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  Subjects -> ENGINEERING (Total: 2277 journals)
    - CHEMICAL ENGINEERING (191 journals)
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    - ENGINEERING (1204 journals)
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ENGINEERING (1204 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Hybrid Journal   (Followers: 6)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 230)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
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Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
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Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
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Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
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Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 1)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 4)
AIChE Journal     Hybrid Journal   (Followers: 30)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access  
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 12)
Applied Clay Science     Hybrid Journal   (Followers: 5)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 7)
Applied Network Science     Open Access  
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 7)
Arid Zone Journal of Engineering, Technology and Environment     Open Access   (Followers: 2)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 4)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 23)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 9)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 3)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 3)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 14)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 41)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Thermal Engineering     Open Access   (Followers: 3)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 5)
Coatings     Open Access   (Followers: 3)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 26)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 254)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 179)
Composites Part B : Engineering     Hybrid Journal   (Followers: 230)
Composites Science and Technology     Hybrid Journal   (Followers: 171)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
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Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 8)
Control Engineering Practice     Hybrid Journal   (Followers: 42)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 25)
CT&F Ciencia, Tecnologia y Futuro     Open Access  
CTheory     Open Access  

        1 2 3 4 5 6 7 | Last

Journal Cover Coastal Engineering
  [SJR: 1.999]   [H-I: 74]   [11 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-3839
   Published by Elsevier Homepage  [3043 journals]
  • Use of a Bayesian Network for coastal hazards, impact and disaster risk
           reduction assessment at a coastal barrier (Ria Formosa, Portugal)
    • Abstract: Publication date: Available online 26 July 2017
      Source:Coastal Engineering
      Author(s): Theocharis A. Plomaritis, Susana Costas, Óscar Ferreira
      Coastal communities are threatened by the impact of severe storms that may cause significant loss or damage of property and life. The main processes causing such impacts at sandy coastlines and nearby coastal communities are storm erosion, overwash and inundation. Coastal response under present conditions and under predicted climate change has been frequently assessed on the basis of numerical models, which in turn can be also used to evaluate the effectiveness of Disaster Risk Reduction (DRR) measures to mitigate the response of the coast to the imposed conditions. However, detailed morphodynamic models are computationally expensive and not commonly used by coastal managers. The present work proposes the construction of a probabilistic Bayesian Network (BN) as a surrogate for the numerical simulations. This BN is trained with a large number of morphodynamic simulations, under a variety of storm conditions and DRR measures, in order to serve as a front-end platform for visualising, analysing and evaluating combined results of the numerical modelling. The BN introduced in an early warning system will be able to serve both, as a predictive and as a working tool to determine impacts and evaluate risk reduction after measures implementation. Here, an example of the implementation and results of such a BN system is presented. The BN system was built for a coastal sector of the Ria Formosa barrier island system (South Portugal) to inform the degree of impact derived from overwash and erosion over the study area. The BN boundary conditions include variable wave height, water level, and wave period. The impact on receptors, including houses and infrastructure, was assessed. In addition, this tool can inform about the effectiveness of a particular DRR measure. The evaluated DRR measures were two primary measures (partial house removal and beach replenishment) and a non-primary measure (improve channels of communication), all measures proposed by local stakeholders. Results show that for a storm with wave characteristics of the 1 in 50 year return period and spring tide conditions, the house removal DRR reduces the overwash impact by 15% and erosion impact by 58%. The implementation of beach replenishment could reduce the erosion impact of the same event by 96% while it would have a smaller effect on the overwash impact (16%). The implementation of non-primary measures would have a much smaller effect on risk reduction. The combined effect of the above DRR measures (mainly house removal and beach nourishment) reduces storm impacts at the study area to a value near zero. The BN surrogates the model simulated onshore hazards and translates them into impacts for the current conditions, which give a high degree of confidence in the potential application of the BN as a management tool.

      PubDate: 2017-08-03T09:12:25Z
       
  • Generation and propagation of ship-borne waves - Solutions from a
           Boussinesq-type model
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): C. Gabriel David, Volker Roeber, Nils Goseberg, Torsten Schlurmann
      Ship-borne waves are of significant interest for the design of port and waterway infrastructure and the maintenance of its surrounding environment. Computation of these nonlinear and dispersive waves has mainly been focusing on their near-field generation as a fluid-body interaction problem. This study presents an approach for the computation of ship waves generated by a moving pressure disturbance with phase-resolving and depth-averaged equations. To support a wide range of applicability, the paper deals with the evolution of the vessel wedge compared to an analytical solution for sub-to supercritical speeds and the assessment of wave patterns from a broad range of pressure term dimensions, including cross-references to findings in other studies. The conducted numerical experiments showcase the typical response of a Boussinesq-type model to a simplified moving pressure disturbance and identify the main factors and criteria for ship-wave propagation in the far-field of a vessel. Finally, a unique field dataset underlines the capability of an extended Boussinesq-type model to compute the propagation of vessel waves over an irregular bathymetry.

      PubDate: 2017-07-23T00:52:27Z
       
  • An analytical model for preliminary assessment of dredging-induced
           sediment plume of far-field evolution for spatial non homogeneous and time
           varying resuspension sources
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Marcello Di Risio, Davide Pasquali, Iolanda Lisi, Alessandro Romano, Massimo Gabellini, Paolo De Girolamo
      In recent years, increasing attention has been paid to assess the dispersal of resuspended sediments and related water quality problems due to dredging operations. This paper presents an analytical model aimed to predict the temporal evolution and spatial distribution in the far field of the suspended sediments concentration increase related to dredging activities or open water sediments disposal. In particular, whatever the dredging source strength and geometry can be considered to define the suspended sediments concentration leaving the immediate vicinity of the resuspension source. Indeed, a feature of the model is the removing of the hypotheses of continuous source and steady state, peculiar to the majority of available theoretical models. Hence, the proposed model is able to describe different dredging resuspension sources and to provide the temporal and spatial picture of the resulting plume. Of course, some hypotheses have to be assumed in order to make possible to achieve the analytical solution of the governing equation: the model is two dimensional in the horizontal plane; the ambient currents are assumed to be homogeneous in space and slowly time varying; the turbulent diffusion coefficients and flocculent settling velocity are homogeneous in space; the water depth is constant; the domain is infinite. Even with its limitations, the model is still able to provide a worst case preliminary assessment of sediments plume migration very useful to guide more detailed numerical analysis and to select the more appropriate simulation scenarios. The analytical model is detailed in order to be used for numerical model testing purposes. A series of practical applications is described through the paper (i) to catch the general features of the involved far field phenomena, (ii) to compare the model results to those of previous researches and (iii) to provide a series of benchmark cases useful for the testing of numerical models. The proposed model may be also used as a first rough prediction of the area affected by plume dispersion by considering different dredging scenarios (i.e. different equipment and operational techniques and forced by site-specific environmental conditions), and thus to provide a basis for more sophisticated modeling aimed to support dredging projects planning and management.

      PubDate: 2017-07-10T03:12:04Z
       
  • Cross-shore variability and vorticity dynamics during wave breaking on a
           fixed bar
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): L. Chiapponi, M. Cobos, M.A. Losada, S. Longo
      In the present experiments a volumetric particle-tracking system (V3V from TSI Inc.) allowed the measurement of the velocity fields generated by regular breaking waves past a fixed bar on a 1:10 rigid plane slope. The measurement volume extended from the wave crest to a portion of the domain below the wave trough, with two sets of monochromatic wave trains with different periods and heights. The aim of the present work is the quantification of the terms in the vorticity balance equation by including all the terms in a fully 3D approach. A possible new vorticity generation mechanism is revealed, that is amplified by the geometry of the laboratory flume and that awaits experimental validation in 3D wave tanks and in the field. The results are new and original and represent a data set for the comprehension of the effects of a submerged berm, for developing conceptual models of vorticity and for the calibration of numerical codes.

