bluuebunny/crossref_metadata_2025 huggingface dataset:
EVALUATION OF DESIGN WATER LEVELS AT THE EMS-DOLLARD ESTUARY CONSIDERING THE EFFECT OF A STORM SURGE BARRIER
Authors: Herrling Gerald , Knaack Heiko , Kaiser Ralf , Niemeyer Hanz Dieter
Published: October 2012

In the Ems-Dollard estuary at the southern North Sea coast a revaluation of design water levels along the German dykes has become necessary, since the safety margin for sea level rise was increased by 25 cm due to a decision of the Lower Saxon Ministry for Environment and Climate Protection. The upstream part of the estuary is protected against high storm surges by a storm surge barrier. The closure of the barrier effects downstream surge water levels due to partial reflection. Deterministic-mathematical modeling is applied to evaluate design water levels and design wave run-up. Three severe storm surge events have been hindcasted by a cascade of three hierarchical models from the Continental Shelf over the German Bight into the area of interest. The models are forced by non-stationary and spatially varying data of atmospheric pressure, wind velocities and directions available of meteorological model investigations. The verification of the storm surge model with water level observations yields good agreements. With respect to legal boundary conditions, the single-value-method is applied to determine the highest expected high water level at Emden. Starting from this target water level, the wind velocities in the meteorological boundary conditions are increased with the aim to increase the surge level at the coast and to match the predetermined design water level at Emden. The responding water levels in the Ems-Dollard estuary assign the new design water levels.
IMPACTS OF DEEP WATERWAY PROJECT ON LOCAL CIRCULATIONS AND SALINITY IN THE CHANGJIANG ESTUARY, CHINA
Authors: Ge Jianzhong , Ding Pingxing , Chen Changsheng
Published: October 2012

With an aim to improve and maintenance water depth along the navigational channel, the Deep Waterway Project has been conducted in the Changjiang Estuary. The structures of dikes and groins have greatly changed the local circulation with the combined effects of astronomical tide and strong freshwater discharge. A high-resolution fully three-dimension unstructured-grid model (FVCOM) has been applied to study the complicated hydrodynamics with the implementation of unstructured-grid dike-groin module. With the model validation with observation data, the simulation shows the dikes and groins has converted the rotational current into reciprocating flow along the navigational channel between the dikes, and produced the geometrically controlled eddies. The significant southward crossover current was produced along the dike during high tide when the water level is higher than the dike height. The strong saltwater intrusion is also revealed in the observation and model simulation.
THE DYNAMICS OF INTERTISDAL MUDFLATS AND SALTMARSHES WITHIN ESTUARIES
Authors: Townend Ian , Rossington Kate , Knaapen Michiel , Richardson Stephen
Published: October 2012

Whilst there has been extensive work on the study of the morphological response of estuaries, due to the transport of sediment under the forcing of waves and tides, and independent studies on the dynamics of saltmarsh, only recently have attempts been made to look at the interaction of the two. This paper furthers this endeavor by adding a simple saltmarsh model into the aggregated scale model of long-term morphology known as ASMITA. The results show the strong interaction between sediment availability within the estuary and marsh depth and, hence, the species that can be sustained. Under low rates of sediment loading the biology is the controlling influence, whereas under higher rates, typical of many UK estuaries, the sediment loading tends to be dominant. The importance of both the rate of sea level rise and the nodal tidal cycle are also explored.
BOLSA CHICA WETLANDS RESTORATION INLET DESIGN
Authors: Jin Weixia , McCarthy Michael
Published: October 2012

Bolsa Chica Wetlands is one of a few recently restored large wetlands in Southern California of the United States. The project required restoration of tidal flooding of some isolated wetlands while minimizing impacts to the shoreline adjacent to the new inlet and maintenance costs, preserving endangered species on site, and maintaining oil field operations along the periphery of the project. The project created a direct connection to the ocean through wetland basins that included a full tidal basin, muted tidal basins and seasonal ponds linked by a series of ocean jetties, levees, water control structures, culverts, and channels. The inlet is a key project feature and has been the focus of numerous technical studies and numerical modeling tasks. As part of theses analyses, a pre-filled ebb bar was designed and about 1 million cubic yards of clean sand from the lowlands dredging was placed offshore to minimize the anticipated impacts of the inlet opening to the shoreline. This paper presents the inlet location selection, inlet and wetland hydrodynamics, inlet dimension optimization, inlet stability analyses, and jettied inlet entrance design. It also discusses findings of comparison between model predictions and field measurements of tidal elevations and sediment accumulations in the wetland basin since the completion of the project in August 2006. This project received the first Project Excellence Award from COPRI (Coasts, Oceans, Ports and Rivers Institute) of the American Society of Civil Engineers in 2008.
DEVELOPMENT OF AN OPERATIONAL ELBE TIDAL ESTUARY MODEL
Authors: Muller-Navarra Sylvin , Bork Ingrid
Published: October 2012

