Coastal Engineering最新文献

{"title":"Impact of banquette structures on a sandy beach profile: Laboratory experiments","authors":"Carlos Astudillo-Gutierrez ,&nbsp;Joan Pau Sierra ,&nbsp;César Mösso ,&nbsp;Vicente Gracia","doi":"10.1016/j.coastaleng.2025.104815","DOIUrl":"10.1016/j.coastaleng.2025.104815","url":null,"abstract":"<div><div>A novel experiment using a mimic banquette is presented. This study investigates the morphodynamic effects of different banquette configurations on a sandy beach under erosive wave conditions. Following a six-hour exposure to irregular waves with significant heights of 0.6 metres, different banquette configurations were tested to assess their role in coastal protection. Wave height evolution, bar parameters, total sediment transport and shoreline position were used to evaluate the coastal protection efficiency of the banquette. The results of the study indicate that all banquette structures effectively reduced the flow of water towards the upper beach, limiting run-up and mitigating backshore erosion compared to a beach without protection. Larger banquettes provided greater stability by forming an active berm that restricted water passage, allowing minimal infiltration. In contrast, smaller banquettes, which allowed overtopping, influenced localized erosion and accretion near the shoreline, while still protecting the upper beach. Morphological changes were primarily observed near the shoreline, while sand profiles in the offshore bar region remained stable due to minimal variations in incident wave heights. Banquette structures also induced wave reflections at their toe, increasing localized erosion, particularly for those preventing overtopping. The findings demonstrate the effectiveness of banquette structures in reducing coastal erosion, with performance variations depending on the size and overtopping capacity. The study offers valuable insights for the optimization of coastal protection strategies, guiding the design of nature-based defences to mitigate erosion impacts on sandy shorelines.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104815"},"PeriodicalIF":4.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653238","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":"Alongshore variability in wave runup and inner surfzone wave conditions on an intermediate beach","authors":"Annika O’Dea ,&nbsp;Britt Raubenheimer ,&nbsp;Katherine Brodie ,&nbsp;Steve Elgar","doi":"10.1016/j.coastaleng.2025.104822","DOIUrl":"10.1016/j.coastaleng.2025.104822","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Alongshore and temporal variability in wave runup and inner surfzone wave conditions are investigated on an intermediate beach using lidar-derived elevation transect timeseries. The lidar scanners were deployed at two alongshore locations separated by &lt;span&gt;&lt;math&gt;&lt;mo&gt;∼&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt;330 m at the U.S. Army Engineer Research and Development Center Field Research Facility in Duck, NC and collected 30 min (41 min) linescan time series at 7.1 Hz (5 Hz) each hour over an 11-day period before, during, and after Hurricane Matthew in October 2016. Runup and water surface-elevation time series at the estimated 0.5-m depth contour were used to determine the extreme runup &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mtext&gt;%&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, the mean runup and inner surfzone water surface elevation, and the significant runup and inner-surf wave heights across sea-swell, infragravity, and all frequency bands. Offshore wave conditions were determined from an array of pressure gauges located in &lt;span&gt;&lt;math&gt;&lt;mo&gt;∼&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt;8-m water depth. Results show that the significant wave height in the sea-swell frequency band &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; was intermittently depth-limited in the inner surf zone, with the ratio of significant sea-swell wave height in the inner surf zone to that in about 8-m depth (&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mi&gt;Z&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;/&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) ranging from 0.42 to 1.31 during low-energy conditions and from 0.19 to 0.39 during high-energy conditions. Significant temporal variability in runup parameters was observed over the 11-day period, with &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mtext&gt;%&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; ranging from 1.07 to 3.07 m at the southern lidar location and from 1.45 to 3.36 m at the northern lidar location. Alongshore differences in &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mtext&gt;%&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; ranged