      PubDate: 2017-07-10T03:12:04Z
       
  • A parametric model for dry beach equilibrium profiles
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Jorge Díez, Adolfo Uriarte, Verónica Cánovas, Raúl Medina
      Predictions of dry beach morphologies are extensively required in coastal research for multiple purposes -e.g., dune erosion forecasting, inundation heights determination and beach fill design optimization. In this paper, we introduce and test a parametric model that describes the equilibrium shape of the dry beach in the cross-shore direction, i.e., an equation for the dry beach equilibrium profile. The model consists of a three-parameter equation formed by two terms: an exponential that defines the foreshore and berm morphology, plus a linear term that defines the slope from the berm to the landward limit as a planar far field behaviour. The three morphological parameters that shape the equation are related to the nearshore wave climate (Hs and Tp) and the sediment characteristics (d50) in a form which is consistent with previous knowledge of dry beach morphodynamics, thus proposing the runup driver ( H L ) 1 / 2 and the dimensionless fall velocity Ω as the fundamental variables defining the equation parameters. We tested the predictive capacity of the model against an independent data set from Narrabeen Beach, which, depending on longshore location and the time of year, offers beach modal states ranging from dissipative to reflective. The exponential term of the equation correctly explains the foreshore and berm morphology under mean wave climate, and the linear term predicts the slope of the asymptotic-planar segment, all with good correlation coefficients (∼0.95) between modelled cross-shore transects and observations. The proposed model helps in defining the main shapes of subaerial beach profiles over the long term and it may also be useful as a coastal management tool for predicting dry beach morphologies.

      PubDate: 2017-07-10T03:12:04Z
       
  • Historical analysis of storm events: Case studies in France, England,
           Portugal and Italy
    • Abstract: Publication date: Available online 4 July 2017
      Source:Coastal Engineering
      Author(s): E. Garnier, P. Ciavola, T. Spencer, O. Ferreira, C. Armaroli, A. McIvor
      An historical analysis of the occurrence of storms and their damage intensity is presented. The work analysed historical large-scale events from The Middle Ages to the 1960s at case study sites along the coasts of North Norfolk (UK); Charente-Maritime and Vendée (France); Cinque Terre-Liguria coast (Italy); Emilia-Romagna coast (Italy) and Ria Formosa (Portugal). The work presented here used a database of events built by the RISC-KIT project, including the characteristics of the storms as well as recorded human impacts. Historical records can provide an important test bed to complement the statistical analysis of the return period of events based on measurements and provide important indicators of past events and their impact that are no longer within the historical memories of resident populations and coastal managers.

      PubDate: 2017-07-10T03:12:04Z
       
  • A Bayesian network approach for coastal risk analysis and decision making
    • Abstract: Publication date: Available online 3 July 2017
      Source:Coastal Engineering
      Author(s): W.S. Jäger, E.K. Christie, A.M. Hanea, C. den Heijer, T. Spencer
      Emergency management and long-term planning in coastal areas depend on detailed assessments (meter scale) of flood and erosion risks. Typically, models of the risk chain are fragmented into smaller parts, because the physical processes involved are very complex and consequences can be diverse. We developed a Bayesian network (BN) approach to integrate the separate models. An important contribution is the learning algorithm for the BN. As input data, we used hindcast and synthetic extreme event scenarios, information on land use and vulnerability relationships (e.g., depth-damage curves). As part of the RISC-KIT (Resilience-Increasing Strategies for Coasts toolKIT) project, we successfully tested the approach and algorithm in a range of morphological settings. We also showed that it is possible to include hazards from different origins, such as marine and riverine sources. In this article, we describe the application to the town of Wells-next-the-Sea, Norfolk, UK, which is vulnerable to storm surges. For any storm input scenario, the BN estimated the percentage of affected receptors in different zones of the site by predicting their hazards and damages. As receptor types, we considered people, residential and commercial properties, and a saltmarsh ecosystem. Additionally, the BN displays the outcome of different disaster risk reduction (DRR) measures. Because the model integrates the entire risk chain with DRR measures and predicts in real-time, it is useful for decision support in risk management of coastal areas.

      PubDate: 2017-07-10T03:12:04Z
       
  • Improved treatment of non-stationary conditions and uncertainties in
           probabilistic models of storm wave climate
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Gareth Davies, David P. Callaghan, Uriah Gravios, Wenping Jiang, David Hanslow, Scott Nichol, Tom Baldock
      A framework is presented for the probabilistic modelling of non-stationary coastal storm event sequences. Such modelling is required to integrate seasonal, climatic and long-term non-stationarities into coastal erosion hazard assessments. The framework is applied to a study site on the East Australian Coast where storm waves are found to exhibit non-stationarities related to El Niño-Southern Oscillation (ENSO) and seasonality. The impact of ENSO is most prominent for storm wave direction, long term mean sea level (MSL) and the rate of storms, while seasonal non-stationarity is more ubiquitous, affecting the latter variables as well as storm wave height, duration, period and surge. The probabilistic framework herein separates the modelling of ENSO and seasonal non-stationarity in the storm wave properties from the modelling of their marginal distributions, using copulas. The advantage of this separation is that non-stationarities can be straightforwardly modelled in all storm wave variables, irrespective of whether parametric or non-parametric techniques are used to model their marginal distributions. Storm wave direction and steepness are modelled with non-parametric distributions whereas storm wave height, duration and surge are modelled parametrically using extreme value mixture distributions. The advantage of the extreme value mixture distributions, compared with the standard extreme value distribution for peaks-over-threshold data (Generalized Pareto), is that the statistical threshold becomes a model parameter instead of being fixed, and so uncertainties in the threshold can be straightforwardly integrated into the analysis. Robust quantification of uncertainties in the model predictions is crucial to support hazard applications, and herein uncertainties are quantified using a novel mixture of parametric percentile bootstrap and Bayesian techniques. Percentile bootstrap confidence intervals are shown to non-conservatively underestimate uncertainties in the extremes (e.g. 1% annual exceedance probability wave heights), both in an idealized setting and in our application. The Bayesian approach is applied to the extreme value models to remedy this shortcoming. The modelling framework is applicable to any site where multivariate storm wave properties and timings are affected by seasonal, climatic and long-term non-stationarities, and can be used to account for such non-stationarities in coastal hazard assessments.

      PubDate: 2017-06-28T19:00:39Z
       
  • On the relation between the direction of the wave energy flux and the
           orientation of equilibrium beaches
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Ahmed I. Elshinnawy, Raúl Medina, Mauricio González
      The Equilibrium beach planform concept has been widely used in recent years as an engineering tool for modeling shoreline changes, designing new beaches and for stability studies of existing ones. It defines the final shape of a beach on a scale of years, which is important for solving erosion problems and for the design of nourishment projects. Throughout the literature, the planform final shape, hereinafter denoted as the Static Equilibrium Beach Orientation (SEBO), is obtained based on the direction of the mean wave energy flux of whole waves impinging on the coast. This paper investigates the effect of beach sediment size and the Shape of the Directional Distribution (SDD) of the energy flux of the wave climate on the direction that dictates the (SEBO). The study employs field data from 32 beaches along the Spanish coast and available long-term databases of directional wave climates. Initiation of sediment motion due to wave action is taken into account in order to filter the directional wave climate to consider only waves that are capable of moving the sediment. The results indicate that the direction of the mean energy flux of filtered waves is more appropriate for the determination of the (SEBO) than that of whole waves. Additionally, the results confirm the importance of both the filtration process of the local directional wave climate and the usage of the whole directional spectra in stability studies and coastal engineering practice.

      PubDate: 2017-06-28T19:00:39Z
       
  • Long-crested wave generation and absorption for SPH-based DualSPHysics
           model
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): C. Altomare, J.M. Domínguez, A.J.C. Crespo, J. González-Cao, T. Suzuki, M. Gómez-Gesteira, P. Troch
      The present work presents a fully comprehensive implementation of wave generation and active wave absorption for second-order long-crested monochromatic and random waves in a WCSPH-based (Weakly Compressible Smoothed Particle Hydrodynamics) model. The open-source code DualSPHysics is used for the scope. The numerical flume resembles a physical wave facility, so that, the moving boundaries mimic the action of a piston-type wavemaker. The second-order wave generation system, capable of generating both monochromatic (regular) and random (irregular) waves, is implemented jointly with passive and active wave absorption. A damping system is defined as solution for passive absorption and is used to prevent wave reflection from fixed boundaries in the numerical flume. The use of active wave absorption allows avoiding spurious reflection from the wavemaker. These implementations are validated with theoretical solutions and experimental results, in terms of water surface elevation, wave orbital velocities, wave forces and capacity for damping the re-reflection inside the fluid domain.

