bluuebunny/crossref_metadata_2025 huggingface dataset:
CHARACTERIZATION OF HYDRODYNAMIC PROCESSES DRIVING TIDAL RIVER ISLAND SHORELINE CHANGE
Authors: Muscalus Alexandra , Haas Kevin
Published: February 2019

Bird/Long Island is a dredge-spoil island located between the north and south channels near the inlet of the Savannah River at the border of Georgia and South Carolina. The island is in a tidally dominant environment and contains cultural and natural resources, including remnants of a Civil War era artillery battery. As a wetland mitigation bank, it is particularly important to the state of Georgia. However, these resources are under threat from documented and ongoing sea level rise, shoreline change (i.e., erosion and accretion) from natural and anthropogenic causes, and land subsidence. In addition to substantial tidal and freshwater flows, the island is subject to locally-generated wind waves primarily from northeast winds, as well as wake from the large container ships transiting to and from the Port of Savannah. A previous study examined the effects of wind and vessel-generated waves on shoreline retreat for the Fort Pulaski National Monument on nearby Cockspur Island (Houser, 2010). The study concluded that while the vessel-generated waves account for nearly 25% of the energy, the wind waves during storm events with increased water levels accounted for the majority of the marsh retreat. Although the proximity of this previous study site to Bird/Long Island is relevant, the different orientations of the islands and the narrowing of the channel create a different hydrodynamic environment. The present work uses field data to characterize the hydrodynamic processes affecting Bird/Long Island, which will improve modeling of its shoreline change.
WAVE INDUCED CURRENT MONITORING USING UAV-BASED PHOTOGRAMMETRY
Authors: Shin Bumshick , Kim Kyu-Han
Published: February 2019

In recent years, due to the development of hardware and video image processing technology, image analysis technique using a wide coastal coastline, it made it possible to analyze the wave runup and swash, current and so on. However, in order to obtain the image information of a large area requires a high-resolution imaging at a high position, however, to the recording technique used in the past, there is a limit of height and resolution. Thus, recently, on the basis of remote sensing techniques, or build spatial information technology using UAV (Unmanned Aerial Vehicle) system, and the research and utilization in various fields it increased. Small UAV platforms is becoming low-cost, miniaturized hyperspectral imaging technology. The direct measurement of wave induce current is tested using image analysis techniques using sea dye maker and UAV. Specially, rip currents are approximately shore normal seaward flows which are strong, localized and rather narrow. In this method, UAV at a region with frequent wave induced current occurrence, and images are continuously obtained in real time. This research investigates the development of wave induced currents using images in East coast of Korea.
COUPLED TIDES, STORM SURGE AND WAVES UNDER VARYING ICE COVERAGES ALONG ALASKAâ€™S BERING AND CHUKCHI COASTS
Authors: Westerink Joannes J. , Joyce Brian , Grumbine Robert , Van der Westhuysen Andre , Feyen Jesse , Pringle William J. , Wirasaet Dam
Published: February 2019

The western coastline of Alaska spans over a diverse topography ranging from low lying tundra to sharp volcanic relief. Included in this range are areas highly susceptible to powerful storms which cause coastal flooding, erosion and have many other negative effects on the environment and commercial efforts in the region. To better understand the multi-scale and interactive physics of the deep ocean, continental shelf, near shore, and coast, a large unstructured grid hydrodynamic model has being developed using the finite element, free surface circulation code ADCIRC coupled to the WAVEWATCH III third generation non-phase resolving wave code. This is a high resolution, accurate, and robust computational model of Alaska's coastal environment capable of simulating tides, storm surges, and storm waves as well as their coupling.
VALIDATION OF INTEGRATED COASTAL PROCESS MODEL FOR SIMULATING WAVE-CURRENT-VEGETATION INTERACTION
Authors: Ding Yan , Rosati Julie D.
Published: February 2019

Vegetation plays an important role in reducing wetland and coastal erosion. It is well-known that vegetation in coastal regions acts as a buffer to reduce wave impact and wave setup, as waves are deformed and energy of waves is attenuated through vegetation zones. Modeling wave deformation and transformation through vegetation zones can quantify wave attenuation effects as a function of vegetation properties, improve our understanding of physical processes, and eventually provide an effective assessment tool for management, control, and design of vegetation zones and wetlands. Wave attenuation effects have been studied for several decades. In addition to physical modeling and field observation, two types of mathematical approaches for modeling effects of vegetation on waves can be identified, i.e., phase resolving wave model and phase-averaged wave model. The former directly simulates dynamic wave shape deformations through a vegetation field by solving the time-dependent fluid flow governing equations. The latter directly computes wave spectral variations in space and time by using a time-averaged wave energy equation. Although a phase-resolving model can give detailed wave phase information as waves propagate through vegetation zones, it needs extensive computing efforts to solve dynamic fluid flow problems.
TIDAL CHANNEL GEOMETRY OF BARRIER EMBAYMENT SYSTEMS IN PUGET SOUND
Authors: CÃ´té Jessica , Ketteridge Kathryn
Published: February 2019

