Search

Tale contributo è incentrato sull'analisi di una struttura multifunzionale per la protezione costiera e la produzione di energia elettrica, sviluppata dalla Seconda Università di Napoli e denominata DIMEMO (Diga Marittima per l’Energia dal Moto Ondoso). Questo dispositivo è stato pensato per essere integrato in frangiflutti portuali, anche esistenti, al fine di produrre energia per effetto del fenomeno della tracimazione. Le prestazioni idrauliche e strutturali sono state valutate in termini di: 1) portata media di tracimazione e coefficiente di riflessione in condizioni ordinarie; 2) pressioni agenti sulla struttura in condizioni estreme. I risultati sono stati ottenuti con il codice di calcolo IH-2VOF e confrontati con gli esperimenti di laboratorio condotti presso l’Università di Aalborg in Danimarca. Inoltre, il modello numerico è stato utilizzato per ottenere informazioni relative ai carichi ondosi sulla struttura in assenza di misure. Questo lavoro rappresenta uno studio preliminare, propedeutico ad un’analisi di sensitività atta a definire la relazione tra alcuni parametri geometrici fondamentali e le prestazioni idrauliche del dispositivo

Many of the most densely populated areas are located near the coast which is a vulnerable system, affected by erosion and flooding [18].In order to provide an efficient coastal management and coastal risk reduction, a fundamental knowledge of the hydrodinamic and morphodynamic processes in the coastal areas is needed. Numerical models are usually adopted to support long-term and short-term predictions. They need to a proper calibration/validation that is possible thanks to field measurements. XBeach [12] is used in this analysis as a tool to describe the morpho-dynamic coastal behavior. Thanks to a monitoring of a coastal stretch of the Emilia-Romagna littoral, at Cesenatico, it was possible a sensitivity analysis and a morphological calibration of the model.

• The OBREC is a multifunctional device to protect harbors and produce energy from incident waves. • The 2DV RANS VOF numerical model was calibrated on experimental results and adopted to assess the pressures across the structure. • The results of the calibrated model well reproduce the tested conditions for ordinary waves in terms of average overtopping discharge and uplift pressures.

The starting point for this paper is the recently developed formula for the shape parameter of the Weibull distribution of overtopping wave volumes at a coastal defence. This shape factor b increases with decreasing relative freeboard and was developed strictly for smooth and impermeable structures like a dike or levee. Data on overtopping wave volumes are available for rubble mound structures, but the distributions of the volumes have never been analysed jointly with smooth-slope distributions and have never been compared with the new formula for smooth and impermeable dikes. This paper describes the analysis of the Weibull b-value for conventional rubble mound breakwaters as well as for low crested structures with the crest at or just above the water level. These data are then compared with the trend for smooth structures. It is concluded that rubble mound structures show more scatter in the b-value than smooth impermeable structures, but the same trend is found. The combined data make even more sense if the b-value is related to relative discharge instead of relative freeboard because the effects of slope angle and wave steepness are implicitly included. An improved prediction formula is proposed representing permeable and impermeable structures.

This research is focused on testing the sensitivity of this model to its input parameters by verifying the effects on key output indicators for coastal managers, such as wave run-up, beach erosion, shoreline retreat and inundation. The model is applied to Cesenatico and calibrated based on the data measured during an extreme storm event, with the mid-term purpose of calibrating the model for the Emilia-Romagna coast, which suffers from subsidence, erosion and flooding.