      PubDate: 2017-06-28T19:00:39Z
       
  • Hydraulic stability of rock armors in breaking wave conditions
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Maria P. Herrera, M. Esther Gómez-Martín, Josep R. Medina
      Armor layers of mound breakwaters are usually designed with empirical formulas based on small-scale tests in non-breaking wave conditions. However, most rubble mound breakwaters are constructed in the depth-induced breaking zone, where they must withstand design storms having some percentage of large waves breaking before reaching the structure; in these cases, the design formulas for non-breaking wave conditions are not fully valid. To characterize double-layer rock armor damage in breaking wave conditions, 2D physical model tests were carried out with a bottom slope m = 1/50. In order to develop a simple method to determine the wave parameters in the depth-induced breaking zone, experimental wave measurements were compared to the numerical estimations given by the SwanOne model. An analysis was conducted to select the best characteristic wave height to estimate rock armor damage when dealing with depth-induced breaking waves; the spectral significant wave height, H m0 , estimated at a distance of 3h s seaward from the structure toe, was found to be the most adequate. A new hydraulic stability formula is proposed for double-layer rock armors in breaking wave conditions, considering the observed potential 6-power relationship between the equivalent dimensionless armor damage and the H m0 at 3h s seaward distance from the structure toe.

      PubDate: 2017-06-28T19:00:39Z
       
  • A new two-step projection method in an ISPH model for free surface flow
           computations
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Haihua Xu, Pengzhi Lin
      In this study, we propose a new two-step projection method in connection with an ISPH model. Compared to the traditional ISPH model that uses the future time step pressure to calculate the intermediate velocity, in the present study the pressure at both current time step and future time step is employed. In addition, the velocity and pressure obtained at the end step of the projection method are re-projected onto the updated particle locations using an interpolation method. While the use of current time step pressure provides a better energy conserving property of the numerical scheme, the interpolation smooths the velocity field and ensures a more stringent constraint for incompressibility condition. The accuracy of the model is further enhanced by implementing C2 consistency kernel approximation for variable and derivative calculation. The model is first calibrated by using the still water and liquid sloshing tests. It is then validated against a series of benchmark tests of linear wave and solitary wave propagation in constant water depth, followed by the case of nonlinear wave transformation over a submerged breakwater. The numerical results are compared to available theories, experimental data, and previously published simulation results. It is shown that the present model can achieve a much better energy conservation than the traditional ISPH model, even with the use of a much larger time step.

      PubDate: 2017-06-28T19:00:39Z
       
  • Parameterization of nearshore wave front slope
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Chi Zhang, Qingyang Zhang, Jinhai Zheng, Zeki Demirbilek
      This study presents an empirical parameterization of wave front slope angle used in the characterization of shoaling and breaking waves in nearshore environment. A large amount of experimental datasets is analyzed for determining possible values of the wave front slope angles. Results indicate that the slope angle increases with wave shoaling and decreases when wave breaks. For the data used here, the maximum slope angle is around 0.8 rad at the breakpoint. Two empirical formulas developed based on data analysis establish relationships between the wave front slope angle and other parameters of engineering interest. Specifically, the first formula expresses the local wave front slope angle as a function of the local wave parameters. The applicability of this formula to regular and random shoaling and breaking waves is verified using extensive datasets. The second formula defines the critical wave front slope angle for wave breaking as a function of the relative water depth and bed slope. This formula is shown applicable to both the first and second breakpoints for regular wave breaking over sloping and barred beaches. A combination of these two formulas provides estimates of the incipient breaking wave heights which are in good agreement with independent experimental data.

      PubDate: 2017-06-28T19:00:39Z
       
  • Tsunami inundation variability from stochastic rupture scenarios:
           Application to multiple inversions of the 2011 Tohoku, Japan earthquake
    • Abstract: Publication date: September 2017
      Source:Coastal Engineering, Volume 127
      Author(s): Nobuhito Mori, P. Martin Mai, Katsuichiro Goda, Tomohiro Yasuda
      We develop a framework for assessing the sensitivity and variability of tsunami inundation characteristics for stochastic physics-based scenarios of mega-thrust subduction earthquakes. The method is applied to the 2011 Tohoku, Japan earthquake, and tested against observed inundation maps at several locations along the Tohoku coast, using 11 different, previously published, rupture models for this devastating tsunamgenic earthquake. The earthquake rupture models differ in fault dimension (length and width), geometry (dip, strike and top-edge depth), as well as asperity characteristics (slip heterogeneity on the fault plane). The resulting source variability allows exploring a wide range of tsunami scenarios for an M w9 mega-thrust subduction earthquake in the Tohoku region to conduct thorough sensitivity analyses and to quantify the inundation variability. The numerical results indicate a strong influence of the reference source models on inundation variability, and demonstrate significant sensitivity of inundation to the details of the rupture realization. Therefore, relying on a single particular earthquake rupture model as a representative case when varying earthquake source characteristics may lead to under-representation of the variability of potential scenarios. Moreover, the proposed framework facilitates the rigorous development of critical scenarios for tsunami hazard and risk assessments, which are particularly useful for tsunami hazard mapping and disaster preparedness planning.

      PubDate: 2017-06-28T19:00:39Z
       
  • Regional coastal flood risk assessment for a tidally dominant, natural
           coastal setting: North Norfolk, southern North Sea
    • Abstract: Publication date: Available online 26 June 2017
      Source:Coastal Engineering
      Author(s): E.K. Christie, T. Spencer, D. Owen, A.L. McIvor, I. Möller, C. Viavattene
      A Coastal Risk Assessment Framework (CRAF) provides two levels of coastal risk and vulnerability assessment, by combining information on the spatially variable hazard and exposure. In Phase 1, areas of greatest risk or ‘hotspots’ are identified. In Phase 2, these hotspots are then analysed in greater detail to identify both direct and indirect extreme event impacts. This approach was applied to the barrier coastline of North Norfolk, eastern England. The CRAF identified high risk coastal hotspots on the basis of both hazard impacts (swash regime (tide + surge + wave runup) and overwash/terrestrial inundation regimes) from a 1 in 115 year return period storm and a range of land use, infrastructure, economic and social vulnerability indicators. Hazard extents and hazard severity, in some locations modified by the presence of intertidal saltmarsh, were calculated for 45, 1–2 km wide sections along the topographically complex coast. When combined with five exposure indicators, eight hotspots were identified along the 45 km long frontage. In a 2nd phase, two of these hotspots, one a chain of small villages (Brancaster/Brancaster Staithe/Burnham Deepdale) and one a small town (Wells-next-the-Sea), were compared in more detail using a suite of coastal inundation and impact assessment models to determine both direct and indirect impacts. Hazards at this higher resolution were calculated using the 1D process-based XBeach model and the 2D LISFLOOD inundation model. Vulnerability to the hazards was calculated using the INDRA (Integrated Disruption Assessment) model with comparison of the two hotspots through the use of a Multi Criteria Analysis (MCA). The selection of hazard hotspots and comparison of hotspots using these techniques allows areas at greatest risk to be identified, of vital importance for coastal management and resource allocation.

      PubDate: 2017-06-28T19:00:39Z
       
  • Towards simulating floating offshore oscillating water column converters
           with Smoothed Particle Hydrodynamics
    • Abstract: Publication date: August 2017
      Source:Coastal Engineering, Volume 126
      Author(s): A.J.C. Crespo, C. Altomare, J.M. Domínguez, J. González-Cao, M. Gómez-Gesteira
      The mesh-free code DualSPHysics is applied to simulate the interaction between sea waves and an Oscillating Water Column device (OWC). In this work, capabilities and limitations of DualSPHysics are shown in simulating OWCs. On the one hand, the new capabilities of DualSPHysics are shown by simulating the effect of mooring systems on a floating offshore OWC. On the other hand, simulations only consider a single-phase (water) so that the full OWC behaviour is partially reproduced, i.e. air pressure fluctuations are not modelled. The model was first validated with one laboratory test that consists of a fixed OWC with an open chamber. Next, water surface oscillations inside the chamber of a real OWC (located in Mutriku, Spain) have been predicted using the prevalent wave conditions observed in the area. Finally, the capabilities of DualSPHysics were demonstrated by simulating an offshore OWC moored to the seabed.

