Coastal EngineeringPub Date : 2025-03-05DOI: 10.1016/j.coastaleng.2025.104740
Mariano Buccino, Sara Tuozzo, Mario Calabrese
{"title":"The wavefront shift method for bay beaches","authors":"Mariano Buccino, Sara Tuozzo, Mario Calabrese","doi":"10.1016/j.coastaleng.2025.104740","DOIUrl":"10.1016/j.coastaleng.2025.104740","url":null,"abstract":"<div><div>Bay beaches, sheltered by one or more headlands, are predominant physiographic features along oceanic and sea coasts. Their distinctive planform is created through wave sheltering caused by diffraction, along with refraction wherever the indentation of the bay is large. The asymptotic scenario entailing no littoral drift along the bay is known as “static equilibrium”, and the shoreline contour associated with this long-term stable state is denoted as the Static Equilibrium Planform (SEP). SEP prediction is a crucial concept for engineering applications, as it serves to either check for the status of existing beaches or address erosion issues via headland control. The practical impact of this topic is reflected in the remarkable body of available literature. This article discusses a new SEP predictor, which focuses on wave diffraction as the primary driver shaping the bay. The approach, denoted as the Wavefront Shift Method (WSM), involves translating the diffracted wavefronts along the crestline of the incident waves. Diffracted wavefronts are obtained numerically by propagating regular waves with a Boussinesq model. Unlike other predictors, e.g. the parabolic equation, WSM does not rely on a mathematical formula established a priori; moreover, it features a clear connection to the physics of beach evolution. In 2021 the authors first introduced WSM for single-headland bays as an empirical result from their numerical investigation. This paper provides the method with a theoretical framework and extends it to include bays sheltered by two headlands. This extension is achieved by exploiting the Fraunhofer theory for the diffraction of light. The comparison with 20 natural bays along the Mediterranean coast indicates that WSM is a well-performing, easy-to-use approach with the potential to reduce, in some situations, the degree of subjectivism and complexity of the existing methods.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104740"},"PeriodicalIF":4.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coastal EngineeringPub Date : 2025-03-04DOI: 10.1016/j.coastaleng.2025.104742
Benjamin K. Norris , Borja G. Reguero , Joseph Bartolai , Michael A. Yukish , Landolf Rhode-Barbarigos , Brian K. Haus , Gabriel Barajas Ojeda , Maria Maza , Javier L. Lara , Michael W. Beck
{"title":"Designing modular, artificial reefs for both coastal defense and coral restoration","authors":"Benjamin K. Norris , Borja G. Reguero , Joseph Bartolai , Michael A. Yukish , Landolf Rhode-Barbarigos , Brian K. Haus , Gabriel Barajas Ojeda , Maria Maza , Javier L. Lara , Michael W. Beck","doi":"10.1016/j.coastaleng.2025.104742","DOIUrl":"10.1016/j.coastaleng.2025.104742","url":null,"abstract":"<div><div>Coastal flooding and erosion are growing issues for coastal communities as their severity continues to worsen with climate change. As a result, there is increasing interest in the use of nature-based engineering as a sustainable and cost-effective strategy for protecting many coastlines globally. Among these approaches, reef engineering aims to integrate both the physical and biological aspects of reef communities to attenuate incident wave energy while still maintaining ecological values. However, few examples currently exist on reef engineering for coastal defense due to the multidisciplinary challenge of constraining physical and biological interactions with artificial reefs. Here, we present the first design iteration of a novel artificial hybrid reef system that intends to provide both coastal defense benefits as well as refugia for corals to enable their future growth. To balance these performance objectives, the pyramidal low-crested reef designs developed here combine two hexagonal sub-units: SEAHIVE® and lattice with tunable porosity. The hydrodynamic performance of these sub-units was tested using a numerical wave tank (NWT), based on the computational fluid dynamics (CFD) modeling suite OpenFOAM, to determine the best configuration of the sub-units for a given set of wave conditions, both as single reefs and as a three-row reef system. The goal was to produce a small subset of reef designs to be tested in a wave flume facility to support model calibration and future design iteration. The reef designs explored herein offer wave energy reduction values greater than 70%, consistent with natural coral reefs as well as other conventional submerged breakwater designs. Further, the highly porous sub-units provide further tunability of hydrodynamic performance when compared with traditional low-crested breakwaters.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104742"},"PeriodicalIF":4.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coastal EngineeringPub Date : 2025-02-26DOI: 10.1016/j.coastaleng.2025.104728
