Coastal EngineeringPub Date : 2025-10-14DOI: 10.1016/j.coastaleng.2025.104893
M. Antuono , A. Lucarelli , G. Colicchio , M. Brocchini
{"title":"The Depth-Semi-Averaged model: Benchmarking and applications to 2D and 3D problems","authors":"M. Antuono , A. Lucarelli , G. Colicchio , M. Brocchini","doi":"10.1016/j.coastaleng.2025.104893","DOIUrl":"10.1016/j.coastaleng.2025.104893","url":null,"abstract":"<div><div>The present work provides a number of applications of the Depth-Semi-Averaged model described in Antuono et al. (2022) for different wave conditions and geometries. These include analytical test cases, experimental benchmarks in 2D and 3D frameworks, and simulations of wave dynamics at a real coastal site. Breaking and non-breaking waves are considered, depending on the specific problem under investigation. The aim of the work is to provide an overview of the model potentialities and limits of application and to highlight its similarities and differences in comparison to existing non-hydrostatic schemes. More specifically, the model accurately captures wave propagation phenomena, including refraction and dispersion in non-breaking cases, and demonstrates satisfactory performance in reproducing wave decay caused by turbulence during breaking.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104893"},"PeriodicalIF":4.5,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326006","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 : 2025-10-10DOI: 10.1016/j.coastaleng.2025.104894
Zongyao Chen , Wen Wei , Xiufang Qiu , Yulu Yang , Heng Wang
{"title":"Effectiveness of restored mangrove wetlands in damping waves","authors":"Zongyao Chen , Wen Wei , Xiufang Qiu , Yulu Yang , Heng Wang","doi":"10.1016/j.coastaleng.2025.104894","DOIUrl":"10.1016/j.coastaleng.2025.104894","url":null,"abstract":"<div><div>There has been a global attention on the feasibility and embodiment of integrating the mangrove wetlands into coastal defense. However, little evidence is related to the restored mangroves (with mangrove trees artificially planted), which is increasingly important under ongoing wetland restoration worldwide. Here, wave propagation across a restored <em>Kandelia obovata</em> mangrove wetland on the Hailing Island, Guangdong Province, China, was observed to examine the wave damping effectiveness of the restored mangroves and their potential in coastal defense. The results showed that waves were attenuated by 26 % as they passed through the studied mangrove wetland. The wave attenuation rate of the bare flat was inversely proportional to water depth, and that of the mangrove forest was linked to its submerged state, peaking when the canopy was partially submerged. The restored mangrove attenuated waves more effectively than the bare flat, and showed reliable wave damping ability even in comparisons with natural marsh and mangrove vegetations. This evidence supports the feasibility of utilizing the restored mangroves in nature-based coastal defense. Furthermore, an idealized model was established to examine how the width of the restored mangrove impacts the gross wave attenuation. It is found that wave height reduction increases under a larger restored mangrove width, while the increase is nonlinear. We then proposed an optimal mangrove width proportion of 15 % for the studied wetland, under which the mangrove wetland showed a reliable gross wave height reduction together with a relatively large efficiency. These findings provide important insights into mangrove-induced wave attenuation and its implications for nature-based coastal defense worldwide.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104894"},"PeriodicalIF":4.5,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326004","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 : 2025-10-10DOI: 10.1016/j.coastaleng.2025.104892
Xianghui Dong , Qingxiang Liu , Stefan Zieger , Ian R. Young , Rui Li , Alberto Meucci , Jian Sun , Kejian Wu , Alexander V. Babanin
{"title":"A 45-year high-resolution unstructured wave hindcast for the Australian coast: Validation and climatological insights","authors":"Xianghui Dong , Qingxiang Liu , Stefan Zieger , Ian R. Young , Rui Li , Alberto Meucci , Jian Sun , Kejian Wu , Alexander V. Babanin","doi":"10.1016/j.coastaleng.2025.104892","DOIUrl":"10.1016/j.coastaleng.2025.104892","url":null,"abstract":"<div><div>This study presents a 45-year (1979–2023) high-resolution wave hindcast for the entire Australian coast, conducted using WAVEWATCH III on an unstructured mesh with a resolution ranging from 1 to 15 km. Incorporating the observation-based source term package (i.e., ST6) and the subgrid-scale reef parameterization, the model performs well in simulating widely-used bulk wave parameters. The simulated significant wave height <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> achieves a correlation greater than 0.96 and exhibits only a centimeter-scale bias when compared to both altimeter and buoy observations. The use of BARRAv2 winds provides a clear advantage under extreme conditions, with negligible underestimation below the 99.9th percentile of <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span>. The model performs particularly well in the Great Barrier Reef (GBR) region, where the bathymetry is complicated and could not be resolved well by typical km-scale wave models. Unlike previously published hindcasts that excessively overestimated wave energy in the GBR, our results show only a marginal <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> bias of approximately −0.05 m, against the shallow water buoys in this specific region. This better performance can be attributed to the subgrid-scale reef parameterization adopted. Long-term validation results demonstrate the robustness of the model framework, with the hindcast showing good temporal homogeneity and reliability. Building upon these results, this study reveals statistically significant increasing trends in wave heights along most of the Australian coast, with particularly pronounced upward trends in extreme wave heights (90th, 95th, and 99th percentiles) in the GBR. Furthermore, the GBR <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> trends based on our hindcast are much stronger than those estimated from previous hindcasts, and this new finding requires further investigation.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104892"},"PeriodicalIF":4.5,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326005","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 : 2025-10-04DOI: 10.1016/j.coastaleng.2025.104881
Weikai Tan , Jing Yuan , Deping Cao , Asim Önder
{"title":"Experiments and large eddy simulations of oscillatory flow over vortex ripples at high Reynolds number","authors":"Weikai Tan , Jing Yuan , Deping Cao , Asim Önder","doi":"10.1016/j.coastaleng.2025.104881","DOIUrl":"10.1016/j.coastaleng.2025.104881","url":null,"abstract":"<div><div>Long-crested sand ripples are ubiquitous seabed features in shallow coastal environments, characterized by the alternating generation of spanwise coherent vortices (SCVs) on either side of ripple crests. While previous studies have elucidated SCV dynamics at moderate Reynolds numbers (<span><math><mrow><mi>R</mi><mi>e</mi><mo>≤</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span>), a range that is common at many beaches and can persist for long wave periods. Nonetheless, their applicability to higher Reynolds number conditions (<span><math><mrow><mi>R</mi><mi>e</mi><mo>∼</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span>) remains uncertain. This investigation combines wall-modeled large eddy simulations (WMLES) and oscillating water tunnel experiments to examine SCV formation at high Reynolds numbers (<span><math><mrow><mi>R</mi><mi>e</mi><mo>∼</mo><mi>O</mi><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span>). The WMLES approach employs a logarithmic wall model for rough surfaces, achieving accurate SCV representation with computational efficiency. Experimental validation demonstrates good agreement in both phase-averaged flow fields and turbulence statistics, confirming the model’s fidelity. Key findings reveal a Reynolds number dependence analogous to the drag crisis phenomenon: SCV intensity diminishes significantly for smooth ripples at <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mi>O</mi><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span>, while surface roughness preserves vortex coherence. Our analysis of numerical results uncovers a positive feedback mechanism governing SCV development, where the residual SCV from the preceding half-cycle promotes early flow separation at ripple crests, facilitating vorticity accumulation and subsequent SCV formation. Analysis of the initial-cycle simulation (starting from a quiescent initial condition) shows that lee-side boundary layer must separate intrinsically during the deceleration phases of the first half-cycle to initiate this positive feedback loop. Both low Reynolds numbers and surface roughness can contribute to this first-half-cycle separation by increasing momentum deficit in the lee-side boundary layer.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104881"},"PeriodicalIF":4.5,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269839","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 : 2025-10-03DOI: 10.1016/j.coastaleng.2025.104890
Linlong Tong , Zhen Huang , Jisheng Zhang , Ning Chen , Dong-Sheng Jeng , Shulin Zhao , Xueyan Li
