bluuebunny/crossref_metadata_2025 huggingface dataset:
MULTI-HAZARD RISK ASSESSMENT FOR TONGATAPU – A COASTAL INUNDATION LENS
Authors: Rowe Edward , Greer Dougal
Published: September 2023

A multi-hazard disaster risk assessment was undertaken for Tongatapu through the Asian Development Bank (ADB) on behalf of the Government of Tonga. This was to inform investments, urban planning and improvements to natural hazard resilience across the island (ADB, 2021). This paper presents the methodology and findings of the coastal inundation and sea level rise components and how these relate to other hazards assessed and the overarching risk assessment. Due to its low elevation and flat topography, Tongatapu, and the Tongan capital of Nukualofa, are vulnerable to pluvial (surface) flooding associated with heavy rainfall and coastal flooding from extreme sea levels and cyclone induced storm surge. Similarly, Tongatapu is vulnerable to damaging winds associated with tropical cyclones, earthquakes particularly associated with the nearby Kermadec Tonga Trench, and tsunami inundation. The study assessed these hazards and considered the influence of climate change on intensity of rainfall and sea levels.
COASTAL SETBACK PRACTICES IN THE CARIBBEAN AND OTHER SIDS: A TOOL FOR ENHANCING RESILIENCE
Authors: Smith David , Mussington Telica , Warner Philip
Published: September 2023

This paper examines and compares existing coastal setback policies in use throughout the Caribbean and in other SIDS globally and considers recent climate change predictions. Recommendations are made for a sciencebased approach to applying setbacks, which incorporates elements of climate change predictions and longer-term observations. Finally, a case-study comparison is presented, between the most promising coastal setback approaches, and the observed incursion of storm waves at a coastal community in Jamaica during a major hurricane in 2004 (Hurricane Ivan – In Jamaica: 17 killed and US$575 million in damages).
FIRST PROJECT OF BIODIVERSITY RESTORATION OF COASTAL AREAS IN POLAND
Authors: Różyński Grzegorz , Szmytkiewicz Piotr
Published: September 2023

Increasingly difficult relations with Russia have triggered the construction of an independent passage from the Baltic Sea to the Polish part of Vistula Lagoon, operational since Sept. 2022. The Polish part of the lagoon is a NATURA2000 site, so environmental disturbances requires compensation measures, one of which is the 1st coastal biodiversity restoration project. It is based on the building with nature paradigm. Experience gained during implementation of this pilot can be treated as a more general learning process towards achieving excellence in biodiversity restoration in basins, mostly lagoons and estuaries, located in moderate latitudes.
SEA LEVEL RISE IMPLICATIONS FOR ESTUARINE MODELLING AND MANAGEMENT
Authors: Khojasteh Danial , Felder Stefan , Heimhuber Valentin , Glamore William
Published: September 2023

Estuaries provide a wide range of environmental, cultural, social, and economic services. These include primary production, water purification, recreational opportunities, navigational routes, and nurseries for aquatic species. However, a growing body of literature indicates that sea level rise (SLR) is increasingly threatening these services in estuaries due to their low-lying topography and proximity to the open ocean. As such, sustainable management of estuaries, adjacent low-lying areas, and associated ecosystems requires a thorough and evidence-based understanding of how different estuaries may respond to SLR over time and space (Khojasteh et al. (2021)). This, in turn, would help policymakers manage the far-reaching impacts and prioritise funds-based adaptation and mitigation strategies. Assessing SLR impacts in estuaries can either be undertaken on an individual site basis or via broader approaches that may be relevant to many estuaries. This study utilises the latter approach and, to this aim, a large ensemble of idealised prismatic and converging estuarine hydrodynamic simulations were conducted.
IT DOES NOT HAVE TO BE SO HARD! APPROACHES TO FORESHORE MANAGEMENT USING ADAPTIVE NATURE-BASED SOLUTIONS AND LIVING FORESHORES
Authors: Lewis Nick
Published: September 2023

The application of coastal, estuarine and river foreshore stabilization and protection has a history of ‘hard’ engineered solutions. Such approaches create species poor environments and often replace diverse natural foreshores. Not without exception, and other than low energy environments that can accommodate a purely vegetation restoration approach, the application of structures such of vertical and subvertical seawalls, rock revetments or similar have predominated. Increasingly, solutions are demonstrating that foreshore erosion protection, improvement and stabilization can have environmental enhancement and biodiversity improvements at its core and, furthermore, offer nature-based solutions that are adaptive to long term trends, such as sea level rise. The discipline is in a dynamic, rapidly evolving and ultimately exciting phase.
ASSESMENT OF WAVE OVERTOPPING ON REEF-FRONTED SHORES
Authors: Astorga-Moar Alejandro , Baldock Tom E.
Published: September 2023

Overtopping has been widely studied to design coastal structures, and it is also an important parameter for coastal management in order to evaluate the protection by natural coastal systems against inundation. Most formulations for open coasts have estimated overtopping using the wave runup (R2 percent), the beach slope and the truncated point, with empirical coefficients to account for further details (e.g. EurOtop, 2018). However, for beaches that are naturally protected by fringing reefs, the knowledge of overtopping is limited, and reliable analytical formulations have not been developed. The aim of this research is to evaluate the previous overtopping model and scaling laws and suggest one model applicable to reef-fronted shores.
DOWNSCALING CLIMATE PROJECTIONS TOWARDS COASTAL HYDRODYNAMICS MODELS
Authors: Biolchi Luis Germano , Unguendoli Silvia , Ferrarin Christian , Valentini Andrea
Published: September 2023

