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Funder: Samsung Display Corp., Carbene-metal-amides (CMAs) are an emerging class of photoemitters based on a linear donor-linker-acceptor arrangement. They exhibit high flexibility about the carbene-metal and metal-amide bonds, leading to a conformational freedom which has a strong influence on their photophysical properties. Herein we report CMA complexes with (1) nearly coplanar, (2) twisted, (3) tilted, and (4) tilt-twisted orientations between donor and acceptor ligands and illustrate the influence of preferred ground-state conformations on both the luminescence quantum yields and excited-state lifetimes. The performance is found to be optimum for structures with partially twisted and/or tilted conformations, resulting in radiative rates exceeding 1 × 106 s-1. Although the metal atoms make only small contributions to HOMOs and LUMOs, they provide sufficient spin-orbit coupling between the low-lying excited states to reduce the excited-state lifetimes down to 500 ns. At the same time, high photoluminescence quantum yields are maintained for a strongly tilted emitter in a host matrix. Proof-of-concept organic light-emitting diodes (OLEDs) based on these new emitter designs were fabricated, with a maximum external quantum efficiency (EQE) of 19.1% with low device roll-off efficiency. Transient electroluminescence studies indicate that molecular design concepts for new CMA emitters can be successfully translated into the OLED device.

The development of the marine renewable energy and offshore aquaculture sectors is susceptible to being affected by climate change. Consequently, for the long-term planning of these activities, a holistic view on the effects of climate change on energy resources and environmental conditions is required. Based on present climate and future climate scenario, favourable conditions for wind and wave energy exploitation and for farming six marine fish species are assessed using a suitability index over all European regional seas. Regarding available energy potential, the estimated changes in climate do not have direct impacts on the geographic distribution of potential regions for the energy industry (both wind and wave based), that is they pose no threat to this industry. Long-term changes in environmental conditions could however require adaptation of the aquaculture sector and especially of its exploitation areas. Opportunities for aquaculture expansion of the assessed species are identified. Possibilities for co-location of these activities are observed in the different climate scenarios. The evaluation of potential zones for the exploitation of marine renewable energy resources and offshore aquaculture represents a stepping-stone, useful for improving decision-making and assisting in the management of marine economies both in the short-term and in the long-term development of these sectors.

The ports sector is critical to global transport and trade. Climate change may compromise port operations, resulting in an increase in operational shutdowns and subsequent economic losses. Here, we present an analysis of historical global risk across the operations of 2,013 ports worldwide and the impacts under a high-end warming scenario, considering atmospheric and marine hazards, industry established operational thresholds, exposure and vulnerability. Increased coastal flooding and overtopping due to sea level rise, as well as the heat stress impacts of higher temperatures, are the main contributors to amplified risk. Ports located in the Pacific Islands, Caribbean Sea and Indian Ocean appear to be at extremely high risk by 2100, whereas those in the African Mediterranean and the Arabian Peninsula (Persian Gulf and Red Sea) are expected to experience very high risk. Estimating risks at the global scale cannot capture site-level details, but these results provide a benchmark for further research and decision-making. Global trade and transport depend on the resilience of the ports sector. Multi-hazard operational risks are estimated for 2,013 ports under historical climate and future warming; of the marine and atmospheric hazards considered, coastal flooding, wave overtopping and heat stress increase risk most.

The effects of sea level rise are now beginning to be detected in seagrass ecosystems. The present work deals with how sea level rise translates into changes on seagrass distribution at local scale and how to provide reliable information and tools to predict the vulnerability of shallow coastal ecosystems to the expected effects. To evaluate mid- and long-term changes in the habitat suitability of Zostera noltei a combination of clustering techniques—Self organizing maps and K means—considering RCP and high-end projections was used. The study, developed at the Bay of Santander, provides evidence indicating that sea level rise will highly affect meadows of Zostera noltei. This species will experience an important spatial variability, mainly in deeper areas, where moderate rising levels will substantially reduce the availability of suitable habitats for this species. This process will intensify over time and seagrass meadows are expected to be severely affected in the long term. A rising level of 0.63 m by 2100 will result in a 14.2% reduction in suitable habitats, while a 51% loss will occur with a sea level rise of 2 m. Our results indicate that large areas of seagrass in the Bay of Santander will be lost with future sea level rise, especially in the absence of major changes to sediment dynamics. However, a review of the main feedbacks and self-amplifying mechanisms regulating their adaptation allows us to be confident about Zostera noltei’s capacity to adapt to changing conditions in the near future. In the long term, there are more doubts regarding this ability and possible responses remain highly uncertain.

This material is based upon work supported by the National Fish and Wildlife Foundation and the U.S. Department of the Interior under grant 43932.This material is also based upon work supported by the National Science Foundation under grant SES‐1331399.This research was also supported in part by the Thomas F. and Kate Miller Jeffress Memorial Trust, Bank of America, Trustee. M. Maza, J.L. Lara, and I.J. Losada are indebted to the Spanish Ministry of Economy and Competitiveness for the funding provided in the RETOS INVESTIGACION 2014 (grant BIA2014‐59718‐R) grant program.

This paper presents the stability analysis of a non-conventional breakwater cross-section integrating an overtopping wave energy converter, named OBREC. The device consists of a traditional rubble-mound breakwater in which the upper part of the armour layer is replaced by a smooth ramp and a reservoir. The analysis of the structure is carried out by combining model scale experiments and numerical simulations based on the Volume-Averaged Reynolds Averaged Navier-Stokes (VARANS) equations. The numerical analysis is used to complete and extend the results of the physical model test campaign, providing a deeper understanding of the pressure distribution and resultant force behaviour in locations where laboratory measurements were difficult to obtain or not available. Results show that the maximum vertical and horizontal total forces on the device are not simultaneous. At the time instant of the maximum total horizontal force, the vertical force is zero or directed downward, due to the significant positive contribution of the force acting on the sloping ramp. Additional numerical simulations show the influence of the submerged ramp length on the forces acting on the structure using the global and local stability analysis. The presence of the shaft contributes positively to the global stability against the sliding failure mode by reducing the uplift force exerted on the horizontal base. Moreover, the stability analysis shows that the critical conditions for the global failure modes occur at different time instants.

Understanding the hydrodynamic performance of floating energy converters is a complex challenge. Hence, physical modelling is necessary to evaluate the performance of innovative designs and validate them. The present paper shows the experimental work performed to validate a new floating semisubmersible structure which combines wave energy converters (3 Oscillating Water Columns, OWC) and wind harvesting (5 MW wind turbine). To characterize the global response of the platform, as well as the OWCs’ performance, an innovative wave tank testing campaign was carried out at the Cantabria Coastal and Ocean Basin (CCOB). The multi-use platform was characterized under the incidence of regular wave tests (with and without wind), operational sea states and survival sea states (combining waves, currents and wind). During the tests wind was reproduced with a portable wind generator and the wind turbine was simulated as a drag disk. The OWC air turbines were experimentally conceptualized by different diameter openings on the upper part of each OWC. This paper describes the experimental testing campaign carried out at the CCOB and presents the most significant experimental results obtained, such as natural periods, movements, loads on the mooring system or accelerations, which are representative of the performance of the multi-use platform presented.

