate toward improved resilience. This study proposes the Coastal Resilience Index (CRI) to quantify storm damage reduction benefits due to beach restoration projects in the context of resilience. The CRI considers metrics of the beach and dune system and disturbance factors such as storm surge and waves, using five non-dimensional factors: Protective Elevation (PE), Volume Density (VD), Protective Width (PW), Crest Freeboard (CF) and wave run-up (WR). The CRI is the summation of these five non-dimensional factors. This study developed a geographic information systems (GIS) based tool to automatically extract morphologic features from historic profiles and profiles extracted from LiDAR data to quantify beach resilience over time.
INTERACTION BETWEEN WAVES AND HANGING HIGHLY FLEXIBLE KELP BLADES
Authors: Zhu Long-Huan , Huguenard Kimberly , Fredriksson David
Published: February 2019

The interaction between waves and flexible blades has drawn recent attention because of the capacity of nature-based infrastructure, such as aquatic vegetation and kelp, to attenuate waves. In this study, a new numerical model was developed to study the wave-blade interaction for both bottom-fixed and suspended blades. The dynamics of the blades simulated by a cable model were coupled with OpenFOAMÂ®-based wave model IHFoam with the immersed boundary method. The results showed that the distribution of the blade-induced vortices was asymmetric with more vortices upstream for the single bottom-fixed blade while more vortices downstream for the single suspended blade. For both submerged and suspended canopies, the vortex distribution is also asymmetric. More vortices concentrate upstream for the submerged canopy. For a suspended canopy, more vortices concentrate upstream and below the bottom of the suspended canopy. Yet near the surface above the suspended canopy, more vortices concentrate downstream. Understanding the distribution of vortices is important for predicting the sediment transport and nutrient distribution.
FINDING BICHROMATIC-BIDIRECTIONAL WAVES WITH ADVs
Authors: De Souza e Silva Mario G. , Kerpen Nils , Rosman Paulo Cesar C. , Schlurmann Torsten , Neves Claudio F.
Published: February 2019

The aim of this study is to investigate Bichromatic-Bidirectional waves to characterize the subtractive wave-wave nonlinear interactions, using adaptive techniques rather than traditional spectral techniques. A physical model test in a 3D-wave basin was conducted and measurements were made with two arrays of ultrasonic sensors of free surface and one array of ADVs. The Hilbert-Huang transform, aided by the Multivariate Empirical Mode Decomposition, was applied to the orbital velocity data and the main characteristics of the infragravity wave (velocity amplitude, period and direction) were extracted with a good precision.
SENSITIVITY OF TROPICAL CYCLONE TRACK TO ASSESSMENT OF SEVERE STORM SURGE EVENT AT TOKYO BAY
Authors: Nakajo Sota , Fujiki Hideyuki , Kim Sooyoul , Mori Nobuhito
Published: February 2019

In total 82 tropical cyclones data was used to determine scenarios of translation speed, minimum central pressure and track for risk assessment of storm surge at Tokyo Bay. The numerical simulation of waves and flows was conducted by solving non-linear long wave equations. The maximum surge height shows that the typhoon passing through along northeast directional track is dangerous for Tokyo Bay. This trend confirms the previous risk assessment was reasonable. However, it has been shown that the typhoon passing through along north directional track is also dangerous although the frequency is low. Especially, it is interesting that the typhoon passing through along northwest directional track causes distinctive resurgence and harbor oscillation.
MODELLING WAVE OVERTOPPING FOR GRASS COVERS AND TRANSITIONS IN DIKE REVETMENTS
Authors: Warmink Jord J. , Van Bergeijk Vera M. , Chen Weiqui , Van Gent Marcel R. A. , Hulscher Suzanne J. M. H.
Published: February 2019

Transitions in the dike revetment or in the grass cover can significantly affect the wave overtopping discharge and the dike cover erosion. At the University of Twente, two PhD students recently started on the challenge of quantifying the effect of (1) waterside transition on the wave overtopping discharge and (2) transitions in grass covered dikes on dike erosion. In this paper we present their preliminary results and outline their future plans. Firstly, new laboratory experiments show that the existing wave overtopping formulas are not able to accurately predict the overtopping discharge in case of transitions on the waterside slope. Secondly, the analytical dike cover erosion model shows that transitions in grass covers significantly affect the location of maximum flow velocity and potential dike cover erosion. In future work, detailed numerical models will be developed for both the waterside slope and the landward slope to further increase our understanding of the effects of transitions on the wave overtopping discharge and the dike cover erosion.
FUTURE CLIMATE EXPERIMENTS ON INTENSITY AND STORM SURGE OF TYPHOON SANBA (2012)
Authors: Toyoda Masaya , Yoshino Jun , Kobayashi Tomonao
Published: February 2019

The recent progress of the global warming raise concerns the future changes of tropical cyclones (i.e. hurricane, typhoon, and cyclone) and their associated coastal disasters. It is thought that the increases of both the sea surface temperature and ocean heat contents by the global warming could increase the intensity of future tropical cyclones. As a method of quantitative assessment for the impact of global warming on tropical cyclones and their storm surges, â€œpseudo-global warming downscalingâ€ is generally adopted using a regional climate model and a storm surge model (Takayabu et al., 2015). Estimating the differences of experiments between present and future climate, we can quantify the future changes of typhoon intensity and storm surge by the global warming. Using the high-resolution typhoon model, we carry out a present climate experiment and pseudo-global warming experiments on typhoon intensity and its storm surge of Typhoon Sanba (2012) in this study. Sanba went northward on the west coast of Kyushu Island and caused a storm surge in Ariake Sea, Japan. Sanba had a minimum central pressure of 900 hPa and a maximum wind speed of 55 m/s. The observed maximum sea level anomaly was 104 cm at Oura, Saga Prefecture. To evaluate the impacts of global warming differences (GWDs) on typhoon intensity and storm surge, sensitivity experiments on different months (August, September, and October) in future typhoon season are also made.
NUMERICAL INVESTIGATION OF BORE HOLE FILLING VOLUME IN A COASTAL AREA
Authors: Adong Feddy , Bennis Anne-Claire , Mouazé Dominique
Published: February 2019

A numerical study is carried out to determine the parameters controlling the filling of a bore hole in Alderney Race. Our final goal is to identify the configuration minimizing the filling. We performed a one-way coupling between a coastal circulation model and a discrete element model for that purpose. Simulations used spherical particles and a monopile technology. We show that: as long as the distance between the hole and the residuals remains smaller than twenty meters, the flow direction plays a negligible role; interaction between moving particles and bottom roughness leads to a slight increase of the filling; the impact of ambient sediments strongly depends on seabed morphology and current effects.