State-of-art modelling has shown a largely altered oceanographic environment as a consequence of climate change. The climate models implemented normally present low temporal and spatial resolutions as they aim at a general understanding on how large scale processes vary in a changing climate. Through downscaling projections towards coastal applications it is possible to reach higher resolutions and much more detailed information. If such an approach is performed using unstructured models instead of finite difference ones, it allows for an even better representation of complex morphologies. The latter enables studying more in depth the behavior of coastal environments, such as deltas, that heavily involve the oceanographic and hydrologic components. One of such areas is the Po Delta located in the Northern Adriatic Sea. With its complex system of lagoons and river branches (Maicu et al., 2018), downscaling is fundamental for representing the local processes driven by the interaction between the basin wide circulation and the freshwater inputs. In the context of the European Strategic Italy-Croatia AdriaClim Project (ID 10252001), hydrodynamic downscaling from regional scenario projections to high-resolution coastal applications is undergoing. The final local, high-resolution implementation is a finite element hydrodynamic model that uses the atmospheric forcing, and hydrologic and oceanographic boundaries from the projections.
MANGROVE AND ITS IMPACTS ON WATER WAVES: A MODEL-SCALE LABORATORY STUDY USING 3D REPLICAS OF TYPICAL RHIZOPHORA
Authors: Chang Che-Wei , Mori Nobuhito , Tsuruta Naoki , Suzuki Kojiro , Yanagisawa Hideaki
Published: September 2023

Mangroves, a major type of nature-based solution in the tropics and subtropics, were evidenced capable of reducing wave energy in tsunami and storm events. The typical species, Rhizophora with its complex root system, was found effective in wave attenuation (Tanaka et al. 2007) and was studied experimentally using artificial tree models (e.g. Maza et al. 2019). To investigate the impacts of mangrove roots on water waves at a finer scale, we conducted experiments using 3D-printed models that replicated the geometry of natural Rhizophora. This study discusses the resistance of mangrove roots and their impacts on fluid velocity and turbulence.
NATIONAL ASSESSMENT OF HURRICANE-INDUCED COASTAL EROSION HAZARDS IN PUERTO RICO
Authors: Torres-Garcia Legna M. , Thompson David , Doran Kara , Buckley Mark , Vargas-Babilonia Priscila , Palmsten Meg L. , Storlazzi Curt
Published: September 2023

Storms are one of the main causes of coastal erosion, causing substantial property and infrastructure losses in coastal communities. Coastal erosion is particularly damaging in underrepresented communities that are unable to meet building and zoning regulations due to limited resources [Lam, 2014]. The United States Geological Survey (USGS) has developed a probabilistic assessment of hurricane-induced coastal erosion for sandy coastlines along the eastern United States and the Gulf of Mexico. However, the current USGS product incorporates an empirical equation with inputs of beach slope and deep-water wave height and period [Stockdon, 2006] to predict the wave runup. Though this is appropriate for open coast sandy beaches, it is not valid for the rocky and reef lined coasts of Puerto Rico due to their complex bathymetries, steep slopes, and large bottom roughness. To expand this tool to Puerto Rico, the USGS has created 1-dimensional XBeach [Roelvink, 2009] models around the island.
THE JOURNEY FROM THEORY TO APPLICATION IN COASTAL MANAGEMENT – A REGIONAL PERSPECTIVE FROM SOUTH WESTERN AUSTRALIA
Authors: Barr Stuart
Published: September 2023

This paper traces the journey from theory to application in several projects undertaken in a regional area of Western Australia. This includes design and construction of coastal rock revetments, low profile geotextile sand container groynes, and beach nourishment projects. The importance of understanding the subtleties of coastal dynamics in a particular area, the application, and limitations of widely applied coastal engineering practices, and the importance of positive relationships with experienced local contractors in delivering coastal projects is outlined.
THE TIDE IS HIGH: NEW INSIGHTS ON COASTAL FLOODING TRENDS AND FUTURES
Authors: Hague Ben
Published: September 2023

Coastal flood frequencies are expected to increase around the world due to sea-level rise (SLR). This is largely related to the emergence of tidal flooding, where coastal flood thresholds are exceeded by astronomical tides alone. We will discuss the concept of tidal flooding and the observed trends from Australia and the United States. We then apply a new risk assessment framework (Hague et al. 2022) to identify which locations are most vulnerable to chronic flooding due to SLR this century. Finally, we discuss the implications of a global application of this framework for coastal engineering and management applications.
MULTI-LINEAR-ELEMENT DEPTH-INTEGRATED MODELS FOR FLOWS WITH A FREE SURFACE
Authors: Yang Zhengtong , Liu Philip L.-F.
Published: September 2023

