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Innovative coastal technologies for safer European coasts in a changing climate

Final Report Summary - THESEUS (Innovative coastal technologies for safer European coasts in a changing climate)

Executive Summary:
THESEUS project examined the development and application of innovative combined coastal mitigation and adaptation technologies generally aiming at delivering a safe (or low-risk) coast for human use/development and healthy coastal habitats as sea levels rise and climate changes (and the European economy continues to grow). The primary objective was to provide an integrated methodology for planning sustainable defence strategies for the management of coastal erosion and flooding which addressed technical, social, economic and environmental aspects accounting for climate change effects.

Main outcomes of the project are the following.
• Development of a holistic approach to assessing and managing coastal flood risk (WP 1)
A comprehensive understanding of the existing flood system to effectively manage coastal flood risk was developed from the Source-Pathway-Receptor-Consequence model. This approach was used to evaluate how the Sources (waves, tides, storm surge, mean sea level, river discharge, run-off), through the Pathways (including coastal defences), 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 socio-economic measures, including hybrid combined approaches.
• Development of technical innovation and best practices in coastal engineering(WP 2)
THESEUS studied the resistance of grass covered sea dikes, as well as methods for upgrading conventional rubble mound coastal structures, the use of artificial reefs as a wave dampening structure, and best practice for beach nourishment. THESEUS also systematically analysed the use of floating wave energy converters for coastal protection purpose.
• Promotion of the preservation and enhancement of coastal ecosystems (WP 3)
THESEUS demonstrated how adopting a systems perspective allows the process understanding of habitats to be integrated with coastal engineering and social aspects of flooding to augment and increase the options available to flood risk managers, and be compliant with the Habitats directive.
• Increase community resilience through the governance dimension (WP 4)
THESEUS analysed risk perception in terms of paradigmatic tensions associated with conflicting pertinence, normative and evidence claims. As such, THESEUS allowed for the clear identification of norms as the main source of varying perceptions regarding coastal risks. THESEUS also developed a simplified model of insurance taking explicitly into account spill-over effects, which has allowed for a rethinking of the issues of scales and linkages, beyond the private/public dichotomy.
• Development of tools to support decision makers in sustainable coastal management (WP 5)
THESEUS developed a powerful tool to help decision makers in defining optimal strategies to minimize risk in the short, medium and long-term scenarios. The resulting software reproduces in a simplified way the most relevant physical processes (coastal erosion and flooding) induced by waves and sea-levels taking into account physical and non-physical drivers, such as climate change, subsidence, population growth and economic development.
• Dissemination of project results (WP 6)
THESEUS dissemination activities were organised on a 360° basis to meet the needs of the scientific community, the coastal managers, the policy makers and the public at large. These activities training events for coastal managers, policy briefs related to the Flood, Habitats and Water directive, a Science-Policy final event in Brussels that was synthesised in a conceptual paper, multimedia material (videos, webinars) disseminated through the project website, informative booklets, a 18-papers fully interdisciplinary special issue on Coastal Engineering “Coasts@Risk: THESEUS, a new wave in coastal protection” (Volume 87, May 2014) and a book “Coastal risk assessment and management in a changing climate” to be published by Elsevier in 2014.

Project Context and Objectives:
Coastal areas are great zones of settlement and play a vital role in the wealth of many nations. Nearly 25% of the world’s population lives within 62 miles (100 kilometers) of a shoreline and many of the world largest cities are located at the coast. Coasts are also home to important and productive ecosystems which are increasingly valued by society.
Large coastal stretches are already exposed to erosion and flooding worldwide, and all the available assessments up to the IPCC Fourth Assessment show that they are threatened by sea-level rise and climate change in a variety of ways. Most recent storms have been very economically disruptive due to flooding, e.g. Hurricanes Katrina (2005) or Sandy (2012) in the USA, and Typhoon Haiyan (2013) in the Philippines.
Climate change combines with and amplifies non-climate stressors on coastal systems. Intense development and overpopulation, poverty, internal conflict, fragmentation and loss of habitat, over-fishing, pollution, and spread of invasive species will impair the resilience of ecosystems, i.e. the ability of the ecosystem to maintain its integrity and to continue to provide critical goods and services to coastal communities, for example, fisheries, storm protection, erosion control, water storage, groundwater recharge, pollution abatement, and retention and cycling of nutrients and sediments. Weakened, unhealthy ecosystems are less resilient to climate change and variability and coastal flood risk may rise.
While in the media and the public mind, coastal floods and erosion are often seen as unnatural and non-allowable, they are natural occurrences, and no amount of investment can reduce risks to zero – residual risk will always remain and society needs to define the acceptable level of this residual.
Traditional technical flood and erosion defences have shown their limits. First, traditional coastal defences had to cope with their impact on the environment: in recent years, greater attention had been paid to the design and selection of coastal defence structures and technologies based on an integrated analysis of their performance and on their environmental and socio-economic implications.
Moreover, what society expects from defences is changing (e.g. widespread moves from hard to soft defences to ‘hold the line’), and these needs will continue to evolve (e.g. the potential for widespread application of surf reefs), and at the same time, climate change is increasing risks.
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 defence planning strategy, should give insurers and financiers the confidence to offer affordable, long-term policies and investments.
Within this context, THESEUS project (“Innovative technologies for safer European coasts in a changing climate”, was launched in December 2009 thanks to the support of the European Commission through the Contract 244104. THESEUS Consortium included engineers, marine ecologists, sociologists, economists, meteorologists and GIS specialists who worked together for 48 months.
THESEUS partners come from all over Europe, including 12 Member States, so that different environmental, socio-economic and climate conditions were considered, balanced between areas exposed to high present risk (North Sea and Atlantic coast) and areas more exposed to future changes (Baltic and Mediterranean Seas). Moreover, since climate change already affected or is going to exacerbate conditions across many coastal areas of the world, international cooperation was realised through the inclusion of 4 International Cooperation Partners (Russia, Ukraine, China, Mexico) and 2 Third Countries (USA, Taiwan).
THESEUS examined the development and application of innovative combined coastal mitigation and adaptation technologies generally aiming at delivering a safe (or low-risk) coast for human use/development and healthy coastal habitats as sea levels rise and climate changes (and the European economy continues to grow).
The primary objective was to provide an integrated methodology for planning sustainable defence strategies for the management of coastal erosion and flooding which addressed technical, social, economic and environmental aspects accounting for climate change effects.
The overall strategy of THESEUS was to learn from the experiences in selected study sites (8 sites overall Europe: Po Delta and adjoining coast, IT; Schedlt estuary, BE/NL; Gironde Estuary, FR; Hel Peninsula, PL; Teign estuary, UK; Elbe estuary, DE; Santander Bay, ES; Varna coastal area, BG), to develop innovative “climate proof technology” and to propose an integrated approach for selecting among these technologies the proper mitigation option in the study sites. This overall strategy allowed:
• strong relation with end users and coastal managers
• continuous feedback between research and practice
• high quality of scientific research on innovative technologies
• real improvement of safety and economic development in given coastal areas.

The research activities consisted of new field sampling, physical model tests, numerical modeling, software development, literature review, and they were divided into the following Work-Packages (WPs):
• WP 1. Risk assessment, policy, management and planning strategy in study sites
• WP 2. Mitigation of flooding/erosion hazard: innovative coastal structures and sediment management
• WP 3. Ecologically based mitigation measures and design
• WP 4. Impact mitigation: society and economy
• WP 5. Risk mitigation options and tools for defence planning strategies in study sites
• WP 6. Project dissemination
• WP 7 Project management

The structure of the project, consisting of two integrated platforms in time series, WPs 1 and 5 (i.e. from where the analysis started and to where the scientific results were collected), and of three sectorial WPs running in parallel (WPs 2, 3, 4 –engineering, ecology and socio-economics), assured both an in-depth investigation within each discipline and and high-level integration of the project perspective and results.
The main objective for WP1 was to define the current risk conditions within the eight case study sites using a common conceptual approach – the Source Pathway-Receptor-Consequence (SPRC) flood system framework. Each Work Task focused on one aspect of the flood system with the aim of achieving a comprehensive overview for each site. This includes consideration of the existing physical flood system (climatic, hydrodynamic and ecological), existing coastal management, local planning and policy and the social perception of risk.
The work of WP2 was aimed at analyzing hydrodynamics and morphodynamics induced by innovative defence systems, such as wave energy converters placed near-shore, or upgraded and improved structures, such as multi-purpose coastal defences characterised by low environmental impact, floating structures, dykes, nourishment, dunes, and mud and sand banks in relation to dredging and operations. These defences were examined by means of new physical an numerical models under different climate scenarios to address the sensitivity to climate change issues such as sea level rise and increased storminess.
The main objectives of WP3 were to conduct field work surveys and experiments across the THESEUS study sites and carry out desk-based reviews in order to: A) examine the role that natural habitats play in coastal defence for example by quantifying wave attenuation across saltmarshes and biogenic reefs. B) Examine approaches for the management and restoration of these habitats under rising sea levels and a changing climates, for example by evaluating the conditions required for saltmarsh propagation. C) Consider the ecology of engineered coastal defense structures and examine ways in which the ecological consequences of hard defences can be modified, for example by incorporating different habitat features into the design of the structures. D) Contrasting the ecological consequences of different management strategies including hold the line (using both hard and soft features), managed realignment and “do nothing” .E) Consider ecological effects of coastal defence in relation to other anthropogenic stressors.