from 0.00 to 0.90 m, with both &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mtext&gt;%&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and the significant swash height &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; typically larger at the northern lidar location. Alongshore variability in most inner surfzone and runup parameters was largest during low-energy offshore wave conditions when the inner surf zone was unsaturated, although this trend was weakest in &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mtext&gt;%&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;. The mean runup elevation &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;/","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104822"},"PeriodicalIF":4.5,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780894","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":"On the uncertainties in stone armor stability","authors":"Giulio Scaravaglione ,&nbsp;Jeffrey A. Melby ,&nbsp;Giuseppe R. Tomasicchio ,&nbsp;Marcel R.A. van Gent ,&nbsp;Alessandra Saponieri","doi":"10.1016/j.coastaleng.2025.104790","DOIUrl":"10.1016/j.coastaleng.2025.104790","url":null,"abstract":"<div><div>The present research aims to investigate the uncertainties in the evaluation of stone armor stability. Data synthesis was achieved by collecting and homogenizing data from 4 distinct studies, considering the inherent variability of the original data. Established stability equations are then applied to the synthetized database to assess both the strengths and limitations of different approaches across deep, shallow, and very shallow water. The results indicate that while nearly all formulations perform well in deep water, some inadequacies emerge in shallow and very shallow water. To address these limitations, the stability equations were recalibrated using the new database, with a focus on error and uncertainty quantification. The refitted Etemad-Shahidi et al. (ES, 2020) and Modified ES (Scaravaglione et al., 2025) equations consistently demonstrate better predictive capability across all water depths. However, damage assessment reveals persistent uncertainties across all formulations, rendering the selection of a single equation inconclusive, mainly due to the high uncertainty of the available laboratory data. Further synthesizing and homogenizing require additional modeling given the varying modeling approaches, the non-homogenous nature of the parametric data, and the limited understanding possible of the detailed laboratory techniques and data analysis carried out.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104790"},"PeriodicalIF":4.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653236","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":"Surrogate root system modeling — A hybrid dune reinforcement","authors":"Lukas Ahrenbeck ,&nbsp;Oliver Lojek ,&nbsp;Johannes Schattmann ,&nbsp;Björn Mehrtens ,&nbsp;Constantin Schweiger ,&nbsp;Viktoria Kosmalla ,&nbsp;David Schürenkamp ,&nbsp;Nils Goseberg","doi":"10.1016/j.coastaleng.2025.104835","DOIUrl":"10.1016/j.coastaleng.2025.104835","url":null,"abstract":"<div><div>Coastal dunes are a critical natural defense against storm surges and sea level rise, yet their stability is increasingly compromised by intensified hydrodynamic forces. To withstand stronger and more frequent storm surges as a result of climate change, engineered natural coastal barriers play an important role. This study systematically investigates the potential of artificial root system surrogates based on the root structure of <em>Ammophila arenaria</em> to augment dune stability under simulated storm surge conditions. Laboratory experiments were conducted in a 1.0<!--> <!-->m wide and 90.0<!--> <!-->m long wave flume, replicating the geomorphological characteristics of a dune profile from Sankt Peter-Ording, Germany, at a scale of 1:7. Three surrogate materials (i) coir grid, (ii) basalt grid, and (iii) coir mat were evaluated across three distinct placement configurations (Crest-only, Crest-Slope and Crest-Slope-Foot) under hydrodynamic regimes corresponding to collision, minor overwash, and heavy overwash. High-resolution 3D-lidar scanning provided quantitative, continuous assessments of erosion volumes and dune profile changes. The experimental results indicate that the flexibility of the materials, particularly coir grid and coir mat, substantially mitigates erosion through attenuation of incoming waves and sediment retention, while the relatively stiffer basalt grid exhibits inferior performance. Comparative analyses of small-scale experiments demonstrate that strategically designed artificial root systems can reduce erosion by 13.3<!--> <!-->% to 47.6<!