In this study, we derive a new set of depth-integrated models for solving unsteady flows that satisfy the Euler equations and nonlinear free surface boundary conditions in the sigma -coordinates. One of the obvious differences between the present approach and the ones directly solving the 3D Euler equations using Finite Element Method (FEM) is that in the present model the vertical velocity and the pressure field are eliminated by integrating the continuity equation and vertical momentum equation, respectively. Therefore, the present models only solve the horizontal velocity components and the free surface displacement in the two-dimensional horizontal (2DH) space. The new models are also more advantageous in using fewer elements in the vertical direction while achieving better performance. At this stage, the capability and application of the new models in dealing with free surface wave propagation problems are addressed.
3D NUMERICAL MODELLING OF FIVE SUBMARINE LANDSLIDE SCENARIOS IN PERTH CANYON, AUSTRALIA TO ASSESS TSUNAMIGENIC HAZARD
Authors: Buller Elise J. , Mollison Kendall C. , Power Hannah E.
Published: September 2023

Submarine canyons have been identified on nearly all margins around the world (Urlaub et al., 2013). Their configuration and morphology has been attributed to several factors including geology, tectonism, sea-level variations, and sediment supply to the region (Laursen and Normark, 2002) with processes occurring over varying temporal and spatial scales driving complex morphologies (Drexler, et al., 2006). A common process in submarine canyons is the mass wasting of sediment in the form of submarine landslides (SMLS) (Brothers, et al., 2013). A SMLS is a displacement of sediment or debris driven by gravity where the downslope forces are greater than the forces that are acting to resist the mass-failures (Mountjoy and Micallef, 2018). The potential tsunami hazard posed by these SMLS was assessed by Buller et al. (2021) using empirical calculations which showed that these SMLSs posed a tsunami threat to the adjacent coastline with calculated wave amplitudes ranging from 2.13 – 15.90 m. However, the tsunami risk assessed in their study was a conservative initial assessment and did not consider how local bathymetry influenced tsunami propagation.
THE IMPLICATIONS OF TRANSITIONAL CLIMATE REGIONS ON COASTAL RISK
Authors: Odériz Itxaso , Mori Nobuhito , Silva Rodolfo , Losada Iñigo J.
Published: September 2023

The latest report of the IPCC-AR6 warned that coastal regions are one of the most vulnerable areas in the current climate emergency. In response, the knowledge concerning projected climatic-impact drivers (total water level, average and extreme waves) is rapidly progressing to reduce future coastal flooding and erosion risks. Climate change also shifts atmospheric circulation and affects the climate regions and their surrounding areas. This study aims to identify transitional wave climate regions and proposes a map of these critical areas. A spatial-temporal and multivariate analysis, based on Machine Learning approaches, was used to classify the wave parameters into climates for the end of the century (2081-2099) under the RCP8.5 scenario.
SEASONAL DRIVERS FOR MANGROVE SEEDLING ESTABLISHMENT
Authors: Gijsman Rik , Horstman Erik , Swales Andrew , MacDonald Iain , Willemsen Pim , Wal Daphne van der , Wijnberg Kathelijne
Published: September 2023

Mangrove forests are located along (sub)tropical shorelines and can contribute to flood risk reduction and shoreline stabilization. Evidence of the wave-attenuating function of mangroves is increasing, but knowledge gaps persist regarding the critical conditions to mangrove forest development. The implementation of mangroves in coastal engineering practice also requires a firm understanding of these critical conditions (Gijsman et al., 2021). Conditions and thresholds for mangrove seedling establishment are key in the long-term development and survival of mangroves. Compared to mature mangrove trees, establishing young mangrove seedlings are much more vulnerable to daily to seasonal fluctuations in hydrodynamics and bed level dynamics (Balke et al., 2015). This study aims to develop a mangrove seedling establishment model to study the biophysical interactions and feedbacks between mangrove forests, tides, waves, sediment dynamics and seedlings. Combining field observations and numerical modelling, we will assess the critical conditions for mangrove seedling establishment on a daily to seasonal timescale.
LANDSLIDE TSUNAMI HAZARD ASSESSMENT: A NUMERICAL MODEL FOR THE SIMULATION OF MULTIPLE LANDSLIDE-INDUCED TSUNAMIS SCENARIOS IN A MONTE CARLO FRAMEWORK
Authors: Cecioni Claudia , Bellotti Giorgio , Iorio Verdiana , Grilli Stephan T.
Published: September 2023

Submarine landslides can pose serious tsunami hazard to coastal communities. However, performing a comprehensive landslide tsunami hazard assessment for a given area is in general difficult in view of the large uncertainties associated with tsunamigenic source parameters. These are often known only approximately, on the basis of estimates of the landslide geometry, slide material properties, and kinematics. Here, we present an efficient model to perform such hazard analyses, based on solving the linear mildslope equation with a time-dependent source term representing the seafloor motion as detailed in Iorio et al. (2021). This approach allows carrying out many computations, for a large number of landslide scenarios, in a Monte Carlo (MC) approach framework, at a reduced computational cost compared to other available methods, while still providing physically accurate simulations of most landslide tsunami generation and propagation.
CAN APPLE LIDAR CAMERAS BE RELIABLY USED FOR COASTAL MONITORING?
Authors: Splinter Kristen D. , Vos Kilian , Gois Jordan , Luker Max , Drummond Chris
Published: September 2023