This paper will present the first year of findings from a research project with the objective of producing empirically based models of tidal channel characteristics that can be broadly applied to design estuary restoration projects in Puget Sound. A combination of field data collection methods and desktop analysis are being utilized to calculate tidal prism, channel dimensions, marsh extent, and water surface elevations to parameterize well-functioning barrier embayments in Puget Sound. The tidal channel data will be used to conduct a regression analysis and develop hydraulic geometry scaling relationships. The goal of the study is to develop one set of regression lines for the Puget Sound basin; however, if the data collection reveals important differences between sub-basins, then two or more regressions may be developed. For example, Hood (2015) found wave exposure contributed to differences in tidal channel geometry in the major river deltas within Puget Sound. Differences in wave exposure and tide range among the sub-regions of Puget Sound could create a need for creating more than one set of scaling relationships (e.g. North Sound and South Sound).
PROCESSES LEADING TO INFRA-GRAVITY PERIOD OSCILLATIONS AND CURRENTS IN PORTS AND MARINAS
Authors: Pattiaratchi Charitha , Wijeratne Sarath
Published: February 2019

In this paper, we take the broad definition of tsunami (â€˜harbour waveâ€™) to describe oscillations in the infragravity (IG) periods (between 30 and 300s) in ports and marinas that often lead to interruption in harbour operations due to excessive vessel movements. The main processes that lead to these oscillations (also called seiches) are examined through the analysis of field measurements of water levels and currents from Western Australia. In a port or marina with lengths of the order of 500m and depths of the order of 10m, the natural oscillation periods are of the order of a few minutes. Changes in water levels in the coastal ocean adjacent to the port can setup oscillations within the port at its natural frequency. This results in water level fluctuations and strong horizontal currents within the port. If the incoming forcing is close to the natural frequency of oscillation resonance conditions may arise resulting in increased agitation inside the port. In addition if the harbour oscillation periods coincide with natural period of moored vessels, harbour operations can be severely interrupted due to strong vessel movements damaging to mooring lines and fenders.
A NOVEL HIGH-RESOLUTION STORM SURGE FORECAST FOR THE GERMAN BIGHT
Authors: NiehÃ¼ser Sebastian , Dangendorf SÃ¶nke , Arns Arne , Jensen JÃ¼rgen
Published: February 2019

Storm surges are one of the most dangerous natural hazards in coastal areas and have the ability to cause great damages including fatalities. To be prepared when another storm surge hits the coast, reliable storm surge forecasts are indispensable. Storm surge warnings are routinely provided for selected tide gauge locations along a coastline through state-of-the-art forecast systems. In Germany, the Federal Maritime and Hydrographic Agency (BSH) (in cooperation with the German Weather Service (DWD)) have the responsibility for storm surge forecasts and warnings along the German North and Baltic Sea coastlines. The operational system in place for the North Sea consists of numerical weather forecast systems, a surge model and model output statistics. It provides accurate high frequency water level forecasts up to six days ahead at selected tide gauge sites (MÃ¼ller-Navarra and KnÃ¼pfer, 2010), but not for the coastline in between. Spatial forecasts are, however, currently not available for two reasons: first, the shallow coast with complex morphological structures leads to strong non-linearities between individual sites hampering simple interpolation schemes (Arns et al. 2015). Second, tidal predictions are limited to tide gauge locations, which do not fall dry during low tide, since the traditional estimation of tidal coefficients requires complete time series covering both low and high waters.
TIDE-TSUNAMI INTERACTION IN A HIGHLY ENERGETIC CHANNEL. A CASE STUDY.
Authors: Winckler Patricio , SepÃºlveda Ignacio , Aron Felipe , Contreras-LÃ³pez Manuel
Published: February 2019

Tsunamiâ€“tide interaction can be assessed using different approaches with increasing levels of complexity. The simplest is to compute the sea level through a linear superposition of the tide and the tsunami computed independently (composite model). Recent studies have found that composite models provide inaccurate results in shallow waters (e.g. Kowalik et al, 2010). A more realistic analysis is achieved by computing the tsunami and the tide together (full model). This approach is appropriate where nonlinear effects may be important due to strong tides or shallow bathymetries. This work is intended to improve the physical understanding of tide-tsunami interaction in Canal Chacao, a highly energetic channel sited in Chile. This channel is dominated by currents of up to 6 [m/s] during spring tide and is located in a region prone to tsunamis. The fundamental question is to assess under which conditions tides and tsunamis can be linearly superposed and in which they interact nonlinearly, thus enhancing or reducing the surface elevation and associated currents.
TSUNAMI PHASE SPEED REDUCTION DUE TO WATER COMPRESSIBILTY
Authors: Abdolali Ali , Kirby James T.
Published: February 2019

Most existing tsunami propagation models consider the ocean to be an incompressible, homogenous medium. Recently, it has been shown that a number of physical features can slow the propagation speed of tsunami waves, including wave frequency dispersion, ocean bottom elasticity, water compressibility and thermal or salinity stratification. These physical effects are secondary to the leading order, shallow water or long wave behavior, but still play a quantifiable role in tsunami arrival time, especially at far distant locations. In this work, we have performed analytical and numerical investigations and have shown that consideration of those effects can actually improve the prediction of arrival time at distant stations, compared to incompressible forms of wave equations. We derive a modified Mild Slope Equation for Weakly Compressible fluid following the method proposed by Sammarco et al. (2013) and Abdolali et al. (2015) using linearized wave theory, and then describe comparable extensions to the Boussinesq model of Kirby et al. (2013). Both models account for water compressibility and compression of static water column to simulate tsunami waves. The mild slope model is formulated in plane Cartesian coordinates and is thus limited to medium propagation distances, while the Boussinesq model is formulated in spherical polar coordinates and is suitable for ocean scale simulations.
XBEACH SIMULATION OF HYBRID COASTAL PROTECTION: A GALVESTON SEAWALL TEST CASE
Authors: Muller J.R.M. , Figlus J. , De Vries S.
Published: February 2019

