bluuebunny/crossref_metadata_2025 huggingface dataset:
WAVE STATISTICS AND SPECTRAL MONITORING IN THE MEDITERRANEAN SEA (i.e. SICILY CHANNEL): 9 YEARS OF WAVE DATA MONITORING
Authors: Terrile Emanuele , De Filippi Gianluigi , Spadaccini Ostilio
Published: December 2012

The main aim of the work if to define and characterized the wave filed in the intermediate water depth of the mediterranean Sea, in particular in the Sicily channel.

Even if is not the appropriate wave spectrum, the jONSWAP spectrum is often used in the Mediterranean Sea as input for the most common third-generation spectral wave models, e.g. SWAN (Booij et al. 1996). The definition of site-specific spectral parameters by means of measured wave data allows to get a better assessment of the wave field in the coastal area with consequent better description of the wave characteristics to be used to design coastal structures.
HOW TO WEIGH COASTAL HAZARD AGAINST ECONOMIC CONSEQUENCE
Authors: Wainwright David , Callaghan David , Jongejan Ruben , Ranasinghe Roshanka , Cowell Peter
Published: December 2012

It is well recognised that sea level change over the coming century will have an extraordinary economic impact on coastal communities. To overcome the uncertainty that still surrounds the mechanics of shoreline recession and stochastic forcing, landuse

planning and management decisions will require a robust and quantitative risk-based approach. A new approach is presented, which has been evaluated using field measurements and assessed in economic terms. The paper discusses a framework for coastal risk analysis which combines four main components 1) the effects of non-stationary

climate, including decade scale variability and anthropogenic change; 2) a full probabilistic assessment of incident wave and surge conditions; 3) determination of storm erosion extents; and 4) the economic impact of combined coastal erosion and

recession. The framework is illustrated in Figure 1. The operation of this framework has been demonstrated, building upon previous work (Callaghan et al., 2008; Jongejan et al., 2011; Ranasinghe et al., 2011). The first three components relate to physical hazards. Using stochastic simulation, we quantify the 'likelihood' side of risk.

That likelihood is typically represented by lines indicating a projected extreme landward shoreline condition and an associated quantitative probability. For the first time, the effects of non-stationary climate (e.g. sea level rise) have been included. This

can be extended to include decadal scale climate variation effects such as beach rotation.

The fourth component requires the determination of values associated with land threatened by coastal erosion during the time frame being considered. We assign a spatially varying value density relationship. The exceedance probability of erosion is

combined with the value density to calculate the expected value of damage at a given point in time. In a non-stationary climate scenario, the exceedance probabilities change with time, and this is also considered. Given a known rate of return on investment, the differentials in the rates of return (between coastal and inland property

investments) are subsequently used to determine the efficient position of the setback line. The results are presented within a GIS framework to effectively feed into the coastal land use planning process. We demonstrate the framework by applying it to

using real data (both physical and economic) for our subject site, Narrabeen Beach in Sydney.
REDUCING SILTATION IN THE JUIST MARINA - IDENTIFICATION OF SEDIMENT TRANSPORT MECHANISMS BY IN SITU MEASUREMENTS AND NUMERICAL MODELLING
Authors: Saalbach Jan , Zorndt Anna C. , Kraemer Knut , Schlurmann Torsten
Published: December 2012

Siltation of the municipal port and marina of the East Frisian island of Juist is investigated by in-situ measurements and hydro-numeric modelling. The combined results can be used to evaluate constructional measures aimed at alleviating siltation effects. Furthermore the collected in-situ measurement data are utilized in the numerical validation process. An alternative port design is evaluated based on results obtained with the hydro-numeric model.
A MULTIPLE-SIZED TRANSPORT FORMULA FOR NONUNIFORM SEDIMENTS UNDER CURRENT AND WAVES
Authors: Wu Weiming , Lin Qianru
Published: December 2012

Nonuniform sediment transport exhibits difference from uniform sediment, even when the mean grain size is the same for both cases. The hiding, exposure, and armoring among different size fractions in the nonuniform bed material may significantly affect sediment transport, morphological change, bed roughness, wave dissipation, etc. It is necessary to develop multiple-sized sediment transport capacity formula to improve the accuracy and reliability of coastal analysis tools. The Wu et al. (2000) formula, which was developed for river sedimentation, is herein extended to calculate multiple-sized sediment transport under current and waves for coastal applications. This formula relates bed-load transport to the grain shear stress and suspended-load transport to the energy of the flow system. It considers the effect of bed material size composition in the hiding and exposure correction factor, which is omitted in many other existing formulas. Methods have been developed in this study to determine the bed shear stress due to waves only and combined current and waves, and in turn to compute the bed-load and suspended-load transport rates using the Wu et al. (2000) formula without changing its original formulation. The enhanced bed-load formula considers the effect of wave asymmetry on sediment transport, calculates the onshore and offshore bed-load transport rates separately and then derives the net transport rate, whereas the enhanced suspended-load formula calculates only the net transport rate due to the limit of available data. The formula has been tested using the single-sized and multiple-sized sediment transport data sets. The formula provides reliable predictions in both fractional and total transport rates. More than half of the test cases are predicted within a factor of 2 of the measured values, and more than 90% of the cases are within a factor of 5. This accuracy is generally reasonable for sediment transport under current and waves, which is very complex and little understood.
ALTERATION IN SALINITY IN THE WESER ESTUARY AFTER 1998: QUANTIFICATION BY ARTIFICIAL NEURAL NETWORKS
Authors: Berkenbrink Cordula , Niemeyer Hanz
Published: December 2012