Boxiang Tang , Kees Nederhoff , T.W. Gallien
{"title":"Quantifying compound coastal flooding effects in urban regions using a tightly coupled 1D–2D model explicitly resolving flood defense infrastructure","authors":"Boxiang Tang , Kees Nederhoff , T.W. Gallien","doi":"10.1016/j.coastaleng.2025.104728","DOIUrl":"10.1016/j.coastaleng.2025.104728","url":null,"abstract":"<div><div>Low-lying coastal areas are highly vulnerable to flooding hazards. High marine water levels may overflow seawalls, render the storm drain system inoperable, and promote pluvial and wave overtopping flooding. Complex interactions between various coastal flooding drivers (marine water levels, precipitation, waves) and urban infrastructure (i.e., the stormwater system, and seawalls) are characterized using a novel, tightly coupled hydrodynamic model. Flood extent field observations of tidal overflow, pluvial flooding, and overtopping flooding, along with storm drain system pressure sensor data are used to evaluate hydrodynamic model performance. High marine water levels, precipitation, and overtopping events are modeled and compared with validation data. Results suggest the hydrodynamic model explicitly resolving both 1D storm drain pipe flow and 2D overland flooding more accurately simulates compound flooding compared to typical 2D overland flow models. Nonlinear compound effects were resolved by comparing combined univariate flood impact to corresponding compound flood impact modeled within a tightly coupled 1D2D infrastructure-resolving model. Projected flood extents were <span><math><mo>∼</mo></math></span>50% greater when compound interactions were resolved. Compound effects vary with event type, event magnitude, and site characteristics. Critically, coastal adaptation strategies protecting against high embayment water levels such as elevating seawalls may exacerbate compound flooding effects in low-lying communities.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104728"},"PeriodicalIF":4.2,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Longitudinal and vertical evolution of wave-induced turbulence within vegetation","authors":"Yunshuo Cheng , Zhong Peng , Yuan Xu , Ying Zhao , Qing He","doi":"10.1016/j.coastaleng.2025.104737","DOIUrl":"10.1016/j.coastaleng.2025.104737","url":null,"abstract":"<div><div>Salt marsh vegetation provides essential morphodynamic and ecological benefits in coastal environments, yet the dynamics of wave-induced turbulence within vegetation remain poorly understood. Laboratory experiments are carried out to reveal the longitudinal and vertical evolution of wave-induced turbulence within vegetation for both non-breaking and breaking waves. Data from non-breaking intermediate waves highlights a nonlinear behavior of the longitudinal turbulent intensity across the vegetation, especially with high stem densities. A modified model is developed to account for the competition between increased turbulence scaling and reduced local wave orbital velocity at the leading edge of vegetation. For breaking waves, bubble clouds in video records and measured turbulence intensity together quantify vegetation's crucial role in buffering the vertical evolution of wave-induced turbulence and consequently reducing near-bed turbulence. Findings are crucial for understanding vegetation's role in shaping coastal morphodynamics and maintaining ecosystem health, with broad implications for coastal management and restoration efforts.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104737"},"PeriodicalIF":4.2,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coastal EngineeringPub Date : 2025-02-26DOI: 10.1016/j.coastaleng.2025.104738
Oxana Repina , Rafael C. Carvalho , Giovanni Coco , José A.Á. Antolínez , Iñaki de Santiago , Mitchell D. Harley , Camilo Jaramillo , Kristen D. Splinter , Sean Vitousek , Colin D. Woodroffe
{"title":"Evaluating five shoreline change models against 40 years of field survey data at an embayed sandy beach","authors":"Oxana Repina , Rafael C. Carvalho , Giovanni Coco , José A.Á. Antolínez , Iñaki de Santiago , Mitchell D. Harley , Camilo Jaramillo , Kristen D. Splinter , Sean Vitousek , Colin D. Woodroffe","doi":"10.1016/j.coastaleng.2025.104738","DOIUrl":"10.1016/j.coastaleng.2025.104738","url":null,"abstract":"<div><div>Robust and reliable models are needed to understand how coastlines will evolve over the coming decades, driven by both natural variability and climate change. This study evaluated how accurately five popular ‘reduced-complexity’ models replicate multi-decadal shoreline change at Narrabeen-Collaroy Beach, a sandy embayment in Sydney, Australia. Measured shoreline positions derived from approximately monthly field surveys were used for 20-year calibration and 20-year validation periods. The models performed similarly on average but with large variability between transects. The set-up of several models was modified to compensate for their sensitivity to imperfect input wave data, and further site-specific improvements were identified. Capturing interannual to decadal-scale variability in cross-shore and longshore dynamics at this site was challenging for all five models. Models appeared to aggregate key processes at this timescale into parameter values rather than representing them directly. This suggests time-varying parameters or changes to model structure may be necessary for decadal-scale simulations.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104738"},"PeriodicalIF":4.2,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coastal EngineeringPub Date : 2025-02-25DOI: 10.1016/j.coastaleng.2025.104726