New floating devices are emerging thanks to a highly active marine renewable energy sector. These concepts, featuring floating offshore wind installations as well as other projects in the wave energy sector require innovative mooring systems. Therefore, a complete analysis of this element is required to achieve a successful design. This paper investigates the behaviour of mooring systems based on catenary configuration thanks to a detailed experimental program. Tests to characterize the properties of the mooring lines, and geotechnical and hydrodynamic trials were also performed on a 1:40 laboratory scale. Mooring truncation problem is normally faced by the researchers working on model testing of mooring lines in deep water, because the depth of the lab is typically small. However, it does not seem to be a problem for offshore floating renewable energy devices which are usually in relatively shallow water. The influence of catenary weight, imposed displacements at the fairlead, wave-current loads and different types of sea bottom friction on the mooring systems were analysed in terms of tensions, movements and shape of force-displacement curve. However, scaling of the sea bottom and the mooring line interaction is a challenge. Although the damping effect was investigated and compared under different movement conditions, the conclusions achieved can be upscale to real scale but it must be noticed that there are limitations due to scale effect issues. A total of 111 test were performed. The influence of the hydrodynamic inertia and drag is negligible on long wave and slow motions, while they have more importance during shorter waves and quick motions. The results reveal the importance of acceleration in the movement being possible to distinguish dynamic and quasi-static performance depending on the acceleration of the mooring line.

This paper explores the role of wave spectral characteristics and wave time history on the estimation of extreme mooring loads on floating offshore wind turbines. This research is applied to the DeepCwind semi-submersible platform located at the BiMEP test site in the North of Spain. Extreme sea states are selected using the inverse first-order reliability method (I-FORM). Mooring loads are modelled by quasi-static and dynamic numerical approaches. Different wave time series are generated numerically for each sea state to investigate the variability in predicted peak loads. All cases simulated incorporate the combined effect of wind and waves. Differences of approximately 30% in peak loads are found for the mooring system, reaching 40–79% for the most extreme sea states. Safety factors are proposed to account for sensitivity to wave groupiness in modelling loads under extreme work conditions of the DeepCwind platform (e.g., pitch and velocity control). A comparison between theoretical and real-sea wave spectra is also modelled to investigate possible differences due to the presence of multiple spectral peaks associated with swell and wind seas. In general, results show differences below 12% in the prediction of loads between both assumptions.

In this work we pilot a methodology to value the annual coastal protection benefits provided by mangroves in the Philippines and identify where these natural coastal defenses deliver the greatest protection. This is the first rigorous, engineering-based, nationwide evaluation of the effectiveness of mangrove habitats as natural defenses. By comparing flood damages for scenarios with and without mangroves, the study estimates the socioeconomic benefits for protecting people and property, to inform conservation and disaster risk reduction policies. Without mangroves, flooding and damages to people, property and infrastructure in the Philippines would increase annually around 25%. These habitats reduce flooding to 613,500 people/year, 23% of whom live below the poverty line. They also avert damages to 1 billion US$/year in residential and industrial property. If mangroves were restored to their 1950 distribution, there would be additional benefits to 267,000 people annually, including 61,500 people below poverty and an additional 453 mill. US$ in avoided damages. Currently, mangroves prevent more than 1.7 billion US$ in damages for extreme events (1-in-50-year). Ultimately, rigorous economic estimates of critical ecosystem services like this will help the national government to integrate the value of mangroves to people, into their national accounting systems.

Shoreline recession due to the combined effect of waves, tides and sea level rise is increasingly becoming a major threat to beaches, one of the main assets of seaside tourist destinations. Given such an uncertain future climate and the climate-sensitive nature of many decisions that affect the long term, there is a growing need to shift current approaches towards probabilistic frameworks able to take uncertainty into account. This study contributes to climate change research by exploring the effects of erosion on the recreation value of beaches as a key indicator in the tourism sector. The new paradigm relates eroded sand to geographic and socioeconomic aspects and other physical settings, including beach type, quality and accesses, yielding monetary estimates of risk in probabilistic terms. Additionally, we look into policy implications regarding tourism management, adaptation and risk reduction. The methodology was implemented in 57 beaches in Asturias (north of Spain).

The estimation of wave energy dissipation produced by saltmarshes has traditionally been obtained in terms of a drag or friction force. The estimation of these forces is made taking into account the characteristics of the saltmarsh (i.e. biomechanical properties, morphology, density) and a hydrodynamic coefficient (i.e. the drag or friction coefficient). The characterization of a vegetated ecosystem by measuring leaf traits, the biomechanical properties of the plants and the number of individuals per unit area involves a lot of effort and is case-specific. In addition, hydrodynamic coefficients are selected on the basis of simplified geometry parameterizations or on calibrations performed in ad hoc studies and accurate estimates rely on their validation under real conditions.Although for a very limited number of species, previous studies have shown that wave damping positively correlates with standing biomass. Therefore, standing biomass can be a unique variable that defines the wave energy attenuation capacity of the ecosystem. In addition, this variable has already been already characterized for many ecosystems by means of traditional plant harvesting or more recently using aerial images. Then, to further explore its relationship with the induced flow energy attenuation, a new set of experiments is proposed using real vegetation, with contrasting morphology and biomechanical properties, and subjected to different incident flow conditions. The experiments are carried out considering four species of vegetation, with contrasting biomechanical properties and morphology, and including two densities per species. Three water depths, wave heights from 0.08 to 0.18 m and wave periods from 1.5 to 4 s are tested. Capacitive free surface gauges and Acoustic Doppler Velocimeters (ADVs) are used to measure wave damping plant capacity along the meadow.A direct relationship between the standing biomass of the meadow and plant induced wave attenuation is found for the eight vegetated conditions. In addition, a single relationship is obtained for the resultant wave damping and the eight standing biomass values. This relationship provides the basis for the use of standing biomass as a key parameter to estimate the coastal protection service provided by different saltmarsh species using a single variable that can be easily quantified from the field.