The City of Galveston is protected from extreme storm impact by a 17-km concrete seawall facing the Gulf of Mexico. Recent studies have shown that the seawall may not be sufficient to protect against a 100-year design storm. Since raising the seawall disconnects the city from the beach and may be very costly, a hybrid approach is explored in which the existing hard structure is fronted and covered by a layer of sand. By means of numerical simulationsï¼Œthe hydro- and morphodynamic effects of adding a sand cover to the Galveston Seawall under extreme storm conditions are further investigated. It was found that by adding a sand cover over the seawall, maximum dissipation is spread over a larger cross-shore extent. This led to the reduction of the wave height at the face of the hybrid structure, as well as the generation of more wave-induced setup. Different hybrid design configurations were simulated, which varied in sand cover dimensions. Differences in wave attenuation, wave-induced setup and required sand cover volumes are discussed. It was found that a hybrid measure shows potential in reducing wave impact during extreme storm events, thereby reducing the required elevation of the Galveston Seawall.
BORROW SITE EXCAVATION IMPACTS ON SEDIMENT TRANSPORT ALONG THE GULFSTREAM PIPELINE, PETIT BOIS PASS, ALABAMA
Authors: Kelley Sean W. , Ramsey John S.
Published: February 2019

Two borrow sites offshore of Petit Bois Pass in coastal Alabama had been identified as a source of 12.2 million cubic meters (mcm) of sand for the restoration of Ship Island (Mississippi). After preliminary design of the borrow sites, a natural gas pipeline was found to pass through the area of planned excavation. Rather than abandon the plans for the affected site altogether, it was decided to investigate the viability of modifying the original plan by leaving an undredged buffer along the path of the pipeline. A 2D sediment transport analysis was performed to estimate the magnitude of impacts to the pipeline from dredging at both borrow sites using a modified dredging plan that includes this buffer.
NUMERICAL SIMULATION OF TROPICAL CYCLONES AND STORM SURGES IN THE ARABIAN SEA
Authors: Soltanpour Mohsen , Ranji Zahra , Shibayama Tomoyo , Ghader Sarmad , Nishizaki Shinsaku
Published: February 2019

Winds, waves and storm surges of Gonu and Ashobaa, as two recent cyclones in the Arabian Sea and Gulf of Oman, are simulated by a system of WRF-FVCOM-SWAN. The employed models are separately calibrated using the available data. Surges are found to be highly dependent on coastal geometry and landfall location, rather than the storm intensity. Comparisons at different stations reveal that the results of models are in a good agreement with measured parameters. Negative surges are also observed in the enclosed basins of the Persian Gulf and Red Sea. The calibrated atmosphere-wave-ocean model can be utilized for the prediction of extreme events, expected to increase in future due to the impact of the climate change.
ANALYSIS OF LONG-CIRCUIT TYPE CAISSONS FOR ATTENUATION OF LONG-PERIOD WAVES
Authors: Gonzalez-Escriva Jose A. , Molines Jorge , Medina Josep R. , GÃ³mez-MartÃ­n M. Esther
Published: February 2019

Breakwaters provide convenient shelter for short-period waves, thus limiting the amount of energy entering the harbor. This wave energy in the port basins may be amplified, due to the wave reflection, disturbing port operations. Anti-reflective Jarlan-type (ARJ) structures (see Jarlan, 1961) have been proposed in the literature, along with other structures, to alleviate wave disturbance within port basins. ARJ anti-reflective mechanism is based on the destructive interference of waves. An anti-reflective zone width, B, must be almost a quarter of the wavelength for maximum efficiency. Longer waves easily enter the port-sheltered area where resonance phenomena could magnify its energy under certain conditions. This low-frequency energy is much more difficult to dissipate. Port resonance is the phenomenon of energy amplification that takes place in a harbor or port basin if the incident waves have frequencies close to those of the natural oscillation of the mass of water in the port basin. These infragravity long waves are frequently reported as causing trouble in cargo handling areas of many ports (see Rabinovich, 2009), even causing breakages of mooring lines and other relevant damage (see Thotagamuwage and Pattiaratchi, 2014).
DEVELOPMENT OF SAND BARS AROUND ISLANDS OFFSHORE OF KRABI IN THAILAND AND THEIR PREDICTION
Authors: Uda Takaaki , Serizawa Masumi , Miyahara Shiho
Published: February 2019