In Germany major harbours are located in the river estu-aries. Because of the growth of container ships and the corresponding draft of these ships, the depth of the chan-nels in the estuaries had to be increased several times. This results in consequences for nature and agriculture. One of these effects might be that the brackish water zone is moving upstream and the surrounding farmers can't provide fresh water to their animals or plants any more. The study presented on the poster will show the effects on salinity in the Weser estuary after the channel deepening in 1998-2000 by using artificial neural networks.
DRAG COEFFICIENT OF VEGETATION IN FLOW MODELING
Authors: Hu Zhan , Stive M. , Zitman T. , Suzuki T.
Published: December 2012

Flow through vegetation has a significant impact on sediment transport and ecosystem robustness in the coastal and fluvial environment. Numerical models (Nepf and Vivoni, 2000; Uittenbogaaard, 2003) have been developed to simulate this type of flow. The success of these models depends on proper characterization of the main processes and appropriate setting of pre-defined empirical coefficients. Among others, the drag coefficient CD is one of the most important coefficients, which influences the mean velocity and the turbulence characteristics (Nepf and Ghisalberti, 2008).
Tanino and Nepf (2008) and Cheng (2011) have derived empirical relationships of CD for flow through emerged rigid vegetation. Both studies confirm that CD is related to canopy properties (plants density, diameter, etc.) as well as flow conditions. However, in both studies CD is estimated by simply equating the vegetation drag force to the water level gradient. Bed shear stress and Reynolds stress were ignored. More importantly, the CD provided by these expressions is depth averaged, which is not suitable for modelling flow and canopy that both vary in vertical (Nepf and Vivoni, 2000). In this study, the CD relation proposed by Cheng (2011) is modified. This new relation depends on the local flow conditions and canopy properties in the vertical. Further, this relation is implemented in an iterative scheme of a 1DV flow model. The modelling results are compared with experiment data of flow through emerged and submerged rigid vegetation. Our results show that when special defined Reynolds number is small, this relation performs less well compare to that when it is larger.
COASTAL ADAPTATION IN THE DEVELOPING WORLD: A CASE STUDY IN DURBAN SOUTH AFRICA
Authors: Geldenhuys Marli , Van Ledden Mathijs , Jonkman Bas , Stive Marcel , Ranasinghe Rosh
Published: December 2012

Much of the world´s population is living along the coast. Along with rising sea levels and an increase in storminess this poses a global problem. Nicholls et al (2008) estimated that forty million people worldwide are potentially exposed in a 1 in 100 year storm event. Very little research regarding coastal adaptation in Africa has been done. Durban, with a population of approximately 3.5 million, is situated on the East Coast of South Africa. The city experienced an extreme storm event in March 2007; which caused significant coastal erosion, damage to the coastline and large financial losses (Phelp et al, 2008). A 500 metre section of the central beaches area of Durban, adjoining the city centre, was selected as the case study area for this study. This coastal section contains valuable infrastructure such as the Addington District Hospital.
DETECTION OF SHIP PATHS ON DOCKING AND QUAY OCCUPATION ANALYSIS BASED ON A VIDEO-IMAGERY SYSTEM AS SUPPORT TO PORT MANAGEMENT
Authors: Gomez Rebeca , Molina Rafael , Camarero Alberto , De los Santos Francisco
Published: December 2012

To manage a quay it is necessary to know the level of activity that is being developed on it. This is an imperative parameter for determining the trend of terminal capacity. This allows, among other things, to improve investments previsions, a better ship waiting time management and to select what kind of ship must operate in the terminal. In Spain, Port Authorities have to apply activity fares to ships and terminal operators, based on their activity level and occupation data. In many cases there are not automated protocols to control this information, or it is directly provided by the operator. From a probabilistic focus of the problem, R.O.M. 0.0. (2001) pointed out the necessity to assume a risk in the development of port activities. This work goes toward this goal by obtaining the areas where a greater density of activity is taking place on a dock. This information allows us to establish a probability map and then, determining a risk. To this end, ship trajectories must be monitored. The trajectories condition the availability of maneuver areas on the dock, the existence of interferences between different kind of ships and they provide fundamental information for the design of mooring systems (fenders, for instance). As a product of knowing ship trajectories we can obtain ship speed and approximation angle (both are data very dependent of each quay geometry and location) and other ship parameters. The aim of this work has been to develop a video - monitoring system of port activities (Molina, R. et al. (2007)), that provides us quay use statistics and areas with greater probability of occupation (for instance, the probability of interaction between big cargo ships and leisure crafts or fishing boats). It is a real time information acquisition system, automated, low cost and able to cover extent areas. Because Port Authorities have disposal of communication infrastructures to serve security and access control, we propose to give them an additional use.
OPEN BOUNDARY CONDITIONS FOR FORCED WIND WAVES IN A COUPLED MODEL OF TIDE, SURGE AND WAVE
Authors: Kim Sooyoul , Matsumi Y. , Yasuda T. , Mase H.
Published: December 2012