Due to local tidal conditions, vessels coming in from the North Sea and bound for the port of Hamburg - more than 100 km upstream - require continually updated hydrological and oceanographic forecasts. The principal objective of the research project OPTEL (Operational Elbe Tidal Estuary Model) is to provide hydrological and oceanographic forecasts about water levels, depths, currents, salinity, temperature and ice conditions for any tidally influenced place on the river Elbe. By using a numerical model, it is ensured that water levels and currents are coupled dynamically, which allows peak water levels, slack water times, and - in 3D modelling - flow profile to be modelled in a physically consistent way and with high resemblance to natural conditions. The model concept including model output statistics (MOS) and first model results are presented.
IMPACT OF RUNOFF ON SALT INTRUSION OF YANGTZE ESTUARY
Authors: Li Tilai , Gao Xiangyu , Zhang Xinzhou , Wang Yinshuang
Published: October 2012

Based on one-dimensional and two-dimensional mathematical coupling models of tidal current and salinity from Datong to Yangtze estuary, the impacting scope of salt intrusion are calculated when the runoff of Datong from 4,500m3/s to 30,000m3/s, and the maximum and average value of salinity at each representative point of the estuary are given. When flow of Datong is less than 10,000 m3/s, if projects of water transfer, pumping and diversion are not taken into account at the lower reaches of Datong, the maximum salinity at the downstream reaches of Xuliujing and the average salinity at the downstream reaches of Baimaosha will exceed drinking water criteria.
ECOLOGICALLY BASED APPROACH TO COASTAL DEFENCE DESIGN AND PLANNING
Authors: Zanuttigh Barbara , Losada Inigo , Thompson Richard
Published: October 2012

Sustainability of coastal areas requires the development of a standard procedure for the selection of equitable defence solutions and the design optimization of existing defences in order to minimize the impact on the environment and maximize positive effects such as species biodiversity and structure colonization. The aim of this paper is to propose a combined method, based on numerical simulations and on collection of ecological data in the field, to provide indications for an environmental friendly construction of breakwaters. This method is applied and tested against the case study of Elmer, UK, where information on existing species and their abundance related to hydrodynamic effects induced by the breakwaters
SPATIAL DISTRIBUTION OF HYPOXIC WATER MASS BASED ON A MONITORING CAMPAIGN OF BAY ENVIRONMENT AT TOKYO BAY, JAPAN.
Authors: Horie Takehito , Furukawa Keita , Okada Tomonari
Published: October 2012

In 2008, a monitoring campaign of bay environment had been done at Tokyo Bay, Japan. This campaign has been a part of implementation of the bay renaissance plan enacted since 2005. The data was collected by 46 institutions in 568 monitoring points in around 2nd July 2008. Dissolved oxygen, salinity and temperature were monitored in sea area basically from the surface to the bottom with 1.0 m vertical spacing at the monitoring points. We analyzed spatial distribution of hypoxic water mass based on this monitoring campaign data. Following results are obtained that 1) Measurement results showed that the bottom hypoxic water mass dominated in the head of Tokyo bay, while dissolved oxygen concentration was high condition in tidal flat and in shallow water, such as the Tama River estuary, Sanbanze tidal flat area and the Ara River estuary. 2) We proposed new parameters, such as CDZ and VDZ, which showed characteristic of spatial distribution of hypoxic water. The proposed parameters could be related to the temporal and spatial development of hypoxic water. Thus, these parameters will extend the interpretation of conservative bottom dissolved oxygen (DOB) data to understand the dynamics of hypoxic water.
A NEW WAY OF ENGAGING COASTAL STAKEHOLDERS: COASTRANGER MS
Authors: Pontee Nigel , Hamer Ben , Morris Kevin
Published: October 2012

The management of coastal change involves a range of stakeholders, ranging from local residents to government officials, whose backgrounds and expertise differ widely. It is necessary that these stakeholders understand the nature of future coastal changes and their potential impacts. This paper describes an innovative approach that has been developed to stimulate public debate and improve stakeholder understanding of the issues that need to be balanced in order to achieve sustainable long term coastal management solutions. The approach involves the creation of an educational tool (CoastRanger MS) that allows users to manage a virtual coast within a pc-gaming type environment.
A COASTAL DEVELOPMENT IDEA FOR GULF OF THAILAND TO IMPROVE GLOBAL TRADES
Authors: Chuen-Im Chanin , Lee Jiin-Jen
Published: October 2012

Marine transport is an important mode of transportation in global trades. Despite its slow speed, more than 80 percent of transporting goods around the world is by sea. At the present time, transportation between Pacific Ocean and the Middle East region are mainly from existing three routes: Malacca Route, Sunda Route, and Lombok Route. There are more than 500,000 ships of all sizes passing through these three routes every year. It would be advantageous from the economic point of view if one can shorten the travel distance by introducing a man-made canal herein called "Siam Canal† which connects the Andaman Sea and Gulf of Thailand. Hydrodynamic simulation is being conducted to evaluate the conditions before and after the introduction of "Siam Canal† to assess the possible modification of the marine environment. A more detailed feasibility study is underway in order to provide a more definitive assessment on the economic, social, political, and environmental impacts of the proposed Siam Canal.
COASTAL VULNERABILITY ASSESSMENT TO SEA LEVEL RISE INTEGRATED WITH ANALYTICAL HIERARCHY PROCESS
Authors: Ozyurt Gulizar , Ergin Aysen , Baykal Cuneyt
Published: October 2012

