bluuebunny/crossref_metadata_2025 huggingface dataset:
FAIRY BOWER OVERTOPPING MONITORING AND DECISION SUPPORT SYSTEM
Authors: Coghlan Ian , Howe Dan , Carley James , Blacka Matt , Crawford Jodie
Published: September 2023

A monitoring and decision support system has been developed to manage dangerous overtopping of the Marine Parade promenade seawall at Fairy Bower, Manly, Sydney Australia. The seawall fronts 750 m of highly used promenade at the southern end of Manly Beach, and experiences overtopping events that are hazardous to pedestrians and potentially damaging to infrastructure, several times per year. The infrequent nature of the events results in members of the public being caught off-guard and unaware of the extent of the hazard. The local council has commenced a program of either deploying signs, staff for raising awareness, or completely closing access to the promenade during overtopping events. A decision support system for forecasting hazardous overtopping events, and a monitoring system for verifying the forecasts and observing conditions, allows the council to better manage the hazard.
COLLABORATIVE LIVING LABORATORIES TO INFORM CANADIAN DESIGN GUIDANCE FOR COASTAL NATURE-BASED SOLUTIONS
Authors: Proosdij Danika van , Murphy Enda , Cornett Andrew , Nistor Ion , Mulligan Ryan , Côté Michelle , Stolle Jacob , Knox Paul , Baker Scott
Published: September 2023

Nature-based solutions (NbS) have been widely applied for managing coastal flood and erosion risk (Bridges et al. 2021). However, they are underutilized in Canada, owing to a variety of factors including, e.g.: (i) uncertainty surrounding the performance of different nature-based solutions across Canada’s diverse coastal climates, geographies, and land uses; and (ii) the lack of authoritative, regionally appropriate design guidance (Vouk et al. 2021). The Nature-based Infrastructure for Coastal Resilience and Risk Reduction project is bringing together a multi-disciplinary team of Canadian researchers, practitioners, and community leaders to develop an improved understanding of the performance of nature-based shore protection systems in diverse Canadian coastal environments. The project involves conducting synchronized and coordinated parallel research activities – laboratory experiments, field monitoring, and numerical modelling – centered on multiple pilot sites along Canada’s Pacific and Atlantic coasts.
USING HYDRODYNAMICS TO IMPROVE SEA STAR FISHERIES IN COASTAL REGIONS
Authors: Burgaard Karen B. , Carstensen Stefan , Fuhrman David R. , O'Neill Finbarr G.
Published: September 2023

Sea stars (starfish) predate on various shellfish such as mussels and clams, and can have a negative impact on the blue-mussel production and aquaculture. This has encouraged the harvesting of sea stars to protect blue mussels and clams from predation, but they are also targeted commercially, as a valuable protein source used e.g. in animal feed. Towed fishing gears can be used to harvest sea stars in coastal regions, however, little is known scientifically about the hydrodynamics around these gears. To better understand the hydrodynamics around towed fishing gears, an experimental investigation has been carried out in a current flume within the DTU Civil and Mechanical Engineering Hydraulics Laboratory.
AN APPLICATION OF 1-D MODEL FOR ASSESSING SALINE INTRUSION IN THE COASTAL AREAS OF THE VIETNAMESE MEKONG DELTA
Authors: Phan ThiNgocThuan , Ly TrungNguyen , Van PhamDangTri
Published: September 2023

Many studies in present years have been conducted to predict the effects of changes in the upstream discharge, hydrodynamics, and saline intrusion in the coastal of the Vietnamese Mekong Delta (VMD) (Smajgl et al., 2015; T. Van et al., 2013); however, the models for the entire delta did not show detail for small areas such as the Ca Mau Peninsula, and other studies were only considered in upstream flooding condition such as the Long Xuyen Quadrangle (Nguyen et al., 2012; T. Van et al., 2013). Besides, several study were using hydraulic models for the whole VMD region; Nevertheless, these studies were only interested in major river systems that applied the Mike 11 salt simulation model for the VMD region. Some hydraulic studies were simulated in specific region such as Long Xuyen Quadrangle. However, a few studies have focused on a complex river system such as Quan Lo Phung Hiep (QLPH) area of the Ca Mau peninsula, which is characterized by a complex river system, inter-regional irrigation works, and a variety of water demands, including marine, brackish, and freshwater-based agriculture. However, coastal studies, particularly those of an inter-regional character with complicated river networks like the QLPH, have received little attention. As a result, this research was carried out to assess the hydrodynamics and saline intrusions of the interwoven river network's coastal area, a complex operating system in a large area affected by both tidal regimes in the West and East Sea, which is characteristic of the Mekong Delta.
AI-BASED DECISION-MAKING TOOLS FOR PORT MANAGEMENT: SHIP-INFRASTRUCTURE OPERABILITY AND OVERTOPPING
Authors: Figuero Andrés , Peña Enrique , Sande José , Costas Raquel , Carro Humberto , Alvarellos Alberto , Rabuñal Juan , Guerra Andrés , Pérez Juan Diego
Published: September 2023

In recent years, port operators have shown an increasing interest in developing innovative automatic learning techniques, to provide complete predictive packages for safety and efficiency systems, trained and calibrated with field database. Another relevant aspect in these kinds of projects is to determine the long wave influence. The port-ship resonance, due to the coincidence between the long wave periods and the ship horizontal motions, causes downtimes with consequent economic losses. The Port Authority of A Coruña (Spain) started years ago to work towards the application of Artificial Intelligence, providing Machine Learning-based models in their facilities of its Outer Port of Punta Langosteira, together with the University of A Coruña. The main objective was to provide a system to predict operability and overtopping with the forecast of maritime climate information.
MODELING COASTAL WATER TABLE FLUCTUATIONS USING PFLOTRAN
Authors: Maple Margit , Coylar Maia , Detwiler Russell , Gallien Timu
Published: September 2023