Tim W.B. Leijnse , Ap van Dongeren , Maarten van Ormondt , Roel de Goede , Jeroen C.J.H. Aerts
{"title":"The importance of waves in large-scale coastal compound flooding: A case study of Hurricane Florence (2018)","authors":"Tim W.B. Leijnse , Ap van Dongeren , Maarten van Ormondt , Roel de Goede , Jeroen C.J.H. Aerts","doi":"10.1016/j.coastaleng.2025.104726","DOIUrl":"10.1016/j.coastaleng.2025.104726","url":null,"abstract":"<div><div>Wave-driven flooding is often neglected or included in an approximate way in large-scale flood hazard assessments and early warning systems, despite its significant contribution to coastal flood hazards. This study introduces a method to incorporate incident and infragravity wave processes into a fast compound flood model by extending the SFINCS software with the SnapWave stationary wave energy solver. This extension efficiently translates offshore incident and infragravity wave conditions to the nearshore, allowing for the estimation of incident-wave-induced setup and the resolution of wave runup and overtopping. A quadtree approach is employed to optimize the grid resolution for wave processes in the coastal zone.</div><div>The approach is validated for Hurricane Florence (2018) along the North and South Carolina coastline of the United States, where observed offshore wave heights reached 10 m. The results illustrate that the impact of the hurricane extended hundreds of kilometers beyond the landfall area due to waves, highlighting its importance as coastal flood driver. In 19% of the coastline analyzed, wave contributions surpassed all other flood drivers combined, with waves contributing to an additional flooded area of 226 km<sup>2</sup> and a flood volume of 62 million m<sup>3</sup>.</div><div>The study also indicates that simpler parameterized methods for including wave-induced setup can lead to significant discrepancies in modeled water depths. The computational efficiency of the extended SFINCS model allows for the simulation of 1,000 km of coastline with limited computational resources. Hereby the critical role of wave effects in coastal compound flood hazard assessments could be demonstrated.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104726"},"PeriodicalIF":4.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coastal EngineeringPub Date : 2025-02-14DOI: 10.1016/j.coastaleng.2025.104727
Thomas J. van Veelen , Heidi Nepf , Suzanne J.M.H. Hulscher , Bas W. Borsje
{"title":"The thresholds of sediment resuspension within emergent vegetation under combined wave-current conditions – A flume experiment","authors":"Thomas J. van Veelen , Heidi Nepf , Suzanne J.M.H. Hulscher , Bas W. Borsje","doi":"10.1016/j.coastaleng.2025.104727","DOIUrl":"10.1016/j.coastaleng.2025.104727","url":null,"abstract":"<div><div>The threshold of resuspension can be described by a critical velocity. Salt marsh vegetation modifies the flow conditions such that the critical velocities for resuspension derived on bare beds no longer apply. Within vegetation canopies, the critical velocity for resuspension was previously shown to decrease under pure current and pure wave conditions. In this study, we experimentally investigated how emergent salt marsh vegetation affects resuspension under combined wave-current flows that are typical for intertidal coastlines. Emergent artificial vegetation canopies inspired by <em>Spartina Anglica</em> and fine noncohesive sediment were placed in a wave-current flume. We set a constant current and incrementally increased the wave height until resuspension was measured. We repeated this procedure with a bare bed, three stem densities, and for a range of wave-current combinations. The critical velocity for resuspension was significantly reduced by vegetation-induced turbulence. Turbulent vortices shed by the stems entrained sediment particles from the bed. The critical velocity for resuspension decreased by 35–64% compared to bare bed conditions, depending on a ratio between the current velocity and wave velocity amplitude. The critical velocity decreased the most under pure current flows and the least under pure wave conditions. Finally, with vegetation present, the stem density did not affect the threshold of resuspension for the range of densities tested here. Our results can be implemented into sediment transport models through an adjusted Shields parameter for vegetated beds, which can be used for the management of salt marshes and the design of interventions for nature-based coastal protection.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104727"},"PeriodicalIF":4.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coastal EngineeringPub Date : 2025-02-14DOI: 10.1016/j.coastaleng.2025.104718