WP4 focused on two elements. First, WP4 developed a coherent portfolio of approaches to increase the resilience to flood and erosion. This portfolio includes ground tested approaches pertaining to insurance scheme, land use planning, business recovery, post crisis management, risk communication and evacuation. Second, for each of these approaches, governance options were generated in a locally assessable format for integration into the THESEUS Decision Support System in WP 5. A double level of uncertainty was taken into account: uncertainty about future climatic state, thus the focus on resilience as the key paradigm, and uncertainty in terms of future available technological options, thus the focus on governance.
As with regards WP5, its main objective was to provide verified methods and an integrated set of calibrated tools that can be used along most European coasts by stakeholders for planning coastal risk assessment and mitigation. An integrated methodology for the selection of the best combination of the mitigation options into a strategical defence plan that accounts for environmental, social, economic and engineering aspects was developed. The methodology was implemented in THESEUS Decision Support System GIS based tool, which was applied and calibrated in 4 sites (Cesenatico, Italy; Gironde, France; Teignmouth, United Kingdom; and Santander, Spain). The exploratory tool (available through the dedicated page on the project website) allows the users to perform an integrated coastal risk assessment, to analyse the effects of different combinations of engineering, social, economic and ecologically based mitigation options, across short (2020s), medium (2050s) and long term (2080s) scenarios, taking into account physical and non-physical drivers, such as climate change, subsidence, population and economic growth.. The holistic approach for risk assessment and management developed jointly by WPs 1 and 5 was delivered through a book to be published by Elsevier by the end of 2014, “Coastal risk assessment and management in a changing climate”.
The main objective of WP6 was to disseminate the results of the project and to establish an efficacious collaboration and exchange of knowledge and experiences between the coastal scientific community, coastal authorities and potential end users. The interdisciplinary special issue “Coasts@Risk: THESEUS, a new wave in coastal protection”, composed by 18 papers, has been delivered and is in press on Coastal Engineering, Elsevier (Volume 87, May 2014). THESEUS results were synthesized for policy makers in a set of policy briefs, drafted on the basis of a template provided by the Commission and disseminated through the project website ( THESEUS final event ( was held in Brussels on October 18th, 2013. The conference was attended by over a 100 participants, of which a fourth were end users, including coastal managers, decision makers and policy makers. The conference was the occasion not only for the presentation of the most relevant results of the project but also for the discussion around working groups of weak points and actions to be taken for improving three key issues addressed by the THESEUS project: risk assessment, risk mitigation, science and policy integration. A conceptual paper was drafted and delivered through the website ( together with all the event proceedings. The most relevant news and project outcomes were regularly disseminated through a mailing list and the project website by means of periodic newsletters ( To promote dissemination within the public at large, videos, multimedia material, webinars and press papers about the project were also delivered through the project webpage, including a video prepared in cooperation with Euronews and webinars done by the Coordinator in cooperation with the FP7 project InnovationSeeds.

Project Results:
The aim of WP1 was to assess present risk conditions in the eight Theseus sites taking into consideration the social, ecological and hydrological aspects of the flood system, providing baseline data and information for the Decision Support Tool (ODs 1.7 and 1.15). This was a fundamental foundation for the all the work in the rest of the project. This entailed establishing the current policies and defense strategies at each site, local stakeholder awareness and perception of risk, the resilience and vulnerability of coastal habitats and the generation of present and future flood maps in response to the effects of climate change (and no change in management).
Underlying the approach was the use of the Source-Pathway-Receptor-Consequence (SPRC) conceptual model which defines the current flood system and the influence of external Drivers such as climate, socio-economic and environmental change on that system. Each of the case study sites developed their own SPR diagrams following guidance from WT1.3. The model provided a useful framework and discussion tool to develop a shared understanding of the flood system by describing and formalizing the concept and its application, and defining the wide diversity of information needed to carry out an appropriate flood assessment. It facilitated stakeholder and inter-disciplinary interactions, providing a clear view of how the flood system was being interpreted and management incorporated. It also helps each discipline to recognize their role in the process and where interactions would be beneficial to the overall flood assessment. The development of the SPR diagrams also helped identify flooding issues for individual sites as well as commonalities across the range of coastal situations.
A key aspect of flood system management is their governance and the perception of flood risk by those potentially affected. WTs 1.1 and 1.7 devised questionnaires and organized group and individual interviews in all of the case study sites. The results of this work showed that existing flood policies and defense design reflect the importance of flood risk relative to other risks in the study sites and this is largely based on experience with flood events. All of the sites have complex institutional structures for flood management with responsibilities found at local, regional and national as well as international levels. Horizontal and vertical cooperation across these structures is essential for successful management, but is not always achieved. For those potentially affected, communication of the science, inclusion in the decision-making process and trust in decision-makers are essential. These interviews also showed an important disparity in the understanding of the concept of risk between scientists and local stakeholders. For the latter group, probability is often not understood – and risk is interpreted as the consequences. It was also found that risk is established by the interviewees using a mixture of expert-based knowledge and personal heuristics. These issues can be best addressed through an ongoing proactive integration of the stakeholder’s experience and values throughout the science based appraisal process. It is therefore recommended that this stakeholder analysis is included in flood risk assessments.

WP1 also made first steps to assist with the inclusion of ecosystems within the flood assessments and Decision Support Tool. WT1.5 carried out a review of coastal habitats considering their functioning in response to flood events and abilities to moderate flood waters. This showed that impacts are diverse and difficult to predict as some changes can result in complete habitat loss, while other habitats are capable of a complete recovery following a similar event. In conjunction with the deliverable on other factors affecting vulnerability and resilience, this information was incorporated into an expert-based methodology for assessing the vulnerability of habitats to flooding (Ecological Vulnerability Index - EVI). As part of this process, mapping of habitats in the case study sites was carried out. The WT also looked at the influence of pollution and debris, including the identification of major sources, and the ways by which these waste materials can be remobilised, transported and relocated to the coastal and marine environment during flood events.
For the more quantifiable aspects of WP1, WT1.2 provided a central, searchable, repository for current and future meteo-marine meta-data for the eight case study sites. This included factors such as (i) mean sea-level rise based on historical data and future conditions, (ii) a large-scale temporary rise of the sea surface caused by high winds and low atmospheric pressure (usually referred to as storm surges), and (iii) extreme wind-generated waves caused by high winds. This provided, for the first time, a consistent data base from which recent and potential future changes could be estimated and which allowed for inter comparisons between the different study sites. Results show that mean sea-level changes appears to be the most relevant factor contributing to observed and potential future changes in extreme sea levels, while changes in other components (such as the wave or storm surge climate) were found to be small and/or highly uncertain. For some sites, processes unrelated to climate change (such as subsidence caused by fluid extraction) may be more relevant, most especially in the North Italian coastal plain. Using available data in the Scheldt estuary, an analysis of uncertainties associated with extreme water levels including the effect of climate change on river flows was also conducted (WT1.6). Following this, WT1.3 looked at assessing the relative effect on risk of future changes in the Sources of flooding (OD1.10). A ranking methodology based on risk multipliers was used to identify the relative magnitude of the components of extreme water level on flood risk. It was found that, for most sites, sea-level rise had the greatest influence on levels of flood risk, particularly in the medium to long term. This methodology could be easily applied to other external Drivers of the flood system such as socio-economic change and also shows that each Driver can be successfully separated into its component parts and their effect estimated individually or in combination.
Using the information generated in the other WTs, WT1.4 generated flood extent maps for each site and for four time periods (current conditions, 2020s, 2050s and 2080s). These considered engineering, oceanographic, climatological, statistical and geographical issues. A common methodology was developed, following the SPRC conceptual model, although the detailed flood and inundation models used varied according to local expertise, model availability and data acquisition. As a result of the flood modeling carried out, variations in temporal and spatial scales (particularly with estuaries), the definition of the met-ocean parameters, the different statistical tools, the numerical and empirical flooding and erosion models available were addressed in each site. It was found that quantitative estimation of flood extents is highly dependent on the quality and resolution of the data considered (e.g. topography, coastal marine dynamics, and defense details) with the final result conditioned by the element which has the lowest resolution. An important result of this task was the assembly of knowledge from the many disciplines required to estimate flood extents and, following the results of WT1.7 it was recognized that the communication of model outputs, especially probability, needs to be developed further. The use of flood extent maps was developed further in WT1.6. In the Gironde estuary, research aimed to improve emergency management by providing authorities with comprehensive action plans and real time flood maps. A prototype early warning system developed using a 2D numerical model of the estuary to compute present and future flood risk maps. These are combined with OSIRIS (created as part of the OSIRIS FP5-IST project) to translate flood forecast data into a list of concrete response actions. The prototype is able to manage the most interchangeable formats among GIS software and tools and has shown it is able to provide appropriate information to those responsible for emergency response and coordination.
As part of the overall understanding of the flood system, the WP also considered the uncertainty within the natural functioning of the coast. WT1.6 investigated innovative methods of assessing environmental change in three sites. In the Po delta, a method to measure the temporal evolution of coastal morphology was developed using an integrated remote sensing approach. The methodology combines and compares measurements of subsidence and vegetation change with the aim of using vegetation changes as a proxy for the impacts of subsidence. Results suggest that subsidence rate maps obtained using DInSAR techniques, integrated to the hyperspectral mixing space, can provide a quantitative parameter to improve the monitoring approach for coastal areas which could be used widely across Europe. In the Scheldt estuary, an integrated remote sensing approach based on satellite multispectral imagery was applied to study the evolution of salt marsh vegetation with respect to channel network morphology. These two parameters are connected to the state of erosion and flooding of coastal ecosystems, and thus were integrated with the hydrological forcing that typically affects them. Results can provide a baseline for the triggering role of extreme events in shaping the dynamics of intertidal systems. The synoptic remote sensing method was also applied on the Erme estuary, UK, to monitor the temporal dynamics of both biotic and abiotic factors in estuarine and coastal ecosystems. These two investigations showed that ecological and morphological parameters can be integrated to identify dominant processes and trends in coastal landscapes. In South Devon, UK, an extensive set of remotely sensed video images recorded at Teignmouth were used to assess the morphological evolution of intertidal sandbanks formed at the distal end of the Teign estuary. The methodology showed that bar migration rates are strongly correlated with the ratio of offshore wave height to the local water depth over the bar; that is large waves breaking on a shallow bar produce rapid shoreward migration of the bar providing an explanation as to why migration rates accelerate as the bar moves into shallower water.
In conclusion, WP1 provided a sound foundation for the Theseus project. As a result of the multi-disciplinary work in WP1, the researchers contacted, contributed to and maintained relationships with multi-disciplinary teams and stakeholders in each site. The challenges of cross-disciplinary understanding and use of language provided the impetus for valuable research discussions to the benefit of the work carried out. In addition to achieving all deliverables within the project, WP1 also produced two guidance notes, Journal papers, and presented papers at a number of international conferences.