Coastal aquifers are highly dynamic groundwater systems. Sea level rise will cause a rise in coastal groundwater tables resulting in increased risk of shallow or emergent groundwater (Befus et al., 2020). Marine water level fluctuations cause the beach groundwater table to oscillate over a relatively large range. Understanding these oscillations is crucial, as shallow (i.e., high) water tables may impact subsurface infrastructure, mobilize sediment, and increase liquefaction risks. Although the impacts of tides and wave setup on coastal water tables have been studied (e.g., Nielsen, 1990; Housego et al, 2021), the cumulative impacts of wave runup, partially saturated flow, complex beach topography, and dual tidal forcing for bay-backed regions have not been explored. This work numerically models beach water table fluctuations which are compared to in-situ swash and beach groundwater observations at Cardiff State Beach in Encinitas, CA.
REINFORCING ECOSYSTEM ENGINEERS WITH ENHANCED VEGETATION AND AN ARTIFICIAL REEF ALONG THE US RHODE ISLAND COASTAL BARRIER SYSTEMS
Authors: Grilli Annette , Schuh Elin , Groetsch Félix , Leone Alexa , Crowley Deborah , Grilli Stephan , Ginis Isaac , Walsh John , Rubinoff Pamela , Damon Christopher , Duhaime Roland , Stempel Peter
Published: September 2023

Beach barrier systems (BBS) act as “ecosystem engi-neers” (EE), protecting the mainland and back bays from direct wave impact and reducing storm surge and flow passing through their inlets. BBS naturally adapt to slowly evolving wave climates by regressing or transgressing. However, observations show that BBS have been destabilized during past periods of fast changes in sea level or wave climate, potentially leading to drowning of the barrier. In this respect, current predictions of large changes in future Sea Level Rise (SLR) and wave climate, combined with anthropogenic effects, are concerning as these could challenge the natural adaptability of BBS. This raises the following questions: (1) can the future protective ability of local EE be predicted? (2) can the added benefits of implementing selected Nature Based Solutions (NbS) to enhance this natural protective ability be quantified, as well as their potentially negative feedback effects? In this study, these questions are considered for the south shore of Rhode Island (RI) through numerical modeling, in part based on earlier regional storm hazard assessment (Grilli et al., 2020). Specifically, here, as part of a NOAA project (“Effects of Sea-Level Rise 2021, Coastal Resilience” program), we assess the efficiency of NbS in changing climate conditions, while integrating local concerns, observed trends, and supporting local ecosystem and people’s way of life.
STUDY OF METHODS FOR DETECTING OCCURANCE OF RIP CURRENT USING IMAGE ANALYSIS
Authors: Shimada Ryo , Ishikawa Toshinori , Komine Tsutomu
Published: September 2023

There are from 2,000 to 3,000 rescues every summer at bathing beaches in Japan, and the main cause of drowning accidents is rip currents. To analyze the rip current, a method for visualizing rip currents with average images can be used. However, in case of the investigation over a long period, such as several months, it is necessary to confirm the occurrence of rip currents through thousands of averaged images by human eyes. In this study, we suggested a new method for detecting the occurrence of rip currents automatically by analyzing the pixel values of averaged images. Images for the analysis were created from video data recorded in March and April 2021 by a camera overviewing the study beach located on the west coast of Japan. The accuracy results of this method were 99 percent for the validation dataset and 57 percent for the verification dataset, respectively. When the wave height was 0.5 m and higher for the verification dataset, the accuracy was 75percent. Therefore, it was considered that this method can detect the occurrence of rip currents when the wave height is 0.5 m and higher. As a result of applying this method to the 3-month image data recorded from October to December 2021, it was found that wave steepness was occurring lower under the conditions of rip currents. In conclusion, this method was able to automatically detect the rip currents from the images, and the conditions of waves when the rip currents that occurred could be investigated using this method.
MODELLING OF SPILLING AND PLUNGING BREAKING WAVES IN SPECTRAL MODELS
Authors: Saprykina Yana , Aydogan Burak , Ayat Berna
Published: September 2023

Based on the data of field experiments and modeling was revealed that the dissipation of the energy of the high-frequency part of the wave spectrum due to wave breaking should compensate the nonlinear growth of higher wave harmonics, which occurs in different ways both for waves breaking with different types and for different methods of modeling a nonlinear source term. The effect of the dissipative term type used on the estimates of sediment transport is discussed.
FROM OFFSHORE TO ONSHORE PROBABILISTIC TSUNAMI HAZARD ASSESSMENT WITH QUANTIFIED UNCERTAINTY: EFFICIENT MONTE CARLO TECHNIQUES
Authors: Davies Gareth
Published: September 2023