When modelling wind-driven long waves combined with tides, wind waves and surges under storm events in limited computational areas, values at open boundaries are the tidal current, the tidal water level, the wind and pressure-induced water level and current. These can be obtained from the extrapolation or the interpolation from large-scale models or observations. At the open boundary, the tide-induced water level and current are usually estimated by the astronomical tidal components. The combined wind and pressure-induced water level at the open boundary has been computed by barotropic law. However, the combined wind and pressure-induced current is ignored in most cases of modelling the wind- driven long wave combined with the tide, the wind wave and the surge. In the study, the method is proposed to estimate the combined wind and pressure-induced current at the open boundary and is described for the performance in the simple case and the real case in comparison with the Orlanski scheme modified by Miller and Thorpe (OSMT) and the passive form of the Flather's condition (FLA).
COASTAL EROSION MANAGEMENT AT YUCATAN, MEXICO: ENGINEERING EFFORTS AND EXPERIENCES
Authors: Gonzalez Leija Mariana Berenice , Alvarez del Rio Enrique
Published: December 2012

The coast of Yucatan, located in the Gulf of Mexico, is a fragile island barrier system where beach erosion has turned into a problem since the last 25 years. This, in combination with hurricane strikes (Gilbert (1988), Isidore (2002)), led to environmental damages along about 300 km, in 60 km of which, the coastal infra-structure is at risk; fact that decreased the coastal development. Mitigate the erosion required emergency protection works mainly made by beach property owners. The lack of planning and engineering design resulted in areas with high ero-sion rates and the destruction of neighboring beaches and properties.
Among the most important causes that enhanced erosion phenomena along Yucatan are: construction of Progreso pier affecting littoral drift causing ero-sion at the west side beaches, shore normal rock-timber and sand-bags groins constructed empirically by property owners accelerating erosion and stimu-lating even more groin construction, during 90´s groin construction shifted to the east (up-drift) of Progreso Port, and in the last 25 years urban, touristic and fisher industries growth in the region, force the construction of jetties for small harbours along the coast. Axis Ingeniería, and academic research institutions, in conjunction with federal and state authorities the promotion of programs for beach rehabilitation consisting on groins removal and the use of soft solutions (i.e. structures based on geosynthetics for shore protection). The Progreso Beach 7 km nourishment has been one of the most successful efforts resulting in the the development of a stable beach for about 10 years, even without maintenance works. Based on local knowledge obtained with the use of measures that have disregarded the equilibrium of sediment transport processes; Axis Ingenieria used these experiences in combination with technical, environmental legal requirements, capabilities of the local community and socioeconomic tools to implement soft and easily removal structures using geotextile tubes along the coast, that had resulted on positive experiences for beach/dune protection and recovery (i.e. Progreso to Chicxulub , Telchac and Las Coloradas beaches , Yucatan). This poster resumes the experiences from projects dealing with coastal erosion issues that AXIS Ingenieria has conducted being the goal the development and implementation of a Yucatan beach manage-ment program.
WHEN DO WAVES BECOME TURBULENT?
Authors: Beya Jose Francisco , Peirson William , Banner Michael
Published: December 2012

Babanin and Haus (2009) recently presented evidence of high levels of turbulence induced by steep non-breaking waves. They proposed a Reynolds-like threshold wave parameter (a2Ï‰/Î½=3000, a wave amplitude, Ï‰ wave angular frequency, Î½ water viscosity) for the spontaneous occurrence of turbulence beneath surface waves. This contradicts the common assumed basis of existing irrotational wave theories and their classical experimental validation. Many laboratory wave experiments were carried out in the early 1960's (e.g. Wiegel, 1964). In those experiments no evidence of turbulence was reported and steep waves behaved as predicted by the high order irrotational wave theories within the accuracy of the theories and experimental techniques at the time. The spontaneous generation of turbulence under waves can have serious consequences for wave modelling, where the irrotational flow assumption has secured its place in engineering design. This contribution describes unique flow visualisation experiments for large scale steep non-breaking waves using conventional dye techniques in the wave boundary layer extending above the wave trough level. The measurements showed no evidence of turbulent mixing for waves up to a2Ï‰/Î½=7000. There is presently no evidence that water waves become spontaneously turbulent (up a2Ï‰/Î½=7000) except within the bed boundary layers, under wind forcing or at breaking. Excellent agreement was found with higher order irrotational theories. Orbital velocities, Stokes drift and Stokes coefficients were measured and compared with theoretical values, suggesting that conventional theories underestimate unforced monochromatic wave non-linearity, although the corrections remain small.
COMPREHENSIVE STUDY OF SWASH-ZONE HYDRODYNAMICS AND SEDIMENT TRANSPORT
Authors: Puleo Jack , Blenkinsopp Chris , Conley Daniel , Masselink Gerd , Russell Paul , Turner Ian , Buscombe Daniel , Lanckriet Thijs , McCall Robert , Poate Timothy
Published: December 2012