      PubDate: 2017-06-11T12:02:46Z
       
  • Video-derived near bed and sheet flow sediment particle velocities in
           dam-break-driven swash
    • Abstract: Publication date: August 2017
      Source:Coastal Engineering, Volume 126
      Author(s): Jack A. Puleo, Douglas Krafft, José Carlos Pintado-Patiño, Brittany Bruder
      This short communication considers a video-based approach to quantify near bed and sheet flow swash zone sediment particle velocities over a mobile bed in a laboratory setting and relate the profile shape to sheet thickness and a velocity that can be measured outside the sheet layer (by for instance a current meter) Near bed high speed imagery was recorded during a dam-break driven swash event in a flume with optically clear walls. Repeated swash events for two different median sediment sizes were tested. Optical Current Meter (OCM) analysis was applied to bed parallel image time stacks extracted at elevations from below the at rest bed to within the lower water column. OCM results were compared to in situ velocity measurements, where possible, obtained with an acoustic Doppler profiling velocimeter (ADPV). OCM results compared well with ADPV measurements for moderate suspended sediment concentrations (based on visual observation; sediment concentrations were not measured). Too high of a sediment concentration over saturated the image and did not provide distinct sediment particle trajectories in a consistent direction for OCM analysis. This saturation occurred during uprush for both sediment sizes. Too little of a sediment concentration provided an inadequate number of sediment particle trajectories to track, such as during flow reversal for the coarser sediment. For coarser sediment, backwash velocities were well resolved in OCM analysis with velocities comparing well (correlation coefficient > 0.8) to ADPV estimates. The dimensionless backwash sheet flow sediment particle velocity profile (normalized by the velocity at the top of the sheet) scaled with the dimensionless elevation (normalized by the sheet layer thickness) to the 0.62 power with 95% confidence intervals for the exponent ranging from 0.47 to 0.76.

      PubDate: 2017-06-11T12:02:46Z
       
  • An overlapping domain decomposition based near-far field coupling method
           for wave structure interaction simulations
    • Abstract: Publication date: August 2017
      Source:Coastal Engineering, Volume 126
      Author(s): Xin Lu, Dominic Denver John Chandar, Yu Chen, Jing Lou
      This paper presents a newly developed Overlapping Domain Decomposition (ODD) method, which forms the basis of a near-far field coupling solver for a wide range of wave-structure interaction problems. In this method, the computational domain is decomposed into near and far fields which are then modeled separately by solving the viscous Navier-Stokes equations (NSE) and the Potential Laplacian equation (PLE) respectively. A Finite volume method (FVM) is adopted to discretize both the NS and PL equations. The free surface problem is solved in both domains but using totally different strategies. In the potential domain, a moving mesh free surface tracking method is adopted where arbitrary polyhedral mesh adapts to the time-varying shape of the interface using vertex-based automatic mesh motion solver. Meanwhile, at the free surface, the boundary conditions are formulated using an ordinary differential equation (ODE) derived from the Bernoulli's equation. In the viscous domain, however, the volume of fluid (VOF) method is used to predict the location of free surface. The novelty of the reported method lies in two-folds. First, the introduction of the so called overlapped buffer zone eliminates the need of performing time costing iterative schemes in the non-overlapping domain decomposition methods to ensure the matching of free surface elevation at the domain boundaries. The concept of a buffer zone is borrowed from the relaxation zone technique which is commonly used near the inlet to ensure a stable wave generation or near the outlet to absorb the reflected waves in numerical wave simulations. Second, an in-house developed OVERSET method is adopted for the viscous domain solver to handle large object displacement in the case of an extreme event. The proposed method has been implemented in the OpenFOAM platform (foam-extend-3.1). To validate the method, the propagation of a solitary wave is first simulated and the resulting wave parameters are compared with the corresponding analytical, as well as pure VOF solution. Meanwhile, a comparison of the CPU time between the single domain approach and the current method has been provided. Next, the measured wave impact loading for a single body which is partially submerged will be used to further test the method. Last but not least, the method is applied to simulate the spilling wave breaking near the beach. Various numerical examples presented in the paper demonstrate the accuracy and efficiency of the proposed method. Towards the end, computation of a sinking semi-submersible platform will be presented to demonstrate further the capability of the method.

      PubDate: 2017-06-11T12:02:46Z
       
  • Simulation of wave overtopping using an improved SPH method
    • Abstract: Publication date: August 2017
      Source:Coastal Engineering, Volume 126
      Author(s): H. Akbari
      An improved Smoothed Particle Hydrodynamics (SPH) method is used to study wave overtopping for different coastal structures. Simulated wave overtopping is too sensitive to the particle movements near the free surface boundary; however, the calculated flow acceleration by means of common SPH methods is not free of errors at this boundary due to the truncation of kernel function and contribution of fewer particles in solving the governing equations. In this paper, this problem is solved by modifying the viscosity of surface particles based on the concept of surface viscosity originally introduced by Xu (2010). By means of the introduced modification, unrealistic particle fluctuation at free surface boundary can be decreased significantly while keeping the model accuracy. This improvement can be used for both Incompressible and Weakly Compressible SPH methods and its implementation is easy and computationally efficient too. Different cases including dam break, solitary wave breaking and wave overtopping at vertical and sloping seawalls are simulated with the modified model and the new model is validated via comparing the results with several experimental and numerical data. Based on this study, free surface boundary can be simulated more accurately by means of the introduced modification and as a result, the predicted values particularly the calculated wave-overtopping rate become more reliable.

      PubDate: 2017-06-11T12:02:46Z
       
  • Experimental study of the hydraulic efficiency of a novel perforated-wall
           caisson concept, the LOWREB
    • Abstract: Publication date: August 2017
      Source:Coastal Engineering, Volume 126
      Author(s): Crina-Stefania Ciocan, Francisco Taveira-Pinto, Luciana das Neves, Paulo Rosa-Santos
      A novel perforated-wall caisson concept, the so-called LOW REflection Breakwater (LOWREB), based on a three-chamber perforated-wall and inner weirs, is under development in the University of Porto – Faculty of Engineering, Portugal. Physical model tests, carried out in the wave basin of the Hydraulics Laboratory of the Hydraulics, Water Resources and Environment Division, Civil Engineering Department, have been used to study the hydraulic processes related to wave reflection. The physical model was built to a Froude scale of 1:50. Test conditions covered two water levels and irregular waves at three significant wave heights (3.0, 4.0 and 5.0 m) and three peak wave periods (10, 14 and 18s). Three models of varying porosity, and vertical slots' arrangements were tested under the same hydrodynamic conditions to study how these affect the LOWREB performance, namely how these affect the wave reflection from the structure, as compared to a plain caisson tested under the same conditions. The experimental study demonstrates that the LOWREB caisson is a valid concept for marine structures, namely harbour breakwaters, because of its wave energy dissipation capacity, for which the inner weirs were found to play a major role. Results indicate that the hydraulic efficiency of the LOWREB caisson increases with wave height for the lower water level, and decreases with it for the highest. Greater efficiency with respect to wave reflection was accomplished with the highest water level.