A new numerical model for addressing long-term coastline evolution on a local to regional scale on highly anthropized coasts is presented. The model, named IH-LANS (Long-term ANthropized coastlines Simulation tool), is validated over the period 1990-2020 and applied to obtain an ensemble of end-of-century shoreline evolutions. IH-LANS combines a hybrid (statistical-numerical) deep-water propagation module and a shoreline evolution model. Longshore and cross-shore processes are integrated together with the effects of man-made interventions. For the ease of calibration, an automated technique is implemented to assimilate observations. The model is applied to a highly anthropized 40 km stretch located along the Spanish Mediterranean coast. High space-time resolution climate data and satellite-derived shorelines are used to drive IH-LANS. Observed shoreline evolution (

The assessment of the projected changes in wave climate due to climate change has been subject of study during the last two decades (Morim et al., 2018), largely due to the severe impacts these changes may have on coastal processes such as flooding and erosion. The wind wave climate is fully described by the sea surface elevation spectrum, which represents the distribution of energy resulting from the contributions of several superimposed waves with different periods and directions. Nevertheless, to this day the standard approach to address the future behavior of wind waves is based on the use of integrated wave parameters (e.g. significant wave height, mean wave period, mean wave direction) as a representation of the full spectrum. In this study, we analyze the changes in wave energy from directional spectra discretized in 24 directions and 32 frequencies in a number of locations distributed across all ocean basins, shedding light on the added value that an assessment based on the full spectrum offers with respect to the standard approach. In addition, the ESTELA method (Pérez et al., 2014) is applied to ease the understanding of the changes obtained in wave energy at the locations of study.The spectral approach helps to assess the projected change in the energy of each wave system that reach a specific location. Results demonstrate that the use of integrated wave parameters can mask important information about the sign, magnitude and uncertainty of the actual projected changes in mean wave climate due to the offset of the expected variations in the different wave systems that integrate the spectrum. It is especially relevant at locations where an increase in the wave period or wave energy is hidden by the application of the standard approach, as these parameters are proven to play a key role in coastal processes. In addition, we reach relevant conclusions about the future behavior of swell systems. For instance, a robust increase in the energy carried by swells generated below 40°S can be observed in every ocean basin and both hemispheres, even beyond 30°N. Similarly, a decrease in the energy carried by northern swells can be observed close to the equator.

Global mean sea level rise and its acceleration are projected to aggravate coastal erosion over the 21st century, which constitutes a major challenge for coastal adaptation. Projections of shoreline retreat are highly uncertain, however, namely due to deeply uncertain mean sea level projections and the absence of consensus on a coastal impact model. An improved understanding and a better quantification of these sources of deep uncertainty are hence required to improve coastal risk management and inform adaptation decisions. In this work we present and apply a new extraprobabilistic framework to develop shoreline change projections of sandy coasts that allows consideration of intrinsic (or aleatory) and knowledge-based (or epistemic) uncertainties exhaustively and transparently. This framework builds upon an empirical shoreline change model to which we ascribe possibility functions to represent deeply uncertain variables. The model is applied to two local sites in Aquitaine (France) and Castellón (Spain). First, we validate the framework against historical shoreline observations and then develop shoreline change projections that account for possible (although unlikely) low-end and high-end mean sea level scenarios. Our high-end projections show for instance that shoreline retreats of up to 200m in Aquitaine and 130m in Castellón are plausible by 2100, while low-end projections revealed that 58 and 37m modest shoreline retreats, respectively, are also plausible. Such extended intervals of possible future shoreline changes reflect an ambiguity in the probabilistic description of shoreline change projections, which could be substantially reduced by better constraining sea level rise (SLR) projections and improving coastal impact models. We found for instance that if mean sea level by 2100 does not exceed 1m, the ambiguity can be reduced by more than 50%. This could be achieved through an ambitious climate mitigation policy and improved knowledge on ice sheets. This research has been supported by the BRGM, IHCantabria and the ERA4CS-ECLISEA project (grant no. 690462).

Adaptation requires planning strategies that consider the combined effect of climatic and non-climatic drivers, which are deeply uncertain. This uncertainty arises from many sources, cascades and accumulates in risk estimates. A prominent trend to incorporate this uncertainty in adaptation planning is through adaptive approaches such as the dynamic adaptive policy pathways (DAPP). We present a quantitative DAPP application for coastal erosion management to increase its utilisation in this field. We adopt an approach in which adaptation objectives and actions have continuous quantitative metrics that evolve over time as conditions change. The approach hinges on an adaptation information system that comprises hazard and impact modelling and systematic monitoring to assess changing risks and adaptation signals in the light of adaptation pathway choices. Using an elaborated case study, we force a shoreline evolution model with waves and storm surges generated by means of stochastic modelling from 2010 to 2100, considering uncertainty in extreme weather events, climate variability and mean sea-level rise. We produce a new type of adaptation pathways map showing a set of 90-year probabilistic trajectories that link changing objectives (e.g., no adaptation, limit risk increase, avoid risk increase) and nourishment placement over time. This DAPP approach could be applied to other domains of climate change adaptation bringing a new perspective in adaptive planning under deep uncertainty. Alexandra Toimil acknowledges the financial support from the FENIX Project funded by the Government of Cantabria. This research was also funded by the Spanish Government through the grant RISKCOADAPT (BIA2017-89401-R).

Reduction of copper(ii) chloride using sodium ascorbate in the presence of pure sodium 5-nitro-tetrazolate (NaNT) forms copper(i) 5-nitrotetrazolate - a known initiatory explosive (DBX-1) - and the novel mixed-ligand copper(i) chloride 5-nitrotetrazolate coordination polymer Cu3Cl(N4C-NO2)2, as well as mixtures of both. The reaction is controlled by the presence of seed crystals and transition metal compounds other than CuCl2. Cu3Cl(N4C-NO2)2 is obtained as a wine-red, air stable, water-insoluble, crystalline and highly sensitive explosive material with a greater crystal density, lower thermal stability and a higher sensitivity toward hydrolysis and shock than DBX-1. Efforts to obtain the stable and pure starting material are improved by crystallisation of NaNT as a tetrahydrate. Cu3Cl(N4C-NO2)2 and Na(H2O)4(NT) were characterised by single crystal and powder XRD, IR spectroscopy, magnetic and thermal measaurements, elemental analysis, particle size measurements, mass spectrometry, and by drop weight testing.

The accurate modeling of the landslide?generated tsunami characteristics in the so-called near-field is crucial for many practical applications. In this paper, we present a new full-3-D numerical method for modeling tsunamis generated by rigid and impermeable landslides in OpenFOAM® based on the overset mesh technique. The approach has been successfully validated through the numerical reproduction of past experiments for landslide?generated tsunamis triggered by a rigid and impermeable wedge at a sloping coast. The method has been applied to perform a detailed numerical study of the near-field wave features induced by submerged landslides. A parametric analysis has been carried out to explore the importance of the landslide's initial acceleration, directly related to the landslide-triggering mechanisms, on the tsunami generation process and on the related wave properties. Near-field analysis of the numerical results confirms that the influence of the initial acceleration on the tsunami wave properties is significant, affecting wave height, wave period, and wave celerity. Furthermore, it is found that the tsunami generation mechanism experiences a saturation effect for increasing landslide's initial acceleration, confirming and extending previous studies. Moreover, the resulting extended database, composed of previous experimental data and new numerical ones, spanning a wider range of governing parameters, has been represented in the form of a “nondimensional wavemaker curve,” and a new relationship for predicting the wave properties in the near-field as a function of the Hammack number is proposed.