Offshore probabilistic tsunami hazard assessments (PTHAs) are increasingly available for earthquake generated tsunamis. They provide standardized representations of tsunami scenarios, their uncertain occurrence-rates, and models of the deep ocean waveforms. To quantify onshore hazards it is natural to combine this information with a site-specific inundation model, but this is computationally challenging to do accurately, especially if accounting for uncertainties in the offshore PTHA. This study reviews an efficient Monte Carlo method recently proposed to solve this problem. The efficiency comes from preferential sampling of scenarios that are likely important near the site of interest, using a user-defined importance measure derived from the offshore PTHA. The theory of importance sampling enables this to be done without biasing the final results. Techniques are presented to help design and test Monte Carlo schemes for a site of interest (before inundation modelling) and to quantify errors in the final results (after inundation modelling). The methods are illustrated with examples from studies in Tongatapu and Western Australia.
TSUNAMI RUN-UP CONSIDERING TIME VARIATION OF DENSITY OF INUNDATION WATER
Authors: Matsutomi Hideo , Arikawa Taro
Published: September 2023

Aiming for the advancement of tsunami load, historical and/or prospective tsunami scale evaluations, practical empirical formulas for evaluating friction factor K of inundation flow and density ρ of inundation water over a movable bed, which can be applied to a tsunami run-up theory, are proposed using experimental data whose amount (range) is increased (expanded) by carrying out additional experiments on ρ and run-up of inundation flow with sediment, and verification data of the above theory under a uniformly sloping movable bed condition are provided. Series solutions with a higher universality to the run-up of tsunami inundation flow with sediment over a uniformly sloping movable bed, in which both K and ρ depend on time, are derived under the conditions depending on an incident bore height h1 at shoreline (or an initial stored water depth), bed slope i, median particle diameter d50 of initial bed material, and examples of the solutions are shown. The solutions are applicable to the case that ρ is independent on time, i.e., the case of inundation flow without sediment over a movable bed or fixed bed. Including the case of inundation flow without sediment, validity of one of the solutions is also verified through a comparison with the verification data on run-up distance.
TOPOGRAPHIC RESPONSE TO HIGH WAVES AND SUBSEQUENT BEACH RECOVERY ON CHIGASAKI COAST
Authors: Tamura Takahisa , Ishikawa Toshinori , Uda Takaaki , Serizawa Masumi
Published: September 2023

Beach topography quickly responds to the action of storm waves, resulting in foreshore erosion and accretion under calm wave conditions after a storm. Field observations were carried out on the Chigasaki coast to investigate these beach changes. It was found that the seabed shallower than 3 m depth was rapidly eroded by offshore sand transport during a storm event with the deposition of sand in a zone at depths between 3 and 5 m, and then the beach recovered within 1–2 years after the storm. Topographic changes immediately after the storm and subsequent recovery under calm wave conditions were calculated using the BG model (a model for predicting three-dimensional beach changes based on Bagnold’s concept). Given the equilibrium slope of fine sand d1 and medium-size sand d2 to be 1/120 during high waves, the erosion of the foreshore zone was numerically reproduced. Moreover, the recovery of the beach topography to a gentle slope under calm wave conditions after the storm was successfully reproduced.
LITTORAL DRIFT GRADIENTS ON THE PORTUGUESE COASTAL SECTOR ESMORIZ‑NAZARÉ: PAST AND FUTURE TRENDS
Authors: Ferreira Margarida , Coelho Carlos , Silva Paulo A.
Published: September 2023

The Northwest Portuguese coastal sector Esmoriz-Nazaré is exposed to a very energetic wave climate that promotes a net littoral drift estimated to be around 1.1x106 m3/year. This study aimed to characterize the littoral drift in the coastal sector Esmoriz-Nazaré, discussing past and future trends by applying two bulk longshore sediment transport formulas: CERC (1984) and Mil-Homens et al. (2013). Generically, the results present a longshore sediment transport variability at the study area. In spite of the differences between the considered formulas, both of them present similar trends along the coastal sector and for the past and future wave climates. In the future, mainly due to changes in the projected waves direction, the net littoral drift is expected to decrease.
SPATIO-TEMPORAL VARIATION OF AEOLIAN SHOREWARD SAND TRANSPORT MEASURED USING NEAR-CONTINUOUS LASER SCANNING
Authors: Vos Sander , Anders Katharina , Wulf Alain de , Vries Sierd de , Lindenbergh Roderik
Published: September 2023

A beach in Mariakerke-Bad (Belgium) was monitored in 2017-2018 for more than a year with a near-continuous laser scan system. From a total of 8500 scans 7700 hourly scan epochs were used to study the spatio-temporal shoreward sand transport at the beach. In order to account for weather influences and other possible disturbances of the scan-system, a time-dependent correction method was applied to reduce rotation errors up to 0.2 degrees in the point cloud orientation (around the zero point of the laser scanner) reducing height errors on the beach to the order of centimeters. Cross shore analysis of the beach profile shows that shoreward transport occurs at most times during the year with an accumulated maximum of 17m3/m throughout the measurement period and maximum transport rates of 0.6 m3/m/day. However most of the shoreward sand transport is redistributed seawards again due to beach shaping leaving a total of about 2 m3/m a year which is below the average values found along the Belgium coast. The spatio-temporal behavior of the shoreward sand transport has been studied with the 4D-OBC analysis technique which identified accumulations of sand in the full 4D point cloud dataset. A total of about 3600 4D-OBC accumulation events were identified and most found accumulations on the beach can be associated with natural (aeolian) processes. Also, accumulations appear to occur during the whole year which is consistent with the previous cross-shore analysis.
CAISSON DESIGN AND VERIFICATION OF FRICTION COEFFICIENT OF CAISSON FOUNDATION FOR TUAS PORT PHASE 1
Authors: Song Tiancheng , Cheng Albert , Khoo Eugene , Zhang Yaodong , Chen Wan Sin , Kui Robin Liao Bin
Published: September 2023