The general aim of WP2 is the development of innovative methods for mitigation of flooding and coastal erosion hazard in the context of increasing storminess and sea level rise.
The WP analyses both hard and soft technologies to increase coastal safety
• by reducing incident wave energy with a totally innovative solution, wave energy converters placed near-shore (WT 2.1) and with multi-purpose coastal defences characterised by low environmental impact, as artificial reefs (WT 2.2) and floating breakwaters (WT2.4);
• by increasing wave overtopping through an innovative dike reinforcement or by increasing wave overtopping resistance, through improved stability of dike inner slope and use of dike covering layers (WT 2.3);
• by upgrading breakwater armour and crown elevation of existing defences to account for sea level rise (WT 2.5);
• by stabilising coastline with beach maintenance, through planning of dredging and nourishment operations, management of borrow areas and reactivation of the littoral drift (WT 2.6).

WT2.1: Barriers for wave energy conversion
WECs are placed in highly energetic seas to harvest energy. In the view of THESEUS wave energy converters are proposed as coastal protection. Prior to THESEUS many wave energy converter designs have been tested in physical models in order to evaluate and optimize the energy production. However, in the view of THESEUS wave transmission is also very important so new tests were needed focusing on measuring the wave transmission of single floating wave energy converters. Wave Dragon, DEXA, SeaBreath and Blow Jet were the devices selected for these physical model test studies.
A single device reduces the wave height only locally behind the device. Due to diffraction and directional spreading the energy spreads and, at the coastline, a single device would have only very limited effect. Therefore, a park of devices will usually be needed to protect a stretch of a coastline. The array configuration will be a compromise between coastal protection and cost of produced energy as for example wave reformation can occur behind the devices if placed too far offshore. The wave height variation behind a park of devices has been calculated with numerical wave propagation models (Mild Slope and Boussinesq models). In these models the devices have been implemented with the transmission properties from the physical model tests. Arrays have been designed and evaluated with the numerical models in the relevant sites (highly energetic seas). The simulations show that if the array configuration is chosen wisely (staggered grid) then the second row of devices addresses almost the same amount of available power as the front row and leads to a more compact layout and more dampening of the waves at the coastline.

WT2.2: Innovative submerged structures
WT2.2 activities have been focus on the ability of different innovative structures to dissipate wave energy in order to be used as an alternative to protect the coast. The working group has used three different approaches: prototype observations, experiments and numerical modeling. In terms of prototype observations, useful information has been obtained by the study of vertical barriers to protect the coast from ship-generated waves. Venice lagoon existing structures was used as motivation. Several barriers were studied, providing useful design tools. The efficiency of nonconventional submerged structures has been compared with traditional low crested structures by means of scaled laboratory test. Additional studies were accomplished to determine the beach profile evolution according to different nonconventional submerged structures. According to the analysis performed on natural barriers wave damping created by submerged plants has been analyzed, on several oceanic species (Posidonia Oceanica, Halodule Wrightii and Thalassia Testudinum), and salt marshes (Spartina Maritima, Spartina Anglica and Puchinelia) by means of small and large scale experiments. Their ability of reduce wave and current energy has been parameterized. This work has been carried out in collaboration with WT3 in order to reinforce the output with ecological factors to be considered in the design. Numerical models based on Navier-Stokes equations have been first calibrated for the different species and their algorithms updated to be used as predictive tools. The work in WT2.2 has been completed with the morphological analysis of the far and near field, to analyze changes in the shoreline. Attending to different detached breakwater configurations, the shoreline evolution has been determined. Several recommendations about the detached breakwater configurations have resulted from the analysis. Recommendations and best practice rules arisen from the research developed in WT2.2 has been incorporated to the guidelines. Wave damping parameterization, for both artificial and natural innovative submerged structures, has been also used to take part of the DSS.

WT2.3 Overtopping resistant and over-washed dikes
An accurate prediction of wave overtopping is required in order to assess vulnerability and resilience of for example dikes and breakwaters. The variation of wave and sea level conditions due to climate change introduce additional uncertainties in dike or breakwater design, mainly due to the reduction of the freeboard of the structures and to the increment of wave energy. Within WT2.3 effort is made to extend knowledge on parameters known to be important in processes ultimately leading to failure. Experience from especially the Netherlands has shown that dike breaches are often caused by wave overtopping, which can provoke erosion on the dike crest and inner slope. Wave overtopping and the related overtopping flow parameters, such as the flow depth and the flow velocity across the dike, are therefore important design parameters for such structures. In WT 2.3 the existing semi-empirical formulae were extended to cover also oblique and short-crested waves. Also numerical models were developed and calibrated to simulate loads on the crest and inner dike slopes.

Achievements compared to pre-existing knowledge:
• Extension of the existing 2D-formulae for predicting the flow velocities and the flow depths at the crest and landward slope of a typical dike geometry to account for wave spreading and obliquity;
• Specific results from physical model test showed that: overtopping flow parameters are reduced for short-crested waves compared to long-crested waves; the flow is significantly reduced for large wave obliquities and the flow direction on the dike crest is similar to the incident wave direction;
• The extended three-dimensional formulae can be used in combination with knowledge on e.g. critical flow velocities for the assessment of the dike resilience against wave overtopping on existing dikes structures.
• No works in literature dealing with numerical modelling with fully 3D RANS models were available in literature at the time the project began. Several aspects, such as oblique wave generation and absorption were implemented in the numerical model to get a predicted tool to cover the objectives. The use of this approach is a clear advance in the field of coastal engineering to study further aspects related with wave overtopping.
• The Wave Overtopping Simulator (WOS), used for field measurements, and the associated wave propagation over the landward slope of a coastal dike was simulated, for the first time using unsteady RANS equations in conjunction with a turbulence model and a VOF method for tracking the free surface variation. An air-entrainment model was also included for simulating the air entrainment process during wave propagation. Comparison of numerical results with field measurements indicates satisfactory agreement and the potential for using a numerical model for such a complex phenomenon.
• The results indicate, as expected, that the overtopping increase in a nonlinear way with wave height, and decrease with the larger incidence angle. The effect of wave period has to be further analysed, as no clear conclusions can be extracted from the study. The fact that the breakwater is porous instead of impervious makes also a noticeable effort in decreasing the overtopping discharge.

