Interaction of Swell and Sea Waves with Partially Reflective Structures for Possible Engineering Applications

In this work, we investigate the interaction between the combination of wind-driven and regular waves and a chamber defined by a rigid wall and a thin vertical semi-submerged barrier. A series of laboratory experiments were performed with different values of incident wave height, wave period, and wind speed. The analysis focuses on the effect of the geometry of the system characterized in terms of its relative submergence d/h and relative width B/L. Results show that for the case of d/h = 0.58 a resonant effect takes place inside the chamber regardless of the wind speed. Wind-driven waves have a higher influence on the variation of the wave period of the waves seaward and leeward of the plate, as well as on the phase lag. Results show that the amplification or reduction of the wave energy inside the chamber is closely related to the wave period as compared to the 1st order natural period of the chamber.A.L.L. is supported by the research group TEP-209 (Junta de Andalucía) and project AQUACLEW. Project AQUACLEW is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (Grant 690462). During the preparation of the manuscript, A.L.L. was doing a research stay at the University of Parma (PhD cotutelle agreement) funded by the Campus of International Excellence of the Sea (CEIMAR) and the University of Granada

Storm characterization and simulation for damage evolution models of maritime structures

This paper presents a new approach to statistically characterize and simulate the wave climate under storm conditions. The methodology includes the joint selection of the parameters that identify storm events (significant wave height threshold, minimum storm duration and minimum interarrival time between consecutive storms) by means of hypothesis testing on the distribution functions of the number of storm events and the elapsing time between storms, providing an improved characterization of the parameters that define storm events. The main wave variables and their temporal dependence are characterized by non-stationary mixture distribution functions and a vector autoregressive model. This allows to adequately reproduce the random temporal evolution of storm events, crucial for the study of damage progression in maritime structures without the use of predefined geometries. The long-term time series of storm events and calm periods is obtained using copula functions which analyze the joint dependence of storm duration and interarrival time for separate climate intervals. The model is applied to hindcast data at a location of the Mediterranean sea close to the Granada coast in Spain to show its ability to reproduce wave storm conditions accounting for the time variability of the storminess. An example of application, using a large number of simulations and a damage progression model in a maritime structure, is presented.This work was performed within the framework of the project AQUACLEW and the research group TEP-209 (Junta de Andalucía). Project AQUACLEW is part of ERA4CS, and ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (Grant 690462). MC wishes to acknowledge the funding provided by the Campus of International Excellence of the Sea (Cei-MAR). The authors would like to thank the MeteOcean group at the University of Genoa for providing the hindcast wave dataset used in this study (http://www3.di cca.unige.it/meteocean/hindcast.html)

Cuantificando la incertidumbre: aplicación a la línea de playa

[ES] A priori no es posible conocer con certeza la forma en planta de un tramo de playa, debido principalmente al desconocimiento del clima marítimo al que estará sometido. En este trabajo se presenta un procedimiento de cálculo cuyo objetivo es el de cuantificar de forma objetiva la incertidumbre asociada a la predicción de la evolución de la línea de playa en términos de probabilidad. A partir de una base de datos oceanográficos y basados en los principios de las funciones ortogonales empíricas (FOE) se propone un procedimiento de simulación de las posibles secuencias de temporales. Estas secuencias sirven de entrada al modelo morfodinámico para generar una base de datos de posibles formas en planta. La probabilidad asociada a cada una de las posibles formas en planta es estimada empleando la técnica de FOE. Se estudia el caso de la evolución de una playa inicialmente recta aguas arriba de un espigón perpendicular a la costa que bloquea todo el transporte longitudinal de sedimentos, sobreEste trabajo forma parte del proyecto europeo HUMOR, financiado por la Comisión bajo el nº de contrato EVK3-2000-22014-HUMOR. El autor principal agradece la financiación del programa de becas predoctorales I3P del CSIC.Payo, A.; Baquerizo, A.; Losada, MÁ. (2004). Cuantificando la incertidumbre: aplicación a la línea de playa. Ingeniería del agua. 11(2):211-220. https://doi.org/10.4995/ia.2004.2529OJS211220112Ashton, A., A. B. Murray, & O. Arnault, 2001. Formation of coastline features by large-scale instabilities induced by high angle waves, Nature, 414, 296-300, 2001De Vriend, H.J., 1991. Mathematical modelling and large scale coastal behaviour. J. Hydraul. Res., Vol. 29(6), 727-753 ppFalqués A., 2003. On the diffusivity in coastline dynamics. Geophysical Research Letters, vol. 30, No. 21, 2119.Hahn, G. J. & Shapiro, S. S., 1967. Statistical Models in Engineering. Wiley, New York, 236 pp.Hallermeier, R. J. (1978), A Profile Zonation for Seasonal Sand Beaches from Wave Climate, Coastal Engineering 4(3), pp. 253-277.Hanson, H. and Kraus, N.C., 1989. GENESIS: A generalized Shoreline Change Numerical Model. Vol. 1: Reference Manual and users guide. US Army Engineer Waterways Experiment Station, Coastal Engineering Research Center. Technical Report CERC-89-19Mooney, C. Z., 1997. Monte Carlo Simulation. Sage University Paper series on Quantitative Applications in the Social Sciences, 07-116. Thousand Oaks, CA: Sage.Payo A., Baquerizo A. & Losada, M.A. 2002. One-line model with time dependent boundary conditions. Proceedings 28th Coastal Engineering Conf. ASCE, World Scientific, Vol. 3, pp 3046-3052Peña, D. 2002. Análisis de datos multivariantes. Mc Graw Hill, MadridRodríguez-Ramírez, A., Ruiz, F., Cáceres, L. M., Rodríguez Vidal, J., Pino, R. & Muñoz, J. M., 2003. Analysis of the recent storm record in the southwestern Spanish coast: implications for littoral management. The Science of the Total Environment 303, pp 189-201Rubinstein, Reuven Y., 1981. Simulation and the Monte Carlo Method. John Wiley & Sons, pp 39-70Vrijling, J.K. and Meijer, G.J., 1992. Probabilistic coastline position computations. Coastal Engineering, Vol. 17, 1-2