A comprehensive study of swash-zone sediment transport was conducted on a macro-tidal beach in Perranporth, UK. The unique study is the first to simultaneously measure suspended sediment and sheet flow sediment concentrations and near bed velocity on a natural beach. Data collected during the study will be used to address the importance of sheet flow processes on swash zone sediment transport and morphology, the variability in the near bed velocity profile and the importance of alongshore and vertical flows, cross-shore advection of turbulence and the inference of swash zone forcing and momentum transfer from remotely sensed data.
THREE-DIMENSIONAL MORPHODYNAMIC MODEL TO SANDY BEACH WITH NON-ERODED HARD BOTTOM
Authors: Hasegawa Yukihiko , Kuroiwa Masamitsu , Matsubara Yuhei , Icimura Yasushi , Nagaishi Yoshiyuki
Published: December 2012

The objective of study is to develop a coastal area model for sandy beach with shore reef such as non-eroded hard bottom. The morphodynamics with exposure and bury of the shore reef are reproduced by advection and diffusion model for suspended sediment concentration. Firstly, model tests associated with sandy beaches with a detached breakwater and groins were carried out in order to investigate the performance of the presented model. Secondly, the presented model was applied to a filed site with both shore reef and sandy beach, the applicability of the model was investigated and discussed.
iCOASST - INTEGRATING COASTAL SEDIMENT SYSTEMS
Authors: Nicholls Robert J. , Bradbury Andy , Burningham Helene , Dix Justin , Ellis Michael , French Jon , Hall Jim W. , Karunarathna Harshinie U. , Lawn Jonathan , Pan Shunqi , Reeve Dominic E. , Rogers Benedict , Souza Alejandro , Stansby Peter K. , Sutherland James , Tarrant Owen , Walkden Michael , Whitehouse Richard
Published: December 2012

UK coasts are subject to widespread erosion in part due to the cumulative effect of human intervention on soft coastlines, and further threatened due to more rapid change due to climate change, especially sea-level rise. At the same time, Shoreline Management now requires predictions of coastal evolution up to 100 years in the future. This leads to the challenge of predicting coastal geomorphic behaviour at the mesoscale (10 to 100 km and 10 to 100 years). Currently, this is often based on expert judgement. However, relevant components for mesoscale coastal simulation are emerging, including: (1) new methods for system-level analysis of coast, estuary and offshore landform behaviour, which include engineering and management interventions in a consistent manner to natural drivers; (2) well validated 'bottom-up' hydrodynamic and sediment transport models such as POLCOMS and TELEMAC; (3) operational 'reduced complexity models' of selected coastal landforms (e.g., cliffs (SCAPE), estuaries (ASMITA), saltmarsh (SLAMM)); and (4) growing observational datasets that allow data-driven approaches to coastal analysis and prediction. The iCOASST Project will use these components to develop and apply an integrated systems modelling framework for mesoscale coastal simulation as explained in this paper.
CHARACTERIZATION OF PROCESSES INVOLVED IN THE RESET OF A SUBTIDAL BAR
Authors: Blossier Brice , Brière Christophe , Roelvink J.A. , Walstra D.J.R.
Published: December 2012

Sand beach profiles can exhibit nearshore sandbars with complex 3D patterns. Under energetic conditions, these patterns disappear and the bars get to a certain extent alongshore uniform. This phenomenon is called a reset. The existing literature mainly concerns the development of the bar patterns (3D) or the cross-shore migration of sandbars (2D). Studies on reset-events from a three dimensional point of view are limited but can be found for instance in Reniers et al. (2004) and Smit (2010). This paper describes an analysis that is aimed at determining the relevant processes involved in the reset of three dimensional subtidal bars and at describing the relative influence of each of these processes. To perform this study, data collected during the ECORS campaign at Le Truc Vert (France) in 2008 are analyzed. In addition, a numerical approach is performed using a research Delft3D model forced by the Xbeach wave generator to investigate the processes involved in a reset-event. The effects of the hydrodynamic external conditions on the flow patterns in the surfzone are investigated. Then the reset is studied in details in order to understand the role of the different processes taken into account by the numerical model. The incident wave energy controls the intensity of the reset. The bar cross-shore migration is controlled by the wave breaking process. The wave breaking position and the dissipation rate of the roller energy controls the generation of Shoreward Propagating Accretionary Waves (SPAW). The straightening of the subtidal bar occurs when the conditions induce a significant longshore current in the surfzone.
DUNE EROSION NEAR SEA WALLS: MODEL-DATA COMPARISON
Authors: Van Geer Pieter , De Vries Bram , Van Dongeren Ap , Van Thiel de Vries Jaap
Published: December 2012

This paper describes the validation of the dune erosion model XBeach with laboratory measurement data of dune erosion in the presence of sea walls and revetments. Simulation results show that the essential dune set back processes are captured by the model and that the measurements at most locations are approximated quite well. Some aspects however
need more attention in further research. The alongshore distance from a fixed structure over which the dune erosion is influenced was not well captured by the model. Also the absence of short wave run-up on the revetment still causes an underestimation of the amount of dune erosion above the revetment. Furthermore the influence of the angle of incidence
was investigated with a conceptual model approach. This revealed a relatively high influence of the angle of incidence on the governing flow pattern in front of a transition between a dune and a fixed structure.
SAND BORROW AREA DESIGN REFINEMENT TO REDUCE MORPHOLOGICAL IMPACTS: A CASE STUDY OF PANAMA CITY BEACH, FLORIDA, USA.
Authors: Taiani Luana , Benedet Lindino , Silveira Lucas , Keehn Stephen , Sharp Nicole , Bonanata Rafael
Published: December 2012