Poda and Po Da Nok Islands are located offshore of Krabi facing the Andaman Sea in the south part of Thailand. A shallow sea extends together with the development of a slender sandbar between these islands, and there is another small island named Tup Island connected by sandy beach. Sandbars can well develop in this area because of the shallow sea. The wave-sheltering effect of these islands affect to another island. On August 2016, field observation was carried out to study the formation of sandbars, and numerical simulation using the BG model was carried out to investigate the interaction of three islands.
PREDICTION OF DYNAMIC AND QUASI-STATIC IMPACTS ON VERTICAL SEA WALLS CAUSED BY AN OVERTOPPED BORE
Authors: Streicher Maximilian , Kortenhaus Andreas , Gruwez Vincent , Hofland Bas , Chen Xuexue , Hughes Steven A. , Hirt Matthias
Published: February 2019

This study comprises a detailed description of the individual overtopped bore impact processes against a vertical wall, situated on top of a dike. A twin peak force impact signal shape was observed with two distinct peaks during every impact. The two peaks were assigned consecutively to the dynamic components (thickness and velocity) or hydrostatic components (run-up of water at the wall) of the impacting bore. The two peaks were termed dynamic F1 and quasi-static F2 impact respectively. Based on available literature semi-empirical equations to describe either the dynamic F1 or quasi-static F2 impact force were investigated and the prediction accuracy evaluated using impact force data from large-scale experiments. The prediction accuracy of the dynamic F1 impacts was very low. The prediction accuracy of the quasi-static impact F2 was increased based on fitting the hydrostatic theory to the maximum run-up measurement at the wall. Based on these findings 80% of the maximum run-up height was effectively contributing to the maximum quasi-static force F2 on the wall. The results coincided well with previous small-scale studies (Chen et al. 2012). After deconstructing the process chain preceding an impact, using the physically most meaningful parameters to predict the impact force, evaluating on a range of existing approaches, and observing the scattered prediction results, it was concluded that the impact behavior is highly stochastic and statistical analysis would be more beneficial.
INTERACTION AND MERGING OF CUSPATE FORELANDS FORMED AT END OF MULTIPLE SANDY ISLANDS UNDER WAVES
Authors: Miyahara Shiho , Uda Takaaki , Serizawa Masumi
Published: February 2019

The shapes of the cuspate forelands formed at the end of multiple sandy islands were investigated, taking seven islands in Korea, Japan, and Russia as examples. When two sandy islands are located successively, the cuspate foreland formed at the end of one island deforms while being subjected to the wave-sheltering effect of the other island. In this study, the BG model (a model for predicting three-dimensional beach changes based on Bagnoldâ€™s concept) was used to predict the topographic changes when waves were incident randomly to the two islands in the downward and upward directions, and the interaction and merging of the cuspate forelands formed at the end of multiple sandy islands were investigated.
RISK REDUCTION IN LOUISIANAâ€™S COASTAL MASTER PLAN: LAKE PONTCHARTRAIN BARRIER
Authors: Leadon Mark , Atkinson John , Fischbach Jordan
Published: February 2019

The State of Louisiana (LA) Coastal Protection and Restoration Authority (CPRA) conducts extensive analytical modeling and project evaluations across an expansive coastal region along the Gulf of Mexico as part of updates to the Stateâ€™s Comprehensive Master Plan for a Sustainable Coast (CMP) on 5-year recurring intervals. The 2017 CMP includes a combination of 45 risk reduction and 79 coastal restoration projects with projected construction and implementation over a 50-year period through 2065 at a projected cost of $50 billion dollars. Risk reduction includes 13 structural and 32 non-structural projects. Structural risk reduction projects consist of continuation of new construction and maintenance of an extensive system of earthen levees, flood walls, flood gates, and pump stations. Non-structural projects consist of a combination of acquisition, elevating, and flood-proofing of residential and commercial structures within projected coastal storm flood risk areas. The Lake Pontchartrain Barrier structural risk reduction project has projected one of the highest cost-effectiveness (CE) values of all CMP projects. This paper will focus on hydrodynamic and risk reduction modeling performed to evaluate a series of conceptual design alternatives for the Lake Pontchartrain Barrier (LPB).
EXPERIMENTAL STUDY ON TSUNAMI FORCES ACTING ON VERTICAL SEAWALLS UNDER OVERFLOW
Authors: Oda Yukinobu , Honda Takahide , Omata Teppei
Published: February 2019

For tsunami seawalls installed along coastline, measures for tsunami disaster assuming overflow are required from the viewpoint of failsafe. Therefore, the tsunami force verified under overflow condition is necessary for the optimal design. Some estimation models of the tsunami forces acting on land structures have already been proposed but they were of a non-overflow condition. In this study, physical model tests for the tsunami force acting on vertical seawalls were conducted to examine the tsunami force characteristics under overflow conditions, and an estimation method of the overflowing tsunami force was proposed and verified.
EXPERIMENTS ON THE DENSITY OF TSUNAMI INUNDATION WATER AND ITS INFLUENCE ON THE TSUNAMI RUN-UP AND DEPOSIT
Authors: Matsutomi Hideo , Konno Fumiko
Published: February 2019

For the sophistication of the tsunami load, future and historical tsunami scale evaluations, the dependency of the density of tsunami inundation water with sediment on the hydraulic quantities, and then the dependencies of the tsunami run-up distance, sediment deposit distance, mean sediment deposit thickness on the density of the tsunami inundation water are examined through a devised small-scale hydraulic experiment. Within the experimental range of this study, it is verified that the density of the tsunami inundation water depends on the Froude number of the incident tsunami inundation flow and the sediment grain size, and the relative tsunami run-up distance (= the run-up distance of the inundation water with sediment/the run-up distance of the inundation water without sediment (= fresh water)), ratio of the tsunami sediment deposit distance to the tsunami run-up distance, ratio of the mean tsunami sediment deposit thickness to the tsunami sediment deposit distance depend on the density of the tsunami inundation water, and four empirical expressions for those dependencies are proposed.
EXTREME METEO-OCEANIC EVENTS
Authors: Mazas Franck , Hamm Luc
Published: February 2019