The evolution of the cross-shore beach profile is tightly related to the evolution of the coastline in both small and large time scales. Bathymetry changes in extreme maritime events can also have important effects on coastal infrastructures such as geotechnical failures of foundations or the modification of the incident wave conditions towards a more unfavourable situation.The available strategies to study the evolution of beach profiles can be classified in analytical, physical and numerical modelling. Analytical solutions are fast, but too simplistic for many applications. Physical modelling provides trustworthy results and can be applied to a wide variety of configurations, however, they are costly and time-consuming compared to analytical strategies. Finally, numerical approaches offer different balances between cost and precision depending on the particular model.Some numerical models provide greater precision in the beach profile evolution, but incurring in a prohibitive computational cost for many applications. In contrast, the less expensive ones assume simplifications which do not allow to correctly reproduce significant phenomena of the near-shore hydrodynamics such as wave breaking or undertow currents, neither to predict important features of the beach profile like breaker bars.In this work, a new numerical model is developed to reproduce the main features of the beach profile and hydrodynamics while maintaining an affordable computational cost. In addition, it is intended to reduce to the minimum the number of coefficients that the user has to provide to make the model more predictive.The model consists of two main modules. Firstly, the already existing 2D RANS numerical model IH2VOF is used to compute the hydrodynamics. Secondly, the sediment transport model modifies the bathymetry according to the obtained hydrodynamics. The new bathymetry is then considered in the hydrodynamic model to account for it in the next time step.The sediment transport module considers bedload and suspended transports separately. The former is obtained with empirical formulae. In the later,the distribution of sediment concentration in the domain is obtained by solving an advective-diffusive transport equation. Then, the sedimentation and erosion rates are obtained along the seabed.Once these contributions are calculated, a sediment balance is performed in every seabed segment to determine the variation in its level.With the previously described strategy, the resulting model is able to predict not only the seabed changes due to different wave conditions, but also the influence of this new bathymetry in the hydrodynamics, capturing features such as the generation of a breaker bar, displacement of the breaking point or variation of the run-up over the beach profile. To validate the model, the numerical results are compared to experimental data.An important novelty of the present model is the computational effort required to perform the simulations, which is significantly smaller than the one associated to existing models able to reproduce the same phenomena.

Although mangroves reduce annual flooding to millions of people there is not a methodology to implement these solutions and it is still difficult to estimate the protection provided by them under different environmental conditions and ecosystem properties. To move forward in the consecution of an engineering approach when implementing these solutions for coastal defense, the first step to make is to better understand and parameterize the basic physical processes involved in flow-mangroves interaction. With the aim of getting a new formulation for wave decay provided by Rhizophora mangrove forests based on flow and ecosystem properties, an experimental campaign was carried out where both wave attenuation and forces on mangrove individuals were measured under different wave conditions. Both, the hydrodynamic conditions and the mangrove forest, were scaled according to field conditions for short waves. The detailed wave attenuation and drag force measurements obtained in these experiments allowed to obtain new formulations of wave decay produced by the forest depending on the flow, i.e.: water depth, wave height and period, and on the forest characteristics, i.e.: individuals submerged solid volume fraction and density. These formulations are used to get attenuation rates under different flow and ecosystem conditions. The resultant curves provide with the wave decay produced by a specific Rhizophora forest subjected to the defined wave conditions. The forest is defined on the basis of its age, considering the differences in individual trees depending on their maturity and the density of the forest as the number of trees per unit area. Wave conditions are defined by the root mean square wave height and the peak period and water depth is also considered. The obtained curves allow to estimate the width of the forest necessary to reach a certain level of protection considering the local flow conditions and the forest age. This can assist in the inclusion of nature-based solutions in the portfolio of coastal protection measures.

Sea-level rise (SLR) is a major concern for coastal hazards such as flooding and erosion in the decades to come. Lately, the value of high-end sea-level scenarios (HESs) to inform stakeholders with low-uncertainty tolerance has been increasingly recognized. Here, we provide high-end projections of SLR-induced sandy shoreline retreats for Europe by the end of the 21st century based on the conservative Bruun rule. Our HESs rely on the upper bound of the RCP8.5 scenario &ldquo, likely-range&rdquo, and on high-end estimates of the different components of sea-level projections provided in recent literature. For both HESs, SLR is projected to be higher than 1 m by 2100 for most European coasts. For the strongest HES, the maximum coastal sea-level change of 1.9 m is projected in the North Sea and Mediterranean areas. This translates into a median pan-European coastline retreat of 140 m for the moderate HES and into more than 200 m for the strongest HES. The magnitude and regional distribution of SLR-induced shoreline change projections, however, utterly depend on the local nearshore slope characteristics and the regional distribution of sea-level changes. For some countries, especially in Northern Europe, the impacts of high-end sea-level scenarios are disproportionally high compared to those of likely scenarios.

Climate-related extreme events such as Hurricane Katrina (2005) or Maria (2017); Superstorm Sandy (2012), extreme precipitation or heat waves have directly hit many ports around the world in recent years. Ports are becoming increasingly aware of the risks of climate change, partly because of these events. However, very few are taking adaptation into practice, often due to the lack of information and the high uncertainties associated with climate change. This paper presents a multi-level methodology for conducting climate change risk assessment in existing ports following a sequential path that starts with a quantitative analysis focused on multi-hazard and multi-impact evaluation with climate information based on indicators. If needed the first level will be combined with a qualitative analysis based on perceived risk of stakeholders in order to determine the necessity of carrying out a high-resolution analysis, increasing the quantity, quality and resolution of input data, climate information and impact modelling aiming at reducing uncertainties. Results provide port managers with essential information to identify hot spots and prioritize adaptation strategies.

Coastal flood risks are rising rapidly. We provide high resolution estimates of the economic value of mangroves forests for flood risk reduction every 20 km worldwide. We develop a probabilistic, process-based valuation of the effects of mangroves on averting damages to people and property. We couple spatially-explicit 2-D hydrodynamic analyses with economic models, and find that mangroves provide flood protection benefits exceeding $US 65 billion per year. If mangroves were lost, 15 million more people would be flooded annually across the world. Some of the nations that receive the greatest economic benefits include the USA, China, India and Mexico. Vietnam, India and Bangladesh receive the greatest benefits in terms of people protected. Many (>45) 20-km coastal stretches particularly those near cities receive more than $US 250 million annually in flood protection benefits from mangroves. These results demonstrate the value of mangroves as natural coastal defenses at global, national and local scales, which can inform incentives for mangrove conservation and restoration in development, climate adaptation, disaster risk reduction and insurance We thank the supporting provided by the World Bank and the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) on the basis of a decision adopted by the German Bundestag. We also acknowledge financial support from the Spanish Ministry of Economy and Innovation (BIA2014-59718-R). Authors are grateful to the useful contributions provided by Borja González Reguero (University of Santa Cruz California), Antonio Espejo, Sheila Abad and Pedro Díaz Simal (IH Cantabria). Pelayo Menéndez acknowledge to the FPI grant from the Spanish Ministry of Economy and Innovation (BES-2015-074343). The authors acknowledge to the National Plan “RISKOADAPT” from the Spanish Ministry of Sciences, Innovation and Universities (BIA2017-89401-R).