This paper discusses a parameter based coastal vulnerability assessment model to sea level rise. The model integrates physical characteristics and human activities with expert perception through an application of analytical hierarchy process (AHP). The results of AHP enables to assign weights to parameters of the model which determine vulnerability of a coastal area to the impacts of sea level rise such as coastal erosion, inundation, flooding due to storm surges, saltwater intrusion to groundwater and rivers. The results of AHP also indicates that sea level rise is not considered as one of the main driving forces of the impacts that might be already present contrary to the reports that state that sea level rise will trigger many problems along coastal areas. The application of the coastal vulnerability assessment model to two different coastal areas of Turkey showed that there is a need for overall evaluation of coastal areas in terms of vulnerability to sea level rise considering all the impacts. It is seen that assessing overall vulnerability is an important tool for national assessments. On the other hand, impact vulnerabilities are important when regional to local planning are considered since a region having a low overall vulnerability might show higher vulnerability for individual impacts. The proposed vulnerability methodology integrated with expert perception enables a simple yet effective representation of the coastal system while enabling decision makers to come up with proactive adaptation measures.
A RISK-INFORMED APPROACH TO COASTAL ZONE MANAGEMENT
Authors: Jongejan Ruben , Ranasinghe Roshanka , Vrijling Han
Published: October 2012

Economic and population growth have led to an unprecedented increase in the value at risk in coastal zones over the last century. To avoid excessive future losses, particularly in the light of projected climate change impacts, coastal zone managers have various instruments at their disposal. These primarily concern land-use planning (establishing buffer zones) and engineering solutions (beach nourishment and coastal protection). In this paper, we focus on risk mitigation through the implementation of buffer zones (setback lines). Foregoing land-use opportunities in coastal regions and protecting coasts is costly, but so is damage caused by inundation and storm erosion. Defining appropriate setback lines for land-use planning purposes is a balancing act. It is however unclear what level of protection is facilitated by current approaches for defining setback lines, and whether this is, at least from an economic perspective, sufficient. In this paper, we present an economic model to determine which setback lines would be optimal from an economic perspective. The results provide a useful reference point in the political debate about the acceptability of risk in coastal zones. The main conclusions are (i) that it is useful to define setback lines on the basis of their exceedance probabilities, (ii) that the exceedance probability of an economically efficient setback line will typically be in the order of magnitude of 1/100 per year, (iii) that it is important to distinguish between situations in which morphological conditions are stationary and non-stationary, and (iv) that long-term uncertainties (e.g. due to climate change) influence the exceedance probability of efficient setback lines but only to a limited extent.
LAGRANGIAN BREAKER CHARACTERISTICS FOR NONLINEAR WATER WAVES PROPAGATING ON SLOPING BOTTOMS
Authors: Chen Yang-Yih , Li Meng-Syue , Hsu Hung-Chu , Lin Ying-Pin
Published: October 2012

In this paper, a new third-order Lagrangian asymptotic solution describing nonlinear water wave propagation on the surface of a uniform sloping bottom is presented. The model is formulated in the Lagrangian variables and we use a two-parameter perturbation method to develop a new mathematical derivation. The particle trajectories, wave pressure and Lagrangian velocity potential are obtained as a function of the nonlinear wave steepness ï¥ and the bottom slope ï¡ perturbed to third order. The analytical solution in Lagrangian form satisfies state of the normal pressure at the free surface. The condition of the conservation of mass flux is examined in detail for the first time. The two important properties in Lagrangian coordinates, Lagrangian wave frequency and Lagrangian mean level, are included in the third-order solution. The solution can also be used to estimate the mean return current for waves progressing over the sloping bottom. The Lagrangian solution untangle the description of the features of wave shoaling in the direction of wave propagation from deep to shallow water, as well as the process of successive deformation of a wave profile and water particle trajectories leading to wave breaking. The proposed model has proved to be capable of a better description of non-linear wave effects than the corresponding approximation of the same order derived by using the Eulerian description.
The proposed solution has also been used to determine the wave shoaling process, and the comparisons between the experimental and theoretical results are presented in Fig.1a~1b. In addition, the basic wave-breaking criterion, namely the kinematical Stokes stability condition, has been investigated. The comparisons between the present theory, empirical formula of Goda (2004) and the experiments made by Iwagali et al.(1974), Deo et al.(2003) and Tsai et al.(2005) for the breaking index(Hb/L0) versus the relative water depth(d0/L0) under two different bottom slopes are depicted in Figs 2a~2b. It is found that the theoretical breaking index is well agreement with the experimental results for three bottom slopes. However,for steep slope of 1/3 shown in Fig 2b, the result of Goda's empirical formula gives a larger value in comparison with the experimental data and the present theory. Some of empirical formulas presented the breaking wave height in terms of deepwater wave condition, such as in Sunamura (1983) and in Rattanapitikon and Shibayama(2000). Base on the results depicted in Fig. 3a~3b, it showed that the theoretical results are in good agreement with the experimental data (Iwagali et al. 1974, Deo et al.2003 and Tsai et al. 2005) than the empirical formulas. The empirical formula of Sunamura (1983) always predicts an overestimation value.
PHYSICAL MODEL ON WAVE DISSIPATION EFFECT OF PERFORATED CAISSON
Authors: Jiang Yunpeng , Chen Hanbao , Ge Longzai
Published: October 2012