The two-step framework for over-threshold modelling of environmental extremes proposed in Bernardara et al. (2014) for univariate analyses is generalized to an event-based framework applicable to multivariate analyses. The distinction between sequential values (temporal observations at a given time step) and the event-describing values (such as storm peaks in univariate POT extrapolations) is further detailed and justified. The classification of multivariate analyses introduced in Mazas and Hamm (2017) is refined and linked to the meaning of the concepts of event, sampling and return period that is thoroughly examined; their entanglement being highlighted. In particular, sampling is shown to be equivalent to event definition, identification and description. Event and return period definition are also discussed with respect to the source phenomena or to response (or structure) phenomena. The extreme event approach is thus proposed as a comprehensive framework for univariate and multivariate analyses for assessing natural hazards, seemingly applicable to any field of environmental studies.
WAVE IMPACTS AT SMALL AND REAL SCALE FOR THE STEPPED SLOPED SEAWALL DESIGN AT DEN OEVER
Authors: Steendam Gosse Jan , Van der Meer Jentsje , Van Steeg Paul , Joosten Ruud
Published: February 2019

The dike in Den Oever has to be improved. To keep the dike as low as possible and to make it suitable for other uses, the choice was made to install a stepped revetment on the sea side. In order to determine the design wave loading, scale model tests and tests at full scale were performed. The comparison shows that loads, as a result of model and scale effects and by averaging the sensor signals, could be decreased by a factor 4 relative to the scale model tests.
ADAPTATION PATHWAY FOR A BARRIER ISLAND TO FUTURE HURRICANES
Authors: Smallegan Stephanie , Mazur Evan
Published: February 2019

The numerical model XBeach is used to simulate hydrodynamics and morphological change of Bay Head, NJ, which is located on a developed barrier island. Bay Head is fronted with a seawall buried beneath its dunes, and the seawall has been shown to mitigate damage due to storm surge and waves during Hurricane Sandy (2012). The objective of this study is to re-evaluate the effectiveness of the seawall in mitigating damage from a synthetic storm and sea level rise, and refine an adaptation pathway previously created for Bay Head. Utilizing the wave and surge data generated from the North Atlantic Coast Comprehensive Study, synthetic Storm 391 is simulated using XBeach. Model results show the seawall is overtopped by storm surge and waves, causing overwash and reducing dune heights. As sea levels rise, the backbarrier region of the barrier island is severely eroded and the seawall acts as a barrier preventing elevated bay water levels from freely flowing across the island and into the ocean, exacerbating sediment transport on the backbarrier. To fully evaluate the capabilities and limitations of the seawall in mitigating storm damage, additional synthetic storms need to be simulated and the results re-evaluated. This will, in turn, lead to a comprehensive, more robust adaptation pathway for Bay Head.
A HIGH-ORDER SPECTRAL ELEMENT UNIFIED BOUSSINESQ MODEL FOR FLOATING POINT ABSORBERS
Authors: Bosi Umberto , Engsig-Karup Allan Peter , Eskilsson Claes , Ricchiuto Mario , Solai Elie
Published: February 2019

Nonlinear wave-body problems are important in renewable energy, especially in case of wave energy converters operating in the near-shore region. In this paper we simulate nonlinear interaction between waves and truncated bodies using an efficient spectral/hp element depth-integrated unified Boussinesq model. The unified Boussinesq model treats also the fluid below the body in a depth-integrated approach. We illustrate the versatility of the model by predicting the reflection and transmission of solitary waves passing truncated bodies. We also use the model to simulate the motion of a latched heaving box. In both cases the unified Boussinesq model show acceptable agreement with CFD results â€“ if applied within the underlying assumptions of dispersion and nonlinearity â€“ but with a significant reduction in computational effort.
DESIGN AND PHYSICAL MODEL STUDIES OF INNOVATIVE LIVING BREAKWATERS
Authors: Baker Scott , Brashear Pippa , Tschirky Paul , Marrone Joseph , Larson Max
Published: February 2019

This paper describes two separate but closely related physical models conducted to support the detailed design of the Living Breakwaters project located in Raritan Bay, New York. One study focused on optimizing and verifying the breakwater design elements to ensure they were well adapted to typical and extreme conditions, while the second study focused on verifying the overall performance of multiple living breakwaters in terms of wave attenuation and impacts on nearshore wave-induced circulation. These investigations generated a large quantity of valuable information concerning the design and performance of the breakwaters that will be used to optimize and support the final design and obtain the necessary permits required for construction.
A MODEL IN FREQUENCY DOMAIN FOR TRANSFORMATION OF FULLY DISPERSIVE NONLINEAR WAVES
Authors: Ardani Samira , Kaihatu James M.
Published: February 2019