      PubDate: 2017-06-11T12:02:46Z
       
  • Regional frequency analysis of extreme waves in a coastal area
    • Abstract: Publication date: August 2017
      Source:Coastal Engineering, Volume 126
      Author(s): C. Lucas, G. Muraleedharan, C. Guedes Soares
      This study analysed the wave data from several locations in a coastal region to identify the areas with comparable wave height statistics and to estimate regional extreme significant wave heights of designated return periods. The regional frequency analysis algorithm executed in this work utilised the significant wave height data from 35 sites (35°–45°N, -6.5°–-11.0°W) in a coastal grid (0.25° × 0.25°) off Portugal in the North Atlantic Ocean, extracted from 44 years HIPOCAS hindcast wave database. Regional frequency analysis algorithms based on L-moments identified the discordant sites (discordant site statistics are substantially diffused from the group of sites statistics), assisted in the formation of homogeneous regions by cluster analyses (data vectors include site characteristics and site statistics) and consequently selected appropriate regional frequency distributions by Z goodness-of-fit test statistic at 90% level of significance to estimate regional extreme significant wave height quantiles of designated return periods. The regional frequency analysis algorithm recognised in certain cases, neighbouring sites as members of diverse regions, revealing that geographical proximity of sites are not ascertaining factors to form homogeneous regions. At-site analyses along with regional frequency analysis enabled to apprehend the precision of the regional extreme quantile as genuine feature of its at-site extreme quantiles.

      PubDate: 2017-06-11T12:02:46Z
       
  • Nearshore placement of a sand dredged mound
    • Abstract: Publication date: August 2017
      Source:Coastal Engineering, Volume 126
      Author(s): Ernest R. Smith, Felice D'Alessandro, Giuseppe R. Tomasicchio, Joseph Z. Gailani
      As a part of the Dredging Operations and Environmental Research (DOER) Program, movable-bed physical model experiments were performed at the U.S. Army Engineer Research and Development Centre's (ERDC), Large-scale Sediment Transport Facility (LSTF) to investigate the fate and evaluate the benefits of nearshore-placed dredged material. The resulting bathymetry was measured with detailed surveys, the migration of the mound was quantified and comprehensive observations of hydrodynamics were obtained. The potential suitability of dredged material placement in the nearshore/surf zone was demonstrated after 10 h of oblique wave attacks. It has been shown that, as the mound was located at the edge of the surf zone, very likely wave breaking induced horizontal circulation may be dominant. A downdrift accretion of the submerged beach was observed, which is due to the transport of part of the sediment suspended by breakers at the mound and captured by the longshore currents. The experiments provided useful validation data for numerical morphological models.

      PubDate: 2017-06-06T11:59:12Z
       
  • Evaluation of XBeach performance for the erosion of a laboratory sand dune
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): Neville Anne Berard, Ryan Patrick Mulligan, Ana Maria Ferreira da Silva, Mohammad Dibajnia
      A new set of laboratory data is used to investigate the bathymetry change of a steep sand dune exposed to waves and high water levels, and subsequently compared to the results of numerical simulations using XBeach. Bichromatic wave boundary conditions are used to simulate a combined short-wave and long-wave field for two water level elevations corresponding to collision with the dune face, and overwashing of the dune crest. In the collision regime case, episodic slumping due to the undercutting of the dune results in sudden erosional events followed by long periods of wave-driven reshaping at the dune toe. In the overwash regime case, morphological changes are faster and sediment transport rates are higher. The XBeach model was used to simulate wave-driven erosion of the dune at the two water levels observed in the laboratory. The model was not able to precisely recreate the cross-shore spatial variability of significant wave height observed in the experiments, however near-bed wave-orbital and mean current velocities were in good agreement with observations. Following rapid initial adjustment, the model results were in agreement with measured dune morphology at successive times. XBeach was sensitive to several parameters that control the rate of erosion including the critical avalanching slope under water, the threshold water depth and the sediment transport formulation, and performed well after careful selection of the best combination of these parameters. Overall, the model predictions were in better agreement with laboratory observations for dune erosion in the overwash regime case than the collision regime case.

      PubDate: 2017-05-01T06:37:37Z
       
  • Application of a buoyancy-modified k-ω SST turbulence model to simulate
           
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): Brecht Devolder, Pieter Rauwoens, Peter Troch
      The objective of the present work is to investigate wave run-up around a monopile subjected to regular waves inside a numerical wave flume using the Computational Fluid Dynamics (CFD) toolbox OpenFOAM®. Reynolds-Averaged Navier-Stokes (RANS) turbulence modelling is performed by applying the k-ω SST model. Boundary conditions for wave generation and absorption are adopted from the IHFOAM toolbox. Simulations of propagating water waves show sometimes excessive wave damping (i.e. a significant decrease in wave height over the length of the numerical wave flume) based on RANS turbulence modelling. This anomaly is prevented by implementing a buoyancy term in the turbulent kinetic energy equation. The additional term suppresses the turbulence level at the interface between water and air. The proposed buoyancy-modified k-ω SST turbulence model results in an overall stable wave propagation model without significant wave damping over the length of the flume. Firstly, the necessity of a buoyancy-modified k-ω SST turbulence model is demonstrated for the case of propagating water waves in an empty wave flume. Secondly, numerical results of wave run-up around a monopile under regular waves using the buoyancy-modified k-ω SST turbulence model are validated by using experimental data measured in a wave flume by De Vos et al. (2007). Furthermore, time-dependent high spatial resolutions of the numerically obtained wave run-up around the monopile are presented. These results are in line with the experimental data and available analytical formulations.

      PubDate: 2017-05-01T06:37:37Z
       
  • Ripple and sandbar dynamics under mid-reflecting conditions with a porous
           vertical breakwater
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): M. Cobos, L. Chiapponi, S. Longo, A. Baquerizo, M.A. Losada
      This research is an experimental study of ripple and sandbar dynamics under regular and random waves in partially reflective conditions. As part of this study, a series of small-scale flume experiments were performed that reproduced the growth and migration of the bedforms, starting from a flat bed or rippled bed, with sediment transport in the bedload regime. The results showed that the evolution and dynamics of sandbar geometry were slower processes than the evolution of ripples. Moreover, they were governed by the wave field, reflective conditions, and sediment characteristics. Sandbar generation was controlled by the intensity of reflection, whereas the location of the crests (or deposition and erosion areas) was constrained by the phase shift of the reflected waves. Significant differences were also found between sandbars under regular and random waves. Sandbars under regular waves showed flat or practically flat troughs. In contrast, sandbars under random waves were almost uniformly covered by ripples. The experimental results showed that the concurrence of ripples and sandbars under partially reflected waves has a spatially modulating effect on ripple characteristics (i.e. growth, shape and migration celerity), which could not be consistently interpreted by using the classical formulas valid for ripples under progressive waves and/or without large-scale bedforms. This variability was more pronounced for regular waves than for random wave trains. Larger ripples develop in the nodes of the free surface envelope (more or less corresponding to the sandbars crests), whereas smaller ripples occurred in the antinodes (or sandbars troughs). The statistics of ripples geometry and celerity were computed with a sample stratification, based on their position in reference to the sandbars. In addition, they were compared in two energetically equivalent tests with regular and random waves, respectively. Although ripples under random waves had a larger wavelength and height than ripples under regular waves, the celerity of migration was comparable. Our results showed that the sandbars modified the equilibrium geometry of ripples. Furthermore, because of roughness, streaming was induced by the highest and longest ripples in the sandbar crests. The spatial modulation of the ripple celerity was found to be related to the local Lagrangian mass transport velocity, which was produced by the quasi-standing wave inside the bottom boundary layer at the grain-diameter scale.

