Coastal Engineering最新文献

{"title":"Long term modelling of longshore sand transport and coastline changes along central COAST of Holland","authors":"Leo C. van Rijn ,&nbsp;Bastiaan J.A. Huisman","doi":"10.1016/j.coastaleng.2025.104841","DOIUrl":"10.1016/j.coastaleng.2025.104841","url":null,"abstract":"<div><div>This paper is focused on the simulation of longshore sand transport (LST) and associated coastline changes at the central coast of Holland with and without structures using 1D coastline models. Results of 2DH models are also given. Two contrasting sites are considered: 1) the large-scale beach plain south the long breakwaters of IJmuiden and 2) the large scale (mega) nourishment site south of The Hague. Both sites have a coastline that was brought significantly out of equilibrium as a result of the interventions, and the coastline changes involved are therefore very insightful for studying both the development towards the new equilibrium coastline orientation as well as the associated rate of coastline change and longshore transports involved. The LST-values were computed with the semi-empirical LST equation of Van Rijn (2014) and analyzed to better understand the actual drivers for coastal change along the coast of Holland coast and performance of the models. The models were forced with measured and simulated wave data from nearby offshore stations over a relatively long period of time between 1979 and 2021 (40 years). The 1D models provided good hindcast results of the long-term net coastal change at the Sand Motor and IJmuiden. The actual coastal curvature in the shadow zone of the long IJmuiden breakwaters was slightly under-represented, but could be calibrated with moderate adjustments. The effect of the wave shadowing zone in the lee of the IJmuiden breakwaters could be represented with sufficient accuracy either by using nearshore wave conditions (using the SWAN wave model) as well as with a much simpler engineering method for wave diffraction of Kamphuis (1992). For the Sand Motor site, the 1D model provided sufficiently accurate predictions for assessments of erosion along the tip, but the area south of the Sand Motor was not represented well because it is affected by the accelerating tidal current and the wave shadowing of the long breakwaters at Hoek van Holland (entrance to Rotterdam harbour). The estimated net annual longshore transport at the original (undisturbed) coastline at both sites are: about 50,000 m³/yr to north at IJmuiden (km 55–65) and about 100,000 m³/yr to north at the Sand Motor site (at km 109). Annual variations are very large at both sites as the contribution of waves from the south-western and northern sectors can vary considerably. Including the harbour breakwaters of IJmuiden, the net LST increases to 300,000 m³/yr to north at km 66 (south of IJmuiden) due to wave shadowing effects. Similarly after construction of the Sand Motor nourishment, the net LST-values at both flanks of nourishments changed drastically.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104841"},"PeriodicalIF":4.5,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771009","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":"Experimental investigation on local scour evolution around a circular monopile in the silty bed under wave-current combinations","authors":"Chunguang Yuan ,&nbsp;Mingxiao Xie ,&nbsp;Jinquan Wang ,&nbsp;Xiaoliang Xia ,&nbsp;Long Xiao ,&nbsp;Na Zhang ,&nbsp;Cheng Cui","doi":"10.1016/j.coastaleng.2025.104842","DOIUrl":"10.1016/j.coastaleng.2025.104842","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Silt is widely distributed in offshore regions where numerous marine structures are located. Compared to sandy bed, silt exhibits lower cohesion and consolidation characteristics, which can significantly influence sediment transport processes. However, there remains a lack of research on local scour and its temporal evolution around circular monopiles in silty beds. This study presents an experimental investigation of equilibrium scour depth and scour process around a slender circular pile in a silty bed (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mn&gt;50&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; = 0.075 mm, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; = 1.64 g/cm&lt;sup&gt;3&lt;/sup&gt;) under steady current and wave-current combined conditions. The normalized scour depth and the dimensionless scour time scale &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; in the silty bed were compared with those in sandy beds under corresponding hydrodynamic conditions, and the effects of parameters e.g. relative water depth, Keulegan–Carpenter (&lt;em&gt;KC&lt;/em&gt;) number, relative current strength &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and Shields parameter were analyzed. Results show that the maximum scour depth around a monopile in the silty bed primarily occurs at the pile sides. Wave superposition significantly influences the scour hole size and the slope angle. Under steady current, the normalized scour depth of the silty bed is generally lower than that of sandy beds and increases with the relative Shields parameter and relative water depth. Conversely, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; in the silty bed is significantly larger than that of the sandy bed and decreases with increasing relative Shields parameter and decreasing relative water depth. Under combined wave-current conditions, the scour depth in the silty bed exhibits a non-monotonic increase-decrease trend with the increase of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, peaking at &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; = 0.8–0.9. For a given &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, due to weaker inter-particle interlocking force, larger sediment transport capacity and reduced bedload supply applied in this study, partial scour depths in the silty bed exceed those in sandy beds with larger &lt;em&gt;KC&lt;/em&gt; numbers. &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; in the silty bed is approximately 10–100 times greater than that of sandy beds under similar hydrodynamic conditions. As &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and