{"title":"Experimental study of bimodal spectral wave-induced dynamic responses in a silty seabed","authors":"Linlong Tong , Zhen Huang , Jisheng Zhang , Ning Chen , Dong-Sheng Jeng , Shulin Zhao , Xueyan Li","doi":"10.1016/j.coastaleng.2025.104890","DOIUrl":"10.1016/j.coastaleng.2025.104890","url":null,"abstract":"<div><div>This study investigates the dynamic responses of silty seabeds to bimodal spectral wave loading, focusing on the impact of these waves on soil dynamics and liquefaction behavior. A series of laboratory experiments were conducted in a wave flume, simulating single-peaked wind waves, single-peaked swell waves, and bimodal spectral waves, which combine high-frequency wind waves and low-frequency swell waves. The results show that the pore pressures induced by bimodal spectral waves builds up over time, leading to a reduction in effective stress and shear strength. The buildup of pore pressures can cause residual liquefaction within a silty seabed, and the depth of liquefaction increases with wave height. When liquefaction occurs, the wave energy dissipates rapidly. The findings indicate that bimodal spectral waves induce deeper and more rapid liquefaction compared to single-peaked waves, with liquefaction progressing from the surface downward. Soil motion was analyzed using Particle Image Velocimetry (PIV), revealing complex flow patterns within the liquefied layers. Under single-peaked spectral wave conditions, shear flow was observed in the liquefied layer. However, under bimodal spectral wave conditions, both shear and plug flows were observed, with plug flow forming near the surface of the liquefied layer and shear flow occurring between the plug flow and the non-liquefied layer during the reversal phase of acceleration. Additionally, the soil particle velocity spectra exhibited multi-peak characteristics due to the nonlinear interactions of stress waves within the seabed.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104890"},"PeriodicalIF":4.5,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269835","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 : 2025-09-28DOI: 10.1016/j.coastaleng.2025.104880
Fatima-Zahra Mihami , Volker Roeber
{"title":"Exploring a conservative staggered scheme for Boussinesq-type equations: Insights into numerical diffusion, dispersion, and wave-breaking","authors":"Fatima-Zahra Mihami , Volker Roeber","doi":"10.1016/j.coastaleng.2025.104880","DOIUrl":"10.1016/j.coastaleng.2025.104880","url":null,"abstract":"<div><div>Accurate and efficient modeling of coastal wave transformation, particularly under wave-breaking conditions, remains a major challenge for Boussinesq-type models. To address this, we introduce and validate a conservative staggered-grid scheme to discretize a set of weakly nonlinear Boussinesq-type equations. The presented approach revisits the staggered finite-difference strategy by ensuring a momentum-conserving solution designed to enhance numerical stability and improve shock-capturing properties. The scheme’s performance is assessed through a series of numerical tests involving monochromatic and spectral linear wave propagation. These tests demonstrate that the conservative staggered scheme is much less sensitive to grid resolution, resulting in approximately one order of magnitude lower numerical diffusion in contrast to the well-established HLLC scheme, while maintaining comparable dispersive accuracy despite using a lower-order spatial reconstruction. Additionally, the scheme introduces a slight negative phase error that compensates for the positive dispersion error inherent in the underlying equations, resulting in improved overall phase accuracy relative to the HLLC scheme. Beyond linear wave propagation, the numerical approach is validated against standard benchmark tests with solitary and spectral breaking waves. In these highly non-linear cases, coupling the conservative staggered scheme with a turbulent kinetic energy (TKE)-based eddy viscosity model yields localized and physically consistent dissipation while preserving the dispersive characteristics of the solution. Compared to conventional hybrid breaking approaches, the TKE-based closure provides enhanced stability, reduced grid sensitivity, and a more accurate representation of energy dissipation during wave breaking. These results underscore the potential of the conservative staggered scheme as an efficient and robust framework for computing complex coastal and nearshore wave processes.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104880"},"PeriodicalIF":4.5,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222984","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 : 2025-09-23DOI: 10.1016/j.coastaleng.2025.104879
Fabio Addona, Luca Chiapponi