      PubDate: 2017-05-01T06:37:37Z
       
  • Numerical investigation of transient harbor oscillations induced by
           N-waves
    • Abstract: Publication date: Available online 25 April 2017
      Source:Coastal Engineering
      Author(s): Junliang Gao, Chunyan Ji, Oleg Gaidai, Yingyi Liu, Xiaojian Ma
      Tsunamis are traveling waves characterized by large amplitudes and long wavelengths close to the coastline. Often, the first couple of leading waves are either leading-elevation N-waves (LEN waves) or leading-depression N-waves (LDN waves). These waves are usually devastating, causing serious damage to coastal infrastructures or even human casualties. Among various natural disasters related to tsunamis, harbor oscillations are one of the most frequent disasters around the world, which can cause excessive movements of moored ships and rupture mooring lines inside the harbor. In this article, transient harbor oscillations induced by various incident N-waves are first investigated. The transient oscillations are simulated by a fully nonlinear Boussinesq model, FUNWAVE-TVD. The incident N-waves include the TS-type and MS-type isosceles LEN and LDN waves. The TS- and MS-type N-waves correspond to the waveform expressions proposed by Tadepalli and Synolakis [1] and Madsen and Schäffer [2], respectively. This paper focuses on the effects of the incident wave amplitude and its type on the relative wave energy distribution inside the harbor. The maximum runup and rundown of various incident waves are also discussed. For comparison, the transient oscillations excited by solitary waves are also considered. The harbor used in this paper is assumed to be long and narrow and has constant depth; the free surface movement inside the harbor is essentially one-dimensional. This study reveals that, for the given harbor, for the range of the incident wave amplitude and the incident wave types studied in this paper, the larger tsunamis lead to a more uniform relative wave energy distribution inside the harbor. The relative wave energy distributions induced by the LDN waves are always more uniform than those induced by the LEN waves, while the relative wave energy distributions induced by the solitary waves are more concentrated than those induced by the various N-waves. When the incident wave amplitude is relatively large, the maximum runups of the LDN waves are considerably larger than those of the solitary waves, while those of the LEN waves are much less than those of the solitary waves.

      PubDate: 2017-05-01T06:37:37Z
       
  • Evaluation of surface wind fields for prediction of directional ocean wave
           spectra during Hurricane Sandy
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): Vanessa C.C. Bennett, Ryan P. Mulligan
      Hurricane Sandy was the largest storm on historical record in the Atlantic Ocean basin with extensive coastal damage caused by large waves and high storm surge. In this study, three different spatially-varying surface wind and atmospheric pressure fields that are used for forecasting or hindcasting hurricane waves on the continental shelf are investigated. These wind fields include two 2D parametric wind models (Holland model, H80; Generalized Asymmetric Holland Model, GAHM), and a 3D atmospheric model with data assimilation (WeatherFlow Regional Atmospheric Modelling System, WRAMS). These wind fields are used to drive wave hindcasts using coupled Delft3D-SWAN hydrodynamic and ocean wave models on a regional grid, and the bulk wave statistics and the directional wave spectra are compared to observations at offshore wave buoys to investigate the impact of differences between the complex wind fields on predictions of the sea surface evolution. The spatial and temporal distribution of bulk wave parameters are different for each wind field. The WRAMS wind field produces wave model predictions in the best agreement with significant wave height observations, followed by the GAHM and H80 wind fields, with mean correlation coefficients of 0.91, 0.82 and 0.75, respectively averaged over 9 sites. The directional wave spectra for Hurricane Sandy was bi-modal predominantly in the two left quadrants of the hurricane, in agreement with buoy observations. The results indicate that a regional atmospheric wind model that has the best description of the wind field is the most appropriate forcing for hindcasting hurricane waves when detailed observations are available. However a parametric vortex model that incorporates wind at multiple isotachs results in very good agreement with wave observations when used in the wave model, and is a useful too for forecasting hurricane sea surface conditions. The results of this study are relevant for other tropical cyclones that undergo extratropical transition or are influenced by other atmospheric disturbances at mid-latitudes, resulting in storms with large spatial size and high asymmetry.

      PubDate: 2017-04-24T06:14:36Z
       
  • On the transfer of momentum from a granular landslide to a water wave
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): Ryan P. Mulligan, W. Andy Take
      The momentum flux from a landslide at impact in a water body is the driving force behind the generation of landslide tsunamis. Analysis of this problem is presented and used to derive idealized theoretical relationships for the maximum wave amplitude in the near-field zone. This is accomplished for momentum transfer using both hydrostatic and hydrodynamic assumptions. For rapidly evolving near-field waves with a supercritical densimetric Froude number, the maximum wave amplitude is also constrained according to the fluid continuity equation. Simplification of the hydrostatic momentum equation is also presented by considering fluid acceleration, resulting in an expression that is independent of length and time scales during wave generation. The results of the novel momentum-based equations are in agreement with laboratory data collected using high-speed digital cameras for granular landslides and previously published experimental data used to develop a semi-empirical equation. Furthermore, the results provide new insight on the range of applicability of theoretical and semi-empirical equations for predicting the maximum near-field wave amplitude of landslide-generated tsunamis.

      PubDate: 2017-04-24T06:14:36Z
       
  • Calibrating and assessing uncertainty in coastal numerical models
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): Joshua A. Simmons, Mitchell D. Harley, Lucy A. Marshall, Ian L. Turner, Kristen D. Splinter, Ronald J. Cox
      Advanced numerical models used to predict coastal change at a variety of time and spatial scales often contain many free parameters that require calibration to the available field data. At present, little guidance (beyond the adoption of the default values provided) is available in the field of coastal engineering to inform the selection of best-fit parameter values. Common calibration techniques can often lack a rigorous quantification of model sensitivity to parameters and parameter-induced model uncertainty. Here we employ the Generalised Likelihood Uncertainty Estimation (GLUE) method to address these issues. The GLUE method uses Monte Carlo sampling to assess the skill of many different combinations of model parameters when compared to observational data. As a rigorous modelling framework, the GLUE method provides a series of standard tools that assist the modeller to analyse model sensitivity, undertake parameter optimisation and quantify parameter-induced uncertainty. In addition, new tools are presented here to identify where unique calibrated parameter sets are required for different observational data (e.g., should the calibrated parameter set differ between alongshore locations at a site) and investigate the convergence of GLUE estimated optimum parameter values over increasing numbers of Monte Carlo samples. As the methodology and philosophy of GLUE is well established in other fields, this paper presents a practical case study to explore the strengths and weaknesses of the method when applied to a relatively complex coastal numerical model (XBeach). The results obtained are compared to a previously reported and more ‘standard’ model calibration undertaken within the context of a coastal storm early warning system. While the GLUE method requires orders of magnitude more computational power, it is shown that its use in place of the more common one-at-a-time ‘trial-and-error’ approach to model calibration, provides: a significant improvement in predictive skill; a more rigorous evaluation of the model sensitivity to parameters; the ability to identify distinct differences in the XBeach model performance dependent on dune impact processes; and additional analysis including the quantification of parameter-induced uncertainty.

      PubDate: 2017-04-24T06:14:36Z
       
  • Applying a Bayesian network based on Gaussian copulas to model the
           hydraulic boundary conditions for hurricane flood risk analysis in a
           coastal watershed
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): A. Sebastian, E.J.C. Dupuits, O. Morales-Nápoles
      In recent years significant emphasis has been placed on quantifying coastal flood hazards in the U.S. using high resolution 2-D hydrodynamic and nearshore wave models. However, these studies are computationally expensive and often neglect to consider the flooding that arises from the combined hazards of precipitation and storm surge in coastal watersheds. This paper describes a method to stochastically simulate a large number of combinations of peak storm surge and cumulative precipitation to determine the hydraulic boundary conditions for a low-lying coastal watershed draining into a semi-enclosed tidal bay. The method is computationally efficient and takes into consideration five tropical cyclone characteristics at landfall: windspeed, angle of approach, landfall location, radius of maximum winds, and forward speed. A precipitation gage network and tidal gage data were used, along with observations from over 300 tropical cyclones in the Gulf of Mexico. A Non-parametric Bayesian Network was built to generate 100,000 synthetic storm events and used as input to an empirical wind set-up model to simulate storm surge within a tidal bay and at the downstream boundary of the watershed. Based on the results, probable combinations of cumulative precipitation and peak storm surge for the watershed during hurricane conditions are determined. These boundary conditions can be easily incorporated into a coastal riverine model to determine flood risk in the watershed.