A method to characterize climate, Earth or environmental vector random processes

We propose a general methodology to characterize a non-stationary random process that can be used for simulating random realizations that keep the probabilistic behavior of the original time series. The probability distribution of the process is assumed to be a piecewise function defined by several weighted parametric probability models. The weights are obtained analytically by ensuring that the probability density function is well defined and that it is continuous at the common endpoints. Any number of subintervals and continuous probability models can be chosen. The distribution is assumed to vary periodically in time over a predefined time interval by defining the model parameters and the common endpoints as truncated generalized Fourier series. The coefficients of the expansions are obtained with the maximum likelihood method. Different sets of orthogonal basis functions are tested. The method is applied to three time series with different particularities. Firstly, it is shown its good behavior to capture the high variability of the precipitation projected at a semiarid location of Spain for the present century. Secondly, for the Wolf sunspot number time series, the Schwabe cycle and time variations close to the 7.5 and 17 years are analyzed along a 22-year cycle. Finally, the method is applied to a bivariate time series that contains (1) freshwater discharges at the last regulation point of a dam located in a semiarid zone in Andalucı´a (Spain) which is influenced not only by the climate variability but also by management decisions and (2) the salinity at the mouth of the river. For this case, the analysis, that was combined with a vectorial autoregressive model, focus on the assessment of the goodness of the methodology to replicate the statistical features of the original series. In particular, it is found that it reproduces the marginal and joint distributions and the duration of sojourns above/below given thresholds.Ministry of Agriculture, Livestock, Fisheries and Sustainable Development of the Junta de Andalucia CONTR 2018 66984Consejeria de Transformacio n Economica, Industria, Conocimiento y Universidades de la Junta de Andalucia POSTDOC_ 21_00724Programa Operativo FEDER de Andalucia 30BE61F30

MarineTools.temporal: A Python package to simulate Earth and environmental time series

This work was performed within the framework of the following projects: (1) AQUACLEW, which is part of ERA4CS, an ERA-NET initiative by JPI Climate, and funded by FORMAS (SE) , DLR (DE) , BMWFW (AT) , IFD (DK) , MINECO (ES) , ANR (FR) with co-funding by the European Commission [Grant 690462] and (2) Flooding and erosion works in coastal areas of Andalusia under a climate change scenario, funded by the Ministry of Agriculture, Livestock, Fisheries and Sus-tainable Development of the Junta de Andalucia [Contrat No. CONTR 2018 66984] . Part of this study has been conducted using E.U. Copernicus Marine Service Information. Funding for open access charge: Universidad de Granada/CBUA.The assessment of the uncertainty about the evolution of complex processes usually requires different realizations consisting of multivariate temporal signals of environmental data. However, it is common to have only one observational set. MarineTools.temporal is an open-source Python package for the non-stationary parametric statistical analysis of vector random processes suitable for environmental and Earth modelling. It takes a single timeseries of observations and allows the simulation of many time series with the same probabilistic behavior. The software generalizes the use of piecewise and compound distributions with any number of arbitrary continuous distributions. The code contains, among others, multi-model negative log-likely functions, wrappednormal distributions, and generalized Fourier timeseries expansion. Its programming philosophy significantly improves the computing time and makes it compatible with future extensions of scipy.stats. We apply it to the analysis of freshwater river discharge, water currents, and the simulation of ensemble projections of sea waves, to show its capabilities.Swedish Research Council FormasHelmholtz AssociationGerman Aerospace Centre (DLR)BMWFWSpanish GovernmentFrench National Research Agency (ANR)European Commission European Commission Joint Research CentreMinistry of Agriculture, Livestock, Fisheries and Sus-tainable Development of the Junta de Andalucia 690462CONTR 2018 6698

A Subtidal Box Model based on the Longitudinal Anomaly of Potential Energy for Narrow Estuaries. An Application to the Guadalquivir River Estuary (SW Spain).