Reinforced precast concrete caisson has been selected as wharf front structure for the project of Tuas Port Phase 1 in Singapore. The caisson structure and foundation were designed to withstand various loading cases comprising loads during both construction and operation stages. It was identified that sliding failure mode of the caisson structures could be one of the critical design checks. The friction tests were conducted under various conditions to assess the Coefficient of Friction (m) between rock mound surface and concrete slab of caissons. The results show that the design value mu of 0.6 for rock mound and concrete interface could be achieved for normal flat concrete surface.
AGENT-BASED SIMULATION OF HURRICANE RISK INFORMATION DISSEMINATION
Authors: Yeates Elissa M. , Chen Chen , Lindell Michael K. , Shao Wanyun , Harris Ce’Ne , Cass Evan
Published: September 2023

The effectiveness of official warning dissemination and interpretation determines the adoption of protective actions in response to hurricane threat. This paper describes the development of a conceptual warning diffusion model that articulates the whole process of the hurricane warning diffusion and individual decision-making, drawing on emergency management and social science bodies of literature. This conceptual model is then partially encoded into a NetLogo agent-based simulation model to demonstrate the effects of various warning diffusion components on evacuation decisions for areas of interest. The translation of the conceptual model into agent-based simulations can inform the coastal engineering and science communities of the importance of communicating risk information to the public, and also helps to identify future research needed to illuminate hurricane risk communication pathways.
YEPPOON SURF POOL: FULL-SCALE VALIDATION OF A CFD MODEL
Authors: Valizadeh Alireza , Mortensen Simon Brandi , Antenucci Jason , Trevis Aaron
Published: September 2023

DHI has been supporting Surf Lakes in the design and optimization of their inland surf pool since 2017. This support has been primarily through providing CFD simulations of various aspects of the design. Whilst the CFD model was verified against basic functionality tests and qualitatively compared to the field data, no quantitative comparisons were available until February 2022, where our high-quality numerical model was compared with the field measurements. The results of that comparison and some details and challenges of the numerical model are addressed in this paper. The agreement between measured data and CFD results is excellent, demonstrating the ability to provide effective design support despite a range of numerical challenges.
WAVE OVERTOPPING REDUCTION BY MODULAR CONCRETE ARMOUR UNITS
Authors: Bakker Pieter , Ruwiel Tim , Koppel Michael van de , Yang Zi Qian , Donnelly James
Published: September 2023

This paper describes a new armour unit called XP-Overtop which is applied together with XblocPlus armour units in a modular armour layer in order to reduce wave overtopping. This unit is placed close to the crest of the structure. Physical model tests have been performed to study the hydraulic stability and the overtopping reduction of the XP-Overtop as a function of the relative freeboard. Based on the model tests performed, the following conclusions can be drawn: 1) XPOvertop generates substantial overtopping reduction which increases with increasing relative freeboard; 2) because of the limited effectiveness and hydraulic stability for a low relative freeboard, it is not recommended to apply XP-Overtop for structures with a relative freeboard below Rc/Hm0=1; 3) the roughness factor γf for a structure with XP-Overtop is a function of the relative freeboard and varies between γf=0.42 and γf=0.41; 4) XP-Overtop enables a designer to reduce the crest level of a structure; 5) this reduction translates to significant reductions in the construction materials, costs and CO2 emissions.
DOES COASTAL WETLAND RESTORATION WORK AS A CLIMATE CHANGE ADAPTATION STRATEGY? THE CASE OF THE SOUTH-EAST OF SICILY COAST
Authors: Musumeci Rosaria Ester , Marino Massimiliano , Cavallaro Luca , Foti Enrico
Published: September 2023

The South-East of Sicily hosts a complex system of coastal lagoons and wetlands of great naturalistic value. The area is under significant anthropogenic pressure due to intensive agriculture and tourism activities, resulting in a decline in biodiversity, ecosystem services, and an increase in coastal erosion and flooding risks, which are further exacerbated by the impact of climate change. The present study investigates the effectiveness of a set of restoration activities to mitigate coastal risks in the region. Specifically, the effects of revegetation interventions in the estuary and in the dune strip are investigated. This was carried out through a numerical modeling developed to simulate coastal flooding under present and climate change scenarios (IPCC AR5). The model consists of a coupled SWAN model for nearshore wave processes and Xbeach for flood modelling. Wave forcing were obtained by means of extreme event analysis associated with 100 years return time. Effects of sea level rise are also included. The results show that the proposed restoration measures reduce the risk of coastal flooding from extreme wave events up to 18percent of the flooded volume.
PREDICTING NEAR-BED SEDIMENT TRANSPORT THROUGH PARTICLE IMAGE VELOCIMETRY
Authors: Hoch Caroline , Weaver Robert J. , Webb Bret , Resio Don , Ward Nikole , Lodge Caleb , Hopkin Olivia , Bouhassira Ruby , Kachouie Nezamoddin N.
Published: September 2023