      PubDate: 2017-04-24T06:14:36Z
       
  • Suspended sediment transport around a large-scale laboratory breaker bar
    • Abstract: Publication date: July 2017
      Source:Coastal Engineering, Volume 125
      Author(s): J. van der Zanden, D.A. van der A, D. Hurther, I. Cáceres, T. O’Donoghue, J.S. Ribberink
      This paper presents novel insights into suspended sediment concentrations and fluxes under a large-scale laboratory plunging wave. Measurements of sediment concentrations and velocities were taken at 12 locations around an evolving breaker bar, covering the complete breaking region from shoaling to inner surf zone, with particular high resolution near the bed using an Acoustic Concentration and Velocity Profiler. Wave breaking evidently affects sediment pick-up rates, which increase by an order of magnitude from shoaling to breaking zone. Time-averaged reference concentrations correlate poorly with periodic and time-averaged near-bed velocities, but correlate significantly with near-bed time-averaged turbulent kinetic energy. The net depth-integrated suspended transport is offshore-directed and primarily attributed to current-related fluxes (undertow) at outer-flow elevations (i.e. above the wave bottom boundary layer). The wave-related suspended transport is onshore-directed and is generally confined to the wave bottom boundary layer. Cross-shore gradients of sediment fluxes are quantified to explain spatial patterns of sediment pick-up and deposition and of cross-shore sediment advection. Suspended particles travel back and forth between the breaking and shoaling zones following the orbital motion, leading to local intra-wave concentration changes. At locations between the breaker bar crest and bar trough, intra-wave concentration changes are due to a combination of horizontal advection and of vertical exchange with the bedload layer: sediment is entrained in the bar trough during the wave trough phase, almost instantly advected offshore, and deposited near the bar crest during the wave crest phase. Finally, these results are used to suggest improvements for suspended sediment transport models.

      PubDate: 2017-04-24T06:14:36Z
       
  • Design requirement for mixed sand and gravel beach defences under
           scenarios of sea level rise
    • Abstract: Publication date: June 2017
      Source:Coastal Engineering, Volume 124
      Author(s): Uwe Dornbusch
      Along many coastlines of the world, beaches provide the primary defence against flooding or erosion with their fate under rising sea levels still only poorly researched. This is particularly the case for the coastline of Southeast England, where ~190km of shingle barriers protect low-lying hinterland or a coastal plain that is at or barely above the present reach of waves. During the Holocene transgression, these beaches moved into their present position through longshore extension and cross-shore roll back. This process stopped more than a century ago with port developments affecting longshore transport and the construction of groynes to hold the beach in place. This was followed by beach recharge and recycling towards the end of the 20th century to build up and maintain beaches as coastal defences in their mid 19th century position. This paper explores the design requirements for these beaches under future sea level rise scenarios of 1 to 5m using recently developed tools. It shows that the presently still semi-natural beaches have to increase in size with crest height elevations having to rise by at least up to 1.26 times the rate of sea level rise and that due to higher longshore wave power, especially during storm conditions in the future, higher and stronger groynes are needed to hold these larger beaches in place. Future design requirements for beaches are sensitive to foreshore levels and orientation of the beach to the dominant waves with those presently characterised by shallow foreshores and oblique wave approach requiring the biggest adjustments. Required size increases will be difficult to implement due to the built-up nature of the hinterland. The engineering alternative would be to replace beaches with hard structures, a process that has already started where maintaining a beach is no longer economically viable or the residual risk associated with overwashing and an eventual tidal breach has become unacceptable.

      PubDate: 2017-04-17T11:38:28Z
       
  • GOW2: A global wave hindcast for coastal applications
    • Abstract: Publication date: June 2017
      Source:Coastal Engineering, Volume 124
      Author(s): Jorge Perez, Melisa Menendez, Inigo J. Losada
      Global wave hindcasts provide wave climate information for long time periods which helps to improve our understanding of climate variability, long term trends and extremes. This information is extremely useful for coastal studies and can be used both directly or as boundary conditions for regional and local downscalings. This work presents the GOW2 database, a long-term wave hindcast covering the world coastline with improved resolution in coastal areas and along ocean islands. For developing the GOW2 hindcast, WAVEWATCH III wave model is used in a multigrid two-way nesting configuration from 1979 onwards. The multigrid includes a global grid of half degree spatial resolution, specific grids configured for the Arctic and the Antarctic polar areas, and a grid of higher resolution (about 25km) for all the coastal locations at a depth shallower than 200m. Available outputs include hourly sea state parameters (e.g. significant wave height, peak period, mean wave direction) and series of 3-h spectra at more than 40000 locations in coastal areas. Comparisons with instrumental data show a clear improvement with respect to existing global hindcasts, especially in semi-enclosed basins and areas with a complex bathymetry. The effect of tropical cyclones is also well-captured thanks to the high resolution of the forcings and the wave model setup. The new database shows a high potential for a variety of applications in coastal engineering.

      PubDate: 2017-04-10T11:31:01Z
       
  • Deriving environmental contours from highest density regions
    • Abstract: Publication date: May 2017
      Source:Coastal Engineering, Volume 123
      Author(s): Andreas F. Haselsteiner, Jan-Hendrik Ohlendorf, Werner Wosniok, Klaus-Dieter Thoben
      Environmental contours are an established method in probabilistic engineering design, especially in ocean engineering. The contours help engineers to select the environmental states which are appropriate for structural design calculations. Defining an environmental contour means enclosing a region in the variable space which corresponds to a certain return period. However, there are multiple definitions of environmental contours for a given return period as well as different methods to compute a contour. Here, we analyze the established approaches and present a new concept which we call highest density contour (HDC). We define this environmental contour to enclose the highest density region (HDR) of a given probability density. This region occupies the smallest possible volume in the variable space among all regions with the same included probability, which is advantageous for engineering design. We perform the calculations using a numerical grid to discretize the original variable space into a finite number of grid cells. Each cell's probability is estimated and used for numerical integration. The proposed method can be applied to any number of dimensions, i.e. number of different variables in the joint probability model. To put the highest density contour method in context, we compare it to the established inverse first-order reliability method (IFORM) and show that for common probability distributions the two methods yield similarly shaped contours. In multimodal probability distributions, however, where IFORM leads to contours which are difficult to interpret, the presented method still generates clearly defined contours.

      PubDate: 2017-04-10T11:31:01Z
       
  • Impulse waves in reservoirs generated by landslides into shallow water
    • Abstract: Publication date: May 2017
      Source:Coastal Engineering, Volume 123
      Author(s): Bolin Huang, S.C. Wang, Y.B. Zhao
      Landslides sliding into shallow water often block watercourses, and in addition landslide-induced impulse waves may result in risks to the safety of the reservoir or waterways over a wide area. Such impulse waves differ from those from landslides into deep water which slide underwater completely. This study conducted twenty-five groups of orthogonal experiments of landslide-induced impulse waves in shallow water where the Froude numbers ranged between 0.6 and 2.0. Based on the experimental results, dimensionless functions of the parameters such as amplitude, wavelength and jet-flow height of the initial landslide-induced waves in shallow water were derived. The predictions from these formulae are very close to those obtained from the experiments. Further, a source model of landslide-induced waves in shallow water was built based on formulae derived from the experiments, and wave propagation and run-up were calculated with the Boussinesq-type equations model. The newly built model of landslide-induced waves in shallow water was used to calculate and analyze two representative examples from landslides in the Three Gorges in China, namely the Qianjiangping landslide-induced impulse wave event and the Xintan landslide-induced impulse wave event. Comparison of the calculations with data from multiple sources indicated that our model for landslide-induced waves in shallow water had high accuracy. Our model for landslide-induced waves in shallow water may help in the predictive analysis of impulse waves and mitigation works for this type of event in reservoirs worldwide.

      PubDate: 2017-04-10T11:31:01Z
       
  • Aeolian sediment supply at a mega nourishment
    • Abstract: Publication date: May 2017
      Source:Coastal Engineering, Volume 123
      Author(s): Bas Hoonhout, Sierd de Vries
      Mega nourishments are intended to enhance growth and resilience of coastal dunes on medium to long time scales by stimulation of natural sediment transport processes. The growth and resilience of coastal dunes largely depends on the presence of a continuous supply of aeolian sediment. A recent example of a mega nourishment is the 21Mm3 mega nourishment known as the Sand Motor. The Sand Motor is intended to nourish the entire Holland coast over a period of two decades. Four years of bi-monthly topographic measurements of the Sand Motor domain provide an opportunity to analyze spatiotemporal variations in aeolian sediment supply using an aeolian sediment budget analysis. It appears that more than 58% of all aeolian sediment deposits originate from the low-lying beaches that are regularly reworked by waves. Aeolian sediment supply from higher beaches diminished after half a year after construction of the Sand Motor, likely due to the formation of deflation lag deposits that constitute a beach armor layer. The compartmentalization of the Sand Motor in armored and unarmored surfaces suggests that the construction height is an important design criterion that influences the lifetime and region of influence for any mega nourishment.