{"title":"Turbulent field beneath monochromatic waves subjected to varying wind conditions","authors":"Fabio Addona, Luca Chiapponi","doi":"10.1016/j.coastaleng.2025.104879","DOIUrl":"10.1016/j.coastaleng.2025.104879","url":null,"abstract":"<div><div>Wind-wave interaction affects momentum, energy, and chemicals transfer at the air–water interface. In this study, we report on the turbulent flow field beneath laboratory monochromatic waves subjected to different wind speeds and direction (following or opposing). The flow field is decomposed into three main components: a mean, a swell-induced, and a fluctuating term, the latter including the effects of wind-induced ripples and turbulence. After a brief survey on the mean and wave-induced fields, we focus our attention on the fluctuating-turbulence field. Our results show that the turbulent stresses increase with increasing water friction, and that the condition of wind opposing the swell results in enhanced momentum transfer at deeper water levels. The distribution of fluctuating kinetic energy (TKE) along the swell phase indicates a maximum at the trough, which was addressed to the kinematics of the free surface by previous researchers. Furthermore, we investigate all the terms in the 2D energy equations that contribute to the TKE production by assuming that waves propagate with a rigid translation. A close look to the TKE budget suggests positive production of TKE on the leeside before the trough for all wind conditions, with destruction of TKE windwards for wind following the swell, possibly due to a sheltering effect. For opposing wind, however, positive production is almost ubiquitous along the swell phase, and this would justify larger mean TKE production for that particular condition. These findings are discussed to address possible causes; the phase-dependent behavior of TKE budgets are attributed to the combined action of swell-induced acceleration, wind shear on the crest, the stochastic phase offsets of the wind waves, and microscale breaking. A quadrant analysis highlights the main direction of momentum transfer and helps the individuation of the bursts, i.e., of strong events that support high momentum transfer. As expected, the net momentum transfer due to the fluctuating components is from air to water, with conditional averages (i.e., the quadrant map of the fluctuating velocities) confirming that finding. Finally, the analysis of the fluctuating principal stresses tensor reports that anisotropy increases for increasing water friction, although the system tends to isotropic conditions immediately below the air–water interface. For wind following the swell, the principal axes approaches the free surface with an angle <span><math><mrow><mo>−</mo><mi>π</mi><mo>/</mo><mn>4</mn></mrow></math></span>, which is typical when a shear current is dominant near the surface. Important implications of these findings include the availability of further data to improve wave forecasting and prediction of swell and wind conditions.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"203 ","pages":"Article 104879"},"PeriodicalIF":4.5,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158366","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 : 2025-09-18DOI: 10.1016/j.coastaleng.2025.104876
Qiujue Jiang , Deqing Zhang , Junfeng Du , Qingping Zou , Anteng Chang , Huajun Li
{"title":"Amplification of nonlinear response of floating photovoltaics by coastal topography: Experimental and numerical study","authors":"Qiujue Jiang , Deqing Zhang , Junfeng Du , Qingping Zou , Anteng Chang , Huajun Li","doi":"10.1016/j.coastaleng.2025.104876","DOIUrl":"10.1016/j.coastaleng.2025.104876","url":null,"abstract":"<div><div>Nearshore coastal regions have become popular for floating photovoltaics (FPV) installations. During propagation over seabed topography towards nearshore FPV systems, waves undergo intricate transformations by shoaling, reflection and refraction, potentially influencing hydrodynamic responses of these emerging marine renewable energy structures in ways that are not well understood. Therefore, wave flume experiments and multiscale fully coupled time-domain fluid-structure interaction (FSI) simulations are performed to examine the topography effect on the nonlinear responses of nearshore FPV systems at a field site in the East China Sea. Experimental results reveal that near-resonant wave interactions in coastal regions drive significant energy transfer among different wave frequencies, amplifying the nonlinear dynamic responses of FPV systems by channeling energy toward their natural modes. As a result, second-order heave and pitch responses are amplified by up to 117.87 % and 136.38 % compared to the case without topography, which in turn lead to an increase in mooring tension. Moreover, the topography-induced amplification of nonlinear wave harmonics enhances the surge mean drift of FPV. This enhancement exhibits a negative correlation with the relative FPV length with respect to the wavelength. Comparisons between experiments and fully coupled simulations for irregular waves indicate that neglecting topography causes the FPV dynamic response model to produce inaccurate estimations of heave/pitch motions, while FSI simulations forced by high-fidelity local wave fields predicted by the fully nonlinear Boussinesq wave model are capable of capturing the observed topographic effect. These findings provide the theoretical basis for design consideration of the safe, cost-effective deployment of efficient FPV systems in coastal waters.