Background: The objective of this study was to evaluate the effects of three single-limb heated wired circuits (SLHWC) for NIV, on ventilatory parameters and humidification performance in a simulation lung model. Methods: Three SLHWC compatible with the MR-850 Heated Humidifier (HH) (Fisher & Paykel, Auckland, New Zealand) were tested: RT-319 (FP) (Fisher & Paykel, Auckland, New Zealand), Respironics 1045770 (RP) (DEAS, Castel Bolognese, Italy) and Intersurgical B/SYS 5809001 (IT) (Intersurgical, Wokingham, UK). A Bipap Vision ventilator (Philips Respironics, Murrysville, PA, USA) in pressure control ventilation (PCV) connected to a test lung was used for simulation. Each SHWC performance was evaluated in four ventilatory conditions: IPAP of 15 cm H2O with FiO(2) 0.3 and 1, respectively; and, IPAP of 25 cm H2O with FiO(2) 0.3 and 1, respectively. EPAP was set at 5 cm H2O. Hygrometric and ventilatory measurements including: relative humidity (RH), temperature (T), Pplat, PIP, PEEP, peak inspiratory flow (PIF), and tidal volume (Vt) were measured. Results: In each FiO(2) group absolute humidity (AH) was similar with FP regardless of the IPAP level employed compared to IT and RP (P < .001). Except for RP at FiO(2) 0.3, AH increased significantly in IT and RP groups as IPAP increased (P < .001). PIP, Pplat, PEEP, PIF, and Vt values were significantly higher with FP and RP in each FiO(2) group compared to IT (P < .001). Conclusions: Humidification performance varied significantly among the three circuits, being FP the only one able to maintain stable AH values during the study with no influence on ventilatory parameters. (C) 2019 SEPAR. Published by Elsevier Espana, S.L.U. All rights reserved.

This paper presents a methodology to evaluate the influence of downtime on the long-term energy yield of a floating wind farm. It is based on the definition and integration of three models: a discrete event model, which simulates failures and reparation times, a floating wind turbine model, which simulates platform motions and operational stops, and a wind farm model, which models wake effects between turbines. The methodology is applied to a wind farm composed by ten floating turbines and located off the coast of Cantabria, Spain. Results indicate that downtime affects significantly the mean energy yield of the farm, which decreases linearly with the mean failure rate, mean reparation time and probability of exceedance of the operational thresholds for the considered case studies.

One approach to identifying and mapping the state of marine biophysical conditions is the identification of large-scale ecological units for which conditions are similar and the strategies of management may also be similar. Because biological processes are difficult to directly record over large areas, abiotic characteristics are used as surrogate parameters. In this work, the Mediterranean Sea was classified into homogeneous spatial areas based on abiotic variables. Eight parameters were selected based on salinity, sea surface temperature, photosynthetically active radiation, sea-wave heights and depth variables. The parameters were gathered in grid points of 0.5° spatial resolution in the open sea and 0.125° in coastal areas. The typologies were obtained by data mining the eight parameters throughout the Mediterranean and combining two clustering techniques: self-organizing maps and the k-means algorithm. The result is a division of the Mediterranean Sea into seven typologies. For these typologies, the classification recognizes differences in temperature, salinity and radiation. In addition, it separates coastal from deep areas. The influence of river discharges and the entrance of water from other seas are also reflected. These results are consistent with the ecological requirements of the five studied seagrasses ( Posidonia oceanica , Zostera marina , Zostera noltei , Cymodocea nodosa , Halophila stipulacea ), supporting the suitability of the resulting classification and the proposed methodology. The approach thus provides a tool for the sustainable management of large marine areas and the ability to address not only present threats but also future conditions, such as climate change.

This study presents IH-LANS (Long-term ANthropized coastlines Simulation tool), a numerical model for addressing long-term coastline evolution at local to regional scales in highly anthropized coasts. In IH-LANS, a hybrid (statistical-numerical) deep-water propagation module and a data-assimilated shoreline evolution model are coupled. Longshore and cross-shore processes are integrated together with the effects of man-made interventions. For every simulation, shoreline changes in response to time varying wave conditions and water levels are evaluated while reducing calibration uncertainty by means of an extended Kalman filter that allows to assimilate shoreline observations. To test model performance, IH-LANS is applied to a highly anthropized 40 km stretch located along the Spanish Mediterranean coast. The model is run during the period 1990–2020 using high space-time resolution climate data and satellite-derived shorelines in order to calibrate the free parameters and validate model outputs. Shoreline evolution is successfully represented (

In the context of growing concern about the threat of flooding posed by climate change in coastal areas, the Spanish plan for coastal adaptation to climate change gave rise to stringent requirements on risk consequence estimates at the regional scale O (100 km). Within this framework, we propose a methodology that combines high space-time resolution climate information (reanalysis databases and projections), local data on exposure that accounts for the most relevant sectors, site-specific vulnerability functions, and flood risk consequence valuation, gridded at 5 m. This approach involves efficient multiple-forcing flood modeling, in which the connection between climate change and potential inundation is primarily established through the definition of a total water level index. This research tackles challenging issues, including the importance of incorporating the effects of existing coastal defenses and local wave effects in port areas, dealing with data at different spatial scales and sectors in an integrated way, and the impact of discounting. The results provide insights into the possible consequences of inaction for a range of future scenarios based on changes in climate and socio-economics over the most relevant sectors. With the goal of prioritizing adaptive action and the efficient assignment of funds, we propose a weight-based integration of the sectoral value-at-risk through the application of Bayesian techniques and expert judgment. The methodology described here was applied to a pilot case study on the coast of Asturias in northern Spain.