Perforated caisson structure was usually adopted by harbor engineering design to reduce wave height and wave forces on the structure. Through wave physical model test, wave height distribution in front of non-perforated and perforated caisson with different directions was studied respectively with the layout of a project in China. And then dissipation effect of wave height of perforated caisson was obtained from comparison of the two cases. It was indicated from the results that reduction effect of wave height had great relation with the position of perforation on the caisson when dimension of caisson and perforation, perforation rate were fixed. The perforated caisson had a remarkable wave-dissipation effect when the perforation was between once the wave height above or below the still water level, which proved the rationality of the recommendation of Code for Design and Construction of Breakwaters. It was suggested for this project that design of perforation should be consistent with the code as possible and near the design high water level.
FUNCTIONAL DESIGN OF WAVE PROTECTION STRUCTURES AND LAYOUT FOR A SPECIAL SITUATED MARINA
Authors: Weichbrodt Frank , Schlamkow Christian , Haverland Torsten
Published: October 2012

Between the breakwaters of the harbour entrance of Rostock-Warnemunde, located at the Baltic Coast of Germany, a small marina is situated. In 1999 these breakwaters were modified in order to meet the nautical requirements of larger ships.

From this time on, serious problems for the pleasure boats were observed due to wave disturbance. New structural measures like floating breakwaters and vertical walls

(small length) showed only poor improvements.

The objective of the investigations was the functional design of wave protection structures and a layout able to meet the user requirements on a modern marina with

focus on competitive sailing sports. The investigations were assigned by the Sport Confederation of the Federal State of Mecklenburg-Vorpommern, Germany.

To accomplish this objective, numerical simulations as well as small scale hydraulic tests were performed at the University of Rostock.
VIDEOIMAGERY TECHNIQUES AND MULTIVARIATED PARAMETER ANALYSIS TO DEFINE 3D MAPS OF VULNERABILITY
Authors: Gomez Rebeca , Molina Rafael , Castillo Carmen
Published: October 2012

The present methodological proposal allows the generation of three-dimensional maps of vulnerability for breakwaters, through the employment of videoimagery techniques and statistical analysis.

On one hand, the knowledge of videoimagery techniques (Molina et al., 2005) as an extended and applicable tool for maritime engineering (ZEUS Project "Zenital Unattended System†) and on the other hand the usefulness of applying statistical techniques to the study of damage evolution in maritime structures motivated the fusion of both to obtain wide information from the images which is not evident to the naked eye.

The 3D maps show graphically the behaviour of breakwaters facing the actions of the environment, and this makes the tasks of conservation, maintenance or design easy and improve damage prediction for a better management during the building process.
VELOCITY DEFECT LAW IN THE WAVE BOTTOM BOUNDARY LAYER
Authors: Abreu Tiago , Michallet H. , Silva P. A. , Sancho F. , Nielsen P.
Published: October 2012

This work presents a simple method based on the defect law (Nielsen,1992) to reproduce the velocity vertical profile within the wave bottom boundary layer. The model results agree fairly well with the ADVP measurements and show that the defect law reproduces typical features of the oscillatory boundary layer: the velocity magnitude first increases with distance from the bed, with an overshoot at approximately 3 cm above the bed. There is a phase shift in the velocity that is maximum at about 1cm above the bed. Processing of the bed shear stress as well as velocities estimates within the sheet flow layer is under progress. (e.g. Ruessink et al., submitted)
PREDICTING WATER FLUCTUATION IN COASTAL ENCLOSED LAGOON USING INTEGRATED TWO-DIMENSIONAL SURFACE AND SUBSURFACE WATER MODEL
Authors: Kong Jun , Song Zhiyao , Zhang Zhuo
Published: October 2012

Based on integrated vertically averaged free-surface and subsurface model, detailed analysis was focused on the water fluctuation in the enclosed lagoon caused by tidal movement. It is shown that when porosity of sand is increased, the water storage capacity in sand beach will be increased and the amplitude of vibration in the lagoon will be decreased. On the contrary, when permeability coefficient is increased, the amplitude in lagoon will be increased, and the phenomena of phase lag will be reduced either. Research reveals there is periodical water exchange between lagoon and out sea on the two sides of the sand beach. The procedure of water going into the lagoon happens differently from that of water coming out from lagoon. Because there is over-height in the lagoon, the time of water transporting from the lagoon to the out sea is longer than the reverse procedure and the maximum of water flux in the first procedure is shorter than the later. Further more the water moving from lagoon to open sea usually happens in the initial stage of flood and later stage of ebb, while the reverse procedure happens in the later stage of flood and initial stage of ebb.
NEW PRACTICAL MODEL FOR SAND TRANSPORT INDUCED BY NON-BREAKING WAVES AND CURRENTS
Authors: Van der A Dominic Alexander , Ribberink Jan S , Van der Werf Jebbe J , O'Donoghue Tom
Published: October 2012

Many existing practical sand transport formulae for the coastal marine environment are restricted to limited ranges of hydrodynamic and sediment conditions. This paper presents a new practical formula for net sand transport induced by non-breaking waves and currents, and currents alone. The formula is based on the semi-unsteady, half wave-cycle concept, with bed shear stress as the main forcing parameter. Unsteady phase-lag effects between velocities and concentrations are accounted for, which are especially important for rippled bed and fine sand sheet-flow conditions. Recently recognized effects on the net transport related to flow acceleration skewness and progressive surface waves are also included. The formula is calibrated against a large dataset of net transport rate measurements from oscillatory flow tunnels and a large wave flume covering a wide range of flow and sand conditions. Good agreement is obtained between observations and predictions, and its validity is shown for bedload dominated steady flow conditions.
DETAILED PLANNING OF BEACH NOURISHMENT BASED ON MONITORING OF COASTLINE UNDULATIONS AND DUNE EROSION
Authors: Madsen Holger Toxvig , Knudsen Soeren Bjerre , Soerensen Per
Published: October 2012