The coastline of Panama City Beach, Florida (FL) has been stricken by several hurricanes during the last decades, especially after 1995. In 1998, beach nourishment projects started being implemented to address the impacts of the hurricanes on the coast. Sources of sand for that purpose are commonly from borrow areas located just offshore of the nourishment site. Impacts of these nearshore dredge pits on adjacent coasts will depend on incident wave conditions, nourishment sediment characteristics and some features of the borrow pit (distance from the shore, depth of cut, cross-shore extent, alongshore extent and orientation - Bender & Dean, 2003; Benedet & List, 2008). The practical goal of the current study was to mitigate for the negative potential effects by discovering the less impactful design of dredge pit geometries on the Borrow Area S1 in Bay County-FL. Five different cut widths and excavation depths within the permitted limits were herein evaluated. Evaluation of morphological impacts on adjacent beaches was carried with the processed-based morphodynamic model Delft3D, calibrated and simulated for a period of 13 years. Results were evaluated in terms of beach volume changes compared against a baseline simulation (no action).Switching from Alternative 1 (6,260,000 m³) to Alternative 2 (5,380,000 m³) does not result in a substantial reduction of the borrow area's projected impact. The cut depth is still deep, and the surface area is unchanged. Alternative 3 (3,555,000 m³) is able to provide more substantial reductions in the borrow area's impact. By reducing the acreage of the borrow area and switching to a uniform cut depth, the projected impact of the borrow area decreases 39% for 1.56 km along the downdrift beach. Under Alternatives 4 (3,060,000 m³) and 5 (2,755,000 m³), the impacts of the borrow area are projected to be less than 3.75 m³/m/yr. While both alternatives are viable, Alternative 5 minimizes potential impacts, and has a uniform cut depth and a volume that still satisfies the project's requirements. Given these considerations, Alternative 5 is the preferred alternative. Additionally, all the alternatives increase the net-accretion along 6.5 km of Shell Island between 0.25 to 1 m³/lm/yr., a valuable side effect in a region with high net erosion. By conducting various simulations an optimal borrow area design has been identified that reduces its effects on the adjacent beaches.
DEVELOPMENT OF DYNAMIC SEDIMENT BUDGET TO PREDICT FUTURE SHORELINE POSITIONS ON A SAND LIMITED SHORELINE IN LOUISIANA
Authors: Agarwal Arpit , Carter Josh , Campbell Matt , Bermudez Hugo
Published: December 2012

A shoreline change analysis was performed along the shoreline of the chenier plain in southwestern Louisiana in an attempt to forecast future shoreline position and to determine the performance of a proposed sand beach nourishment project along the shoreline which extends 14 km west of the western jetty of Calcasieu Pass, Louisiana and runs through the community of Holly Beach, Louisiana. Observations of shoreline morphology revealed a solitary sediment wave traversing the project site from east to west since the 1960's. The genesis of the sediment wave is unknown and is unexplored in this work. The presence of the sediment wave masked the long-term shoreline change rates along the project site and therefore biased the predictions of future shoreline positions due to the transient nature of the sediment wave morphology. Standard coastal engineering methods used to predict future shoreline positions include simple translation of the shoreline based on measured shoreline change rates (referred to herein as historical linear progression or HLP) and one-line numerical models. For the project site, due to the presence of this sediment wave the HLP approach to predict future shoreline positions is not applicable. One-line shoreline morphology models such as the US Army Corps of Engineer's GENESIS model require the assumption that the beach profile can be represented by an equilibrium beach profile which was developed for sand rich shorelines. The project site profile composition of a sandy veneer extending to a depth of approximately -1.2 to -2 m over a muddy bottom violates this assumption, and therefore the traditional one-line model cannot be applied. Therefore, a dynamic sediment budget (DSB) method was developed to predict future shoreline positions based on available historical data, longshore transport rates, known morphological processes, statistical estimates of storm events, beach nourishment diffusion, and a relationship between volume change and shoreline change based on existing profile composition. This method was validated with existing data and was able to predict 20 years of morphology within ±15 m of measured shoreline positions.
Modeling swash zone sediment transport at Truc Vert Beach
Authors: Van Rooijen Arnold , Reniers Ad , Van Thiel de Vries Jaap , Blenkinsopp Chris , McCall Robert
Published: December 2012

A one-dimensional hydrostatic version of the XBeach model (Roelvink et al., 2009) is applied to hindcast swash morphodynamics measured during an accretive, and an erosive tide at Le Truc Vert beach (France) in early spring
2008 (Masselink et. al, 2009; Blenkinsopp et al., 2011). Swash hydrodynamics are solved by applying the nonlinear
shallow water equations, and sediment transport rates are obtained from a combined intra-wave Nielsen and Bagnold
type transport model. Reasonable predictions of morphological change in the swash were obtained. Nevertheless, the model underpredicts the water level setup and/or wave run-up during the accretive tide, which is hypothesized to be related to 2D-effects.
BEACH EROSION COUNTERMEASURE USING NEW ARTIFICIAL REEF BLOCKS
Authors: Kim Kyuhan , Shin Sungwon , Pyun Chongkun , Kim Hyun Dong , Kobayashi Nobuhisa
Published: December 2012