This Overtopping Manual gives guidance on analysis and/or prediction of wave overtopping for flood defences attacked by wave action. It is primarily, but not exclusively, intended to assist government, agencies, businesses and specialist advisors & consultants concerned with reducing flood risk. Methods and guidance described in the manual may also be helpful to designers or operators of breakwaters, reclamations, or inland lakes or reservoirs. Developments close to the shoreline (coastal, estuarial or lakefront) may be exposed to significant flood risk yet are often highly valued. Flood risks are anticipated to increase in the future driven by projected increases of sea levels, more intense rainfall and stronger wind speeds. This risk may also increase by increasing value of assets in flood risk areas or by increasing number of people in such areas. Levels of flood protection for housing, businesses or infrastructure are inherently variable. In the Netherlands, where two-thirds of the country is below storm surge level, large urban and rural areas may presently (2016) be defended to a flood probability of 1:10,000 years or even minimum of 1:100,000 years, with less densely populated areas protected to 1:1,000 years with a minimum of 1:300 years. In the UK, where low-lying areas are much smaller, new residential developments are required to be defended to 1:200 year return. Understanding future changes in flood risk from waves overtopping seawalls or other structures is a key requirement for effective management of coastal defences. Occurrences of economic damage or loss of life due to the hazardous nature of wave overtopping is more likely, and coastal managers and users are more aware of health and safety risks. Seawalls range from simple earth banks through to vertical concrete walls and more complex composite structures. Each of these require different methods to assess overtopping. Reduction of overtopping risk is therefore a key requirement for the design, management and adaptation of coastal structures, particularly as existing coastal infrastructure is assessed for future conditions. There are also needs to warn or safeguard individuals potentially to overtopping waves on coastal defences or seaside promenades, particularly as recent deaths in the UK suggest significant lack of awareness of potential dangers. The first edition of the EurOtop (2007) was well received in the coastal engineering community and has been used as code for many projects. Guidance on wave run-up and overtopping before 2007 have been provided by previous manuals in UK, Netherlands and Germany including the EA Overtopping Manual edited by Besley (EA, 1999); the TAW Technical Report on Wave run up and wave overtopping at dikes by Van der Meer (TAW, 2002); and the German Die Küste (EAK 2002). Significant new information was obtained from the EC CLASH project collecting data from several nations, and further advances from national and other European research projects. Since EurOtop (2007), new information was established on wave overtopping over very steep slopes up to vertical, on better formulae up to zero relative freeboard, on better understanding of wave overtopping over vertical structures; including the effect of foreshores and storm walls; and on individual overtopping wave volumes. Furthermore, insight can now be given by systematic videos on how a specific overtopping discharge looks like in reality. These videos can be found on the website. This Manual takes account of this new information and advances in current practice. In so doing, this manual will extend and/or revise advice on wave overtopping predictions given in the Rock Manual (2007), the Revetment Manual by McConnell (1998), British Standard BS6349, the US Coastal Engineering Manual (2006), and ISO TC98 (2003).

Breakwaters under construction are prone to undesired reshaping because their core is not designed to withstand severe or moderate wave loads. While the reshaping of a finished breakwater was subject of comprehensive research, few studies dealt specifically with the reshaping mechanisms of a breakwater under construction, i.e. of the breakwater core. This paper presents a set of experimental tests focused on the reshaping of rubble mound breakwater trunks and roundheads undergone during the construction phase. The study accounts for oblique wave attacks and grading of the construction material. Better insights on how and how far such reshaping takes place are derived in the perspective of providing coastal designers and constructors with valuable information for optimising the selection of the fractions and volumes of the construction materials and for taking into account potential damages within the construction schedule and therefore additional costs.

European oceans will be subject to massive development of marine infrastructure in the near future. The development includes energy facilities, e.g. offshore wind farms, exploitation of wave energy, and also development and implementation of marine aquaculture This change of infrastructure makes the concept of multi-use offshore platforms particularly interesting. The development of new concepts requires effective marine technology and governance solutions. Simultaneously, both economic costs and environmental impacts have to remain within acceptable limits. These concerns are at the core of the MERMAID project funded under ‘The Ocean of Tomorrow’ call for proposals. At the end of the project, a set of specific guidelines are produced in order to assist future stakeholders within the offshore industries with a view to planning, establishing and operating their businesses in the most optimal way. The multi-disciplinary and cross-sectorial approach of this project is very innovative and the EU benefit lies in the case studies that address four EU-regional seas. MERMAID established close links with the other projects, TROPOS and H2OCEAN, funded under the same ‘The Ocean of Tomorrow’ topic in order to enhance complementarities and synergies.

Existing coastal management and defense approaches are not well suited to meet the challenges of climate change and related uncertanities. Professionals in this field need a more dynamic, systematic and multidisciplinary approach. Written by an international group of experts, Coastal Risk Management in a Changing Climate provides innovative, multidisciplinary best practices for mitigating the effects of climate change on coastal structures. Based on the Theseus program, the book includes eight study sites across Europe, with specific attention to the most vulnerable coastal environments such as deltas, estuaries and wetlands, where many large cities and industrial areas are located. Existing coastal management and defense approaches are not well suited to meet the challenges of climate change and related uncertanities. Professionals in this field need a more dynamic, systematic and multidisciplinary approach. Written by an international group of experts, Coastal Risk Management in a Changing Climate provides innovative, multidisciplinary best practices for mitigating the effects of climate change on coastal structures. Based on the Theseus program, the book includes eight study sites across Europe, with specific attention to the most vulnerable coastal environments such as deltas, estuaries and wetlands, where many large cities and industrial areas are located.