WT2.4 Floating breakwaters
Floating breakwaters (FBs) were investigated in order to examine their ability to protect coastal areas (open sea, in mild wave conditions) and to protect delicate ecosystems in a lagoon environment (marshes, tidal flats, etc) against the wave action.
An inventory of all existing typologies pointed out that some FB type and geometries, not sufficiently investigated, may have had a large potential as mitigation option for coastal protection. Physical model tests were than performed in order to fill these gaps, focusing geometries that may be pre-fabricated, to reduce costs and impact at construction phase. On the other hand, very large or very small structures, floating islands or mat-type FBs, were considered unsuited to Theseus case studies.
Based such tests, numerical investigations and literature results, new simple formulae were developed that could predict with good and controlled accuracy the transmission and dissipative characteristics of fixed and floating FBs. These were inserted in the DSS and appear be essential to evaluate of the efficiency of any mitigation options based on FBs. Two approaches were proposed. A linear regression of all results and an approach based on the correction of the Macagno formula. It is worthwhile mentioning that the latter approach pointed out that efficiency is strongly related to the natural period of oscillation, and this observation has practical implications on design.
Tests carried out in the Venetian lagoon at prototype scale, were analysed and the wave attenuation induced by a specific type of FB compared to traditional fixed structures was found. FBs are not extremely effective but in some cases they are more suited than fixed structures due to the invariance of the response to SLR. The observed attenuation is sufficient for a lagoon environment.
Other experimental investigation focused on an innovative type of permeable FB, schematically represented as a cluster of pipelines aligned in direction of the incident waves, suited to dissipate short wave energy in lagoon environments. A simple model was calibrated to interpret the results.

WT2.5 Upgrade of existing defences
Work Task 2.5 focuses mainly on maritime rubble mound breakwaters attacked by waves and built with quarry materials. Reinforcement consists in changing superstructures and armour layers. If MSL rise is 1 m, it has been shown by CETMEF that the crest of these structures will have to be heightened between 2 and 3 m in order to keep the same overtopping volumes. Moreover the structures will have more severe damages and mass of the armour units will have often to be doubled. Probabilistic design moderates the conclusions because it keeps into account the whole set of events including in particular shoaling waves. Cost Benefice Analysis applied in Le Havre shows that reinforcement is economically justified with a 1 m MSL rise. The Reliability Based Design used by AUTh determines the most economic strategy taking into account the costs of construction and failure. It differs from the Probabilistic Design used by CETMEF where the required hydraulic performance is given.

At AAU comparison has been made between measurements from model test and estimations for horizontal wave loads and individual overtopping waves on crown wall superstructures from state of the art design formulae for horizontal wave loads. From the comparison it was concluded, that the existing formulae were performing very well in deep water wave conditions. However, in shallow water depth limited waves, the design formulae were seen to be significantly overestimating the wave loads on the crown wall and underestimating the number of overtopping waves. Modified design formulae were used to evaluate the relative influence from the MSL rise on typical crown wall superstructures in terms of increased wave loads and increased wave overtopping. From the study it was concluded, that especially the shallow water structure was influenced by the MSL rise due to the increase in maximum wave heights as a result of the rising water level. When evaluating the modification options for increasing the crest height of the structure, it was concluded that when only heightening the crown wall a very big increase was observed in the wave loads. If the crown wall was heightened in combination with an extra added layer of armour units to the breakwater, only a relatively small increase in wave loads was observed. Bigger wave loads were obtained for the parapet wall compared to the loads on a plain crown wall. The overtopping wave volumes were seen to be slightly reduced by the parapet compared to the crown wall in small overtopping conditions. Physical tests have been performed in a wave flume at AAU in scale 1:30 on two different rubble mound breakwaters designed for deep and shallow water wave conditions. CETMEF has studied in a wave flume at Le Havre University in scale 1:30 the modification of armour layers to cope with wave overtopping and armour stability after MSL rise.

A VARANS-type model, called IH2-VOF, has been used by UC to study wave-structure interaction for coastal structure re-shaping geometries in wave overtopping and hydraulic loads. Numerical tests show that increasing the length of the berm reduces the mean overtopping discharge as expected. The same trend has been observed when freeboard reduces or even becomes emerged. A greater reduction has been observed for the emerged berm. The influence of the berm has been observed to decrease when the mean wave period increases. The influence of the rise of the crown-wall level has been detected in the mean overtopping discharge. Larger reductions have been observed for both smaller wave heights and wave periods.
[06/02/14 15:58:46] Arianna Morelli: Concerning breaches in groins it appears from field surveys and theoretical modelling that they usually generate negative hydrodynamic and morphodynamic effects in the nearshore zone. Within a system of groins, where gaps between the groins are much bigger than groins length, additional groins constructed in such locations are likely to mitigate the sand erosion.

WT 2.6 Coastline and beach stabilisation (nourishment, dredging operations, borrow areas, sandbanks)
The activities of this task dealt with shore protection by use of “soft” coastal engineering solutions. The state of the art review, elaborated on the basis of literature studies and participants’ experience, ensured identification of some gaps in the know-how. The initial activities aimed at filling in these gaps comprised theoretical in-depth studies on nourishment/dredging operations and managed realignment, numerical modelling of coastal and estuarine hydro-, litho- and morphodynamic processes, as well as experiments in field and laboratory. Numerous precious preliminary findings were provided, mainly by investigations carried out with respect to the project study sites. As described in the 18th month activity report, new light has been shed on a few issues, e.g. optimisation of dredging-nourishment operations, beach reshaping under storms, sediment deficit on the shore profile due to anticipated sea level rise, long-term morphodynamics of sandy shores in conditions of a changing climate and sedimentation patterns in the estuary caused by the tidal hydrodynamic asymmetry.

Then the studies concentrated on the following problems: optimal nourishment maintenance, long-term evolution of the nourished seashore, evolution of the artificial beach during storms and beach resilience to erosion, nourishment efficiency, optimisation of combination of nourishment and dredging operations (alternative sources of sand), reduction of tidal flood threats by artificial sandbanks in the tidal estuary, influence of underwater excavations on nearshore hydrodynamics and lithodynamics, silting-up of waterways and its effect on local grain size distributions, as well as impact of the turbidity maximum on tide propagation in the estuary. These investigations (reported in 19-36 month activity report and in the project deliverables, as well as described in scientific papers) comprised the following issues: assessment of artificial shore nourishment efficiency and lifetime, together with optimisation of initial nourishment volumes and grain sizes, optimised location of sediment placement (submerged versus emerged) and the borrow areas, criteria for applicability (profitability) of sand accumulation fences, findings concerning coexistence of groins and nourishment, assessment of the estuarine morphological change, feasibility of construction of artificial sandbanks in the river mouth, interrelationships between the turbidity maximum and tidal hydrodynamics, a generic bottom roughness and friction model for fully-developed turbulent flow down to the bottom into the transient and viscous boundary layers. The most significant results were next applied the final outputs of the project: Guidelines (WT5.5) and DSS (WT5.6).