The overall coastline management strategy for the central section of the Danish North Sea coast is to halt the process of coastal retreat and maintain a certain safety level against flooding. The sudden erosion of 10-25 m of a dune during a storm or a gale is thus a cause for concern. Such local dune erosion is often observed where an inward coastline undulation is situated off a section of the coast where the dune is not in equilibrium with the rest of the profile. During a storm this latent dune erosion is then released. By analysing the migration of coastline undulations and detecting the profiles with latent dune erosion the expectation is that the majority of large-scale dune erosion can be foreseen and avoided by adaptation of the nourishment programme.
EFFECT OF SAND BYPASSING AT SAKUMA DAM IN TENRYU RIVER AS A MEASURE AGAINST EROSION OF TENRYU RIVER DELTA COAST
Authors: Miyahara Shiho , Uda Takaaki , Furuike Kou , Serizawa Masumi , San-nami Toshiro , Ishikawa Toshinori
Published: October 2012

The long-term evolution of the Tenryu River delta associated with sand bypassing at several dams is investigated using the contour-line-change model considering the change in grain size. The effect of the increase in sediment yield from the river mouth on the nearby coasts is numerically predicted. When the sediment yield is artificially increased, the supplied sediment is mainly deposited around the river mouth, resulting in a large shoreline advance, but it takes a longer time for a sandy beach far from the river mouth to recover. Another measure, such as sand bypassing of the coast, is required to recover sandy beaches downcoast.
FIELD MEASUREMENT OF AEOLIAN SAND FLUX USING CERAMIC SAND FLUX SENSOR UD-101 AT A SAND DUNE
Authors: Udo Keiko , Junaidi Junaidi , Aoki Shin-ichi , Mitsushio Shota , Kato Shigeru , Mano Akira
Published: October 2012

This study conducted field observations in terms of the number of blown sand impacts and wind velocity at an open ocean beach in Japan, in order to investigate characteristics of the aeolian sand transport flux over a sand dune slope. Charnock constant of a roughness length equation calculated from wind velocity data had a larger value over the slope compared to over a flat. Furthermore, the aeolian flux over the slope tended to be larger than that over the flat. Characteristics of the Charnock constant and the aeolian flux over the flat and the slope were demonstrated from the field measurements.
STATE-OF-THE-ART IN JAPAN ON CONTROLLING WIND-BLOWN SAND ON BEACHES
Authors: Hotta Shintaro , Harikai Souichi
Published: October 2012

In order to prepare general guidelines for controlling the wind-blown sand in the region from the shoreline to the landward end of the dry beach, a literature review was carried out. The review showed that controlling wind-blown sand on a beach surface can be done by using a suitable combination and arrangement of sand fences and trenches.
PICK-UP RATE OF SUSPENDED SAND DUE TO TSUNAMI
Authors: Yoshii Takumi , Ikeno Masaaki , Matsuyama Masafumi , Fujii Naoki
Published: October 2012

The pick-up rate formula which can apply to wide-range of grain size was presented through dimensional analysis and laboratory experiments. The result of the dimensional analysis revealed that there are three must-considered non-dimensional parameters: "non-dimensional sand grain diameter†, "non-dimensional settling velocity†, and "non-dimensional shear stress†. The pick-up rate formula which considers these parameters can predict the pick-up rate of 0.08 mm and 0.2 mm grains measured in the experiment with sufficient accuracy. The topography change around a harbor due to tsunami was measured in the laboratory experiment and compared with the result of numerical simulations. The numerical simulation with the presented pick-up rate formula shows a better agreement with the laboratory experiment than that with Takahashi et al. (2000)'s model.
EFFECT OF EXTERNAL TURBULENCE ON SEDIMENT PICKUP RATE
Authors: Okayasu Akio , Fujii Keiichiro , Isobe Masahiko
Published: October 2012

Influence of turbulence on sediment pickup rate was investigated. Pickup rates with external turbulence generated by a grid structure were measured in a channel. It was found that the rates were much larger than those for non-turbulent conditions. A new formula in which external turbulence was taken into account for Shields parameter evaluation was proposed. In the formula, effect of inertia force by turbulence acting on sediment particles was included as well as the enlarged drag force caused by fluctuating velocity.
MODELING ON-SHORE SEDIMENT TRANSPORT USING ENERGETICS MODELS
Authors: Zhao Qun , Kirby James T , Puleo Jack A
Published: October 2012

In this paper, we re-derived the Bagnold formula and showed that the net onshore sediment transport is correlated to the bottom shear stress. The reformulated model is tested with data and
and showed very promising future.
SHEETFLOW SEDIMENT TRANSPORT UNDER ASYMMETRIC WAVES AND STRONG CURRENTS
Authors: Dong Le Phuong , Sato Shinji
Published: October 2012