Coastal areas are important settlement zones and play a vital role in the wealth of many nations. Nearly 25% of the world's population lives within 62. miles (100. km) of a shoreline. Roughly 600. million people live in coastal regions that are less than 10. m above sea level, and this figure is likely to increase more rapidly (up to 50% over the next 25. years) than global population projections, reflecting coastal urbanization. Many of the world's largest cities are located at the coast (e.g., Tokyo, Guangzhou, Bangkok, Istanbul, London, Lagos, New York, Buenos Aires), and of course include critical infrastructures such as energy facilities, ports, and airports. Coasts are also home to important and productive ecosystems that are increasingly valued by society.

In this section, a number of case study sites show how, by developing a holistic view of the existing coastal flood system, assessment of the impacts of flooding and erosion can be carried out, further research needs identified and appropriate mitigation options selected.

Despite the fact that the wave energy is a large resource of energy, the wave energy sector has not still delivered a cost competitive solution. The structural design of wave energy device (SDWED) project aims at accelerating the development of the sector. The project gathers international research communities around the development of design tools and a common design basis for wave energy devices in order to make these devices more competitive. The prospect of an overall wave-to-wire model has the potential of lowering the cost of energy and increasing the reliability of wave energy devices.

It is increasingly recognized that a comprehensive understanding of the existing flood system is necessary to effectively manage coastal flood risk. This involves consideration of the social and ecological dimensions in addition to the hydrological aspects that have been the traditional focus of flood analysis. Social aspects are important, as they represent both the reason for flood management and the growth in exposure, as well as providing the context within which any decision will be made. Coastal species and habitats are inherently important for the flood management ecosystem services that they provide for flood management. The flood flow, depth, and extent determine the potential for flood damage. The conceptual model adopted here for coastal risk assessment is based on the Source-Pathway-Receptor-Consequence model, which is a simple linear conceptual model for representing flood systems and processes that lead to a particular flooding consequence. This approach is being used to evaluate how the Sources (waves, tides, storm surge, mean sea level, river discharge, run-off), through the Pathways (including coastal defenses), affect the Receptors (inland system), generating economic, social, and environmental Consequences. Collectively, this more holistic analysis of the flood system can identify likely trends in flood risk and the wide range of potential mitigation options embracing engineering, ecological, or socioeconomic measures, including hybrid combined approaches.

In this chapter, the issue of sustainable decision making for successful coastal flood management is examined. In this setting, a key concept is sustainable development, defined as a pattern of resource use that aims to meet human needs while preserving the environment so that these needs can be met not only today, but also for future generations. Sustainability for a given coastal system requires: (1) efficient protection to life and goods, and preserving socioeconomic development and opportunities of coastal areas; (2) maintenance of the environmental assets; and (3) short-, medium-, and long-term scenarios accounting for climate change effects. Different tools for sustainable decision making are presented. Design should be aimed at providing “continuity of daily life”—before, during, and after a flood, to avoid the detrimental social and economic impact that would otherwise result. A development that intrinsically provides flood resilience, through an adequate defense planning strategy, should give insurers and financiers the confidence to offer affordable, long-term policies, and investments. While planning coastal risk management strategies, coastal managers need to assess risk across a range of spatial and temporal scales. geographic information systems–based tools are one efficient way to support them in the decision-making process through a scenarios analysis starting from social, economic, and environmental information integrated into a common platform.

The Emilia Romagna littoral is located in the northeast of Italy and comprises 130 km of low and sandy coast, most of which are strongly urbanized. The Emilia Romagna beaches face the Northern Adriatic Sea, a relatively shallow epi-continental shelf with low tidal amplitude. A general erosive tendency is mainly caused by the reduced sediment transport rates of the rivers and by the increased anthropogenic subsidence. Subsidence, eustatism, and erosion of dunes pose a serious threat for coastal flooding. Cesenatico municipality is included in the province of Forlı`-Cesena. The site is famous for its marina and is a well-known tourist resort with a sandy beach rich in bathing facilities.

This paper attempts to summarize the current state of the wave energy converters worldwide, introducing the most promising devices to date and the governing processes behind their operation. This also includes an overview of existing and potential power take-off (PTO) systems for wave energy converters.