In this study, mathematical derivation and numerical verification of a wave transformation model in frequency domain is discussed. This wave model is fully dispersive and nonlinear; and is derived based on the WKB assumptions. Transforming the problem into the frequency domain and using multiple scale analysis in space and perturbation theory, the model is expanded up to second order in wave steepness. This fully dispersive nonlinear wave model is a set of evolution equations which explicitly contains quadratic near-resonant interactions. The comparison between the presented model, the existing fully dispersive model and a nearshore model with different set of laboratory and field data shows that the presented model provides significant improvements particularly at higher frequencies.
PHYSICAL MODEL TESTS OF WAVE OVERTOPPING AND FORCES ON BREAKWATER CROWN WALLS
Authors: Franco Leopoldo , Bellotti Giorgio , Cecioni Claudia
Published: February 2019

This paper describes new physical model tests aiming at measuring both wave overtopping and wave induced forces on rubble mound breakwater crown walls. The physical model and the equipment used for the measurements are described in detail. For the completed tests, a detailed analysis is reported, by evaluating the properties of the incoming waves at the toe of the breakwater and some statistical parameters to describe the wave induced forces and pressures on the crown wall. Careful analysis is also carried out to evaluate how the distribution of the pressures changes with time. It is found that the upper part of the wall is subjected to the first large quasi-impulsive action of the wave; the lower part of the wall is afterwards flooded and a quasi-hydrostatic pressure develops along the height of the wave wall. As far as the pressures on the base of the crown wall are concerned, they develop after a quite large time lag after the maximum of the horizontal force. First attempts to correlate the maximum horizontal force with some explanatory variables such as the ratio of the crest freeboard and of the significant wave height of the incoming waves indicate a promising correlation, also in agreement with the existing literature on the topic. The overtopping rate are also measured and compared with empirical formulas. The correlation between the wave induced forces and the average overtopping discharge on the breakwater is also investigated.
A NUMERICAL CALCULATION FOR INTERNAL WAVES OVER TOPOGRAPHY
Authors: Kakinuma Taro , Ochi Naoto , Yamashita Kei , Nakayama Keisuke
Published: February 2019

The internal waves propagating from the deep to shallow, and the shallow to deep, areas in the two-layer fluid systems, have been numerically simulated by solving the set of nonlinear equations, based on the variational principle in consideration of both the strong nonlinearity and strong dispersion of internal waves. The incident wave in the deep area, is the BO-type downward convex internal wave, which is the numerical solution obtained for the present fundamental equations. In the cases where the interface elevation is below, or equal to, the critical level in the shallow area, the disintegration of the internal waves occurs remarkably, leading to a long wave train. The lowest elevation of the interface, increases after its gradual decrease in the shallow area, where the interface is above the critical level, while the lowest elevation of the interface, increases through the internal-wave propagation in the shallow area, where the interface elevation is below, or equal to, the critical level, after its steep decrease around the boundary between the area over the upslope, and the shallow region.
2D OVERTOPPING AND IMPACT EXPERIMENTS IN SHALLOW FORESHORE CONDITIONS
Authors: Gruwez Vincent , Vandebeek Ine , Kisacik Dogan , Streicher Maximilian , Altomare Corrado , Suzuki Tomohiro , Verwaest Toon , Kortenhaus Andreas , Troch Peter
Published: February 2019

This paper introduces the 2D experiments conducted for the CREST project in the wave flume of Ghent University. The experiments focus on wave interactions with low-crested sea dikes fronted by a shallow foreshore and mildly to steeply sloping beaches, which is a very typical situation along the Belgian coast. Foreshore slopes of 1/20, 1/35, 1/50 and 1/80 were tested for a range of low to high energy wave conditions, a variation in wave steepness and two water levels. The main goal was to obtain a dataset in which the effects of the infragravity waves on the wave-structure interactions (i.e. wave overtopping and impact forces) can be studied. The tests included high spatial resolution surface elevation measurement tests, which is new for beaches including a dike in the inner surf zone. From the first results it became clear that the foreshore slope influences the wave transformation up to the dike toe. The influence is apparent comparing to existing (semi-) empirical models for prediction of the spectral wave period at the dike toe and wave overtopping at the dike crest. The high spatial resolution data show a steep increase in infragravity significant wave height in the very shallow area in front of the dike.
ANALYSIS OF WAVE RUN UP DYNAMICS AT JOGEHAMA BEACH JAPAN
Authors: Inukai Naoyuki , Shinohara Masaya , Ochiai Tokimitsu , Yamamoto Hiroshi
Published: February 2019

The big wave suddenly arrived at the beach, Niigata prefecture Japan in May 2014. And three children were carried off to the sea by the wave, though they played on the beach. When the accident occurred, the significant wave heights was 1.2m, and the wave period was 7.9 seconds. The beach characteristic topography has the cusp topography and steep slope. We tried to understand the reason why this accident occurred. Firstly, we reproduced the wave condition when the accident occurred. Secondary, we made the survey to understand the geographic feature of the beach. After the survey, we obtained the geographic data for the numerical simulation from the aerial photograph which were taken by UAV (Unmanned aerial vehicle). Finally, we comprehended the wave dynamics on the beach by the numerical simulation. We simulated the wave dynamics by the horizontal two dimensional numerical model and the vertical two dimensional numerical model.
MODELING WAVE ATTENUATION DUE TO SALTMARSH VEGETATION USING A MODIFIED SWAN MODEL
Authors: Christie Elizabeth , MÃ¶ller Iris , Spencer Tom , Yates Marissa
Published: February 2019