--> <!-->%, thereby matching or surpassing the 23<!--> <!-->% to 40<!--> <!-->% reductions documented for natural vegetation. These findings provide critical insights for advancing nature-based coastal defense strategies and highlight the necessity for further large-scale investigations to refine material properties and deployment configurations.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104835"},"PeriodicalIF":4.5,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739562","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":"Impact of mooring configurations on wave attenuation of porous floating breakwater: A comparative experimental study","authors":"Kaiqing Luo,&nbsp;Yiyong Dong,&nbsp;Jing Yuan","doi":"10.1016/j.coastaleng.2025.104823","DOIUrl":"10.1016/j.coastaleng.2025.104823","url":null,"abstract":"<div><div>Floating breakwaters are increasingly used for coastal protection, especially in deep-water environments where traditional fixed breakwaters are impractical. The performance of porous floating breakwaters (PFBs) is highly dependent on their mooring systems, which has not been thoroughly investigated to date. This study presents a comparative experimental investigation of four mooring systems, i.e., fixed, pile-restrained, catenary, and taut, for PFBs, focusing on their wave transmission coefficients (<span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span>) and motion response (heave, surge and pitch). The PFB, constructed from cubically packed stainless-steel spheres, was subjected to periodic waves with varying steepness and ratio of width (<span><math><mi>B</mi></math></span>) to wave length (<span><math><mi>L</mi></math></span>). Fixed mooring, with no dynamic response, provided good wave attenuation, especially when fully submerged (<span><math><mrow><msub><mrow><mi>K</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>≈</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span> for <span><math><mrow><mi>B</mi><mo>/</mo><mi>L</mi><mo>≥</mo><mn>0</mn><mo>.</mo><mn>18</mn></mrow></math></span>). Pile-restrained mooring, allowing vertical motion, performed comparably to emerged fixed mooring, with minimal impact from heave motion. Catenary mooring, characterized by high compliance, exhibited poor performance for long waves (<span><math><mrow><msub><mrow><mi>K</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>&gt;</mo><mn>0</mn><mo>.</mo><mn>8</mn></mrow></math></span> for <span><math><mrow><mi>B</mi><mo>/</mo><mi>L</mi><mo>&lt;</mo><mn>0</mn><mo>.</mo><mn>3</mn></mrow></math></span>) due to large surge and heave motions. Taut mooring, with high stiffness due to pre-tensioned mooring chains, demonstrated superior attenuation when fully submerged, outperforming fixed mooring in some cases. However, its performance degraded when the PFB was not fully submerged and without the pre-tension. The study highlights the critical role of restricting translational motions (surge and heave) in enhancing wave dissipation. Submergence was also found to be a key factor, with fully submerged PFBs dissipating more energy. These findings provide valuable insights for optimizing mooring systems in practical applications.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104823"},"PeriodicalIF":4.5,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860383","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":"Experiments on Tsunami-induced scour at circular and rectangular onshore structures","authors":"N.S. Amiri ,&nbsp;D.J. McGovern ,&nbsp;T. Rossetto ,&nbsp;R. Day","doi":"10.1016/j.coastaleng.2025.104818","DOIUrl":"10.1016/j.coastaleng.2025.104818","url":null,"abstract":"<div><div>An experimental study of the scour development around circular and rectangular structures exposed to tsunami-induced flows is presented. Tsunami waves of different periods (147 s, 49 s, and 20 s) are generated in a flume at 1:50 Froude-scaled to analyse the scour processes around these structures. This study demonstrates how the geometry of the structure significantly impacts the scour depths. The results show that the rectangular structure experiences the maximum scour depth compared to square and circular structures, reaching approximately 0.16 m, this is primarily due to a strong vortex caused by the lateral boundary separation and greater blockage ratio. The evolution of scour depth was found to be time-dependent, with the maximum depth achieved early in the inundation phase and slumping observed towards the end of inundation, reducing the final scour depth by approximately one-third.