Although mangroves reduce the daily risk of flood for millions of people, it is still difficult to estimate the protection they provide for variable wave conditions and forest characteristics. This aspect is crucial for the promotion of conservation and restoration of mangrove forests and for the estimation of how the coastal protection service they provide will evolve over time. This paper presents evidence and a new method for the estimation of the relationship between mangrove forest age and wave attenuation. The forest under analysis is characterised by the age of the Rhizophora mangrove trees, where consideration is given to the differences in the maturity of its individual trees and the density of the forest. Environmental conditions are defined by water levels and incoming wave height and period. A set of empirical and analytical relations expressing wave attenuation as a function of the submerged solid volume fraction (SVF) are presented. Changes is tree morphology and forest characteristics with forest age, as well as the contribution of the tree canopy, are taken into account. Results indicate that, after restoration, it may take only 5 years to obtain a forest's maximum coastal protection capacity. Additionally, such capacity appears to be maintained throughout the forest's lifetime with minor variations, provided the forest is not affected by any conditions altering its health, such as extreme wave events or anthropogenic action that may modify its habitat. Our findings present a new approach to quantifying the protection provided by mangroves without requiring any calibration. These findings can also assist in planning mangrove restoration and assessing associated benefits by providing the incorporation of nature-based solutions or ecosystem-based adaptation into coastal management.

A family of heterometallic [Cat][TixMO(x+1)(O2CtBu)2x+2] rings is reported where Cat=a secondary or tertiary alkyl ammonium ion, x=7, 8 or 9, and M=FeIII, GaIII, CrIII, InIII and AlIII. The structures are regular polygons with eight, nine or ten vertices with each edge bridged by an oxide and two pivalates. The size of the ring formed is controlled by the alkylammonium cation present. In each case a homometallic by-product is found [Cat][TixO(x+1)(O2CtBu)2x−1].

This study presents the design, development, scheme and field validation of an early-alert ocean wave system. It is designed to automate, improve, analyse, design and manage the daily construction activities of any harbour at construction stage. The objective is threefold: a) maximise construction safety, with regards to well-known hazards which occur during construction, especially breakwaters that interact with high-energy sea states, b) optimise the transport, by means of specialised vessels, of the refill material, and c) to minimise the construction delay and disruption on a daily basis, thanks to short-term construction forecasting (96 h). The system, known as PATO, offers short-term sea states characteristics, at any point near harbour structures, and relevant wave-structure interaction parameters at any harbour construction stage. The system is able to assist harbour project managers by providing accurate ocean wave data through a user-friendly interface.

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 25 km) for all the coastal locations at a depth shallower than 200 m. 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.

En un contexto de crecientes impactos y riesgos socio-económicos en las costas del planeta, la protección costera basada en ecosistemas surge como un nuevo paradigma que une los principios de protección, sostenibilidad y resiliencia, a la vez que proporciona múltiples beneficios. Este artículo ofrece una perspectiva sobre qué son y cómo se pueden utilizar las defensas naturales en el diseño, planificación y gestión de costas. La política pública muestra un creciente interés por su implementación general y el cuerpo de conocimiento y experiencia alrededor de la también denominada infraestructura ?verde? es creciente, pero aún existen importantes barreras que salvar. Una de ellas es estandarizar su diseño en términos ingenieriles, así como reconocer los aspectos que los diferencian respecto a enfoques tradicionales. La adaptación climática y la reducción de riesgos son áreas en las que su utilización puede ser más significativa, debido a la variedad de servicios que ofrecen. Tanto desde el punto de vista técnico como económico, existen argumentos sólidos para evitar la degradación de los ecosistemas, avanzando su restauración y conservación, como también desde la perspectiva de la defensa de las costas. In a context of increasing socio-economic impacts and risks in the coastal areas of the planet, coastal protection based on ecosystem features becomes a new paradigm that combines the principles of conservation, sustainability and resilience, while providing multiple benefits. This paper provides a perspective on what these are and how they can be used in the design, planning and management of the coastal zones. Policy-makers are calling for further uptake and implementation across the board and the body of knowledge and experience around the socalled ?green? infrastructure is growing, but there are still major barriers for a widespread uptake. One of them is to standardize designs in engineering terms, recognizing the different characteristics compared to traditional engineering solutions. Climate adaptation and risk reduction are areas where its use may be more significant, for the variety of services they offer. Both technically and economically, there are strong arguments to prevent degradation of ecosystems and to advance in their restoration and conservation, as well as from a coastal defense perspective.

The effect of vegetation patchiness on solitary wave propagation, attenuation and wave-induced forces is studied both experimentally and numerically. Vegetation patchiness is simulated with rigid cylinder configurations built by one, eight and four patches tested under emergent, near emergent and submerged conditions. These configurations are parameterized by means of a new parameter (equivalent length, Le), which is used to relate cylinders distribution with wave attenuation capacity. This new parameter allows comparing results for the three patches configurations. Larger attenuation rates are found for higher wave heights and shorter wave periods. The influence of water depth is also considered by means of the submergence ratio (SR) in order to account for the percentage of water column affected by vegetation. Higher attenuation rates are obtained for emergent conditions. High correlations are found between wave attenuation and a new set of parameters, the depth wave number (kLe × SR), that accounts for submergence conditions and field characteristics and a new Reynolds number ( R e s L e ), that is calculated considering the field vegetation dimensions affecting the flow. Experimental results are extended using IHFOAM, a three dimensional Navier-Stokes equations solver, to analyze wave forces on individual cylinders and wave propagation patterns showing the variability of forces magnitude and direction associated to vegetation patchiness.

A regression-guided classification is implemented in statistical downscaling models based on weather types for downscaling multivariate wave climate and modelling extreme events. The semi-supervised method classifies the atmospheric circulation conditions (predictor) and the estimations from a regression model linking the circulation with local marine climate (filtered predictand). A weighted factor controls the influence of the predictor and predictand in the weather patterns to improve the performance of the classification to reflect local marine climate characteristics. In addition to the analysis of the variance explained by the predictor and the predictand, the selection of the optimal value of the weighted factor is based on the predictand response in order to avoid subjectivity in the solution. The statistical models using the guided classification are applied in the North Atlantic. The new technique reduces the dispersion of the multivariate predictand within weather types and improves the model skill to downscale waves and to reproduce extremes.

Coastal development and climate change are dramatically increasing the risks of flooding, erosion, and extreme weather events. Coral reefs and other coastal ecosystems act as natural defenses against coastal hazards, but their degradation increases risk to people and property. Environmental degradation, however, has rarely been quantified as a driver of coastal risk. In Quintana Roo, Mexico, a region on the Mexican Caribbean coast with an annual tourism economy of 10 billion USD, coral reefs constitute a natural barrier against flooding from hurricanes. This study spatially quantifies the risk reduction benefits of the Mesoamerican Reef in Quintana Roo for people, buildings, and hotel infrastructure. The risk reduction benefits are substantial. For example, the reefs prevented 43% additional damage during Hurricane Dean (2007) and provide nowadays hazard risk reduction for 4.3% of the people, 1.9% of the built capital, and 2.4% of the hotel infrastructure, per year. The annual benefits are estimated in 4,600 people, 42 million USD damage prevention for buildings, and 20.8 million USD for hotel infrastructure. The study also compares the risk reduction of coral reefs with (i) the protection offered by dunes and (ii) the increase in coastal risk from sea-level rise. The risk reduction of dunes is more critical where there are no coral reefs offshore and for small return-periods storms. Sea-level rise, however, will make the more frequent storms more impactful and will drive significant increases in annual expected damages across the region. However, we demonstrate that, in coral reef environments, the contribution of reef degradation to coastal risk is larger than the expected increase in risk from sea level rise. However, the spatial distribution of the risk reduction benefits from reefs differs for people and infrastructure, and in particular for hotels, which receive the most protection from reefs. Furthermore, many sections present larger benefits than the typical costs of restoration. This valuation makes a compelling case for protecting and maintaining this natural infrastructure for its risk reduction service, but also allows the development of piloting innovative strategies, such as risk finance and insurance strategies, that can align environmental and risk management goals.