Vegetated shorelines have been increasingly recognized for their contribution to natural coastal protection due to their ability to dissipate wave energy. Within the UK, salt marshes are beginning to be included in flood defence schemes. Predicting wave dissipation over vegetation requires accurate representation of salt marsh canopies and the feedback relationship between vegetation and wave conditions. We present a modification to the SWAN vegetation model, which includes a variable drag coefficient and a spatially varying vegetation height. Its application is demonstrated by modelling wave propagation over UK salt marshes. The third generation wave model, SWAN includes a vegetation module for calculation of wave attenuation over vegetation. Wave dissipation is determined based on the vegetation properties and a drag coefficient. This drag coefficient, C_D, is used to calibrate the model, and a fixed value is used per model run. Empirically the drag coefficient has been found to vary with ambient wave conditions. Typically the drag coefficients are defined empirically as a function of either the stem Reynolds number, Rev, or the Keulegan-Carpenter number, KC. The parameter values have been shown to vary with vegetation type. In this paper, we modify the SWAN vegetation module to include a temporally varying CD. This allows the drag coefficient to vary with ambient wave parameters, which gives an improved prediction under time varying wave conditions (e.g. passage of a storm) and includes the change in wave conditions as they travel through the vegetation. We also incorporate spatially varying vegetation height into the model to further improve the representation of the complexity of vegetated shorelines. Using the new formulation we find improved prediction of wave dissipation over both idealized laboratory and field salt marsh vegetation.
MORPHODYNAMIC MODEL TO SIMULATE SHORELINE EVOLUTION AT ANY COASTAL MOUND
Authors: Tomasicchio Giuseppe R. , Francone Antonio , D'Alessandro Felice , MedellÃ­n Gabriela , Torres-Freyermuth Alec , Barbaro Giuseppe , Frega Ferdinando
Published: February 2019

The work presents the results of a field and numerical study aimed to investigate the resistance and resilience, associated to an artificial shoreline perturbation, on a sandy beach. A temporary groin was deployed on a micro-tidal sea-breeze dominated beach to induce a shoreline perturbation. Wave conditions during the field experiment were highly correlated with sea breeze wind events, inducing a persistent alongshore sediment transport. A new one-line numerical model of beach evolution was calibrated and verified with the field surveys, reproducing both the sediment impoundment and subsequent beach recovery after the groin removal. Thus, the numerical model was able to simulate the mechanisms controlling the growth and decay caused by an artificial perturbation.
REVIEW OF ICE CHALLENGES AND ICE MANAGEMENT IN PORT AREAS
Authors: Ruiz de AlmirÃ³n de Andrés Cayetana , Saarinen Sami , Uuskallio Arto
Published: February 2019

Winter navigation in harbors located in arctic areas becomes very challenging due to cold weather, ice drift, brash ice growth, ice collar formation in wharves and icing of structures and equipment. The loading frequency and nature of the cargo vessel traffic is affecting in the ice management needs in the harbour. There are no standard solutions for ice management in harbor areas and each location must be locally studied simultaneously with the port design identifying the associated ice challenges. This work brings together the challenges related to winter navigation in ice-covered waters and ice management methods currently used in Arctic harbors.
RESPONSE OF OREGON INLET TO PEA ISLAND BREACHING
Authors: Velasquez-Montoya Liliana , Sciaudone Elizabeth J. , Overton Margery F.
Published: February 2019

This study aims to assess the effects of a new inlet on the hydrodynamics of a semi-permanent tidal inlet and the back-barrier sound. Research on dual-inlet interactions is motivated by the increased vulnerability of barrier islands to breaching during hurricanes, phenomenon that can have important consequences on the hydrodynamics and morphology of a barrier island system with pre-existing inlets. This particular study takes place in the northern Outer Banks of North Carolina, where Oregon Inlet is the main inlet connecting the Atlantic Ocean with the Albemarle-Pamlico Sound. During Hurricane Irene in 2011, Pea Island â€“ the island south of Oregon Inlet â€“ was breached creating a new inlet that remained open until 2013. Dual-inlet interactions between Oregon Inlet and the new inlet in Pea Island are analyzed by means of numerical modeling experiments. Changes in flow velocities, water levels, and the tidal prism of Oregon Inlet due to the new inlet are computed for different wave and water level conditions. In addition to the actual inlet that opened in 2011, the effects of idealized inlets with different geometries and location are also included in this study. Results indicate that the original breach in Pea Island did not modify the dynamics of Oregon Inlet. Instead, its effects were restricted to a 5 km radius that extended mostly into the sound. The relative small size of the breach and its distance from Oregon Inlet are the two main factors that prevented dual-inlet interaction. Exploration of idealized breaching scenarios in Pea Island suggests that inlet spacing and breaching geometry play a major role in multiple inlet stability theory.
AEOLIAN SEDIMENT TRANSPORT AT A MAN-MADE DUNE SYSTEM; BUILDING WITH NATURE AT THE HONDSBOSSCHE DUNES
Authors: Wittebrood Marloes , De Vries Sierd , Goessen Petra , Aarninkhof Stefan
Published: February 2019