WP3 was completed on time with all deliverables (ID3.1 ID3.2 ID3.3 ID3.4 ID3.5 ID3.6 ID3.7 ID3.8 ID3.9 and OD3.10) achieved. Results of WP3 as a whole are presented in OD3.10 “Integrated report on ecological outcomes of alternative management strategies”.
Since the completion of the WP3 deliverables our work has focused on translating results from WP3 to WP5 deliverables. Chapter 4 of the THESUES Guidelines book titled “Ecological approaches to coastal risk mitigation” has been also delivered. Results from WP3 have been translated to the DSS specifically focusing on the Environmental Vulnerability Index (EVI) that was developed to categorise the vulnerability of different coastal habitats to sea level rise and an increase in magnitude and frequency of storm events. Coastal habitats that an EVI has been developed for include: grasslands, deciduous woodlands, pine woodlands, sand dunes, sub-tidal hard substrates, rocky shores, Sabellaria reefs, mussel beds, oyster beds, soft bottom sediments and seagrass meadows.
WP 3 has contributed 5 manuscripts to the THESEUS special issue in Coastal Engineering, which are now in press. More generally, there are 30 published manuscripts from within WP3.
WP3 itself focused on 5 broad areas: 1) the role of natural habitats in coastal protection, 2) the management and restoration of natural habitats, 3) ecological considerations in the design of coastal defence structures, 4) ecological consequences of alternative coastal defence options and 5) effects of multiple ecological stressors.
Key Results
WT3.1 investigated the role of natural habitats in coastal protection. Extensive attenuation measurements were made over intertidal habitats, including mussels beds, oysters reefs, Sabellaria reefs, and salt marshes. Significantly we found that wave attenuation by salt marshes under differing exposures to wave action and tidal regimes from sites in Europe and China (SKLEC, BU, SOTON, NIOZ) are fairly similar. 39-92% of the wave energy can be attenuated within the first 25 meters from the leading edge of the marsh and this is dependent on vegetation structure, type and water height. These data sets allowed us to evaluate the role of such habitats in coastal protection and give a rank order of attenuation. In general, this data shows that habitats that are higher in the intertidal are more important for direct attenuation of dynamic storm events, compared to habitats located at lower inter-tidal elevations. Still, low-tidal habitats can contribute indirectly to stable coastal defence configurations through substrate stabilization, which reduces wave-exposure on the long-run providing suitable conditions for higher-elevation habitats. The importance of below-ground biomass for sediment stabilization by coastal vegetation has been demonstrated. Results showed that even intensively grazed seagrass meadows with hardly any canopy can still stabilize soft bottom environments and thereby enhance wave attenuation. These conclusions represent a significant advancement in our understanding of the role of intertidal habitats to coastal protection. These results are discussed in OD3.3 and ID3.4 lead by NIOZ (formally KNAW).
We completed a database on the distribution of dunes and salt marshes at an EU scale and of biogenic reefs at the various study sites (summarized in ID3.1 led by EID). This database allows us to identify potential locations where soft-mitigation options (use of sub-, inter- or supra-tidal coastal ecosystems for coastal defence) might be a reasonable option. Furthermore, the data can be used for modelling of habitat suitability and examples of this have been developed for the Scheldt (NIOZ) and Santander Bay (UC). Subsets of these data were used to relate habitat requirements to occurrence. Subsequently, spatial indicators were developed to provide tools to assess long-term stability and resilience to forcing by waves, tidal currents or grazing and show potential use for other coastal ecosystems that are important for defence (e.g. dunes, mussels and oysters). These indicators are based on results from analysing patch-size distributions and spatial autocorrelation and variance. These methods are relatively easy to employ and are of low-cost. For example, with salt marshes it was shown that the spatial structure of the vegetation can influence current velocity and wave exposure, indicating the potential for (re-) establishment and long-term stability, which is essential to assess if these ecosystems can be used as part of the coastal defence. These results are discussed in OD3.3 and ID3.4.

The management and restoration of natural habitats was investigated in WT3.2 focusing on salt marshes, primarily due to their importance for wave attenuation as discussed above along with sand dunes. The restoration of natural habitats is discussed in the THESEUS Guidelines. For salt marshes spatial indicators based on aerial images were examined to assess their long-term stability. We found that more wave exposed salt-marshes will go through longer cycles of range contraction and expansion due to erosion and subsequent regrowth, compared to marshes that are more sheltered. We identified factors limiting marsh establishment by comparing salt marshes across Europe and by setting up experiments analysing the growth and establishment of Spartina to better understand the response of saltmarshes under rising sea levels. Results showed that the critical growth potential for Spartina seedlings to successfully establish is determined to a large degree on the tidal range and less so on inundation frequency. Measurements on coastal defence value of diverse biogenic habitats have been carried out. A significant result from the project was that for Sabellaria alveolata a specific range of particle sizes is used to build tubes. Therefore, adjustment in available sediments, either through changes in the depositional regime or as a consequence of nourishment, will most likely have a negative effect the development of S. alveolata reefs.
Research into techniques of dune vegetation were carried out to help facilitate the natural regeneration of coastal dunes or to create a new dune system at the THESEUS study sites in France, Spain and the UK. Results have indicated that autumn is the best season for planting cuttings or seeds. In general, geotextile is essential in high slope planting. However, further work has shown that seasonality of wind speed and its association with sand accretion is important and has a significant impact on seedling survivorship during the winter.
In order to investigate the ecological considerations in the design of coastal defence structures as part of WT3.3 broad-scale surveys of structures in the UK, Ireland, Italy, Bulgaria, Ukraine and the Netherlands were completed. The colonisation of newly constructed schemes by biota was monitored. Using existing, newly built structures or those under construction, sampling assessed impacts on soft sediment infauna and on birds. Modification of detrital pathways by structures was investigated in Italy and showed effects on infauna from detritus exported from the structures. Gabions containing different sized stones as potential habitats were deployed in the UK and the Netherlands and sampled at the end of their deployment. Considerable engineer and end-user/stakeholder engagement was initiated to inform the ‘BIOBLOCK’ design. A prototype was cast in concrete and successfully deployed. The final design comprised multiple habitat types including rock pools of varying depth and diameter, pits of varying depth, horizontal ledges and overhangs. The deployment of the BIOBLOCK created significant international interest including proposals to incorporate this approach into a new scheme in Jakarta, Indonesia. The diameter of the pits (2.5 cm) on the BIOBLOCK were selected as this has previously been shown to provide better habitat than larger pits. This has yielded both scientifically interesting results and a practical demonstration of the minor impact on structural integrity, but at the same time the potential biodiversity gains (drilled pools contained a total of 16 species compared to 12 species on surrounding rock) that can be made at minimal cost. Furthermore, permission was granted for interventions on various existing and new structures in the UK including drilling rock pools. Surveys of natural and artificial structures focused on rock pools to inform BIOBLOCK design. Larger-scale deployments of modified ‘wave breaker blocks’ were monitored on Plymouth Breakwater. Habitat units were installed in seawalls as part of renewal schemes at the Plymouth Site. Experiments to identify conditions for ‘gardening’ of desired species (e.g. of conservation importance) were completed in Italy. Novel habitats features were also included in the design and construction of a new seawall at Shaldon in the Teign Estuary Study site. Adding habitat feature at this stage represents a major advancement as it is the only European example of habitat features being added to a structure at the construction phase. Results indicate that the novel habitat features support more species than the surrounding areas of wall.

Along the Adriatic coastline, the threatened canopy forming alga Cystoseira barbata was successfully transplanted onto coastal defence structures. Along the Adriatic coastline, the significance of modification of detrital pathways was demonstrated; these processes occur on very short time scales. Soft macrobenthic communities can change depending on the presence of hard structures and the morphodynamic conditions of beaches, following a clear bio-morphodynamic gradient. This work contributed first to ID3.2 ID3.6 and finally ID 3.9 all lead by SOTON (formally BANGOR).
WT 3.4 investigated the ecological consequences of alternative coastal defence options. The initial focus was on understanding the consequences of coastal flooding and specifically the responses of plants and animals to dynamic floods. Novel experiments examined the effects of salt water inundation on survival, growth and flowering of coastal grassland species from different functional groups and looked at the accumulation of stress metabolites in the plants along with the associated herbivory/palatability changes in plants subject to salinity stress. Results showed that for instance Trifolium repens inundated seawater for 0, 2, 8 and 24 hours gave a clear gradient with high death and small plant sizes after onward growth with increasing duration of inundation. However, effects varied between species, woody plants such as juvenile trees and shrubs appear to be more tolerant of prolonged immersion than herb and grass-like species. A significant advancement was that this work directly contributed to the development of EVI implemented in the THESEUS DSS.
In 2011 we initiated a monitoring program for a managed realignment at South Efford within the Plymouth study site. This showed that extent of inundation and availability of sediment are essential for successful marsh generation. To date the assemblage shows damage and degradation of pasture, but as yet little to indicate succession to marsh plants. Work on managed realignment also showed that for a new saltmarsh to establish there must be a sufficient propagule supply to allow marsh plants to develop and sediment supply to allow the marsh to accrete and keep up with the pace of sea level rise. ID3.7 contrasted the use of hard defence schemes to managed realignment synthesizing work from WT3.3 and was led by UoP.
The effects of multiple ecological stressors were investigated in WT3.5. A comprehensive analysis (from both existing published data and direct novel research carried out within THESEUS) of cumulative stressors that are likely to act on coastal marine ecosystems in parallel with environmental pressures arising from flooding and related coastal defence interventions. This knowledge was summarized in ID3.5 lead by UNIBO.
A synthesis of the occurrence of multiple anthropogenic stressors at THESEUS (including climate related changes, pollution, land use, tourism, over-exploitation of marine resources, invasive species, etc) on the resilience of ecosystems as well as the capability of ecosystems to provide fundamental ecosystem services, including coastal protection, was carried out. This was done for the THESEUS study sites and also at a coarser resolution at an EU scale, and identified sensitive areas that require precautionary management. We also identified five strategies for successful recovery: raising public and political awareness, legal action and enforcing management plans, reducing cumulative human impacts, protecting or restoring biodiversity and complex ecosystems, and long term planning, as recoveries can take many decades, particularly for longer-lived species and complex ecosystems. This information was complemented using ArcGIS maps which were collected for the THESEUS study sites and was summarized in ID 3.8 to be used as part of WP5 and the DSS lead by UNIBO.
Key advances from WP3 include new insights and understanding of the role of intertidal habitats to coastal protection and how best to manage and restore these habitats in order for them to function as a form of coastal defence. This work is summarized in the THESEUS Guidelines. The vulnerability of a range of coastal habitats was assessed and this information was adapted for the THESEUS DSS in the form of the EVI. Novel demonstration schemes of how to incorporate habitat into hard structures was carried out with particular success with the BIOBLOCK.