Experiments have been conducted to investigate the sheetflow sediment transport of uniform sand under asymmetric oscillatory flows in combination with relatively strong opposite currents. Two kinds of nearshore waves were performed, namely, velocity asymmetric waves and acceleration asymmetric waves. Image analysis technique is utilized to study major influences of wave shapes and current through observing the instantaneous sheetflow layer thickness. Maximum sheetflow layer thickness was formulated and incorporated to an enhanced Watanabe and Sato's formulation. The new conceptual model is examined its validity for a wide range of experimental conditions
MECHANISM OF OFFSHORE SAND DISCHARGE INTO SUBMARINE CANYON TRIGGERED BY CONSTRUCTING DETACHED BREAKWATER CLOSE TO SHORELINE
Authors: Yamada Koji , Uda Takaaki , Suwa Yoshio , San-nami Toshiro , Furuike Kou , Ishikawa Toshinori
Published: October 2012

Several submarine canyons have developed offshore of the Aramata region of the Shimoni-ikawa coast in Toyama
Bay, which is one of the three deep bays in Japan. The Kurobe River with a steep bed slope flows into the sea
immediately north of this region, and a large amount of sediment has been supplied to this area, which has been
transported by southward longshore sand transport. However, beach erosion has occurred owing to the decrease in sediment supply from the Kurobe River. Furthermore, since the construction of detached breakwaters as a measure
against beach erosion, offshore sand transport has accelerated and beach erosion has become more severe. In this
study, aerial photographs and bathymetric survey data were analyzed, then the mechanism of offshore sand transport
was investigated using the BG model proposed by Serizawa et al. (2007).
PREDICTION OF NET BEDLOAD TRANSPORT RATES OBTAINED IN OSCILLATING WATER TUNNELS AND APPLICABILITY TO REAL SURF ZONE WAVES
Authors: Gonzalez-Rodriguez David , Madsen Ole Secher
Published: October 2012

Experimental studies of sediment transport rates due to nearshore waves are often conducted in oscillating water tunnels (OWTs). In an OWT, the oscillatory motion produced by the piston propagates almost instantaneously along the entire tunnel. Consequently, unlike the wave motion in the sea or in a wave flume, flow in an OWT is uniform along the tunnel, and second-order wave propagation effects (such as Longuet-Higgins's streaming) are absent. The effect of these hydrodynamic differences between OWT and sea waves on sediment transport rates has generally been neglected. In this paper we present a simple, practical formulation to evaluate bed shear stresses and bedload transport rates due to asymmetric and skewed waves plus a current in an OWT, based on fitting the exact results of a rigorous, analytical model of the OWT wave-current boundary layer. By then accounting for real wave effects we find that wave propagation significantly affects the predicted period-averaged net sediment transport rates. Such real wave effects can therefore not be neglected when comparing nearshore transport models with OWT data.
AN IMPLICIT 2-D DEPTH-AVERAGED FINITE-VOLUME MODEL OF FLOW AND SEDIMENT TRANSPORT IN COASTAL WATERS
Authors: Wu Weiming , Sanchez Alejandro , Zhang Mingliang
Published: October 2012

An implicit depth-averaged 2-D finite volume model has been developed to simulate sediment transport and bed morphological changes under actions of currents and waves near coastal inlets. The model computes the depth-averaged 2-D shallow water flow and non-equilibrium transport of total-load sediment, accounting for the effects of wave radiation stresses and turbulent diffusion induced by currents, waves and wave breaking. The model uses a quadtree rectangular mesh to locally refine the mesh around structures of interest or where the topography and/or flow properties change rapidly. The grid nodes are numbered by means of an unstructured index system for more flexibility of mesh generation. The SIMPLEC algorithm is used to handle the coupling of water level and velocity and the Rhie and Chow's (1983) momentum interpolation method is adopted to determine the intercell fluxes on non-staggered grid. Well-developed longshore current and wave setup determined with the reduced 1-D momentum equations are used as the cross-shore boundary conditions. The model has been tested in several laboratory and field cases, showing good performance. In particular, it can use a long time step and is efficient in computation on a PC platform. It has a potential for simulation of long-term coastal morphodynamic processes.
SWASH ZONE BED LEVEL CHANGES AND SEDIMENT ENTRAINMENT AT THE SURF-SWASH BOUNDARY
Authors: Jensen Stine Gro , Aagaard Troels , Baldock Tom E.
Published: October 2012

In the process of estimating the effect of sediment advection into the swash zone from bore collapse, a method in which buried self-logging pressure transducers are used to measure bed level changes in the swash zone, over a timeframe of several hours to inter-swash level, has been tested against bed level changes obtained from rod measurements. The test shows perfect agreement in the upper and mid swash while minor disagreement (1 cm) in the lower swash occurred. The deployment of self-logging pressure transducers has proven to be an accurate, easy and flexible method to obtain highly detailed data on water levels and bed elevations in the swash zone. Water levels derived from the pressure transducers show that swash zone characteristics vary from the upper to lower swash. Using pressure transducers in the swash zone coupled with measurements of the hydrodynamics and sediment concentrations at the outer boundary of the swash zone will improve the ability to explain the role of sediment advection from bore collapse. In relation to this, a method which consistently identify bores at the surf-swash boundary and quantifies the suspended sediment load carried by such bores prior to their collapse and run-up in the swash zone, is also presented.
A HYBRID MODEL OF SWASH-ZONE LONGSHORE SEDIMENT TRANSPORT ON REFLECTIVE BEACHES
Authors: Jiang Angela Wenping , Hughes Michael , Cowell Peter , Gordon Angus , Savioli Juan Carlos , Ranasinghe Roshanka
Published: October 2012