Coastal communities are growing globally, promoted by the ocean’s abundant opportunity for food, recreation, tourism, and green energy. Erosion and accretion along the coast significantly affect the safety of these communities and longevity of coastal infrastructure. To better predict rates of erosion and accretion, sediment transport models and active-bed thickness prediction techniques are of particular importance. Two dimensionless parameters, the Shields and Ursell parameters, are often used to predict rates of sediment transport and wave linearity. The goal of this project is to analyze sediment movement in a laboratory wave flume using particle image velocimetry (PIV). From the analysis we estimate the dimensionless parameters and instantaneous active-bed thickness to predict volumetric sediment transport rates as waves propagate shoreward.
INFLUENCE ON EVENT-SPECIFIC CALIBRATION DATA IN MODELLING SUBAERIAL STORM EROSION UNDER COMPLEX BATHYMETRY
Authors: Jin Hyeok , Do Kideok , Kim Inho , Kang Tae-Soon , Choi Heung-Bae
Published: September 2023

Key parameters in the process-based model for morphological changes during storm events (i.e., XBeachX, Roelvink et al., 2018) should be adjusted to simulate morpho-hydrodynamics to a specific area of interest, leading to site-, profile-, and event-specific calibration. Although 2-dimensional simulations (area model) eliminate variability in calibrated parameters along with each profile in complex bathymetry, the degree to which datasets having different wave conditions influence model performance is still unclear in the area model at a given parameter space. The main objective of this study is to examine the influence of event-specific calibration data (single storm event and storm clusters) in modelling subaerial storm erosion under complex bathymetry. Using bathymetric field data over four different storm conditions, this study presented guidance for the selection of event-specific data in modeling calibration.
EFFECTS OF SHELLS ON AEOLIAN SEDIMENT TRANSPORT ON A NATURAL BEACH
Authors: Strypsteen Glenn , Rauwoens Pieter
Published: September 2023

Studying aeolian sediment transport in coastal areas is challenging. Therefore, a location with a small number of supply-limiting elements (e.g., shells, moisture and vegetation) and a long fetch length is frequently chosen to allow for a better comparison of predicted and observed transport rates (Strypsteen et al., 2021). Many natural beaches, however, contain an abundance of shells and shell fragments/hash due to pounding and fracturing in the surf zone and literature on this topic is rather scarce. Direct field studies on the impact of shells on aeolian sediment transport rates have been limited. This study reports on a two-day measurement campaign on the upper beach of Koksijde, Belgium, where data on aeolian transport rates, mass flux profiles, surface moisture, wind conditions, and grain size distributions were collected. The goal of the experiment was to measure aeolian sand transport on the upper beach as input for dune growth and to find out how a shell pavement affected these transport rates during a strong, oblique onshore wind.
NUMERICAL SIMULATION OF GRAVEL NOURISHMENT TO THE SEISHO COASTLINE IN JAPAN
Authors: Funahashi Yuya , Shibayama Tomoya , Esteban Miguel
Published: September 2023

It is feared that as a consequence of the potential future intensification of tropical cyclones due to ongoing climate change the patterns of coastal erosion around the world could change. In this study, the mesoscale meteorological model WRF (Weather Research and Forecasting), the third-generation stand-alone wave model SWAN (Simulating WAves Nearshore), and the coastal deformation model XBeach (eXtreme Beach behavior) are combined to calculate the short-term coastal deformation caused by high waves during the approach of Typhoon No.21 (Paolo) in 2017 to the Seisho Coast and Niigata Coast in Japan (Nishida and Shibayama, 2020). The model is then applied to predict future patterns of coastal erosion. Potential countermeasures to prevent future coastal erosion are then examined. The construction of detached breakwaters, which are currently used as a countermeasure against coastal erosion in many parts of the world, is often opposed by local residents due to the changes they can produce on the fishing environment and landscape. Therefore, it is often desirable to stabilize the beach without constructing structures offshore. Thus, gravel nourishment is proposed as a countermeasure against the short-term erosion that can be caused high waves, and its benefits and impacts were verified through numerical simulations.
LONG TERM MORPHOLOGIC MODELLING OF DELTA DEVELOPMENT IN BRETON SOUND RESULTING FROM A PROPOSED DIVERSION STRUCTURE
Authors: Lu Qimiao , Scott Fred , Tun Yarzar , Nairn Rob
Published: September 2023

Sediment deprivation, hydrologic alteration, subsidence, sea level rise, and saltwater intrusion have been causing significant land loss in coastal Louisiana. Breton Sound combined with the nearby Barataria Bay, and Mississippi River Delta have lost approximately 1800 square kilometers (or 447,000 acres) of land, representing one of the highest land loss rates in the world since the 1930s when the Mississippi River was leveed. To address this problem, the Coastal Protection and Restoration Authority (CPRA) initiated several sediment diversion projects in the Lower Mississippi River (LMR). The Mid- Breton Sediment Diversion (MBrSD) project is one of the costal restoration projects proposed to restore natural processes in Breton Sound, which can strategically reestablish hydrologic flows, carry land-building sediments, nourish marshes and sustain land.
FIELD OBSERVATIONS AND MODELING OF BEACH CUSP EVOLUTION IN THE PRESENCE OF AN ARTIFICIAL VEGETATION PATCH
Authors: Mansur Maqsood , Salatin Reza , McCormack Tyler , Chen Qin , Hopkins Julia , Dickhudt Patrick J.
Published: September 2023

