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A new method to update wave and current values in a time evolving beach morphology model is developed. The method is based on the assumption that small bottom perturbations induce small variations in the hydrodynamic magnitudes resulting in a new set of linearized perturbed equations that can be solved easily. The method has been tested for I-D as well as for 2-D bathymetries showing its capabilities. INTRODUCTION Evaluating the responses of beach morphology to changing wave conditions, particularly during a storm, is one of the most important challenges of coastal scientist and engineers. A number of conceptual, physical and numerical models have been developed during the last decades in order to characterize and determine beaeh processes and changes. Coastal area morphodynamic models are used to predict the short-term (hours to days) and medium-term (weeks to months) bathymetric changes associated with varying wave and current conditions. Schemes of this type have been under intensive development for the past twenty years, see De Vriend (1996) as a general reference, work having concentrated on two-dimensional, depth-averaged (2DH) schemes 0Hicholson et al., 1997). These models begin operations by calculating the initial wave and current fields on a fixed bed. The sediment transport field is then computed using either a semi-empirical sediment transport formulation or by solving the time-dependent diffusion-advection equation for suspended sediment concentrations. Next, bed level changes are computed 1) Postdoctoral Researcher, Ocean & Coastal Research Group, Dpto de Cienclas y Tecnicas del Agua y del Medio Ambiente, Universidad de Cantabria, Avda de los Castros sin 39005 Santander, Spain. fmi@puer.unican.es 2) Professor, Ocean & Coastal Research Group, Dpto de Ciencias y Tecnicas del Agua y del Medio Ambiente, Universidad de Cantabda. medina@puer.unican.es

Se ha analizado teórica y experimentalmente los movimientos medios inducidos por la propagación de un tren de ondas de pequeña amplitud sobre un medio disipativo y reflejante cualquiera. A partir de la solución de teoría lineal, y sin considerar los efectos de rotura del oleaje, se ha obtenido la evolución de las magnitudes promediadas (nivel medio, flujo de masa, etc.) en el medio, teniendo en cuenta la transformación del oleaje. Las modificaciones del tren de ondas a su paso por el elemento disipativo-reflejante producen un desequilibrio espacial de las magnitudes medias, que se traduce en una sobreelevación y modulación del nivel medio y una disminución del flujo de masa. Esta variación espacial del caudal medio induce un sistema circulatorio de corrientes con estructura vertical. Dicho flujo ha sido modelado de forma analítica a través de la resolución del problema de contorno bidimensional de la función de corriente media. La teoría se ha aplicado a medios emergidos y sumergidos, tanto artificiales (dique permeable) como naturales (campo de algas), obteniéndose en todos ellos un buen ajuste de los resultados experimentales.

In many applications, Cu base Shape Memory Alloys (SMA s) are a more economical alternative to other systems showing Shape Memory Effect (SME). However, bearing in mind the potential use of these SMA it is becoming increasingly important to develop suitable techniques to join them satisfactorily to themselves and to another material. In that sense, a liquid phase diffusion bonding process with silver/copper interlayers is proposed for bonding Cu base SMA s to the ASTM-1045 steel with semi-hard denomination. Specimens have been metallographically characterized by SEM. The bend strength of the bonded part is attained over 80% of that of the base materials. For checking the SME, the ratio of the total heat measured in forward to reverse thermoelastic martensitic transformation, measured by Differential Scanning Calorimetry (DSC), has been used.

The copper-based alloys studied belong to the group of those materials showing Shape Memory Effect (SME). Diffusion Bonding (DB) procedure is an alternative joining method of welding copper-based Shape Memory Alloys, traditionally welded by techniques like electron bean welding (EBW). However EBW provides embrittlement to the joint. This situation has been corrected by DB as confirm the SEM-EDS study presented here.A material shows SME when once has been thermomechanically deformed, it is able to recover its original (as fabricated) shape by means of a simple heat-up. This pheno menom is possible only for those materials which have β phase prone to undergo martensitic transformation. DB technique estimulates diffusion processes betwen materials by the combination of pressure, temperature, time, surface materials roughness and atmosphere condition in the experimental unit with the aid, sometimes, of a third material, in foil or plated form, which is known by the name of interlayer. The parameter set and details of attaing diffusion bonding joints procedure are under a patent developed recently by the authors .

The influence of wave reflection and energy dissipation by breaking and by porous flow induced by a permeable submerged structure on second-order mean quantities such as mass flux, energy flux, radiation stress, and mean water level is analyzed. For this purpose, analytical expressions for those mean quantities in terms of the shape functions are obtained. The dependence of those quantities on the incident wave characteristics, structure geometry, and permeable material characteristics is modeled, extending the writers' previous work including wave breaking. Two models for regular waves are presented: a 2D model to be applied to submerged trapezoidal breakwaters and a 3D model for submerged permeable rectangular breakwaters. Both models are able to reproduce experimental wave height transformation as well as mean water level variations along the wave flume with reasonable accuracy. Results give useful information for engineering applications of wave height evolution and set-up and set-down evolution in th...

The ability to predict coastal flooding events and associated impacts has emerged as a primary societal need within the context of projected sea level rise (SLR) and climate change. The duration and extent of flooding is the result of nonlinear interactions between multiple environmental forcings (oceanographic, meteorological, hydrological) acting at varying spatial (local to global) and temporal scales (hours to centuries). Individual components contributing to total water levels (TWLs) include astronomical tides, monthly sea level anomalies, storm surges, and wave setup. Common practices often use the observational record of extreme water levels to estimate return levels of future extremes. However, such projections often do not account for the individual contribution of processes resulting in compound TWL events, nor do they account for time-dependent probabilities due to seasonal, interannual, and long-term oscillations within the climate system. More robust estimates of coastal flooding risk require the computation of joint probabilities and the simulation of hypothetical TWLs to better constrain the projection of extremes (Serafin [2014]).