The hydrodynamics and sediment transport in the swash zone is currently outside the domain of coastal-area models, which is a significant limitation in obtaining littoral sediment-transport estimates, especially on steep reflective beaches where the waves practically break on the beachface. In this study, an existing process-based coastal model (MIKE 21) is combined with a theoretical derivation of swash processes, resulting in an innovative hybrid modelling approach that is capable of estimating longshore sediment transport in the swash zone. The method relies upon estimation of swash hydrodynamics from an extended ballistic swash model with friction included. The terminal bore and other incident wave properties were computed from the output of a spectral-wave model (MIKE 21 SW). The Bagnold-type equation was applied to estimate gross transport volumes and the longshore component was computed for the sand volume displaced during the up-rush. The newly developed hybrid modelling approach was applied to Jimmys beach, a steep reflective beach (D50 = 0.3 mm, gradient=0.1) along the northern shoreline of Port Stephens, Australia. The model results yield the alongshore swash transport pathways and the indicative transport volumes. A point of divergence is identified at the beach erosion area, which is of critical importance in terms of shoreline erosion and management. The preliminary results suggest that swash-zone transport can account for a large percentage of the total littoral drift for such beaches. However, further field or laboratory data are required to test model utility, as well as to tune calibration parameters based on the site-specific conditions.
LATTICE BOLTZMANN SIMULATION TO CHARACTERIZE ROUGHNESS EFFECTS OF OSCILLATORY BOUNDARY LAYER FLOW OVER A ROUGH BED
Authors: Ding Lei , Zhang Qing-He
Published: October 2012

The 3-D lattice Boltzmann method was applied to characterize roughness effects of oscillatory boundary layer flow over a rough bed. The direct numerical simulation was carried out and the flow resistance of the flat and fixed bed was investigated. The position of the theoretical bed, equivalent roughness height and the behavior of friction factor at small values of relative roughness were obtained using the log-fit method.
AN INTRODUCTION TO EVENT-BASED MODEL FOR THE STUDY OF SEDIMENT TRANSPORT IN THE SWASH ZONE
Authors: Shanehsazzadeh Ahmad , Holmes Patrick
Published: October 2012

Erosion and accretion of the beach face and consequently the movement of the coastline are the direct result of net sediment transport in the swash zone. Different models have been introduced in order to predict hydrodynamic parameters and, thereafter, movement of particles. However, the capability and comprehensiveness of the models in different conditions are still questionable. In reviewing models established for sediment transport in the swash zone, one can easily conclude that in the most cases the transport of bed load has been predicted traditionally by the application of quasi-steady formula. Scientists have identified many of the important physical processes driving sediment transport throughout the swash zone, but a detailed description of the small-scale sediment dynamics is still far from complete. In this paper the behaviour of coarse sediment particles in the bed load mode of transport in response to the flow regime experienced in the swash zone are investigated. Accordingly, a model called event-based model is introduced for prediction of the beach profile change, and the results of the model are compared with some laboratory data. The comparison between the results of the model and measured beach profile in the laboratory reveals that the results of the model developed in the present study on the basis of the event-based concept are very promising, particularly in the range of flow for which the behaviour of sediment particles is more accurately understood.
LABORATORY EXPERIMENT ON CROSS-SHORE BARRIER SPIT EVOLUTION BY STORM DYNAMICS
Authors: Xuan Tinh Nguyen , Larson Magnus , Donnelly Chantal , Tanaka Hitoshi
Published: October 2012

Every year there are many severe storms occurring around the world, in general, and in Japan, in particular. The occurrence of storms is expected to increase because of the global warming effects. An increasing wave height together with a rising mean water level during a storm create a high possibility for waves to overtop the beach crest causing a lot of sediment to be eroded to offshore areas or deposited in the inland direction. The study of the barrier island response to storms has therefore become very important in terms of sediment transport and beach morphology change, as well as damage to nearshore structures due to runup overwash and inundation overwash. However, changes in the beach profile and prevailing sediment transport mechanisms during a real event are difficult to obtain. Thus, laboratory studies are necessary to conduct. This study presents a laboratory experiment on the impact of storms on a sandy barrier islands. The main aim is to investigate the entire barrier island (or sand spit) response due to storm conditions considering the increase in water level due to storm surge. Also, further development of an analytical model for barrier profile change caused by runup overwash is presented and obtained results overall captured order-of-magnitude barrier face retreat and volume changes after the storm.
OPTICAL TECHNIQUES FOR MEASURING SWASH ZONE MORPHODYNAMICS
Authors: Stancanelli Laura Maria , Musumeci Rosaria Ester , Marini Alberto , Foti Enrico , Caceres Rabionet Ivan , Sanchez Arcilla Agustin
Published: October 2012