Vegetation has been shown to reduce beach erosion by attenuating wave energy and trapping sediments (Feagin et al., 2015). To date, most of the studies on erosion reduction by vegetation are either theoretical, numerical, or based on laboratory experiments. Field data that quantify the effectiveness of beach vegetation as a protective measure against erosion is sparse owing to the difficulty in conducting controlled field experiments (Feagin et al., 2015). To improve our understanding of wave-beach-vegetation interaction, we conducted a field experiment from September 19 to October 10, 2021, at the US Army Corps of Engineers’ Field Research Facility (FRF) in Duck, North Carolina, as part of DUNEX (DUring Nearshore Event eXperiment). For this experiment, we installed a patch of artificial vegetation in the swash zone, constructed out of materials with known mechanical properties, to test how beach vegetation attenuates wave energy and reduces erosion. It is to be noted that we used zipties to build our vegetation patch.
THE SELECTION AND DESIGN OF VEGETATED DUNES AS PREFERRED MAIN COASTAL PROTECTION SYSTEM FOR BEIRA, MOZAMBIQUE
Authors: Nieuwenhuis Odelinde , Heineke Esther , Letitre Peter , Wilms Tom
Published: September 2023

The coastal city of Beira is vulnerable to cyclones, storm surges, sea-level rise and floods from intensive rainfall events because of its low-lying situation. Cyclone Idai in 2019 has proven this again. A significant improvement of the coastal protection scheme is needed to provide sufficient protection for Beira to protect from hazards from sea and climate change for decades to come. The coastal protection infrastructure is to be integrated into the urban and natural environment of Beira, whilst seeking socio-economic, environmental and urban synergy. In this context, we performed an extensive flood and erosion risk assessment, feasibility study and design, environmental and social scoping study and set up an implementation strategy for the selected preferred alternative and priority measures. This included an intensive stakeholder engagement process throughout the project (2020-2022).
ANISOTROPIC EDDY VISCOSITY A BENCHMARK CASE STUDY IN AN IDEALISED TIDAL ESTUARY
Authors: Leo Annalisa De , Collecutt Greg , Smith Mitchell , Stocchino Alessandro , Syme Bill
Published: September 2023

Numerical schemes for solving the full shallow water equations require a turbulence closure model to represent the momentum diffusion caused by turbulence that the velocity fields do not explicitly capture. Typical models include Smagorinsky, depth-U*, Prandlt, and k-epsilon. All of these models predict isotropic eddy viscosity – i.e. the diffusion of momentum acts equally in all directions. However, it is known that when modelling saline transport within an estuary with a 2D scheme, mass dispersion is present in the longitudinal direction due to the depth velocity profile. In a 2D numerical scheme, should diffusion of momentum also be applied anisotropically? In this paper we present a benchmark case study between laboratory measured velocity results and those from numerical simulations using TUFLOW.
APPLICATION OF CROSS-SHORE MORPHOLOGICAL MODELS FOR PERCHED BEACHES
Authors: Kroeders Merel , Mol Arjan , Thadi Supriya , Franco Leopoldo , Bianco Marco Del , Rijn Leo van
Published: September 2023

Perched beaches are beaches that are supported at the offshore side by a submerged structure. The advantages of such design schemes are that less dredged material is required, and more protected waters are created in front of the beach. Apart from the hydraulic stability of the submerged structure itself, the stability of the beach needs to be studied in order to make sure it fulfils the requirements during its design lifetime. Aspects that play a role here are the expected sand losses over the submerged structure, the (dynamic) equilibrium profile of the beach and the performance during storm conditions. In order to study the morphological responses of such beaches, morphological models should be applied that can take into account the influence of the submerged structure. This paper discusses two cross-shore models that have been used to study a large perched beach project that is under construction in unusually deep waters, severe wave climate (mostly unidirectional) and small tidal range. The models applied are SBEACH (Larson et al., 1989) and CROSMOR (Van Rijn et al., 2003). First the models are validated and calibrated hydrodynamically by comparing the wave transmission and wave setup with measurements from 2D flume tests. Next, the models have been used to predict the future cross-shore development of the beach.
OBSERVATION AND NUMERICAL MODELING OF A DUNE OVERWASH AND BREACHING EVENT
Authors: Winters Maria A. , Jr. Michael A. Angelis, , Gallien Timu W.
Published: September 2023

Sea level rise will significantly increase the need for building and upgrading coastal protection such as artificial coastal dunes or berms (Wong et al., 2014). Human constructed dunes are frequently deployed to limit wave runup and overtopping and mitigate damage from flooding events (e.g., Gallien et al., 2015). Although dune erosion modeling and validation on storm surge dominated beaches is common in the literature, only limited work considers energetic long period swell conditions typical of coastal California. In this study three morphological models are used to simulate dune erosion response to long period swell and compared to high resolution in-situ hydromorphological field observations.
A 2500-YEAR SEA LEVEL RECORD FROM PHRA THONG ISLAND, THAILAND
Authors: Kumar Rahul , Switzer Adam D. , Gouramanis Chris , Bristow Charlie S. , Brill Dominik
Published: September 2023

Temporally changing coastline configurations and local sea-level changes pose a considerable threat to coastal communities and infrastructure. However, regional sea-level (RSL) histories spanning the last 3000 years have not been widely studied in Southeast Asia, even though the region shows significantly different RSL records from place to place (Horton et al., 2005). This period is crucial for understanding sea-level changes from pre-industrial time. Here, we investigate the record of past sea-level(s) preserved within the stratigraphy of the beach ridge system of Phra Thong Island (PTI), Thailand.
APPLICATION OF A NUMERICAL MODEL AND BATHYMETRIC INVERSION ALGORITHMS TO ENHANCE UNDERSTANDING OF NEARSHORE CHANGE
Authors: Oades Elora M. , Mulligan Ryan P. , Palmsten Margaret L.
Published: September 2023