Two-dimensional and three-dimensional laboratory experiments were conducted to investigate not only the flow mechanism near the submerged breakwater but the performance of two newly developed eco-friendly artificial reef blocks. The results of two-dimensional experiments proved that new artificial blocks (EREEB) showed a better performance than TTP in terms of wave attenuation due to wave breaking turbulence near the crest of the structure. Three-dimensional experiments convinced that installing another type of new artificial block (WERF) in between submerged breakwater reduced the return flow velocity more than 50% compared with the gap between the breakwaters is empty. Therefore, these two types of newly developed artificial reef block can contribute the counter measure of beach erosion and habitat of sea lives.
MORPHOLOGICAL MODELING OF A HIGHLY DYNAMIC TIDAL INLET AT SHIPPAGAN GULLY, CANADA
Authors: Logan Seth , Nistor Ioan , Cornett Andrew , Faure Thierry , Drouin Alain
Published: December 2012

This paper is presenting the results of an extensive field and numerical modeling investigation of a morphologically dynamic tidal inlet. Shippagan Gully is a tidal inlet located near Shippagan, New-Brunswick, Canada, on the Gulf of Saint Lawrence. It is a particularly complex tidal inlet due to the fact that its tidal lagoon transects the Acadian peninsula and is open to the Bay des Chaleurs at its opposite end. As such, two open boundaries with phase lagged tidal cycles drive flow through the inlet, alternating direction with each tide and reaching velocities in excess of 2 m/s. Hydrodynamic and morphological processes at the site are further complicated by the presence of a highly variable wave climate. Presently, shipping practices through the inlet are limited due to continual sedimentation within and immediately offshore from Shippagan Gully. As such, an extensive field study, desktop analysis and numerical and morphological modeling of Shippagan Gully have been conducted in order to provide guidance for future works. Modeling was conducted using the CMS-Wave and CMS-Flow numerical modeling system. Sedimentation inside the inlet was shown to be ebb tide-induced deposition; while wave induced deposition was demonstrated elsewhere. The methodology and selected results of this study are presented herein.
PLANNING, PRELIMINARY DESIGN, AND INITIAL PERFORMANCE OF THE NAGS HEAD BEACH NOURISHMENT PROJECT
Authors: Kana Timothy W , Kaczkowski Haiqing Liu
Published: December 2012

A 3.5 million cubic meter beach nourishment project was completed along 16 kilometers of shoreline at Nags Head, North Carolina, 32 kilometers south of the US Army Corps of Engineers Field Research Facility at Duck. The project is the largest locally-funded nourishment accomplished to date in the United States. Three ocean-certified hopper dredges and one cutterhead suction dredge constructed the project between May and October 2011. This paper discusses the planning, design, and initial performance of the project. Nags Head is exposed to high waves from the northeast which generate net southerly transport over the long term. A key design issue for the project was the large gradient in erosion rates from north to south. Fill sections were varied accordingly based on documented volume erosion rates and model simulations for the area. Permitting involved over five years of environ¬mental reviews because of the need to work during fair-weather summer months in the relatively high-energy setting. The design also built on prior work in connection with a federal nourishment project scheduled for the area if and when funds become available. Two offshore areas strategically located close to south Nags Head were utilized for construction which proceeded efficiently under summer waves until late August when Hurricane Irene impacted the area. The hurricane and fall northeast storms produced rapid adjustment of the construction profile but no net loss of sand from the project area. Post-project surveys show initial profile equilibration was largely confined to the inshore zone inside the 3.7 meter (m) [âˆ'12 foot (ft) NAVD] contour. Depth of closure at decadal scales is estimated to be âˆ'7.3 m (âˆ'24 ft NAVD).
EROSION AND ACCRETION ON CURVED BEACH
Authors: Do Kideok , Kobayashi Nobuhisa , Suh Kyung-Duck
Published: December 2012

The performance of a large nourishment project on Bethany Beach, Delaware is evaluated using available beach profile, wave and tide data during September 2007 to September 2010. The volume of the placed sand with the median diameter of 0.31 mm was about 500 m3/m along the curved shoreline of 1.8 km length. The nourished beach was attacked by two severe storms in May 2008 and November 2009. The eroded sand volume above the mean sea level (MSL) was about 70 m3/m for each of the two storms and emergency repairs were necessary. The numerical cross-shore model with multiple cross-shore lines is used to compute the cross-shore and longshore sediment transport. The beach erosion above MSL is shown to be caused by the offshore sand transport and the alongshore gradient of the longshore sand transport rate. The performance of the nourished beach is predicted to be sensitive to the sand diameter in the range of 0.23 to 0.45 mm.
LONGSHORE TRANSPORT AND SEDIMENTATION IN A NAVIGATION CHANNEL AT BLANKENBERGE (BELGIUM)
Authors: Zimmermann Nicolas , Trouw Koen , Wang Li , Mathys Mieke , Delgado Rosalia , Verwaest Toon
Published: December 2012