</div><div>The analysis of the sediment’s angle of repose in scour processes shows that over-steepened slopes exceeding the natural angle (31°) were observed, reaching maximum slope angles of 84° on the side face and 70° on the front face of rectangular structures. Scour depths depended not on the magnitude of Shields parameter but rather on the duration for which the Shields parameter exceeded its critical threshold (<span><math><mrow><mi>θ</mi><mo>&gt;</mo><msub><mrow><mi>θ</mi></mrow><mrow><mi>c</mi><mi>r</mi></mrow></msub></mrow></math></span>). This research advances our understanding of scour mechanisms acting on different coastal structures, emphasising the influence of wave parameters, structural geometry, and sediment dynamics on scour mechanisms, offering a foundation for developing improved design guidelines for coastal infrastructure resilience against tsunami-induced scour.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104818"},"PeriodicalIF":4.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653237","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":"REEF3D::NHFLOW—A high-performance non-hydrostatic solver for coastal wave propagation","authors":"Hans Bihs,&nbsp;Widar Weizhi Wang","doi":"10.1016/j.coastaleng.2025.104819","DOIUrl":"10.1016/j.coastaleng.2025.104819","url":null,"abstract":"<div><div>In this paper the new three-dimensional non-hydrostatic wave model NHFLOW is presented. It solves the non-hydrostatic Euler equations on a <span><math><mi>σ</mi></math></span>-coordinate grid, which follows the free surface and bottom topography, allowing for grid refinement near the water surface. The governing equations are treated with a Godunov-type scheme. A pressure correction algorithm is implemented, which results in excellent dispersion properties. Together, this delivers a unique combination of shock-capturing properties and dispersive wave modeling capabilities. The structure of the coefficient matrix of the Poisson equation is simplified through a deferred correction approach, increasing the iterative solver’s performance significantly. In order to model propagating waves with a high level of accuracy, the numerical fluxes are reconstructed with the fifth-order WENO scheme. Developed within the open-source hydrodynamic framework REEF3D, the new model is fully parallelized and utilizes the domain decomposition strategy with MPI communication between processors. This paper showcases the capabilities of this new and efficient non-hydrostatic model through verification and validation with a range of laboratory and real-world wave propagation cases.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104819"},"PeriodicalIF":4.5,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756935","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":"Alongshore velocities and turbulence in the swash and surf zone forced by oblique, monochromatic waves on smooth and rough impermeable beaches","authors":"Alexandra E. Schueller ,&nbsp;Thomas Pendergast ,&nbsp;Kelsey Fall ,&nbsp;Hyungyu Sung ,&nbsp;Dawson Ethier ,&nbsp;Ryan P. Mulligan ,&nbsp;Jason Olsthoorn ,&nbsp;Nimish Pujara ,&nbsp;Jack A. Puleo","doi":"10.1016/j.coastaleng.2025.104812","DOIUrl":"10.1016/j.coastaleng.2025.104812","url":null,"abstract":"<div><div>Wave breaking on beaches drives complex nearshore flow patterns and turbulence. A series of controlled laboratory experiments were conducted to better understand swash and surf zone hydrodynamics on smooth and rough planar impermeable beaches under obliquely incident waves. The experiments were performed in a 26.0 m long, 20.6 m wide, and 1.0 m deep wave basin using a fixed concrete beach with a 1:10 slope. The beach surface was roughened through sandblasting following smooth surface experiments to allow a direct comparison between smooth and rough bed conditions. Regular waves with heights of 0.10 m, 0.125 m, and 0.15 m and a period of 2.0 s were generated with the wave paddle positioned at angles of 0°, 10°, and 20° with respect to the beach. An array of sensors recorded high-frequency data on water surface elevations and velocities at multiple cross-shore positions. Differences in the cross-shore velocities were most evident near the breaker zone, with peak onshore velocities approaching 0.8 m/s. Bed roughness was found to delay wave breaking and modulate velocity profiles compared to smooth bed conditions. Alongshore velocities remained predominantly positive, indicating consistent wave-driven mean flow along the beach, generally increasing with wave paddle angle, and measurements over the smooth bed contained larger nearbed gradients and alongshore flows during flow reversal. Mean nearbed turbulent kinetic energy (<em>k</em>) in the surf zone was on the order of 10⁻³ m²/s². Roughness resulted in an increase of nearbed <span><math><mrow><mi>k</mi></mrow></math></span> of approximately 12 % at the sensor closest to wave breaking. Analysis of nearbed Reynolds stresses close to the wave breaking location showed roughly a factor of 2 increase for beach normal waves compared to obliquely incident waves. This may suggest influence of reflections off of the beach increased by the intermediate-to-steep slope in this study.