During extreme wave events, shoaling occurs farther from shore, extending the surf zone width and intensifying wave breaking (Thornton and Guza, 1983; Mulligan and Hanson, 2016). Remote sensing using digital cameras is an inexpensive way to gather continuous observations of the surf zone and calculate water depths based on phase speed. This study investigates the robustness of the newly released version of cBathy (Holman et al., 2013; Holman and Bergsma, 2021), a bathymetric inversion algorithm. cBathy is employed in moderate to energetic wave conditions using synthetic water level data generated by the non-hydrostatic numerical phase resolving model, SWASH (Simulating WAves till Shore) (Zijlema et al., 2011; Gomes et al., 2016; Fiedler et al., 2019). The overall performance results are described by the variation in root-mean-squared errors (RMSE) with significant wave height, and with depth. The results show that RMSE are dependent on water depth, significant wave height, and domain coverage by breaking waves. cBathy V2.0 consistently performs better than the preceding version, when comparing depth estimates to survey observations.
PRELIMINARY INVESTIGATION OF SHORELINE RESPONSE IN SAN JUAN, LA UNION, PHILIPPINES
Authors: Antonio Isaiah Josef , Burhan Joseph , Morales Djuric , Lim Jose Jerard Adrian , Leon Mario De
Published: September 2023

Coastal erosion has been affected by environmental factors and human development. The investigation of the coastal erosion in San Juan, La Union covers the analysis and quantitative data that can be applied to protect the coastal community, to minimize economic losses, and to plan for the improvement of coastal process response. The main objective of this study was to investigate the shoreline response based on the extent of the coastal erosion problem of the 5.36 km - coastline of San Juan La Union and predict the long-term erosion pattern and shoreline change. The characteristics of the triggering factors of coastal erosion were evaluated during normal and extreme weather conditions. The areas along the coastline were characterized whether it experienced dominant deposition or erosion. Changes in shoreline position were assessed to predict future shoreline change scenarios. Sediment transport analysis was conducted by using the Kamphuis Formula and the CERC Formula.
TUMBLING EXPERIMENT FOR THE ESTIMATION OF ABRASION AND MASS LOSS OF COASTAL SEDIMENTS FROM AN ARTIFICIAL COARSE-CLASTIC BEACH
Authors: Bertoni Duccio , Pozzebon Alessandro , Ruol Piero , Favaretto Chiara
Published: September 2023

In order to assess the accretive or erosive pattern of a stretch of coast, it is essential to estimate its sediment budget, i.e. the quantification of all sources and sinks of sediments. The sediment budget is the basis of a reliable coastal management plan (Ruol et al., 2018). In fact, coastal erosion is usually the result of a negative balance of factors, both natural and anthropogenic, that operate on different scales, none of which may be considered the single cause. Recently, a massive abrasion rate of coarse-clastic sediments was documented in artificial nourished beaches. The mechanism is associated with both mild wave conditions and extreme stormy events, which could also induce chippings. This phenomenon could decrease the durability of nourishments (Bertoni et al., 2012 and 2016) and is usually not considered in the sediment balance. The mass loss due to abrasion can lead to errors in the analysis of erosive and accretive patterns after the nourishment and consequently to erroneous coastal management strategies. Moreover, the sediment grain size in a given beach (naturally present or selected for nourishments) is strictly related to the typical wave energy. The abrasion mechanism and the possible pebble
chipping change the sediment grain size, which could become unstable and not adequate for the local wave climate. Based on the large cost of nourishments, which also require strong monitoring in the subsequent years, it is crucial to understand the abrasion and mass loss rates of the filling sediments to extend the life of artificial beaches as long as possible.
UNDERSTANDING 3D SAND WAVE DYNAMICS FOR ENGINEERING PURPOSES
Authors: Overes Pauline , Borsje Bas , Luijendijk Arjen , Dorbrochinski Joao , Hulscher Suzanne
Published: September 2023

Due to ambitious green energy goals the pressure on the offshore area is increasing at an unprecedented pace. These offshore developments, such as wind farms, require detailed bed level predictions. However, the uncertainty in these predictions increases dramatically when dynamic bed forms, such as sand waves, are present. This is the case in many areas, such as the North Sea, Taiwan Strait and the Banks Strait Australia. Sand waves can grow up to 25 percent of the water depth, have wavelengths of hundreds of meters and migrate with several meters per year. Due to their dynamic nature and size they may pose a threat to offshore activities, such as the construction and maintenance of wind farms and ship navigation. Cables and pipelines may become exposed and foundation could become unstable, due to the migration and/or shape changes of sand waves. Currently data-driven methods are applied to predict future bed levels. The use of process-based numerical models could improve the accuracy of these predictions and help quantifying uncertainties over time. Additionally, these models give insight into the effects of extreme events and human interventions, and provide a solution for data-scarce areas.
EXPERIMENTAL STUDY ON WAVE-INDUCED SCOUR IN FRONT OF SLOPING COASTAL STRUCTURES AND THE INFLUENCE OF BED PROTECTION
Authors: Goedhart Wisse , Hofland Bas , Kuiper Coen , Ockeloen Wouter , Schipper Matthieu de
Published: September 2023