The harbour of Blankenberge in Belgium experiences strong sedimentation in its entrance channel requiring frequent dredging. In order to investigate under which conditions this sedimentation is the most pronounced, the instationary coastal model XBeach is used. This paper presents results of long-term morphology modelling of channel sedimentation after applying a specific methodology for input reduction. A reduced time series representative of the annual wind-wave climate is run in combination with a representative tide and a constant morphological acceleration factor (morfac) to cover one year of erosion-sedimentation. While this approach does come with side effects, it has the important advantage to be easy to implement and to preserve part of the climate history compared to other approaches such as MorMerge and a time-varying morfac approach (described in the paper). With this approach and default settings, XBeach is shown to reproduce both qualitatively and quantitatively well the measured sedimentation. Results show that tide, wind and waves all contribute significantly to the total sediment transport, and that both continuous transport and individual storm events cause strong sedimentation. Some aspects of morphological modelling methodologies are discussed, relative to the calibration, input reduction and long-term modelling methods.
PERFORMANCE OF PERCHED BEACH NOURISHMENTS
Authors: Musumeci Rosaria Ester , Cavallaro Luca , Foti Enrico
Published: December 2012

Perched beach nourishments are popular measures to contrast beach erosion in the presence of steep beaches. Inspired by a real case-study, in the present work the performance of two configurations of the submerged barrier used to protect the toe of the beach are experimentally investigated. Measurements have been gathered concerning wave reflection and transmission, stability and scours around the submerged sill, and beach profile evolution. Both accretive and erosive wave conditions have been considered here. A comparative analysis on the evolution of the two configurations of the sill, shows that the armoring of the filter behind the rubble mound structure is a very effective measure to increase the level of beach protection (e.g. the shoreline retreat under erosive wave attack is reduced to a third). The comparison of the experimental results with an analytical model to predict the equilibrium profile of perched beaches shows that the key phenomena controlling the process are related not only to wave reflection but also to wave dissipation mechanisms at the sill. Moreover, the comparison of the experimental results with field data proves that notwithstanding the several simplifying assumptions considered in the physical modeling, several phenomena are reasonably predicted by the model (e.g. beach evolution, stability and scours).
LAND COVER AND SEDIMENT LAYERS AS CONTROLS OF INLET BREACHING
Authors: Kurum Mustafa Onur , Overton Margery , Mitasova Helena
Published: December 2012

Understanding the processes that take place during a storm leading to coastal morphological change has been a challenging topic for coastal engineers. Over the years, many models have been developed to predict the coastal response to storms evolving from the one dimensional empirical models to two or three dimensional process based models. We hypothesized that the predictive capacity of these models can be improved by incorporating the site specific effect of the land cover features that are in place at the time of the storm. In this work, we present a case study of the development of the Pea Island breach, Outer Banks, North Carolina during Hurricane Irene in August 2011. The inclusion of the land cover effects into the model significantly improves the predictive capability of the model results.
DESIGN OF DETACHED BREAKWATERS FOR COASTAL PROTECTION: DEVELOPMENT AND APPLICATION OF AN ADVANCED NUMERICAL MODEL
Authors: Karambas Theophanis V.
Published: December 2012

An advanced nonlinear wave, sediment transport and bed morphology evolution 2DH model, for the design of coastal protection structures, has been developed. The extended Boussinesq equations, including higher order non-linear terms, which can describe the propagation of highly nonlinear waves in the shoaling region, surf and swash zone, are used. The bed and suspended load transport are estimated with a quasi-steady, semi-empirical formulation, developed by Camenen, and Larson ('A unified sediment transport formulation for coastal inlet application', Technical report ERDC/CHL CR-07-1, US Army Engineer Research and Development Center, Vicksburg, MS, 2007) for an oscillatory flow combined with a superimposed current under an arbitrary angle, involving phase-lag effects in the sheet flow layer. Model results are compared with experimental data (morphology evolution behind detached breakwaters). The agreement between numerical simulations and data is quite satisfactory. Also, model predictions agree with the tombolo/salient criteria found in the literature. The methodology can be applied to the design of detached breakwaters, which are used as coastal protection structures.
COUPLED WAVE-BED DYNAMICS, ATCHAFALAYA SHELF, LOUISIANA
Authors: Sahin Cihan , Safak Ilgar , Sheremet Alexandru
Published: December 2012

Observations of waves, currents, suspended sediment concentration and acoustic backscatter are used to re-investigate the interaction between the combined wave-current flow and cohesive sediments on the muddy Atchafalaya inner shelf. Observations support the previously proposed bed reworking cycle by waves of mobilization and resuspension of bed sediment, erosion, deposition with fluid mud formation and consolidation. Suspended sediment concentration profiles are estimated based on the acoustic backscatter of a current profiler. A one-dimensional vertical bottom boundary model is used to reconstruct the vertical structure of the flow characteristics, and estimate parameters difficult to observe directly, such as bottom shear stress. Estimated bed position, concentration profiles and computed bottom stresses remarkably support the previous findings on the bottom stress-resuspension relation, critical shear stress for erosion and bed density variation throughout a storm.
BEACH CHANGES CAUSED BY EXTENSION OF OFFSHORE BREAKWATER AND LIMITATIONS OF ARTIFICIAL REEFS CONSTRUCTED AS A MEASURE AGAINST BEACH EROSION
Authors: Noshi Yasuhito , Uda Takaaki , Hoshigami Yukiyoshi
Published: December 2012