Smart phones are becoming ubiquitous devices that can be exploited for citizen science applications, including coastal monitoring (Harley et al., 2019). In 2020, Apple released new versions of their iPhone (12+) and iPad Pro (2020+) that included built-in LIDAR functionality. These were accompanied by a series of commercial applications (e.g., 3DScanner, Scaniverse, and many others) built to capture high resolution objects at close range using mesh or point-cloud formulations. The built-in GPS of the iPhone/iPads however is of low accuracy (~5m horizontal) compared to the demands for scientific surveys. Fortuitously, commercial hand-held RTK-GNSS units (e.g., EOS Arrow Gold, Pix4D viDoc, RedCatch) that can talk directly to the smart phones and provide surveygrade positioning have also been recently developed. The Pix4D viDoc and RedCatch devices are targeted at photogrammetry applications rather than the internal LIDAR scanner, while the EOS Arrow family is application independent. In the past year, several papers have been published examining the ability of smartphones equipped with LIDAR to be used in various geophysical applications ( Luetzenburg et al. 2021; Mokros et al. 2021; Spreafico et al. 2021). This then begs the question – can these smart phones equipped with LIDAR be reliably used for coastal monitoring with existing (free) commercial applications?
EXPANDING COASTSAT SHORELINE DETECTION ALGORITHM TO TRACK COASTAL VEGETATION AND URBAN CHARACTERISTICS FROM SATELLITE DATA
Authors: Lanza Adriana , Sullenberger Ryan M. , Chen Justin G. , Hopkins, Julia
Published: September 2023

Classical survey methods involve making in situ measurements of shoreline locations, which can never scale to the time spans and spatial extent necessary to cover large coastal areas. For 50 years now, satellites have provided images of the earth with reasonable resolution that can provide some insight into shoreline evolution over large timescales and wide areas. Determining shoreline location from satellite imagery involves a general pipeline of image pre-processing, segmentation of the image into water and beach, and then determination of the shoreline location. The goal of the research here is to expand the capabilities of CoastSat to include identification of coastal vegetation and tracking of vegetated shoreline evolution. Accurate measurements of coastal vegetation extent and evolution from satellites may help our understanding of the health of shoreline ecosystems as sea levels rise and storms become more intense. Shoreline trends observed from satellite imagery will provide information to coastal communities that can be used for effective spatial planning, sustainable coastal development, coastal engineering projects, and mitigation of climate change impacts.
TSUNAMI EVACUATION IN A MASSIVE CROWD EVENT USING AN AGENT-BASED MODEL
Authors: Flores Constanza , Lee Han Soo , Mas Erick , Salar Jonathan
Published: September 2023

Under emergencies, individuals tend to move faster than during normal conditions, i.e., evacuation vs non-evacuation scenarios (Helbing et al., 2000; Cornes et al., 2019; Chen et al., 2018). Evacuations because of false alarms, terrorist attacks, fires, or disasters like earthquakes or tsunamis can quickly increase stress levels in people. Activities such as carnivals, festivals, sports, pilgrimages, and marches gather thousands of people in one place. In the literature, open space tsunami evacuations in places such as beaches are scarce. Studies from Takabatake et al. (2018) and Lanza et al. (2021) have integrated beach users in their simulations. However, studies involving massive tsunami evacuations including socio-psychological interactions, to our knowledge, are not documented. The main objective of this study is to assess human behavior in a hypothetical scenario such as a massive tsunami evacuation in a coastal area, using Valparaíso City as a case study.
DEVELOPMENT OF FLOOD RISK REDUCTION INVESTMENT STRATEGIES THROUGH GLOBAL FLOOD RISK TOOL AND APPLICATION OF ADAPTATION PATHWAYS
Authors: Bos Matthijs , Watering Michael van de , Trommelen Joost
Published: September 2023

Flooding is an issue of growing concern worldwide. Cities around the world are threatened by sea level rise, land subsidence as well as extreme river discharges and intensified precipitation during short periods of time. The interaction of these phenomena potentially causes severe flood problems. In addition, cities are often densely populated centres with high socio-economic development and sophisticated networks of water-related infrastructure. Hence, the impact and damage of flooding can be significant and very costly. In addition to climate change and socio-economic growth, many cities are sinking as a result of land subsidence. In response to these issues, Royal HaskoningDHV has been developing the Global Flood Risk Tool (GFRT). The GRFT is Royal HaskoningDHV’s cloud-based platform that delivers accurate and comprehensible flood risk analysis and recommends strategic investment proposals to reduce risk on losing lives and economic damages to the society, infrastructure, industries and businesses.
NUMERICAL SIMULATION OF DRIFTWOOD TRANSPORT BY WAVES IN A LABORATORY BASIN
Authors: Murphy Enda , Cornett Andrew , Nistor Ioan
Published: September 2023

Driftwood plays an important role in coastal ecosystems but, in large accumulations, can have negative impacts and pose hazards to navigation, infrastructure and communities (Murphy et al. 2021). The ability to accurately predict the fate and transport of coastal driftwood is central to informing sustainable management practices. However, there is a paucity of numerical modelling studies focused on driftwood transport in coastal waters (Murphy et al. 2021). Models developed for rivers (e.g. Ruiz-Villanueva et al. 2014) lack consideration of processes affecting driftwood transport and accumulation in coastal environments, such as wind waves. Murphy et al. (2020) conducted experiments in a 50-m by 30-m wave basin, wherein model driftwood was released and tracked within a 1/30 scale physical model of a sandy beach system with various coastal structures. The tests revealed that several factors influence the mobility of coastal driftwood exposed to waves, beaching and washoff processes in particular.
BIG COASTAL MANAGEMENT REQUIRES BIG COASTAL MONITORING: TWO DECADES OF OPERATIONAL COASTAL IMAGING AT AUSTRALIA’S GOLD COAST
Authors: Drummond Chris , Blacka Matt , Turner Ian
Published: September 2023