In the course of the project Workpackage 4 has identified, ground tested, and prepared for integration into THESEUS’s DSS a structured portfolio of tested operational innovative tools and protocols for policy and management purposes of coastal flooding risks (that is presented in details within OD 4.8).
This portfolio included options related to insurance programs, land-use planning, business recovery planning, post flood recovery, risk communication and evacuation planning. It includes an analysis of the potential conflicts and synergies between envisioned options. Its most innovative feature lies into the analysis of the dual nature of mitigation option in terms of vulnerability reduction and resilience enhancement. In terms of specific options, each relating to a specific worktask, several results are highlighted here below.
The objective of WT 4.1 was to guide policy-makers towards the design of efficient insurance programs that are dovetailed with adequate coastal erosion and flooding mitigation strategies in the selected case studies sites. A revised version of the insurance scheme survey guide was arranged so as to reflect the overall aim of this task, which is the design of efficient insurance programs and the identification of the necessary incentives for their adoption by property owners, that will encourage loss reduction measures against natural hazards and provide recovery funds to disaster victims. In order to explore how society perceives risk of coastal hazards and insurance schemes, semi-structured interviews were conducted in the different EU case study areas (Spain, UK, France and Italy). The aims of these interviews were exploratory rather than focused on obtaining definitive responses and data for statistical analyses. From the ground testing it was found that the insurance industry in the UK is extremely well developed. The whole of the sector is composed of private companies operating in the commercial marketplace. There is no state subsidy for insurance companies in the UK. In the case of the Santander study site, there is an Insurance Ministry. Its objective is to indemnify, by way of compensation, those losses deriving from extraordinary events that take place in Spain and affect risks therein located. On the other hand, insurance against flooding is not available in Cesenatico. Finally, in Gironde, there is an insurance system, named Cat Nat (catastrophes naturelles). It calculates the direct damages but not the indirect ones. Insurance regulations in Gironde seem not to be sufficiently clear for individuals and companies. It should be noted that the heterogeneity of input coming from field work in the study sites is due to the difficulty of having direct access to insurance companies to answer the surveys and because in some cases insurance against flooding was not even available. The key innovation and progress beyond the state of the art for this WT lies into (a) the development of simplified models of insurance taking explicitly into account spillover effects, (b) rethinking the issues of scales and linkages, allowing development that goes beyond the private/public dichotomy, (c) developing a model clearly highlighting that the communication of resilience to the insurance decision makers is a business relevant information.

WT 4.2 aims to analyse how spatial planning can support the resilience of coastal areas. Its contribution to OD4.8 includes conceptual issues related to spatial planning and its integration with FCERM as well as the ground-testing results. Ground-testing used in-depth qualitative interviews in five THESEUS study sites in Bulgaria, France, Poland, Spain and the UK. Interviews were carried out with planners from both local and strategic levels, with FCERM strategic regulators (e.g. EA), key developers, local councillors and community members. The findings are discussed in the report and guidelines for resilience enhancement are provided. The role of spatial planning as a coastal risk mitigation option has been prepared of incoporation into the DSS by enabling an examination of the impact of changing the distribution, density and form of urban land uses. The extensive groundtesting led to a clarified recognition of the fact that spatial planning has a role to play in improving resilience to coastal flood and erosion threats. There are a number of EU policies calling in varying ways for greater integration between FCERM and spatial planning. A key part of the research was therefore to examine the extent to which these have been incorporated in the different locations and to understand how changes were experienced in each context. The research found that none of the locations had achieved complete integration; integration was problematic but was seen to offer potential benefits; integration varied widely between the locations; the term resilience is little known and poorly understood by spatial planning practitioners; tensions between groups can be exacerbated if a narrow view of resilience is adopted; community engagement is not widely used and a lack of good practice exacerbated existing difficulties. A fundamental progress beyond the state of the art lies in the fact that the results obtained allowed for the building within the planning system of the ability to “multi source” learn from shocks – real AND scenarized. Their integration within THESEUS allowed for the development of land use planning processes taking into account the ecological functional values of (fromWP3) and the economic shadow value (from WP1).
The aim of WT 4.3 was to thoroughly explore the potential for Business recovery planning to contribute to safer coasts. This allowed for the ground-tested clarification of central associated conceptual issues including governance implications. The ground testing, achieved via in-depth interviews with businesses, was undertaken in five THESEUS study sites. A method for estimating the potential flood damages avoided by BDR planning, to be incorporated in the DSS, is included. As BDR planning is primarily concerned with adapting the response and consequence phases of the SPRC model, we have found that large businesses are more likely to adopt a BDR planning process – the largest potential for enhancement of BDR planning therefore exists in the SME business sector. Our work also showed that most BDR planning is generic (i.e. all-hazards) and does not always include flood risk even in flood risk zones. Furthermore, where they have been adopted, BDR plans are stronger in terms of warning receipt and response than in terms of recovery planning which is a general weakness. Finally we show that experience of a flood is currently the single most important driver in determining whether a business does or does not have a BDR plan (with the exception of a legal obligation to do so). The key innovative result of this task is the development of guidelines in order to get Business Continuity Planning to become a locally led and facilitated dynamics available to all businesses regardless of scale; second, our guidelines encompasses issues that will foster that business continuity plans be explicitly designed to feed insurance scheme, land use planning and post-flood recovery. This integration could only be conceptually achieved within the context of THESEUS.
Work Task 4.4 focused on the psychosocial dimensions of flood risk management, which influence both the evolution of local resilience strategies and citizens’ behaviors (Tapsell 2011). In particular, the Post-Crisis Response Guidelines examined three main areas: (a) The role of dissemination, education and involvement in the disaster cycle; (b) The role of Critical Facilities in community response and return to normalcy; (c) The psychosocial aspects in evacuation planning (together with WT 4.6) and warnings. Previous studies and ground testing suggested operative measures for safer European Coast, which have been directly related to the principles of resilience. This particular choice highlighted the relation between scientific research and policy making for coastal managers. This is particularly relevant in breaking the “solitudes” between post crisis recovery public services and actions on vulnerability assessment. A review of interdisciplinary literature was undertaken during the entire project and qualitative and quantitative ground testing was carried out in the Italian sites of Cesenatico and Bellocchio. The following key innovations have been produced: Dissemination, education and involvement have been considered as cross-cutting elements in determining the effectiveness of non-structural flood mitigation measures. The interactions among organizational, behavioural and social dimensions have been pinpointed as critical elements for reducing vulnerability. If mitigation measures could be defined as strictly context-dependent, actions on community patterns are needed to produce changes in risk management culture at large. A “Collateral Social Damage Index” has been created to integrate psychosocial perspectives in flood management. In particular, the concept of “critical facilities” referred to infrastructural damages and psychosocial consequences of floods in the Decision Support System (DSS) and in Post Crisis Management Guidelines. A function of life losses with appropriate mitigation measures has been included in the Decision Support System to increase options for vulnerability assessment. The model developed by Penning–Roswell et al. (2005) has been used as background to produce the estimated number of people exposed to death or injury in the area involved by computer simulations. The original function was adapted to the technological features of the Decision Support System, which allowed detailed and ground oriented definitions of risk zones based on demographic areas. The “evacuation calculator” has been interfaced in the life losses function (in cooperation with WT 4.6). An analysis of mobility infrastructure and escape route in Cesenatico was performed, as the general criteria reported in official evacuation planning manuals referred to American roads. Similarly, psychological literature suggests that driving behaviors during emergencies could differ from ordinary setting.
Through extensive empirical work conduced within WT4.5 (risk communicationà we show that coastal risk communication entails the iterative identification and explicitation of all stakeholders heuristics, values and understanding of the coastal system. Furthermore we have identified the paradigmatic understanding of the coastal system as the key gap between experts and laypersons. The design and use of the DSS constitutes a key locus where this iterative communication work can occur. Using a DSS is therefore a unique opportunity to allow for deliberation between DSS experts, users and stakeholders. This can be achieved through the design of a cognitive pathway associated with the use of the DSS. Rather than designing another standard “risk communication scheme” using overused and abused theoretical and empirical approaches, which are ontologically narrow, within THESEUS we chose to start from Renn’s theoretical synthesis presented above and ground it into the experience of flooding and erosion by key individuals and the general population in study sites. We have therefore focused on the idea that coastal flooding and erosion risks under climate change is to be approached through the analysis of the Relevance, Evidence and Normative claims that capture the various determinants of perception discussed above. The goal in the risk communication scheme is therefore (1) understand how those affected by flooding and erosion risk theorize the risks they are facing; (2) understand how this local theorizing of risk is fed by questions of costs and benefits, is fed by knowledge and is oriented by values; (3) from these understanding see how risk can be managed in technological terms, governance terms, and political terms through a proactive understanding of risk perception and the importance of contexts in the shaping of these perceptions. Finally these three goals are integrated into the communication scheme that is proposed.
WT 4.6 entailed the development of evacuation procedure and evacuation planning software. The work was based on feedback from experiences on previous disasters which resulted in mass evacuation, data collection on sites and face-to-face interviews with stakeholders and authorities. The full methodology was included in OD 4.8 and 4.1 including guidelines for application in the case study sites). The methodology for mass evacuation planning was ground truthed in two different sites: the Gironde estuary and the coastal area of Cesenatico. A new version of the software for calculation of evacuation times was also delivered, and it has been already integrated in the Theseus DSS. This work task led to the two following central progresses beyond the state of the art: evacuation software made available for local government with the data requirements AND data collection procedure clearly spelled out.