wave-induced Shields parameter increase, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; sh","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104842"},"PeriodicalIF":4.2,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714354","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 coupled numerical model for interactions between waves and flexible vegetation blades","authors":"Huiran Liu,&nbsp;Pengzhi Lin","doi":"10.1016/j.coastaleng.2025.104838","DOIUrl":"10.1016/j.coastaleng.2025.104838","url":null,"abstract":"<div><div>In this study, we developed a 2-D fully coupled numerical model to investigate interactions between waves and flexible vegetation. The model integrates a flexible vegetation dynamics model—capable of simulating large deflections of vegetation blades under external forcing—into the Reynolds-Averaged Navier-Stokes (RANS) fluid solver NEWFLUME. A two-way coupling methodology transfers hydrodynamic fluid forces to drive blade motion, while the reactive forces from the blade are incorporated as source terms in the fluid momentum equations. The model was validated against experimental data for flexible vegetation under regular wave conditions, demonstrating its capability to predict blade deformation and wave attenuation characteristics. Numerical experiments across a wide range of Cauchy numbers (0.01–10,000) revealed distinct behavioral regimes in how vegetation flexibility affects wave attenuation. When <em>Ca</em> &lt; 1, flexible vegetation behaves similarly to rigid vegetation, whereas <em>Ca</em> &gt; 1 exhibits power-law decay in both wave attenuation rate and hydrodynamic forces. Highly flexible vegetation exhibits up to an 81 % reduction in wave height attenuation rate compared to rigid conditions, with blade motion patterns transitioning from cantilever beam-like oscillations to complex whip-like motions as flexibility increases. Further validation with large-scale experiments confirmed the model's ability to simulate irregular wave attenuation through a flexible vegetation domain. The model captured complex hydrodynamic features, including three-layer mean flow structures under irregular wave conditions and velocity amplification at blade tips that exceed local flow velocities in highly flexible vegetation.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104838"},"PeriodicalIF":4.2,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714353","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":"2025-07-21","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":"Nonlinear stiffness and hysteresis phenomena of harbor oscillations","authors":"Zhenjun Zheng ,&nbsp;Xiaozhou Ma ,&nbsp;Yujin Dong ,&nbsp;Guohai Dong","doi":"10.1016/j.coastaleng.2025.104832","DOIUrl":"10.1016/j.coastaleng.2025.104832","url":null,"abstract":"<div><div>This study investigates the nonlinear stiffness and hysteresis of harbor oscillations using a fully nonlinear Boussinesq wave model. Numerical results confirm the presence of two nonlinear phenomena in harbor oscillations: hardening stiffness, where the resonant frequency increases with the response amplitude, and hysteresis, where the harbor's response to incoming waves is influenced by its previous oscillatory state.</div><div>For gravity waves neglecting surface tension, the restoring force is gravity. The nonlinear restoring term in the wave equations is typically expressed by the surface gradient term <em>g</em>(<em>h</em>+<em>η</em>)▽<em>η</em>. As <em>η</em> increases, the nonlinear restoring term intensifies, thereby providing a basis for the emergence of nonlinear stiffness.</div><div>The nonlinear stiffness and hysteresis phenomena are identified as case-specific. The Duffing oscillator model is adopted to explain these characteristics. It is determined that the nonlinear stiffness parameter and damping coefficient of oscillatory patterns significantly influence the nonlinear stiffness and hysteresis observed in harbor oscillations. A larger stiffness parameter and smaller damping coefficient make nonlinear stiffness more likely to occur. Conversely, if the stiffness parameter is small and the damping is large, nonlinear stiffness is less likely to manifest. Furthermore, a high damping coefficient indicates that the harbor quickly releases the energy from past oscillations to the open sea, preventing the system from retaining a 'memory' of its previous states and thus minimizing hysteresis. The case-specific nature of these nonlinear phenomena highlights the importance of considering specific oscillatory pattern when assessing harbor dynamic response.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104832"},"PeriodicalIF":4.2,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694996","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":"Deriving nearshore bathymetry and waves characteristics from a single UAV video","authors":"Adrien N. Klotz ,&nbsp;Paula Gurruchaga ,&nbsp;Rafael Almar ,&nbsp;Athina M.Z. Lange ,&nbsp;Erwin W.J. Bergsma","doi":"10.1016/j.coastaleng.2025.104820","DOIUrl":"10.1016/j.coastaleng.2025.104820","url":null,"abstract":"<div><div>Nearshore bathymetry and water surface elevation are estimated using the temporal correlation method and the sky glint method, respectively, from a 14 min UAV video captured at Torrey Pines State Beach, CA, USA, under relatively energetic wave conditions (<span><math><mrow><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>96</mn></mrow></math></span> m) generating breaking waves. The estimated bathymetry shows strong agreement with in-situ measurements, with an RMSE of 0.74 m, a bias of 0.52 m, and <span><math><mrow><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>=</mo><mn>0</mn><mo>.</mo><mn>98</mn></mrow></math></span>, comparable to other established methods. More importantly, the resulting depth estimation remains unaffected by the abrupt transitions caused by wave breaking and the presence of wave-induced foam in the surf zone. At the breaking point, the temporal correlation method consistently estimates wave celerities at this point, providing accurate depth measurements - a persistent challenge in nearshore bathymetry studies. A methodology to assess the correlation significance of the estimated bathymetry is presented. These results highlight the method’s potential for monitoring nearshore morphological changes such as induced by storms. The application of the sky glint method shows a tendency to overestimate individual wave heights (RMSE <span><math><mrow><mo>=</mo><mn>0</mn><mo>.