The use of different optical systems based on computer vision approach, for measuring swash zone morphological changes, is here proposed. In particular, such techniques are able to achieve quite accurate 2D and 3D reconstruction of the sandy bottom in dynamic conditions under regular waves. They are considered truly non-invasive, since there is no interaction of the hardware with the water motion. The optical techniques have been applied both at small and at large scale facilities for the investigation on the seabed interaction with the fluid motion within the swash zone. The performances of well-established more traditional measurement instruments have been compared with the proposed optical instruments both at small and large scales. In both cases satisfactory results have been gathered during the present experimental campaign.
WAVE-INDUCED OVERWASH AND DESTRUCTION OF SAND DUNES
Authors: Figlus Jens , Kobayashi Nobuhisa , Gralher Christine , Iranzo Vicente
Published: October 2012

Numerical modeling of the rapid dune profile changes that may occur due to wave overtopping and sediment overwash during a storm is challenging. One of the reasons is the limited amount of available field and laboratory data related to the problem. Another reason is the complex interaction of hydrodynamics, morphological changes and sediment transport in the intermittently wet and dry zone of the dune profile. We modified the cross-shore numerical model CSHORE on the basis of three laboratory overwash tests with different dune geometries in front of a low-crested vertical wall to include the capability to predict profile evolution due to wave overtopping and overwash. Experimental results show that the transition from minor to major overwash is fairly rapid and that the resilience of the dune against destruction by wave-induced overwash is dependent on its geometry. Computed results compare well with the measured hydrodynamics, profile changes, wave overtopping rates and sediment overwash rates, requiring only one empirical parameter to be calibrated. Only the erosion in front of the vertical wall in the last phase of each test is not predicted well by the model. Additional comparisons with field data on profile evolution involving overwash verifies the field capabilities of CSHORE.
AN ANALYTICAL MODEL TO PREDICT DUNE AND CLIFF NOTCHING DUE TO WAVE IMPACT
Authors: Larson Magnus Per , Sunamura Tsuguo , Erikson Li , Bayram Atilla , Hanson Hans
Published: October 2012

A model was developed to calculate the evolution of a notch in a dune or cliff due to wave impact. Analytical solutions were derived to the model for schematized conditions regarding forcing and dune/cliff properties. Comparisons were made with laboratory experiments where the time evolution of the notch was measured. Values of the transport coefficients in the analytical solutions were determined by least-square fitting the solutions to the laboratory data. Some of these coefficients could be related to the ratio between parameters describing the forcing and the dune/cliff strength. The evolution of the dune notch displayed a linear behavior at short times, whereas the cliff notch showed a more complex response for cases where a feedback between the notch and a beach formed seaward of the cliff occurred.
DUNE MIGRATION AND SAND TRANSPORT RATES IN TIDAL ESTUARIES: THE EXAMPLE OF THE RIVER ELBE
Authors: Zorndt Anna Christina , Wurpts Andreas , Schlurmann Torsten , Ohle Nino , Strotmann Thomas
Published: October 2012

Large parts of the tidal estuary of river Elbe (Germany) are characterized by regular patterns of sand dunes. They are presumed to evolve due to complex sand transport mechanisms and show multi-faceted migration patterns. Direction and magnitude of their migration are influenced by hydrodynamic boundary conditions such as river runoff and tides. Dune Migration can lead to residual sand transport rates, depending on its direction and magnitude and the dune's characteristics. The understanding of dune migration patterns and associated sand transport is the basis of an effective sediment management as well as an important requirement for planning offshore structures. This study focuses on methods for computing migration and sand transport rates in automated ways. In a comparison and validation of different approaches, a cross-correlation technique was found to produce best results. From a unique data set of up to six annual bathymetrical multi-beam soundings between 1995 and 2010, dune characteristics and migration rates were processed and analysed autonomously. The findings show that in a long perspective, average dune migration and sand transport rates in the present study reach are directed upstream.
BOUNDARY LAYER FLOW AND SAND TRANSPORT UNDER FULL SCALE SURFACE WAVES
Authors: Schretlen Jolanthe J.L.M. , Ribberink Jan S. , O'Donoghue Tom
Published: October 2012

Existing models for wave-related (cross-shore) sand transport are primarily based on data from oscillatory flow tunnel experiments. However, theory and former experiments indicate that flow differences between full scale surface waves and oscillatory flow tunnels may have a substantial effect on the net sand transport. In this paper, high resolution measurements of boundary layer flow characteristics, sheet-flow layer sediment concentrations and net sand transport rates under full scale surface waves are presented. These experiments were performed in a large wave flume (GWK) for different wave conditions with medium (D50 = 0.25 mm) and fine (D50 = 0.14 mm) sand. It is shown that, especially under sheet-flow conditions, small wave induced net currents are of large importance for the total sand transport rates under these conditions.
GRAVEL BEACHES WITH SEAWALLS
Authors: Van der Werf Ivo , Van Gent Marcel R.A.
Published: October 2012

This paper focusses on some fundamental aspects of gravel beaches and revetments with dynamic rock slopes. Obviously, the response of gravel beaches depends on parameters such as the wave height and the stone size. Here, other parameters such as the permeability of the subsoil, the influence of sand in the pores of gravel, and the influence of seawalls have been studied. The results from the physical model tests indicate that a homogeneous mound of gravel with an initial slope of 1:8 leads to a more dynamic response than a gravel beach with an impermeable subsoil. The results also show that if the pores are filled with sand, the response becomes less dynamic. Placing a seawall on a gravel beach may be interesting for gravel beaches that serve as (man-made) sea defence. Furthermore, the results provide insight into the magnitude of scale effects.