WP5 primary objective was to provide an integrated methodology for planning sustainable defence strategies for the management of coastal erosion and flooding, which addresses technical, social, economic and environmental aspects. More specific objectives were :
• to evaluate the efficiency, equity and sustainability effects of the different mitigation options for erosion and flood risk in a given coastal area, for short, mid and long terms scenarios developed in WP 1,
• to develop a verified methodology for the selection of the most appropriate defence strategy in a given coastal area, under uncertain future conditions,
• to provide guidelines for the selection and design of defence strategies, including ecologically based mitigation measures and innovative coastal technologies,
• to develop a software tool for the management of coastal risks.

WP 5 was organized as a bottom up process leading from partner experience to the delivered tools through:
• virtual application of mitigation options examined in WPs 2, 3, 4 in the study sites and selection of the most promising options; in this first stage selection is based on qualitative considerations (WT 5.1);
• detailed evaluation of the physical, ecological and socio-economic consequences of the selected options in present conditions and in the future considered considering WP1’s scenarios as depicted in WP 1 (WT 5.2);
• selection of the preferred strategy in cooperation with authorities and stakeholders, combining different criteria (economic development of present generation, environmental and cultural heritage preservation, equitable distribution of costs and benefits) aiming to assure a sustainable development of the society and of the environment in the area (WTs 5.3 and 5.4).

The two main products of this WP were a book of guidelines (WT 5.5) and a GIS based Decision Support System (DSS).
WT 5.1 IDENTIFICATION OF MITIGATION OPTIONS – identified the risk mitigation options that could have been reasonably applied to the different study sites based on the assessment of the site conditions performed in WP1 and on the results derived from modeling activities, surveys and measurements performed suggested in WPs 2, 3 and 4. The options were discussed with authorities and stakeholders; a qualitative screening based on existing policies and management strategies, legal, social and environmental constraints was carried out leading to the selection of a few more suitable mitigation options. The preliminary design of the mitigation option in the study sites raised a number of practical difficulties, for instance the evaluation of the costs and the level of details required for estimating the social, economic and environmental effects of the mitigations.
WT 5.2 EFFICIENCY, EQUITABILITY, SUSTAINABILITY OF MITIGATION OPTIONS UNDER UNCERTAIN CONDITIONS – evaluated the mitigation options selected in WT 5.1 considering the different background of the project participants. Hydraulic efficiency of the selected mitigation options in WT 5.1 was verified in the study sites by means of different models characterized by a different degree of complexity (analytical models, 1D models, 2D models, expert judgment). Environmental sustainability was examined by means of the results achieved within WP 3 about habitat vulnerability and expected changes of habitat depending on changes of the hydraulic regimes. As with regards the economic perspective and its approach in this WT, the results of questionnaires and other experiments in several of the study sites were used as a starting point to evaluate from a qualitative and quantitative point of view the effects of different scenarios and the performance of different mitigations. Considering the uncertain estimates and the different scales of social, economic, ecological and engineering costs and benefits, it was decided to adopt a quali-quantitative multi-criteria methodology for assessing vulnerability and risk and for evaluating the efficiency, equity and sustainability effects of the different mitigation options.
WT 5.3 SELECTION OF THE DEFENCE STRATEGY – In all THESEUS sites, mitigation options were identified, combined into portfolios and a methodology for the selection of the optimal portfolio was proposed. The methodology is based in all cases on the Source-Pathway-Receptor-Consequence approach developed within WP 1, and has been applied in different ways depending on the data resolution, on the extension of the site and on the available modeling tools but keeping the coherence of the approach and of its goal towards sustainable development and safety of the sites accounting for the changing climate conditions.
WT 5.4 IMPLICATIONS OF MITIGATION OPTIONS FOR FUTURE POLICIES, MANAGEMENT AND PLANNING STRATEGY – were discussed discussed among scientists, policy makers and coastal managers for the study sites. These discussions provided the input required for both OD 5.5 “Identification, impact and selection of mitigation options in study sites with implication for policies and regulations” and the THESEUS book of Guidelines, WT 5.5. The results of the focus groups were also the starting basis for one of the THESEUS special issue paper on Coastal Engineering: “Innovation in coastal risk management: An exploratory analysis of risk governance issues at eight THESEUS study sites“.
WT 5.5 -PREPARATION OF GUIDELINES FOR THE DESIGN OF ECOLOGICALLY FRIENDLY DEFENCE TECHNOLOGIES delivered a book to be published by Elsevier (book title “Coastal risk assessment and management in a changing climate”), compile the new knowledge developed within the project, innovative approaches to mitigate climate change impacts due to erosion and flooding and a methodological approach aiming at integrating all relevant aspects concerning natural and human systems. The application of this approach to study sites guides the user identifying the key challenges at similar coastal areas and providing the required information to export the project output to other sites. The book is composed of 7 main chapters, besides Introduction and Conclusion: Developing a holistic approach to assessing and managing coastal flood risk; Innovative engineering solutions and best practices to mitigate coastal risk; Ecological approaches to coastal risk mitigation; Non-structural approaches to coastal risk mitigation; Towards sustainable decision making; Application to case studies worldwide (including not only the 8 THESEUS European case studies, but also Cancun, Mexico, and the Yangtze estuary, China, thanks to the effort of the partners from ICPCs).
WT 5.6 - DEVELOPMENT AND EXAMPLE APPLICATION OF A SOFTWARE TOOL FOR COASTAL RISK MANAGEMENT delivered THESEUS-DSS, which has been defined as a scoping tool to assess risk conditions and consequences of mitigation options against flooding and erosion at a given coastal site. The DSS supports decision-making to resolve ambiguity regarding the choice of the combination of intervention measures from an available portfolio. The exploratory tool allows the users to perform an integrated coastal risk assessment, to analyse the effects of different combinations of engineering, social, economic and ecologically based mitigation options, across short (2020s), medium (2050s) and long term (2080s) scenarios, taking into account physical and non-physical drivers, such as climate change, subsidence, population and economic growth. The software fundamentals aim at exportability in different sites but include a site-dependent component since the software should be based on high spatial resolution information on wave climate, habitats, society and mitigation options which will vary depending on the site. The main foundation of this DSS is that it has to be “Open and Parametric”, not only in terms of source code and technology but, first of all, in terms of usability. It is also an “Interactive” tool so that users can verify a lot of combination of scenarios and while testing the scenarios be trained to a fully interdisciplinary risk assessment in the area and to the selection of the best solution or combination of solutions for risk mitigation. In the DSS actually the term “best” solution means “sustainable”, i.e. protecting the coast while preserving its socio-economic development and the integrity of the ecosystem services. The DSS was calibrated in Cesenatico, in the Gironde Estuary, in the Teign estuary and in Santander Bay, therefore in 4 of the 8 sites examined within THESEUS. An English manual detailing the software architecture, functions and methodology was also prepared. Software and manual (OD5.6) are available through THESEUS website (