The objective of the present study is to demonstrate the informative capacity of the longitudinal anomaly of potential energy (LAPE) in the analysis of the magnitude and spatiotemporal variability of estuarine processes. For this purpose, a LAPE balance equation is formulated. The LAPE integrates and varies with the vertical and longitudinal density distribution. The formulation is applied on a subtidal scale to each box or stretch of the Guadalquivir River estuary, a narrow, highly turbid, weakly stratified, and strongly anthropized estuary. Data recorded by a large network of monitoring stations in 2008 and 2009 are used to quantify advective transports as well as the transports associated with longitudinal dispersion and vertical turbulent mixing in different hydraulic regimes. In low-river flow conditions, (river flows Q < 40m3s−1), the magnitude of LAPE transports decreases upstream and varies locally, depending on neap-spring tidal cycles. The direction of the net LAPE transport creates convergence zones that are particularly consistent with maximum levels of estuarine turbidity. During high-river flows (Q > 400m3s−1), this convergence disappears and the maximum longitudinal density gradient moves towards the mouth. More specifically, tidal pumping -induced LAPE governs during these conditions and manages to compensate the sum of the mean nontidal and dispersive and differential advective LAPE transports. However, during the postriverflood period, the mechanisms controlling recovery downstream from the mouth are the longitudinal dispersive and differential advective LAPE transports. Furthermore, the convergence zone reappears with a longitudinal gradient of the net LAPE transport that is even greater than in low-river flow conditions.This research was partially funded by the Campus de Excelencia Internacional del Mar (Cei-MAR) and the Spanish Ministry of Economy and Competitiveness, Project PIRATES (CTM2017-89531-R). It was also supported by AQUACLEW. Project AQUACLEW is part of ERA4CS, an ERA- NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Commission.We would like to thank two anonymous reviewers for the thoughtful contribution that has signicantly improved the quality of the paper. Datasets for this research are available in http://doi.org/10.5281/ zenodo.3459610. This study is a tribute to the memory of RichardW. Garvine, whose research was the inspiration for our work

Interacción entre la reflexión y la generación de formas de lecho

Este artículo presenta un análisis de la evolución temporal de las características hidrodinámicas del oleaje, por medio de la valoración del coeficiente de reflexión, y de las características morfodinámicas del lecho, a través del perfil de fondo. Se ha realizado una serie de 10 ensayos en canal de oleaje bajo las siguientes premisas: reflexión parcial del oleaje originado por un dique vertical poroso, oleaje fuera de la zona de rompientes y transporte del sedimento por fondo. En el análisis experimental se observa que durante la generación y evolución del lecho, se reduce el módulo del coeficiente de reflexión entre un 4% y un 9%, así como que la fase se reduce, a su vez, desplazando la envolvente del oleaje y del perfil de fondo hasta un veinteavo de longitud de onda. Los efectos adversos de este desplazamiento en el frente del dique expuesto al oleaje son por una parte la sobrelevación del oleaje, y por otra, la erosión del lecho a pie de dique

Formas arqueadas en la playa de Carchuna (Granada)