Beach changes on a pocket beach of 6.5 km length bounded by Ryugu and Unoko Points facing the Pacific Ocean in Fukushima Prefecture were investigated using the contour-line-change model. The shoreline recession and excess deposition of sand in the central and southern parts of the study area, respectively, between 1980 and the 1990s were triggered by the wave-sheltering effect due to the extension of the offshore breakwater of Hirakata fishing port south of the study area. Although artificial reefs were constructed in the eroded area of the study area as a measure against beach erosion, their protective effect was limited because the wave-sheltering effect of the offshore breakwater of the fishing port is much larger than that of the artificial reefs.
BEACH CHANGES AROUND DAWU FISHING PORT IN TAIWAN CAUSED BY OBSTRUCTION OF LONGSHORE SAND TRANSPORT AND MEASURES
Authors: Kumada Takayuki , Uda Takaaki , Liu Jimmy J. Y.
Published: December 2012

The Dawu fishing port breakwater has been extending since 1956 in Taitung City located in the southeast part of Taiwan, obstructing southward longshore sand transport. Because of the blockage of longshore sand transport at this fishing port, severe downcoast erosion occurred, resulting in the wave overtopping damage to Route No. 9 extending along the coastline, and urgent measures were required to enhance the safety of the route. As measures, beach nourishment using coarse materials including gravel produced from the construction of a road tunnel was planned, as well as the construction of groins on the downcoast. We first analyzed beach changes around this fishing port using past aerial photographs and bathymetric survey data, and beach changes were reproduced using the contour-line-change model considering changes in grain size. Then, the effect of measures was investigated using the model.
MORPHODYNAMICS OF A CARIBBEAN BEACH FRINGED BY A CORAL REEF
Authors: Ruiz de Alegria-Arzaburu Amaia , Mariño-Tapia Ismael , Enriquez Cecilia , Silva-Casarín Rodolfo , González-Leija Mariana
Published: December 2012

The morphological response of two adjacent beaches, on the Mexican Caribbean coast, exposed to the same offshore wave climate is compared, where one of the beaches is fringed by a coral reef and the other is not. Detailed topographic and bathymetric measurements were collected from 2007 to 2011using a differential GPS and double-frequency echo-sounder. Offshore waves were continuously measured by the NOAA 42056 directional buoy, and nearshore waves were measured from May to September 2007 using an acoustic wave and current profiler to validate the use of offshore waves in the analysis of beach morphodynamics. Investigations showed that the beach with the fringing coral reef was the more stable under the same offshore energetic wave conditions of different directions. The implications of the fringing reef on the local hydrodynamics and energy dissipation were evaluated with the SWAN third-generation spectral wave model. The model was first validated with wave measurements collected at intermediate (forereef) and shallow waters (reef lagoon) with Aquadop profilers. Numerical results indicate that during shore-normal energetic conditions, the fringing reef is capable of reducing the incoming wave energy by up to 65%.
A COASTAL AREA MODEL CONSIDERING WAVE-CURRENT INTERACTION AND ITS APPLICATION TO WIDE-CRESTED SUBMERGED BREAKWATER
Authors: Kuroiwa Masamitsu , Seif Ahmed Khaled , Matsubara Yuhei , Ichimura Yasushi , Mase Hajime , Abualtayef Mazen
Published: December 2012

This study is concerned with development of a 3D morphodynamic predictive model for considering wave-current interaction by using wave action balance equation. The developed model was applied to model tests associated with a detached breakwater and wide-crested submerged breakwaters, and the influences of strong currents around the structures into wave height distribution and bathymetry change were investigated. Furthermore, the morphodynamics around the artificial reefs in the Uradome Beach, Tottori, Japan, was computed. From the computed results, a large scour hole due to strong rip-currents in the opening of the reefs was reproduced. The applicability of the model was confirmed.
DEVELOPMENT AND FIELD VALIDATION OF A 2DH CURVILINEAR STORM IMPACT MODEL
Authors: Roelvink Dano , Stelling Guus , Hoonhout Bas , Risandi Johan , Jacobs Walter , Merli Davide
Published: December 2012

The formulations of the 2DH process-based, nearshore morphological model XBeach were extended to allow for curvilinear grids using a finite volume approach. The formulations were tested for schematic cases such as a circular island and a field validation study was carried out for the case of storm erosion during a construction phase of the soft sea defense of the Maasvlakte-2 extension of Rotterdam port. It was found that the 2D curvilinear version performs significantly better than individual 1D runs. The overall skill of the 2D model for this case can be classified as 'reasonable' while the prediction of the erosion can be classified as 'good'.
SEDIMENT BUDGET FORMULATION VIA EXHAUSTIVE SEARCH METHOD
Authors: Engle Jason A. , Legault Kelly R. , Rosati Julie D.
Published: December 2012

A regional sediment budget for St. Augustine Inlet and St. Johns County, Florida, was developed for the 1999 to 2010 period. Development of the sediment budget had three main objectives: characterize the transport pathways and magnitudes for the 1999 to 2010 period, compare to an earlier sediment budget for 1974 to 1995 (Srinivas and Taylor 1998), and provide input to numerical modeling of the region (Reports 2 and 3, Beck and Legault 2012a,b). An innovative method was developed to create an inlet sediment budget using high quality measured volume changes for an inlet and beach system. Methods described in the Coastal Engineering Manual (CEM-V-6 2008) and Bodge (1999) were applied to determine the extent of inlet influence along the adjacent beaches, the total inlet sink, and a regional sediment budget for a given set of measured volume changes occurring at St. Augustine Inlet in northeast Florida, U.S.A.