2022 marks over two decades since the construction of the Narrowneck multi-purpose reef at the Northern Gold Coast, Queensland. The reef was implemented in 2000 in parallel with 1.1 million m3 of beach nourishment which is one of the most innovative and large-scale coastal management projects in Australia (Boak et al. 2000). Effecting beach management works of this scale also required implementation of a cutting edge coastal monitoring program, with the Water Research Laboratory (WRL) working alongside Gold Coast City Council to establish an Argus camera system at Surfers Paradise in 1999 (Turner et al, 2004). At the time, this station was the forefront of coastal monitoring technology, providing weekly shoreline position, intertidal morphology and rectified imagery of the beach. The monitoring system now provides Council with aerial imagery and measurements of the complete 32 km of beaches within the littoral drift dominated sediment compartment, every hour of the day. This paper reflects on two decades of monitoring system advances, and presents the challenges and capabilities in operating such a significant beach monitoring network over such a long period of time.
THE COASTAL MACRO-VORTICES DYNAMICS: A CASE STUDY IN HONG KONG WATERS
Authors: He Chang , Stocchino Alessandro , Yin Zhen-Yu
Published: September 2023

Coastal circulations are basic information when considering sediment transport and water quality in the oceanic environment, particularly the macro-vortices dynamics which greatly affected the mass transfer and extended the residence time (Hasegawa et al., 2009). Large-scale macro-vortices could be formed in the lee or around natural obstacles such as islands and headlands during the interaction between geographical features and coastal circulations induced by tides and winds. Pearl River is the second largest river in China considering discharge, delivering 3.26 × 1011 m3 freshwater every year into the South China Sea (SCS) through eight outlets (Wu et al., 2016). Hong Kong (HK) is located downstream of the Pearl River Estuary (PRE), acting as a bridge between the PRE and the SCS, as shown in Figure 1. HK possesses more than 200 islands as well as narrow channels and complex coastlines, which have a great impact on shaping local flow structures. In addition, prevailing southwest winds blow during the summer, while stronger northeast winds gust during the winter. Embracing tides from the SCS and river discharge from the PRE, HK waters is an energetic and interesting area and worth a detailed investigation.
MONTE CARLO SIMULATION OF BARRIER-ISLAND SYSTEMS AND TSUNAMI HAZARDS
Authors: Irish Jennifer L. , Weiss Robert , Dura Tina
Published: September 2023

Robust characterization of the future tsunami hazard is critically important for resilient planning and engineering in coastal communities prone to tsunami inundation. The hazard from earthquake-generated tsunami waves is not only determined by the earthquake's characteristics and distance to the earthquake area, but also by the geomorphology of the nearshore and onshore areas, which can change over time. In coastal hazard assessments, a changing coastal environment is commonly taken into account by increasing the sea-level to projected values (static). However, sea-level changes and other climate-change impacts influence the entire coastal system causing morphological change (dynamic). Here, we present the modeling framework and results initially published in Weiss et al. (2022), which employs within a Monte Carlo framework the barrier island-marsh, lagoon- marsh evolution model of Lorenzo-Trueba and Mariotti (2017) and the tsunami model Geoclaw (e.g., LeVeque et al. 2011). We compare the runup of the same suite of earthquake-generated tsunamis to a barrier system for statically adjusted and dynamically adjusted sea level and bathymetry over the period from 2000 to 2100. We employ Representative Concentration Pathways 2.6 and 8.5 without and with treatment of Antarctic ice-sheet processes (e.g., Kopp et al. 2017) as different sea-level projections.
BEACH GROUNDWATER IMPACTS ON WAVE OVERTOPPING FLOODING
Authors: Delisle Marie-Pierre , Kim Yeulwoo , Gallien Timu
Published: September 2023

Coastal flooding is a growing socioeconomic and humanitarian hazard (e.g., Nicholls, 2010). Increased beach groundwater levels may inundate low-lying areas and simultaneously propagate swash impacts onto higher beach and backshore elevations. Generally, coastal flood modeling and risk assessment characterize only surface flows, neglecting beach groundwater and swash zone processes such as infiltration and porous media flow. Numerous studies have considered the effects of swash on groundwater (e.g., Gourlay, 1992). Infiltration leads to reduced wave runup (Pintado-Patino et al., 2015) and is promoted by low beach groundwater levels (Bakhtyar et al., 2011), suggesting that beach groundwater plays a critical role in infiltration/exfiltration processes. Notably, the impacts of beach groundwater on swash flows and subsequent consequences on coastal flooding have not been explored. Coastal flooding from wave overtopping is expected to occur around the maximum tide. However, recent field observations suggest maximum overtopping lags behind high tide and is in phase with maximum groundwater levels. In this study, a turbulence and depth resolving numerical model is developed to examine the interaction between beach groundwater and wave overtopping processes.
MODELLING OF DEBRIS MOTION DRIVEN BY TSUNAMI WAVE BREAKING
Authors: Kihara Naoto , Kaida Hideki , Tsurudome Chiaki
Published: September 2023