This paper presents the influence of aeolian sediment transport on the initial morphological evolution of beach and dunes at the man-made dune system â€˜Hondsbossche Dunesâ€™ at the Dutch coast. In total 35 million m^3 dredged material was used for the construction of a beach, dune and foreshore system. This study focused on differences in morphological response within the five different realized dune profile types. A conceptual framework was developed, based on the assessment of (1) environmental forcing, (2) sediment supply from aeolian and marine sources and (3) dune types. These three components were quantified from an analysis of measured profile evolution and the application of an aeolian sediment transport model for the first 19 months since the project delivery date in May 2015. Morphological changes were most pronounced in the first seven months after construction. Dune growth of a profile type at this location is determined by a temporal and alongshore variability in local processes that determines the aeolian sediment supply towards the dunes and the dune geometry that determines the capacity of the profile type to capture the sediments. The model simulations managed to qualitatively reproduce alongshore variations in dune growth as a result of spatial variations in sediment availability, grain size, profile shape and interaction with vegetation. Overall, this study shows the relevance of both marine and aeolian processes in such man-made dynamic systems that are comparable to natural systems. Continuing the monitoring and modelling of this system will improve the quantitative knowledge for design optimization of the Building with Nature philosophy.
SHEAR STRESS MEASUREMENTS AT THE SEA BOTTOM BY MEANS OF FERROFLUIDS
Authors: Viviano Antonino , Stancanelli Laura M. , Musumeci Rosaria E. , Foti Enrico
Published: February 2019

An innovative measurement technique is proposed for investigating shear stress at sandy bottoms. This technique is based on the adoption of a ferrofluidic sensor and of an optical readout strategy. An experimental campaign is carried out for evaluating its performance. Experiments differ for the ferrofluidic sensor configuration (difference in the magnetic field) and for the bottom configurations (fixed bed or sandy bed). Calibration of the ferrofluidic sensor for the range of the investigated hydraulic condition and of the controlling magnetic field is presented. The ferrofluidic technique is promising when applied at sandy bottoms, as neither adhesion processes between sand grains and ferrofluid or influence of impacts of grains on the measurement are observed. In particular, the preliminary measure performed indicated that the ferrofluidic sensor is capable of sensing the different bed roughness.
A LATTICE BOLTZMANN APPROACH FOR THREE-DIMENSIONAL TSUNAMI SIMULATION BASED ON THE PLIC-VOF METHOD
Authors: Sato Kenta , Koshimura Shunichi
Published: February 2019

Free surface flow problems occur in numerous disaster simulations, such as tsunamis inland penetration in urban area. Simulation models for these problems have to be non-hydrostatic and three-dimensional because of the strong non-linearity and higher-order physical phenomena. Despite all the progress in the modern computational fluid dynamics, such simulations still present formidable challenges both from numerical and computational cost point of view. The lattice Boltzmann method (LBM) has been attracting attention as an alternative fluid simulation tool to overcome the problems. In current study, LBM for three-dimensional tsunami simulations is developed which are coupled with the piecewise linear interface calculation with the Volume of Fluid (VOF) approach. This model is for an efficient three-dimensional tsunami simulation by a one-fluid formulation, where the lattice Boltzmann equation is assigned to solve for a single virtual fluid. Various benchmark problems are also carried out to validate the utility of the proposed models in term of coastal engineering.
BARRIER ISLAND GROUNDWATER
Authors: Housego Rachel , Raubenheimer Britt , Elgar Steve , Gorrell Levi , Wadman Heidi , McNinch Jesse , Brodie Kate
Published: February 2019

Storms can have long-term impacts on the groundwater flows and subsurface salinity structure in coastal aquifers. Previous studies have shown that tides, wave driven infiltration, and storm surge elevate the groundwater level within the beach (Nielsen 1999, Cartwright 2004). The resulting bulge of high groundwater propagates inland, and may cause flooding up to several days after a storm has passed (Gallien 2016). In addition, waves, tides, and storm surge force saltwater to infiltrate into the aquifer above the fresher terrestrial groundwater, and storm-driven pulses of salinity may persist for months (Robinson et al. 2014). Here, observations of groundwater heads and salinities collected continuously for three years are used to examine the effects of ocean storms, wind-driven fluctuations in sound water levels, and morphological changes on a barrier island aquifer.
AN INTEGRATED AND INTERACTIVE TOOLBOX FOR THE DESIGN OF COASTAL INFRASTRUCTURE
Authors: Scheel Freek , De Boer Wiebe , Luijendijk Arjen , Stive Ronald , Bouw Ruud
Published: February 2019

Coastal engineering design studies often rely on detailed numerical models that involve various mono-disciplinary physical processes, complex numerics and large computational demands. As a consequence, these models are particularly useful to address specific questions that arise during project phases focusing on detailed design. In contrast, during early project phases focusing on project feasibility, proof-of-concept and preliminary engineering efforts, these detailed numerical models suffer from their aforementioned characteristics. Now, aspects such as interactivity, flexibility and multi-disciplinary assessment are of importance. Simple yet fast tools and empirical relations offer a lot of potential to fill this gap, but are typically not as systematically developed as detailed numerical models. This results in a deficit in consistent integration of disciplines, robustness, interactivity and potential flexibility.