The erosion of the seabed in front of coastal structures induced by waves can lead to multiple types of failure in stability or function of the structure. On this topic most research has been done into erosion in front of vertical structures (e.g. Xie, 1981). For sloping structures a knowledge gap exists in the understanding of the processes that lead to erosion of seabed material directly in front of the structure. Available studies for sloping structures were done with regular waves (e.g. Sumer and Fredsøe, 2000) or for a low number of irregular waves (e.g. Den Bieman et al., 2019). In this study the main parameters that lead to development of scour in front of sloping structures are investigated. Additionally a method is presented that will help with predicting maximum scour depth when designing a sloping coastal structure.
ANALYTIC SOLUTION FOR THE VELOCITY FIELD AROUND SUBMERGED PERMEABLE BREAKWATERS
Authors: Kim Jeongin , Park Yong Sung
Published: September 2023

In this paper, an analytic solution to the scattering of water wave by submerged permeable breakwaters in infinite-depth water is presented. The analytic solution of the velocity field around the permeable breakwater under the linear wave train in deep water condition is sought by formulating a nonhomogeneous Riemann-Hilbert problem. To deal with the nonlinearity due to the permeability of the plates, a perturbation method is applied in terms of a small parameter representing permeability. We present the leading order solution (impermeable breakwaters) and the first order solution (permeable breakwaters) of the spatial velocity field. The validity of the leading order solution was verified through comparison with the solutions suggested by Evans (1970). Then, the impermeable and permeable breakwater’s reflection and transmission coefficients are compared in order to investigate the effects of permeability. The analytical solution presented in this research can be used for designing breakwaters, such as calculating the force applied to the breakwaters, and for validation of numerical simulations or experimental results.
ENGINEERED FRINGING REEFS: ENGINEERING WITH NATURE SOLUTIONS FOR COASTAL EROSION CONTROL
Authors: Allen Matthew , Geldard Justin , Lowe Ryan , Beaton Christopher
Published: September 2023

Over the past decade there has been extensive growth in the proposed use of ecosystem approaches to mitigating coastal hazard risks. Conventional engineering approaches typically rely on fully emergent breakwaters or seawalls like rubble mounds, caissons or panel attenuators that use concentrated, high energy methods to reflect and/or violently break wave energy. However, naturally occurring fringing reefs (coral or rocky) which protect vast portions of the world’s coastline from coastal erosion are typically submerged or partially emergent structures that attenuate energy though distributed energy mechanisms: drag dissipation and low energy wave breaking (Lowe, 2021). Multi-functional engineered reefs were designed and installed at two sites, Mon Choisy, Mauritius and C.Y. O’Connor beach in Western Australia. The reefs are designed replicate ecosystem services provided by naturally occurring reefs.
DEVELOPMENT OF PREDICTING MOTION OF FLOATING CAISSON UNDER REGULAR AND IRREGULAR WAVES
Authors: Hiraishi Kohshi , Arikawa Taro
Published: September 2023

Breakwaters for outer harbor facilities are considerably affected by wave conditions, rendering the control of caisson motion difficult. Its motion during breakwater installation is important to improve its operational efficiency and safety. In recent years, caisson motion has been studied using 3D solid-gas-liquid three-phase simulations. Nakamura et al. (2021) investigated the dynamic characteristics of floating caissons under regular and irregular waves. Takagi et al. (2021) studied its sway and contact with mounds when the bottom clearance was changed and demonstrated the validity of their numerical method. However, due to inevitable scale effects of the small-scale experiments and simulations, these studies require examination at a large scale. In this study, the numerical simulation developed by Arikawa et al. (2009) was used to investigate the motion characteristics of life-sized floating caissons under regular and irregular waves for case studies conducted at the Port of Kochi (Ishimi et al. 1996).
A COMPOSITE MODELLING APPROACH FOR THE RETROFITTING AND REHABILITATION OF AN HISTORICAL COASTAL ASSET
Authors: Altomare Corrado , Gironella Xavi , Sospedra Joaquim , Domínguez Alejandro J.C Crespo and José M.
Published: September 2023

The Pont del Petroli pier is a coastal structure located in the coastal town of Badalona, north of Barcelona, in Spain. The pier was built in the 60s to allow mooring of petroleum tankers, but fallen in disuse in 1990. Restored between 2003 and 2009, the pier is now regarded as a historical and social asset of the Catalan coast. In January 2020 the storm Gloria (Amores et al., 2020), characterized by extreme wave conditions (recorded offshore significant wave heights in excess of 8.5 m) and lasting for nearly two days, caused flooding events, casualties and severe damages to several structures in Spain. The pier head platform was damaged, four supporting piles failed and part of footbridge beam was washed away. There is no recorded wave climate that hit the pier so strong during its 50-year life. To reproduce the conditions that led to the failure of the pier a compositemodelling has been carried out at Universitat Politènica de Catalunya (UPC). The outcomes of the work provide further insight and information on the interaction between waves and the key pier elements (platform, footbridge, piles, pile caps) and aided the design for the structural retrofitting, including the study of four different alternatives for the pier head platform and the footbridge attached to it.
DIRECTIONAL SPECTRA OF INFRAGRAVITY WAVES DURING STORMY CONDITIONS
Authors: Matsuba Yoshinao , Roelvink Dano , Reniers Ad J.H.M. , Rijnsdorp Dirk P. , Shimozono Takenori
Published: September 2023

Both magnitude and directions of infragravity (IG) waves are essential information for accurate hindcast/prediction of coastal hazard due to stormy waves (e.g., coastal inundation and beach erosion). However, conventional reconstruction methods of directional spectra relying on linear wave theory are not applicable to IG waves which are composed of free (linear) and bound (nonlinear) components. This study proposes a novel method to reconstruct directional spectra of IG waves and presents diverse wave directions of free IG waves during stormy conditions.