When a giant tsunami approaches onshore, offshore vessels and other floating objects move following the current of the tsunami. Some of the waterborne debris are transported to tsunami inundation areas and those debris impact buildings. For evaluations of debris impact loads, types of debris having the potential to impact and damage the structures are identified by considering debris impact hazard region. According to ASCE7-22, the debris impact hazard region shall be determined by the empirical model proposed by Naito et al. (2014) in a simple manner. Furthermore, numerical debris transport modelling using massless tracers also shall be permitted to use for the determination. On the other hand, numerical debris tracking (nDT) modellings which solve the equation of motion of debris have been developed (e.g., Kihara and Kaida, 2019). In this study, a surface roller modelling is incorporated into the nDT model of Kihara and Kaida (2019) to simulate debris motions driven by tsunami wave breaking. To validate the model, simulations of hydraulic experiments focusing on the motion of offshore debris reported by the Nuclear Regulation Authority (NRA) of Japan are carried out (Oda et al., 2021).
PHYSICS-INFORMED DEEP LEARNING OF NEARSHORE WAVE PROCESSES
Authors: Chen Qin , Wang Nan , Chen Zhao
Published: September 2023

The paper introduces the NWnets, a physics-informed deep learning model for reconstructing nearshore wave fields and mapping bathymetry. The physics encoded into the deep neural networks are the wave energy balance equation and dispersion relation. Insights into the model capability are gained through application of the NWnets to a laboratory experiment of wave transformation over a circular shoal. If the bathymetry and discrete measurements of wave height are available, the NWnets model is capable of simulating nearshore wave transformation. Moreover, the extended NWnets can be used for depth inversion if the bathymetry is unknown. Two methods for simultaneously estimating water depths and surface waves are presented. If surface wave number and limited wave height measurements are available from remote sensing platforms, the first method employs wave numbers and scarce measurements of wave height as training data. The second method utilizes scarce wave height and limited water depth measurements as training points to reconstruct bathymetry and wave fields. The results show that both methods are capable of simultaneously mapping the bathymetry and waves when the locations of training points are appropriately distributed.
CASE STUDY OF INTEGRATED COASTAL ZONE MANAGEMENT IN IVORY COAST: STABILIZATION OF A MIGRATING TIDAL INLET BY SOFT PROTECTION MEASURES
Authors: Dissez Aurélie Le , Walther Régis , Ochou Abé Delfin , Eric Valère Djagoua
Published: September 2023

The village of Lahou Kpanda (Grand Lahou, Côte d'Ivoire), located to the immediate west of the mouth of the Bandama River, on the barrier island of the Tagba lagoon, is highly vulnerable to coastal erosion. It is directly threatened by the migration of the river mouth, which has been occurring at an average speed of 160 m/year over the last 10 years, as well as by the risks of flooding and coastal flooding which the effects of climate change will exacerbate further. This article presents the study, beginning in 2019 and financed by the WACA programme, which contributed to the choice and dimensioning of a sustainable solution for stabilization of the Grand-Lahou sandy barrier island.
NUMERICAL MODELLING OF TSUNAMIS GENERATED BY GRANULAR LANDSLIDES IN OPENFOAM
Authors: Romano A , Lara J , Barajas G , Losada IJ
Published: September 2023

Landslide-generated tsunamis are a relevant source of hazard for coastal areas. In this paper, the preliminary modelling results of tsunamis generated by deformable landslides by using computational fluid dynamics (CFD) methods, in OpenFOAM, is presented. The numerical approach presented here consists in modelling the granular material by using a Coulomb viscoplastic rheology. This numerical model is applied to reproduce three literature benchmark cases (2D submerged, 2D and 3D subaerial, respectively). Some preliminary qualitative and quantitative numerical results, compared to the experimental ones, are presented in the paper.
THE INFLUENCE OF A CROWN WALL ON WAVE OVERTOPPING OVER BREAKWATERS
Authors: Eldrup Mads Røge , Andersen Thomas Lykke , Doorslaer Koen Van , Meer Jentsje van der
Published: September 2023

This paper investigates the influence of a crown wall on wave overtopping on rubble mound breakwaters. Existing data is used to modify the EurOtop overtopping formula updated by Eldrup et al. (2022) to cover the influence of the crown wall. The effect of raising the wall above the armour crest (elevated wall) or lowering the wall below the armour crest (lowered wall) is investigated. A crown wall at the armour crest level is considered as the reference case. By increasing the elevation of either the armour crest or the crown wall, overtopping is reduced and by lowering either of them, overtopping increases. The influence of the crown wall height, elevated or lowered compared to the armour crest, is not considered accurately in the present design guidelines and thus corrections are suggested. For an elevated wall, a modified crest width has been defined, to better describe the presence of the armour crest in front of the wall. For the lowered wall the effective freeboard might be taken as the average of the wall and armour freeboards. The improvement compared to existing methods is significant, especially for breakwaters with a large elevated wall. The proposed modifications to the EurOtop Manual increase the range of applicability with respect to the wall configuration.
COMPARATIVE ASSESSMENT OF NON-CONSERVATIVE AND CONSERVATIVE RANS FORMULATIONS FOR COASTAL APPLICATIONS INVOLVING BREAKING WAVES
Authors: Saincher Shaswat , Sriram V.
Published: September 2023