In this work, we present several applications of the 2D-3D multi-domain couplings for Navier-Stokes models developed and validated in its companion (Di Paolo et al., submitted). The methodology is used to carry out some relevant simulations which include long regular and irregular waves, solitary wave propagation on a shallow foreshore, focused wave group transformation on a planar beach, wave impact on a cylinder and finally, the numerical twin of a complex laboratory experiment to analyse the performance of a perforated breakwater under wave action. Results agree well with the full 3D simulations and laboratory experiments and demonstrate the feasibility of using the 2D-3D coupled methodologies presented in Part I to successfully replace full 3D modelling. For all the cases considered, the application of coupled methodologies have resulted in a drastic reducing of the computational time without decreasing the accuracy of the full solution.

Estimation of the flow energy dissipation induced by an ecosystem that accounts for its characteristics (i.e. biomechanical properties, morphology, density) and the incident hydrodynamic conditions is crucial if ecosystem-based coastal protection measurements want to be implemented. Characterization of a vegetated ecosystem by measuring leaf traits, biomechanical properties of plants and the number of individuals per unit area involves a lot of effort and is case-specific. Standing biomass can be a unique variable defining the flow energy attenuation capacity of the ecosystem. To explore its relation to the induced energy attenuation on the flow, a new set of experiments using real vegetation with contrasting morphology and biomechanical properties, and subjected to different incident flow conditions is presented. The obtained standing biomass-attenuation relationships will help to quantify the expected coastal protection provided by different vegetated ecosystems based on their standing biomass and the flow conditions.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/-qaKkBWZApk

The use of CFD for numerical representation of laboratory wave flume and basins, commonly known as numerical wave tanks (NWT), has become more popular in recent years with the aim of improving knowledge in the field of wave-structure interaction (WSI), both fixed and floating, due to advances that have been made in numerical modelling, mainly with the reproduction of three dimensional problems. The use of this technique is displacing even traditional approaches based on the use of potential flow equations, due to the versatility provided by the CFD approach, which allows considering nonlinear interactions between structures and waves, and above all, extreme events such as wave breaking. However, implementation of these models as a complementary tool to physical modeling facilities is not yet standardized and requires further development to hybridize these two techniques, numerical and experimental, in order to obtain a better knowledge of physical processes. Implementation still requires overcoming existing modeling limitations and the additional steps to be taken focus on the following areas are: a) numerically mirror wave generation and active/passive absorption in physical installations; b) numerical resolution of WSI problems, which to date depends on each WSI case; c) computational cost, which may be the bottleneck for NWT implementation; and, finally, the most important feature that is where the added value of the hybrid approach lies, d) the exchange of information between the laboratory measurements and the results of the numerical simulations in order to obtain a better understanding of WSI problems. This paper will present an analysis of the main aspects described above for the implementation of hybrid techniques for the study of WSI problems (floating and fixed). The latest advances in modeling developed with IHFOAM solver (ihfoam.ihcantabria.com), and physical modeling procedures to link laboratory and numerical tools will be presented. The main objective is establishing a standard procedure to implement this technique in any physical installation.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/6mAQccSrREM

Focused on offshore wind energy operation and maintenance applications, this work presents a detailed accessibility analysis of the North Sea. After a review of existing normative dedicated to inspection and access of offshore wind turbines, a rigorous mathematical formulation of relevant accessibility parameters is given by means of the set theory. Long-term and high-resolution metocean data are extracted from reanalysis databases and used to evaluate spatial and temporal variability of such parameters. Respectively restricted by significant wave height and mean wind speed, access by workboat and helicopter is evaluated. Being affected by both wave height and wind speed. Access by offshore crane is also analyzed. It resulted that the UK coast and the southern region of the North Sea are highly accessible, while the coast of Denmark and Norway undergoes more severe metocean conditions. This is, however, balanced by a higher wind resource. Moreover, a strong seasonality is ascertained, together with a drastic reduction of accessibility during daytime in a vast part of the basin. Accessibility during daytime in winter and autumn is very difficult for the whole North Sea. Among the studied farms, Dogger Bank is by far the one with the highest resource and lowest accessibility, while Thorntonbank III the one with the lowest resource and highest accessibility. In addition, accessibility is non-linearly related to wind speed and wave height limits chosen for the access strategies covered. Copyright © 2016 John Wiley & Sons, Ltd.

Offshore wind energy is moving towards a future where the main challenge is to cope with the increasing water depth needed to access more and better wind resources. One of the first steps to be undertaken is the development of floating structures to support either wind turbines or measurement devices for the proper characterization of wind energy resources. The use of floating devices for measuring wind speed involves a number of uncertainties not presented by seabed fixed systems. These sources of uncertainty or error are present both in instantaneous wind measurements and averaged (10 min or hourly) values because of (i) variability in the measurement height, (ii) the tilt of the anemometer and (iii) the relative velocity between the anemometer and the wind, among others. In this paper, a methodology for assessing the error in the wind measurement characterization because of the movement of a floating meteorological mast is presented. By the numerical simulation of a floating mast, the short- and long-term error in the characterization of the wind at different heights has been evaluated. In general, the error because of the tilt can reach up to 80% of the total error; the error because of the variation of the vertical position of the anemometer reaches values of up to 15% in some cases; moreover, the error associated with the relative velocity between the anemometer and the wind, for averaged values, is significantly less. Finally, it can be concluded that the total error is lower than 0.5% for 10 min averaged wind speed of up to 24 m/s. Copyright © 2016 John Wiley & Sons, Ltd.

This paper presents a methodology to assess the walk-to-work accessibility of a floating wind turbine. The system composed by the vessel and the platform is modelled in the frequency domain as a rigid, possibly constrained multibody system. Non-linear actions, such mooring and viscous forces are linearised. Extreme maxima for the response variables are calculated assuming that crests are Rayleigh distributed. Two vessels are studied: a catamaran equipped with fender, and a supply vessel mounting a motion-compensated gangway. For the catamaran, accessibility is possible when no-slip conditions between the vessel fender and the ladder landing platform are ensured. For the supply vessel, accessibility is possible when the gangway motions are below the hydraulic system compensation limits. The catamaran is able to handle wave heights up to 2 m, provided that it can work under head sea conditions and take advantage of the shielding effect of the platform. The supply vessel allows personnel transfer with wave heights up to 5 m, but it is important that roll motions are not excited. The proposed methodology and the calculated maps are a valuable source of information for decision-making during personnel transfer to and from offshore floating platforms.