[ES] La playa de Carchuna, en la provincia de Granada, tiene una serie de cúspides de playa de gran escala no periódicamente espaciadas, que se mantienen en la misma posición longitudinal aunque sus dimensiones pueden variar transversalmente. Este artículo estudia la formación de la morfología de la playa, continuando el trabajo de Ortega et al. (2003), y concluyendo que la principal causa de formación del sistema de cúspides son los patrones de propagación del oleaje sobre antiguos valles fluviales sumergidos. Otros mecanismos, como el sistema circulatorio asociado a la rotura, juegan un papel importante en el mantenimiento de la morfología. La instalación en Noviembre de 2002 de una estación de monitorización costera ha permitido obtener datos reales sobre el comportamiento de la playa y validar algunas de las hipótesis teóricas.Los autores agradecen la financiación prestada por el Ministerio de Ciencia y Tecnología (Proyecto CICYT REN2002-01038/MAR) y por la Dirección General de Costas del Ministerio de Medio Ambiente a través del convenio de colaboración firmado con el Grupo de Puertos y Costas de la Universidad de Granada para el estudio de la playa de Carchuna.Ortega, M.; De Los Santos, FJ.; Losada, MÁ.; Baquerizo, A. (2004). Formas arqueadas en la playa de Carchuna (Granada). Ingeniería del agua. 11(3):281-288. https://doi.org/10.4995/ia.2004.2538OJS281288113Aldaya, F., 1969. Los mantos Alpujárrides al sur de Sierra Nevada. Acta Geol. Hisp. 4, 126-130.Aldaya, F., 1970. La sucesión de etapas tectónicas en el dominio alpujárride. Cuad. Geol. 1, 159-181.Aldaya, F., 1981. Hoja 20-44, Albuñol, Escala 1:50.000. Mapa geológico de España. Instituto geológico y minero.Aarninkhof, S. G. J. & R. A. Holman, 1999. Monitoring the nearshore with video. Backscatter 10, 8-11.Ashton, A., Murray, A.B., Arnault, O., 2001. Formation of coastlines features by large-scale instabilities induced by high-angle waves. Nature 414, 296-300.Ortega-Sánchez, M., Losada, M.A. and Baquerizo, A. (2003). On the development of large-scale cuspate features on a semi-reflective beach: Carchuna Beach, Southern Spain. Marine Geology, 198 (3-4), pp 209-223.Baquerizo, A., M. A. Losada and I. J Losada (2002). Edge wave scattering by a coastal structure. Fluid Dynamics Research, 31. pp. 275-287.Bowen, A.J., Inman, D.L., 1971. Edge waves and crescentic bars. J. Geophys. Res. 76, 8662-8671.Guza, R.T., Inman D.L., 1975. Edge waves and beach cusps. J. Geophys. Res. 80, 2997-3012.Kirby, J.T., Dalrymple, R.A., 1983. A parabolic equation for the combined refraction-diffraction of stokes waves by mildly varying topography. J. Fluid Mech. 136, 543-566.Lippmann, T.C., Holman, R.A., 1989. Quantification of sand bar morphology: a video technique based on wave dissipation. J. Geophys. Res. 94 (C1), 995.1011.Van Enckevort, I. M. J. & Ruessink, B. G., 2001. Effect of hydrodynamics and bathymetry on video estimates of nearshore sandbar position. Journal of Geophysical Research, 106, 16969-16980

Análisis de los cambios de densidad en el estuario del río Guadalquivir mediante la Anomalía Longitudinal de la Energía Potencial (ALEP)

El objetivo de este estudio es analizar el origen, intensidad y persistencia de los procesos estuarinos a partir de la anomalía de la energía potencial en estaurios débilmente estratificados o bien mezclados. Para ello, se propone una modificación de la densidad de referencia, densidad media vertical, por la densidad media vertical en una sección situada aguas abajo del punto en cuestión. La nueva formulación da lugar a la variable ‘anomalía longitudinal de la energía potencial’ (ALEP). Esta se aplica al estuario del río Guadalquivir, el cual se segmenta en cinco tramos donde se asume que los procesos son homogéneos. Los resultados indican que la aplicación de la ALEP aporta información sobre los procesos estuarinos que producen cambios espaciales y temporales en la salinidad, la temperatura y la concentración de sólidos en suspensión.Este estudio ha sido parcialmente financiado por el Campus de Excelencia Internacional del Mar (Cei-MAR), por el proyecto AQUACLEW, que es parte RA4CS, y ERA- NET iniciado por el JPI Climate, y fundado por FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) con co-financiación de la Comisión Europea, y por el proyecto Multi-criteria analysis for Physical and bIotic Risk Assessment in EStuaries (PIRATES) que forma parte del Programa Estatal de investigación, desarrollo e innovación orientada a los RETOS de la sociedad (CTM2017-89531-R). Los datos de este estudio se han extraído de Navarro et al. (2019) [Creative Commons Attribution 4.0 Licencia internacional, derecho de acceso abierto]

Frontshear and backshear instabilities of the mean longshore current

An analytical model based on Bowen and Holman [1989] is used to prove the existence of instabilities due to the presence of a second extremum of the background vorticity at the front side of the longshore current. The growth rate of the so-called frontshear waves depends primarily upon the frontshear but also upon the backshear and the maximum and the width of the current. Depending on the values of these parameters, either the frontshear or the backshear instabilities may dominate. Both types of waves have a cross-shore extension of the order of the width of the current, but the frontshear modes are localized closer to the coast than are the backshear modes. Moreover, under certain conditions both unstable waves have similar growth rates with close wave numbers and angular frequencies, leading to the possibility of having modulated shear waves in the alongshore direction. Numerical analysis performed on realistic current profiles confirm the behavior anticipated by the analytical model. The theory has been applied to a current profile fitted to data measured during the 1980 Nearshore Sediment Transport Studies experiment at Leadbetter Beach that has an extremum of background vorticity at the front side of the current. In this case and in agreement with field observations, the model predicts instability, whereas the theory based only on backshear instability fai led to do so