Two-phase Reynolds Averaged Navier-Stokes (RANS) simulations of breaking waves are susceptible to an unphysical thickening of the plunging crest. This is often times incorrectly attributed to deficiencies in the interface capturing scheme although, in reality, the issue stems from the nature of density treatment in momentum advection. If the density is considered face-centered in the advection term, the resulting formulation is conservative whilst if the density is modeled as a cell-centered quantity, the resulting formulation is non-conservative. Despite both approaches having been extensively applied to wave-breaking simulations in the literature, there is no study comparing both formulations for the same breaking scenario. In the present paper, we extensively compare both formulations for several depth- and steepness-induced breaking problems simulated using our in-house solver: IITM-RANS3D. Through these simulations, our work successfully addresses the following research questions: (a) how and why density treatment affects the physics of overturning and subsequently the plunging jet’s topology and (b) what are the implications of choosing a particular formulation for simulating a violent wave-structure interaction scenario?
WAVE OVERTOPPING CHARACTERISTICS FOR A DOUBLE VERTICAL WALL AND THE EFFECT OF PARAPETS
Authors: Spek Bart-Jan van der , Bijl Eelco , Meer Jentsje van der , Streicher Maximilian , Troch Peter , Guillermin Pierre-Yves
Published: September 2023

The mean wave overtopping discharge and extreme overtopping volumes were assessed for a double vertical wall solution, including the combined effect of the mutual distance and effect of parapets, also known as wave return walls or bullnoses. New empirical functions were derived for predicting the mean overtopping discharge and maximum overtopping volumes applicable for this design case. This study demonstrates the importance of analyzing the statistical characteristics of extreme overtopping volumes, especially for cases with low number of overtopping waves and steep volume distributions. It is argued that derivation of these statistics is essential for design of coastal structures and required drainage system at the hinterland. The analysis has shown that performing repetition tests is valuable, especially with cases of low number of overtopping waves. Generating more data allows for the derivation of more reliable statistics and in turn enables better quantification of the associated uncertainties. Statistical parameters of wave overtopping volumes showed that it provides critical design input for drainage and enable the generation of synthetic overtopping events with realistic distributions of wave overtopping volumes.
FLEXIBLE FLUID-STRUCTURE INTERACTION OF A FLEXIBLE PLANT MODEL FOR NATURE-BASED SOLUTIONS
Authors: Henteleff Ross , Markov Acacia , Stolle Jacob , Nistor Ioan , Sriram V
Published: September 2023

Nature-based solutions (NBS) represent a new field of research and engineering applications, becoming increasingly popular in the coastal engineering field. Salt marsh restoration, an example of NBS, is particularly appealing due to the variety of benefits they can provide, especially their capacity to induce sediment accretion, potentially keeping pace with sea-level rise. This study investigates the applicability of the flexible fluid-structure (FSI) interaction module being developed for open-source software REEF3D to the motion of marsh plants under wave action using data from a physical model study performed by Paul et al. (2016). The model consistently overestimates the drag force response of a flexible plastic plant surrogate under wave action. This suggests that this new tool may not be suited for this case. However, further investigation must be performed to test the limits of the model’s application.
STABILITY OF BURIED SCOUR PROTECTION IN SHALLOW COASTAL WATERS
Authors: Kerpen Nils B. , Schendel Alexander , Forgan Henry , Peters Dirk Jan , Zigterman Erik , Schlurmann Torsten
Published: September 2023

Physical model tests were conducted to verify the stability of a conceptual scour protection design placed around monopiles in varying water depth and under combined wave and current load. The tests were performed in a 3D wave-current basin at Ludwig-Franzius-Institute, Leibniz University Hannover in a model scale of 1:35. As a unique boundary condition compared to previous studies, the scour protection around the monopile was placed below a mobile sand bed. Before waves and current could act on the scour protection, the overlaying sand layer had to be eroded. The scouring process of this sand layer was evaluated, and the stability of the armour layer of the underlying scour protection quantitatively assessed. The characteristics of the scour development and the damage of the armour layer were described as a function of several wave-current load combinations and different morphodynamic stages of the beach.
EVALUATION OF BIAS CORRECTION METHODS FOR DETERMINING FUTURE DESIGN WAVE HEIGHT BASED ON MEGA-ENSEMBLE CLIMATE PROJECTION
Authors: Watanabe Kunihiro , Kato Fuminori , Hosaka Koichi , Zaha Takehito , Takagi Toshimitsu
Published: September 2023

Mega-ensemble climate projection results are expected to be used for investigating future changes in design condition, such as wave height and storm surged. However, climate models are known to have some uncertainties making bias correction necessary. We performed wave modeling was performed based on typhoon tracks extracted from megaensemble projections. Three bias correction methods were investigated, and the variation induced by these methods was evaluated. The corrected future wave heights showed variations among various locations, and they were larger than the variations caused by the difference in bias correction methods for the return periods of 1/30 and 1/50. This result suggests that appropriately selecting a correction method is not a significant issue in coastal planning.
ON WAVE TRANSMISSION AT SUBMERGED RUBBLE-MOUND BREAKWATERS WITH LARGE TIDAL RANGE
Authors: Leone Elisa , Brancasi Alberica , Ciardulli Francesco , Francone Antonio , Sigurdarson Sigurdur , Tomasicchio Giuseppe R. , Kobayashi Nobuhisa , Chiaia Giancarlo
Published: September 2023