Shannon Brown, Annika O’Dea, Ian Conery, Katherine Brodie
{"title":"Assessing shorelines extracted from satellite imagery using coincident terrestrial lidar linescans","authors":"Shannon Brown, Annika O’Dea, Ian Conery, Katherine Brodie","doi":"10.1016/j.coastaleng.2025.104718","DOIUrl":"10.1016/j.coastaleng.2025.104718","url":null,"abstract":"<div><div>Numerous algorithms have been developed to facilitate the extraction of shoreline position from satellite imagery, including the CoastSat algorithm. Previous analyses comparing CoastSat satellite-derived shorelines (SDS) to morphological data have highlighted that there are site-specific errors in outputs that are likely related to concurrent wave runup conditions, but the data required to test this relationship are rarely available. Here, we present a novel comparison of lidar-derived runup and beach elevation data to CoastSat satellite-derived waterlines (SDW) extracted using two image sources (Sentinel-2 and PlanetScope) and two threshold algorithms (Otsu and weighted peaks). Results show that while SDW extracted using Otsu thresholds correlated better with lidar-derived waterlines (LDW), SDW extracted using the weighted peaks threshold were consistently positioned in the upper swash and therefore correlated better with a runup bulk statistic. Assigning the best-fit runup bulk statistic as the waterline elevation to weighted peaks SDW resulted in SDS with less scatter than the Otsu SDW due to the more consistent waterline elevation. Horizontal errors for the converted datum-referenced shoreline were lowest when SDW were converted to SDS using best-fit measured runup bulk statistics and a measured slope. However, for weighted peaks SDW from both image sources, assigning the best-fit parameterized runup bulk statistic and an average slope in the SDW to SDS conversion still reduced error by <span><math><mrow><mo>∼</mo><mn>20</mn><mtext>%</mtext></mrow></math></span> to <span><math><mrow><mo>∼</mo><mn>35</mn><mtext>%</mtext></mrow></math></span> when compared to the tidal elevation and average slope. These findings confirm that runup corrections can improve native SDS outputs, although the magnitude of the final shorelines error depended on the specific imagery product, local beach slope, threshold technique, runup parametrization, and chosen reference contour.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104718"},"PeriodicalIF":4.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Minutely monitoring of swash zone processes using a lidar-camera fusion system","authors":"Yoshinao Matsuba , Yoshimitsu Tajima , Takenori Shimozono , Kévin Martins , Masayuki Banno","doi":"10.1016/j.coastaleng.2025.104724","DOIUrl":"10.1016/j.coastaleng.2025.104724","url":null,"abstract":"<div><div>The advancement of effective remote sensing technologies is critical for understanding the dynamics of coastal systems, enabling efficient and sustainable management strategies. Video cameras have been widely used for this purpose, significantly advancing our knowledge of coastal dynamics. However, traditional optical devices cannot directly provide three-dimensional (3D) information, such as beach profiles or runup heights. Recently, lidar scanners have gained attention within the coastal research community for their ability to directly capture high-resolution data on hydro-sediment interactions near shorelines across various scales, providing valuable insights into coastal dynamics. This study presents a fusion system that combines a 3D lidar with a video camera, capable of simultaneously capturing 3D coordinates and surface colors of beaches and nearshore waves. The fusion system was tested at two coastal sites in Japan, demonstrating its high potential for coastal monitoring. At the Hasaki coast, characterized by fine sand, it captured alongshore variations in topographic changes, linked to runup heights and seepage processes over one day. At the Namiita coast, characterized by a mixed sand-gravel beach, the fusion system observed the development of cusp structures over 3 h. The data suggest sand accumulation around gravel and gravel retrieval from the beach surface following an increase in tide level. Although this fusion system was tested at only two coastal sites in Japan, it demonstrates high flexibility and potential for studying swash zone processes across diverse spatiotemporal scales and beaches, including mixed sand-gravel beaches.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"199 ","pages":"Article 104724"},"PeriodicalIF":4.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}