</mo><mn>59</mn></mrow></math></span> m and Bias <span><math><mrow><mo>=</mo><mn>0</mn><mo>.</mo><mn>31</mn></mrow></math></span> m) compared to in-situ pressure sensor measurements. Surface elevations time series derived from the video are phase-coherent with in-situ pressure sensor measurements but overestimations are attributed to the use of a linear Modulation Transform Function (MTF). While further study is required, this proof of concept could constitutes a non-labour-intensive, remotely sensed method for generating water surface elevation datasets for sea state assessments and hydrodynamic model forcing. This study demonstrates the abundance of information that can be extracted from a 14 min UAV flight, offering a cost-effective, high-frequency sampling and high-resolution approach for coastal managers and researchers to monitor and study their nearshore environments, with potentially short - daily - revisit time.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104820"},"PeriodicalIF":4.2,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704267","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 energy transfer of tsunamis generated by subaerial granular landslides: A 2D numerical analysis","authors":"Alessandro Romano ,&nbsp;Giorgio Bellotti ,&nbsp;Gabriel Barajas ,&nbsp;Javier L. Lara","doi":"10.1016/j.coastaleng.2025.104821","DOIUrl":"10.1016/j.coastaleng.2025.104821","url":null,"abstract":"<div><div>Tsunamis generated by landslides represent a significant hazard in coastal, fjord and lake environments. Their accurate modeling, using both physical and mathematical models, is crucial for activities such as risk assessment and mitigation strategies. Both approaches can provide valuable insights on the physics of landslide-tsunamis; however, due to the very complex nature of the problem, more efforts are needed to further understand the basic process of tsunami generation and propagation. In this sense, the study of the problem from an energetic perspective can provide valuable information, especially focusing on the energy transfer mechanisms between landslides and water waves. This paper presents a two-dimensional (2D) numerical study aimed at the energy mapping of tsunamis generated by subaerial granular landslides. To this end, several parametric simulations are carried out with OpenFOAM®, systematically varying some selected governing parameters (landslide falling height, water depth, and slope angle). For each simulation, several dimensionless energy quantities were computed and analyzed to investigate the energy transfer mechanisms between the landslide and the water waves. Further, the ability of some parameters to describe the efficiency of the energy transfer process for tsunami generation and propagation is investigated. At least for the cases considered in this study, it appears that the shape of the landslide vertical front at the impact and the extent of the submerged path are more important than the landslide velocity at the impact in terms of tsunamis generation efficiency. Finally, synthetic energy quantities have been examined from a broader perspective to derive overall insights into the energy transfer process between subaerial granular landslides and tsunamis, leading to the formulation of a first basic version of a nondimensional energy wavemaker curve.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104821"},"PeriodicalIF":4.2,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685788","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":"2025-07-18","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":"HyWaThy: Hybrid modeling of nearshore Waves with different baThymetric states","authors":"Manuel Zornoza-Aguado,&nbsp;Beatriz Pérez-Díaz,&nbsp;Laura Cagigal,&nbsp;Sonia Castanedo,&nbsp;Fernando J. Méndez","doi":"10.1016/j.coastaleng.2025.104837","DOIUrl":"10.1016/j.coastaleng.2025.104837","url":null,"abstract":"<div><div>Coastal areas such as sandy beaches are highly pressured environments by humans worldwide, as they provide a wide range of ecosystem services that directly benefit societies. The growing concentration of human settlements along these coasts arise the need for improved coastal management strategies, where a robust knowledge of nearshore processes is fundamental. Given the inherently dynamic nature of sandy beaches, advancing our knowledge of nearshore hydrodynamics requires accurate modeling of the complex interaction between bathymetry and waves: bathymetric features affect wave propagation towards the coast, while waves, in turn, reshape the seabed through longshore and cross-shore sediment transport. This study presents a methodological advancement beyond the dynamic downscaling of wave conditions over a static bathymetry by introducing a coupled hybrid metamodel that simulates nearshore waves while accounting for the different bathymetric states of the beach. For doing so, statistical methods and numerical models are combined in La Salvé beach (Spain) to capture the bathymetric configurations using Principal Component Analysis applied to field-surveyed data, as well as to propagate waves from a single offshore point to a two-dimensional nearshore domain. The phase-resolving, non-hydrostatic XBeach model is employed to simulate key physical processes in the surf zone, including refraction, shoaling, diffraction, reflection and breaking. Once trained, the coupled hybrid metamodel can reconstruct nearshore hydrodynamics –represented by spatial fields of significant wave height and mean wave direction— in a matter of seconds. The model performance is numerically validated, showing satisfactory accuracy for the study site.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"202 ","pages":"Article 104837"},"PeriodicalIF":4.2,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703373","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":"2025-07-17","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}