The present paper provides the results of an experimental and numerical investigation on a submerged rubble-mound breakwater with the aim to study its performance in terms of wave transmission in condition of large tidal range. The experimental investigation has been conducted at the EUMER laboratory of the University of Salento. In the 2D wave flume, a small-scale physical model of a submerged breakwater has been constructed and exposed to different wave conditions and water levels. The experimental observations have been used to calibrate the numerical model CSHORE and to investigate the fraction of the different energy dissipative contributions due to wave breaking, to bottom friction and to porous mound. Additional tests have been numerically conducted to cover a wider range of wave conditions and water levels, allowing to better evaluate the behavior of the submerged rubble-mound breakwater in condition of large tidal range.
AFTER THE 1972 STOCKHOLM CONFERENCE: 50 YEARS OF COASTAL MANAGEMENT IN PORTUGAL
Authors: Coelho Carlos
Published: September 2023

Stockholm Conference, held in 1972, represents the first United Nations Conference on the Human Environment. The declaration presented at the end of the conference considered the need for principles to inspire and guide in the preservation and enhancement of the human environment. Past 50 years over this event, some analyses are demanded. Thus, based on Stockholm Conference main proclamation, this work aimed to present an evaluation of what was the Portuguese coastal management over the last five decades, highlighting what was done and what is still missing. The Stockholm Conference outputs pointed out the importance to preserve the environment. The Portuguese coastal management along the last 50 years experienced different strategies. Presently, it is evident the importance of monitoring, integrated studies, combining social, economic and environmental aspects, stakeholder’s involvement, education and dissemination. However, Portuguese coastal areas still face multiple environmental challenges and conflicts, which continuously demand for an adequate coastal management, looking for a sustainable future.
WIND AND WAVE TRAINED ARTIFICIAL NEURAL NETWORKS FOR THE FORECASTING OF WAVE CLIMATE IN HARBOUR AREA
Authors: Cavallaro Luca , Iuppa Claudio , Castro Elisa , Faraci Carla , Musumeci Rosaria Ester , Foti Enrico
Published: September 2023

Nowadays, maritime transportation has expanded rapidly, involving the need to enhance several navigation-related issues, particularly concerning the safety of navigation, which is significantly impacted by weather conditions. In this regard, creating a wave forecasting system could facilitate vessel movement at the harbour entrance or inside the sheltered area. Wave characteristics are usually estimated using numerical models, which generally require high computational costs, making them inadequate for nowcasting and forecasting wave climate. The current study describes the implementation of a forecasting methodology for the port area of Augusta (Sicily) based on an Artificial Neural Network (ANN) that attempts to deliver a trustworthy response and the numerical model but with a significant reduction in the computational time.
MAXIMUM MOMENTUM FLUX FOR STABILITY ANALYSIS OF MODEL AND PROTOTYPE BREAKWATERS
Authors: Jayewardene Indra FW , Golshani Aliasghar , Couriel Ed
Published: September 2023

None of the established formulae for breakwater armour stone stability, Hudson (1958) or van der Meer (1987), explicitly account for the water depth at the toe of the structure. More recently, Hughes (2004), Melby and Hughes (2004), Melby and Kobayashi (2011) have developed equations for stability and runup utilising the concept of wave momentum flux which explicitly accounts for the water depth of the wave probe(s) in close proximity to the structure. The equations are adapted to three forms; namely (1) linear, (2) extended-linear and (3) non-linear. In the paper linearity is assessed by using the Ursell number at each probe depth. Also, due to the placement of probes at various depths in MHL’s 2D wave flume it is possible to correlate the linearity of the wave measurement for the same time series and subsequently test the appropriateness of the momentum flux equation applied for assessment of stability and runup. The stability and runup data from 43 2D physical model tests where stability was previously assessed using van der Meer’s and Hudson’s equations are assessed using the momentum flux equations and an evaluation of the results has been made. It was found that the estimation of notional permeability and selection of the use of the plunging or surging formulae was critical to obtaining a closer match between measurement and prediction. The equations were also utilised in conjunction with numerical models to evaluate the armour size for repair of two breakwater heads in South Camden Haven and Bellambi. The maximum momentum flux equations were found to perform satisfactorily at these locations where the Ursell numbers were found to be high and the waves non-linear.
MONITORING MOORED BOAT MOTIONS INDUCED BY WAKE FROM PASSING VESSELS, A CASE STUDY: WILLIAMSTOWN MARITIME PRECINT
Authors: Machado Daniel A. , Clarke Linden , Derkani Marzieh H. , Gilbert Lindsey C. , Sumputh Deven
Published: September 2023

Wash and wake from marine traffic can result in undesirable social and environmental impacts in coastal and waterway areas. This case study focused on identifying the cause-effect relationship between the propagation of wake induced waves from passing vessels and the motions of moored boats in the Williamstown Maritime Precinct, Victoria, Australia. The study involved field monitoring and data analysis, developing methods and insights for the local study area, which can be applied to other areas experiencing similar issues.