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104812"},"PeriodicalIF":4.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144671051","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":"A new framework for selecting observation points and reconstructing wave fields under sparse observations","authors":"Tao Lv ,&nbsp;Aifeng Tao ,&nbsp;Yuzhu Pearl Li ,&nbsp;Gang Wang ,&nbsp;Yuanzhang Zhu ,&nbsp;Jinhai Zheng","doi":"10.1016/j.coastaleng.2025.104836","DOIUrl":"10.1016/j.coastaleng.2025.104836","url":null,"abstract":"<div><div>In the context of increasingly frequent typhoons, tropical cyclones, and severe coastal storms that pose growing risks to maritime safety and offshore infrastructure, accurate reconstruction of ocean wave fields under sparse observation conditions has become a critical yet underexplored challenge. We propose a hybrid neural network model that integrates physical prior knowledge into a deep learning framework to optimize key observation point selection and enable high-accuracy reconstruction of wave statistics. The model comprises a U-Net-based decision network (Actor) for selecting observation points and a U-Net–GAN-based reconstruction network (Critic) for wave field recovery. A hybrid loss function incorporating physical constraints and region-specific sensitivity heatmaps guides the model toward high-impact observation areas, while spatial clustering strategies ensure broad spatial coverage. The closed-loop optimization mechanism leverages reconstruction error feedback to iteratively refine both observation strategies and reconstruction performance. Experiments using hourly multi-variable ERA5 reanalysis data in the South China Sea demonstrate that, under sparse observation settings, our approach significantly outperforms conventional deployment strategies in reconstruction accuracy, validating its effectiveness for resource-constrained marine monitoring applications.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104836"},"PeriodicalIF":4.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144671053","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":"Wave-induced incipient motion of non-buoyant plastic particles: Laboratory experiments","authors":"Giulia Bonanno ,&nbsp;Giovanni Passalacqua ,&nbsp;Claudio Iuppa ,&nbsp;David R. Fuhrman ,&nbsp;Carla Faraci","doi":"10.1016/j.coastaleng.2025.104848","DOIUrl":"10.1016/j.coastaleng.2025.104848","url":null,"abstract":"<div><div>The incipient motion of nine non-buoyant plastic particles, having different shapes and densities, beneath surface waves is systematically investigated on both smooth and rough beds in a 2D flume. In each test, ten identical particles are placed on the bed, and the threshold for motion is defined when at least half of the particles move during each wave cycle. Experimental results are first compared with the classical Shields curve, originally developed for natural sediments under steady flow. To enhance predictive accuracy, the present dataset was combined with additional data sets from the literature acquired under steady flows, and the consolidated data were subjected to a systematic analysis. As has been established for steady flows, the effects of static friction and hiding-exposure need to be accounted for. However, it is found that these alone are not sufficient to achieve reconciliation with the classical Shields diagram for parameterizing incipient motion conditions. To ensure consistency with classical formulations based on steady flows, the shear velocity near the bed was estimated under wave forcing by applying a phase-averaging method. The peak near-bed velocity during the wave crest phase was extracted and used to compute the corresponding friction velocity. The novelty of this study is that an additional function, depending on the ratio of boundary layer thickness to particle size, has been incorporated to parameterize incipient motion beneath unsteady (oscillatory) wave-induced flows to account for the partial submergence of particles within the boundary layer. After accounting for this additional dependence, reconciliation with the Shields diagram is achieved, with remaining scatters being of the same order of magnitude for all the considered datasets. The proposed framework improves predictions of plastic debris mobility under both steady and wave-driven flow conditions.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104848"},"PeriodicalIF":4.5,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827621","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}