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104876"},"PeriodicalIF":4.5,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183850","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 : 2025-09-18DOI: 10.1016/j.coastaleng.2025.104878
Dag Myrhaug, Bernt J. Leira
{"title":"Discussion/comments of “Drag coefficient prediction model for simulating breaking waves propagating on partly submerged vegetated sloping beaches using a RANS model” by Yanxu Wang, Quanlin Qiu, Zegao Yin, Xiutao Jiang and Xuan Zang","authors":"Dag Myrhaug, Bernt J. Leira","doi":"10.1016/j.coastaleng.2025.104878","DOIUrl":"10.1016/j.coastaleng.2025.104878","url":null,"abstract":"<div><div>The purpose of these comments and discussion has been to point out how wave statistics can be incorporated in applications of the drag coefficient model for regular breaking waves propagating on partly submerged vegetated sloping beaches proposed by Wang et al. (2025). This is demonstrated by using a distribution of the surf parameter provided by Myrhaug and Fouques (2007). Examples of results are given by applying a Phillips wave amplitude spectrum for wind sea.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"203 ","pages":"Article 104878"},"PeriodicalIF":4.5,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109401","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 : 2025-09-15DOI: 10.1016/j.coastaleng.2025.104877
Margaret Libby , Tori Tomiczek , Daniel T. Cox , Pedro Lomónaco
{"title":"Green-gray connections: Coupled equations of wave attenuation and structural response for engineering design of hybrid infrastructure","authors":"Margaret Libby , Tori Tomiczek , Daniel T. Cox , Pedro Lomónaco","doi":"10.1016/j.coastaleng.2025.104877","DOIUrl":"10.1016/j.coastaleng.2025.104877","url":null,"abstract":"<div><div>A quantitative method is proposed for predicting the engineering performance of a hybrid green-gray system comprised of a mangrove forest seaward of a conventional engineered structure to mitigate wave action. The method coupled existing empirical equations to (1) predict the wave height attenuation of random waves transmitted through the mangrove forest and (2) use the resulting significant wave height as input to existing equations to estimate wave overtopping on a vertical wall or rubble-mound revetment or wave force on a vertical wall. The predicted wave height attenuation was parameterized by a drag coefficient obtained from an empirical relation developed from previous laboratory results. The method was validated with data from two large-scale wave flume studies of wave overtopping and wave force, which used similar model mangroves at 1:2 and 1:1 scale, respectively. The method conservatively predicted the overtopping of a vertical wall or rubble-mound revetment within a factor of 1.7 for discharge rates greater than 1 × 10<sup>−3</sup> m<sup>3</sup>/s/m and a factor of 3.5 for discharge rates greater than 1 × 10<sup>−4</sup> m<sup>3</sup>/s/m. The predictions of wave forces were also conservative and were within a factor of 1.3 compared to the measurements. The overprediction of the wave force increased slightly with mangrove forest density, indicating a possible interaction between the waves and the green and gray features that reduced the wave forces more than expected from the wave attenuation alone. The apparent interaction was small, and the results of the proposed method were reasonable compared to the observations. The present results show promise for a design approach which assumes independent performance of the components to motivate a calculation coupling empirical equations to estimate the performance of hybrid green-gray systems for coastal defenses. Future study is necessary to parameterize wave attenuation by natural mangrove forests and to account for nonlinear processes such as wave breaking and wave-induced setup.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":"204 ","pages":"Article 104877"},"PeriodicalIF":4.5,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269838","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}