Based on energy conservation a new analytical formulation for the evaluation of wave damping under the combined effect of waves and both following and opposing currents is presented. The formulation obtained for regular and random waves allows the derivation of analytical expressions for the vegetation drag coefficient as a function of wave damping parameters. These parameters are calibrated using a unique experimental set obtained in a large-scale wave basin considering the interaction of waves and currents with real vegetation representative of salt marshes, namely Spartina anglica and Puccinellia maritime. Comparisons show the quality of the analytical formulation under different hydrodynamic conditions, vegetation species and various Reynolds numbers formulated in terms of plant characteristics such as the deflected plant length accounting for the flow-induced bending of the vegetation. The new formulation can be useful to be implemented in phase averaged and phase resolving numerical models of wave propagation.

In recent years, the impact of climate change on sea surface waves has received increasingly more attention by the climate community. Indeed, ocean waves reaching the coast play an important role in several processes concerning coastal communities, such as inundation and erosion. However, regional downscaling at the high spatial resolution necessary for coastal studies has received less attention. Here, we present a novel framework for regional wave climate projections and its application in the European region. Changes in the wave dynamics under different scenarios in the Northeast Atlantic Ocean and the Mediterranean are analyzed. The multi-model projection methodology is based on a statistical downscaling approach. The statistical relation between the predictor (atmospheric conditions) and the predictand (multivariate wave climate) is based on a weather type (WT) classification. This atmospheric classification is developed by applying the k-means clustering technique over historical offshore sea level pressure (SLP) fields. Each WT is linked to sea wave conditions from a wave hindcast. This link is developed by associating atmospheric conditions from reanalysis with multivariate local waves. This predictor–predictand relationship is applied to the daily SLP fields from global climate models (GCMs) in order to project future changes in regional wave conditions. The GCMs used in the multi-model projection are selected according to skill criteria. The application of this framework uses CMIP5-based wave climate projections in Europe. The low computational requirements of the statistical approach allow a large number of GCMs and climate change scenarios to be studied. Consistent with previous works on global wave climate projections, the estimated changes from the regional wave climate projections show a general decrease in wave heights and periods in the Atlantic Europe for the late twenty-first century. The regional projections, however, allow a more detailed spatial characterization of the projected changes under different climate scenarios. For example, changes in significant wave heights for the RCP8.5 scenario for the 2070–2099 time period indicate a general decrease of about 10 cm in Southern Europe (Portuguese, Spanish and French coasts) with respect to present conditions. This decrease is due to a higher occurrence of dominant and moderate Azores high pressure systems over the North Atlantic Ocean and a decrease in the persistence of intense low pressure systems at high latitudes.

In this work an analysis of suitable locations for the development of wave energy farms is carried out based on representative operation and maintenance parameters. The analysis is applied globally on the basis of long-term global climate data set. Availability and accessibility levels are assessed first by considering different wave height thresholds. Secondly, the O&M access limits are quantified in terms of the weather windows and waiting period between them considering different windows lengths and scenarios. Finally, the O&M cost per kW h is calculated for a wave energy converter based on a point absorber concept. O&M costs has been calculated following the methodology proposed on Guanche et al. (2014). As expected, results show that locations with mild wave climate have very low O&M costs per kW h. Some areas with high wave resource, such as Scotland, Spain or Nova Scotia present reasonable O&M costs compared to the power production in these areas. However, other locations with high resource like Chile or Australia resulted in extremely high O&M costs due to the inaccessibility of these sites during long periods of time.

A new solver for wave and structure interaction is used for three-dimensional simulation of an Oscillating Water Column (OWC). The CFD model solves the Reynolds Averaged Navier–Stokes equations for two incompressible phases (water and air). Laboratory experiments are conducted on a small scale to validate the numerical results. Air and water pressures and velocities as well as the free surface evolution inside and outside the chamber are modeled with notably good agreement. The model is further used to improve understanding of relevant processes and shows potential for use detailed analysis. Even if the experimental problem analyzed had a two-dimensional behavior, the three dimensional domain of the wave flume was numerically simulated in order to prove the capabilities of OpenFOAM ® .

This paper presents an innovative vertical breakwater cross-section integrating an overtopping wave energy converter, named OBREC-V, and the analysis of its hydraulic performance and stability response to hydraulic loading. The structure is composed of a vertically-faced caisson with a sloping ramp on the top, a reservoir and a set-back crown-wall. The analysis of the structure is carried out by performing numerical simulations based on the Volume-Averaged Reynolds Averaged Navier-Stokes (VARANS) equations. The numerical simulations are performed to compare the performance of a traditional and innovative vertical caissons under the action of irregular waves, in terms of wave reflection, overtopping and wave acting forces. Results show that the reflection coefficients are lower than those computed in front of the traditional breakwater, with a reduction of up to the 40%. New formulations are proposed to better estimate the reflection coefficient and the wave overtopping at the rear side of the structure taking into account the non-conventional geometry of the device. The analysis of the forces indicate that the non-conventional geometry of the innovative OBREC-caisson increases the overall stability of the structure. The values of the safety factor against sliding, Cs, on innovative caissons are similar or greater than those calculated on the traditional vertical structure for almost all the tests. The downward force on the ramp and reservoir and the time lag between the vertical and horizontal forces, lead to a significant reduction of the maximum destabilizing forces Fs in the innovative breakwater, whose values range between 60 and 80% of the ones computed on the traditional structure. The obtained results show the co-benefits, in terms of functionality and hydraulic stability, that an OBREC-V entails with respect to a traditional vertical breakwater.

This paper analyses the importance of mooring design parametrisation on the dynamic behaviour of mooring loads. An exhaustive sensitivity analysis is performed to evaluate the variability of mooring loads because of inaccuracies in the definition of model inputs, including physical and numerical parameters. Results show a relevant dependence on the length and significance in other parameters, such as the weight together with the hydrodynamic equivalent diameter and the drag forces. An inaccuracy below 1% in the mooring reference length can generate loads of up to twice the design, and an incorrect definition of the weight or the drag coefficient in the mooring design can lead to a design load variability of up to 30%. Stiffness plays a crucial role in snap events, reaching load differences of 19% depending on the stiffness selected. This research is based on a set of numerical models capable of predicting the mooring system response. A dynamic numerical model with two schemes of resolution is implemented and calibrated according to an experimental test campaign. Other sources of results provided by a quasi-static model and commercial software, Sesam (DNV-GL), are incorporated. In general, the dynamic numerical models show a good accuracy with an experimental database composed by a set of 2D prescribed movement tests at the fairlead of the mooring system.