      PubDate: 2017-04-03T08:15:27Z
       
  • Prediction formula for the spectral wave period Tm-1,0 on mildly sloping
           shallow foreshores
    • Abstract: Publication date: May 2017
      Source:Coastal Engineering, Volume 123
      Author(s): Bas Hofland, Xuexue Chen, Corrado Altomare, Patrick Oosterlo
      During the last decades, the spectral wave period T m-1,0 has become accepted as a characteristic wave period when describing the hydraulic attack on coastal structures, especially over shallow foreshores. In this study, we derive an empirical prediction formula for T m-1,0 on shallow to extremely shallow foreshores with a mild slope. The formula was determined based on flume tests and numerical calculations, mainly for straight linear foreshore slopes. It is shown that the wave period increases drastically when the water depth decreases; up to eight times the offshore value. The bed slope angle influences the wave period slightly. For short-crested wave fields, the strong increase of T m-1,0 starts closer to shore (at smaller water depths) than for long-crested wave fields.

      PubDate: 2017-04-03T08:15:27Z
       
  • Simulating wave setup and runup during storm conditions on a complex
           barred beach
    • Abstract: Publication date: May 2017
      Source:Coastal Engineering, Volume 123
      Author(s): Alexandre Nicolae Lerma, Rodrigo Pedreros, Arthur Robinet, Nadia Sénéchal
      The purpose of this study is to assess the ability of the SWASH model to reproduce wave setup and runup in highly dissipative stormy conditions. To proceed we use data collected during the ECORS Truc Vert’08 Experiment, especially during the Johanna storm in the winter of 2007-008 (wave setup under H s= 8.2m and T p= 18.3s and runup under 6.4m and peak period up to 16.4s). We test different model settings (1D and 2D mode) and model forcing (spectral and parametric) to reproduce sensor measured wave setup at several locations in the nearshore area and video measured runup on two beach profiles. For the whole tested configurations, the wave setup is reproduced accurately. Results considering all the sensor locations in the near shore area in 1D and 2D are significantly correlated to the observations with respectively ρ ² =0.66 and 0.81; RMSE=0.13m and 0.08m without any significant bias. Observations and simulations of runup are investigated in terms of spectra and statistic component. 1D simulations produces an overall overestimation and no significant improvement is obtained by modifying the breaking parameters. The results for 2D simulations are fairly satisfactory reproducing significant swash height (S), but are significantly improved with spectral forcing than parametric with respectively ρ ² =0.73 and 0.71, RMSE=0.19m and 0.43m. Generally, the model reproduces accurately the infragravity component but tends to overestimate the incident component, leading to an overestimation of the energy density for moderate wave conditions and more accurate results for higher-energy wave conditions. Results in 2D with spectral forcing show a saturation of the infragravity component with a threshold around H s=4 to 5m, which is comparable to the observations collected at Truc Vert Beach. As regards the conventional statistical parameter for runup estimation (R 2%) three methods are applied to derive the 2% exceedence value for runup from observed and simulated shoreline vertical elevation time series. When R 2% is based on the sum of wave setup and half of the significant swash height, results provided by the model are close or even better than estimations provided by empirical formulas from the bibliography. Defining R2% as the exceeded 2% values of the time, derived considering the cumulative distribution function of the entire water-level time series also provide fairly good results. Results using only runup maxima time series are less satisfactory. In the two last cases, R 2% is slightly underestimated for moderate wave conditions (H s<4m; T p ≈ 14s) and overestimated for higher-energy wave conditions. Generally results shows that where extreme wave conditions are concerned, the model setting must be considered carefully because the simplification of 1D (rather than 2D), or the use of parametric wave description (rather than spectral), can be a source of significant inaccuracy or overestimation in simulated run-up values.

      PubDate: 2017-04-03T08:15:27Z
       
  • An experimental method to verify the failure of coastal structures by wave
           induced liquefaction of clayey soils
    • Abstract: Publication date: May 2017
      Source:Coastal Engineering, Volume 123
      Author(s): Valeria Chávez, Edgar Mendoza, Rodolfo Silva, Anahí Silva, Miguel A. Losada
      Although the dynamics involved in the liquefaction process are understood reasonably well, experimental work to reproduce the sinking of structures due to liquefaction, which is representative and repeatable, has so far not been recorded. In this work, three sets of experiments were performed in an attempt to fill the gaps in the knowledge by modelling a small scale reproduction of the failure. Firstly, an analysis of the role of the proportions of the initial fine sediment and water content is presented; secondly, a group of tests involving a vertical breakwater were performed, and thirdly, an experiment was carried out to reproduce the failure of a submerged structure on a clayey bed in the presence of waves. From these experiments, we were able to set thresholds for bed composition, below which soil liquefaction is likely to occur. It was determined that the potential to liquefy increases with the initial water content and that soils of 40% or more clay content may liquefy. This methodology has proven to be repeatable, allowing the reproduction of the sinking of coastal structures due to liquefaction of the underlying soil.

      PubDate: 2017-03-08T02:34:38Z
       
  • Modelling of long waves generated by bottom-tilting wave maker
    • Abstract: Publication date: April 2017
      Source:Coastal Engineering, Volume 122
      Author(s): Heng Lu, Yong Sung Park, Yong-Sik Cho
      In order to generate very long waves in laboratory, a bottom-tilting wave maker is designed and used at the University of Dundee. This new type of wave maker can produce waves longer than solitary waves in terms of the effective wavelength, which provides better long wave model. Nonlinear and dispersive numerical models are built for modelling the wave tank. A shock-capturing finite volume scheme with high-order reconstruction method is used to solve the governing equations. By comparing to the experimental measurements, the numerical models are verified and able to approximate the resulting waves in the wave tank.

      PubDate: 2017-02-15T17:59:22Z
       
  • Comparison of inundation depth and momentum flux based fragilities for
           probabilistic tsunami damage assessment and uncertainty analysis
    • Abstract: Publication date: April 2017
      Source:Coastal Engineering, Volume 122
      Author(s): Hyoungsu Park, Daniel T. Cox, Andre R. Barbosa
      Annual exceedance probabilities of the maximum tsunami inundation depth, h Max , and momentum flux, M Max , conditional on a full-rupture event of the Cascadia Subduction Zone (CSZ) were used to estimate the probability of building damage using a fragility analysis at Seaside, Oregon. Tax lot data, Google Street View, and field reconnaissance surveys were used to classify the buildings in Seaside and to correlate building typologies with existing fragility curves according to the construction material, number of stories, and building seismic design level based on the date of construction. A fragility analysis was used to estimate the damage probability of buildings for 500-, 1000-, and 2500-year exceedance probabilities conditioned on a full-rupture CSZ event. Finally, the sensitivity of building damage was estimated for both the aleatory and epistemic uncertainties involved in the process of damage estimation. Probable damage estimates from the fragility curves based on h Max and on M Max both generally show higher damage probability for structures that are wooden and closer to the shoreline than those that are reinforced concrete (RC) and further landward of the shoreline. However, a relatively high and somewhat unrealistic damage probability was found at the river and creek region from the fragility curve analysis using h Max . Within 500m from the shoreline, wood structure damage shows significant sensitivity to the aleatory uncertainty of the tsunami generation from the CSZ event. On the other hand, RC structure damage showed equal sensitivity to the aleatory uncertainty of the tsunami generation as well as the epistemic uncertainties due to the numerical modeling of the tsunami inundation (friction), the building classification (material and date of construction), and the type of fragility curves (depth or momentum flux type curves). Further from the shoreline, the wood structures showed similar aleatory and epistemic uncertainties, qualitatively similar to the RC structure sensitivity closer to the shoreline.

      PubDate: 2017-02-15T17:59:22Z
       
 
 
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