One of the important tools used to disseminate the results of the THESEUS project was the project website OD 6.1. The website has been online since March 2010 (M 4) and has been updated during the entire duration of the project.
The website contains a news section, project objectives and project strategy, information on the work packages, information on the project partners and information on the study sites. The website contains also a password protected document section (with all internal deliverables and to the project restricted documents) and an open document section containing all official deliverables, outreach materials and meeting proceedings. The website also contains the ‘Open THESEUS Archive’ with all publications acknowledging THESEUS, and in agreements with the Special Clause 39 of the project. The website is continuously updated with new pictures, movies, news-items and newsletters. Additionally a list of all meetings, conferences and workshops where THESEUS was represented was maintained, as well as a list of all press releases in which THESEUS research was highlighted and a list of all dissemination products created by the project.
Several Wiki articles on innovative coastal defense techniques has been integrated in the Coastal and Marine Wiki translating two main deliverables from WP2: Integrated inventory of data and prototype experience on coastal defenses and technologies and from WP 3: Natural habitats for coastal protection and relevant multi-stressor coastal risks. Report and European Scale overview and are available from the website Publishing the articles on the Coastal and Marine Wiki has the advantage that it increases the visibility of these deliverables and the information will be easy accessible after the ending of the THESEUS project.
The website served also to facilitate the organization of all internal meetings by handling the registrations and providing a central point from where information on the meetings was available. For the final dissemination event, the THESEUS - Science-Policy Interface event, a dedicated website was constructed to improve the visibility of the conference and to serve as a central information point. The dedicated webpage contains information on the conference, the venue, a short background of the key speakers and easy redirect to the meeting proceedings.
The main deliverable of the project, the THESEUS decision support system is also downloadable from the website after a short registration period at

The THESEUS leaflet (OD 6.2) has been produced and printed in 2000 copies which have been distributed by the partners. The leaflet is also available in digital format from the project website at:
Three booklets on coastal risk (OD 6.3) have been created to promote social awareness towards the risks of flooding and the necessity of improving coastal resilience and distributed among stakeholders the general public. As people are more likely to feel connected when they are faced with examples close to their homes, each of the 3 booklets also focuses on flooding related challenges to 4 of the THESEUS case study sites (South Devon coastline (Southwest-Britain), the port town Cesenatico at the Northern Adriatic coast of Italy, the Gironde estuary in France and the Scheldt estuary in Belgium and the Netherlands). To optimally reach the people living at these sites, the three booklets were written in English (1000 copies each) and the local languages spoken at the study sites (Italian -1000 copies, French -500 copies and Dutch -1000 copies). The booklets in the local language were distributed locally in schools, at local fora and during public events. The English versions were distributed among stakeholders and policymakers at international events. The booklets are also available as E-booklets through the project website.
A dissemination DVD of the THESEUS project has been produced (OD 6.4). The DVD gives a general overview of the THESEUS project (THESEUS trailer) and includes a multilingual promotion movie, made in cooperation with Euronews and DG Research and Innovation. The 100 copies of DVD have been distributed for dissemination. Both movies are also accessible through the website.
The key results of the THESEUS project were bundled into 18 scientific papers published in a special issue in the journal Coastal Engineering (OD 6.5). The printed version is expected to be available with some delay shortly after April 2014. These publications themselves are also available as separate articles through the ‘Open THESEUS Archive’ in which project partners are progressively posted all their scientific publications acknowledging THESEUS in respect to the Special Clause 39
The archive currently holds 144 publications which acknowledge THESEUS, of which 80 are peer reviewed A1 publications. This number is expected to increase as at the moment more than 13 A1 articles are still to be published. According to the OpenAire database ( with 80 scientific A1 publications the THESEUS project ranks among the top 10 of the most publishing European projects listed under the theme “Environment (including Climate Change)”. Of these 187 projects THESEUS is preceded only by HERMIONE, EPOCA, ICE2SEA, CARBOCHANGE and ACQWA.

The impact of the scientific output by THESEUS is substantial with currently 51 peer reviewed publications included In Science Direct. These publications have been cited 104 times, averaging at 2.04 citations per publication. The calculated h-index of the THESEUS scientific output is 5.
A brochure bundling all policy-relevant outcomes (OD6.6) is created. The brochure combines 6 policy briefs (Preliminary Flood Risk Assessment, Flood hazard maps and flood risk maps, Flood risk management plans-preparedness, Flood risk management plans- prevention, Flood risk management plans- protection, habitat enhancement on coastal defence structures) with recommendations regarding the EC Flood Directive 2007/60/EC and the EC Habitats Directive 92/43/EEC.
An overview of all dissemination publications is available from the website at:

Most project partners are involved in several research projects and have links with local administrations and authorities. Activities of THESEUS were presented since the start of the project at 102 international and national conferences, workshops and meetings. An overview is available at: During many of these events networking with End Users and policy makers took place.
The results of the project were presented to Selected End users and policy makers at the THESEUS - Science-Policy Interface event held on October 18th 2013 in the Royal Belgian Institute of Natural Sciences in Brussels:
The conference was attended by over a 100 participants, of which a fourth were end users, including different decision and policy makers. The outcomes of the working group sessions were combined in a concept paper presented to the European Commission and available through the project website.

Three sets of training workshops have been held. The first was organized in Ukraine, Sevastopol November 6-8 2012. The overall focus as on the newly developed Decision Support System: the DSS concept was explained and the end-users were informed about the goals and preliminary results of the project. The end-users were also trained on methods for risk assessment using overview of current policies and practices.
A second training event was held in Taiwan September 23, 2013. At this 4day event THESEUS scientists informed Taiwanese marine scientists, policy makers, experts and interested persons of the results by THESEUS.
The main training event was held during the final event of THESEUS in Brussels October 18, 2013. Participants got an extensive overview of the possibilities provided by the THESEUS decision making software (DSS) and participated in a demonstration where the DSS was used to tackle a predefined problem using a predefined scenario.
4 different Web seminars on the THESEUS project have been submitted to innovationseeds.
Different presentations of the THESEUS project results, including all presentations presented during the Science Science-Policy Interface event are available in pdf and movie format from the project website.

Between July 2011 and February 2013 six E newsletters were prepared and send to project members, relevant stakeholders, end users, advisory board. The newsletters include information on project deliverables, meetings where THESEUS was present, and training and outreach activities organized within the project. The six newsletters can be accessed online at:
Since the beginning of the project 51 newsflashes were posted on the website. Interested persons can subscribe to the THESEUS newsflashes through RSS feeds.

Potential Impact:
The holistic approach to the analysis of flood events and risk analysis developed in WP 1 combines the systematic attempt to understand the different– physical, ecological and social – aspects of the flood system and allows exportability in the coastal areas worldwide to provide a sound basis for risk assessment. This information and data can then be used in the development of other management tools –including the Decision Support System to be developed by WP 5- which support the selection of robust coastal management strategies.
The results from physical and numerical investigations carried out within WP2 lead to the assessment of the performance of innovative and traditional defences in the context of increasing storminess and sea level rise. These results will be translated into Guidelines in WP5 and will support more effective coastal defence plans through a more reliable design and advanced technologies (such as wave energy converters for beach protection; optimized design and/or upgrading of breakwaters/revetments, sea dikes, reefs/submerged structures, floating breakwaters; best practices for coastline stabilisation by beach nourishment and dredging strategies).
The final results generated from WP3 will inform the management of coastal habitats. The full spectrum of management strategies for coastal environments will be contrasted ranging from the ecological consequences of the “do nothing” though to the considerations needed for ecologically successful managed realignment to “hold the line” using both hard and soft options. These results are of direct relevance to those involved in coastal management and conservation and those responsible for coastal defence. These results will be translated from WP3 to WP5 to inform the Guidelines and the Decision Support System (DSS) tool.
The research of WP4 has the potential to contribute to safer European coast in a way that mobilizes, in a mutually reinforcing way, state, private and individual resources. In order to propose resilience (safety enhancing) mechanism that are simultaneously cost effective, and mutually reinforcing, the research has been focused on reaching a balance between individual actions and its relation with perception, stakeholder level potential influence on safety enhancement in the face of coastal flood and erosion, business level action, local, regional and national government level action. In terms of socio-economic impact this approach should be able to provide risk mitigation option – resilience enhancement mechanism that will not only reduce the damage from flood and erosion to come but to achieve this in a way that allow for constant learning and increase in resource use efficiency. Finally, a key element that lies at the core of the social dimension of THESEUS is the transversal work on local level risk and exposure memory.
The methods developed by WP5 can be used along the European coasts and worldwide for risk assessment and mitigation. Specifically the Decision Support System (DSS) reproduces in a simplified way the most relevant physical processes (coastal erosion and flooding) induced by waves and sea-levels taking into account physical and non-physical drivers, such as climate change, subsidence, population growth and economic development. It is a scoping tool to support decision making in coastal management in order to help to resolve ambiguity regarding the choice of the combination of intervention measures for erosion and flooding from an available portfolio. The guidelines update the existing information about coastal risk assessment and management through the outcomes of the project, focusing on the need of long-term sustainable defence planning strategies, accounting for uncertainty and climate changes and promoting resilience of the whole coastal system. The application of the methodology included in the guidelines and the DSS by the relevant decision makers will have wide societal implications.
As for WP6, the Informative booklets on coastal risks, the THESEUS special issue in Coastal Engineering , the brochure including policy-relevant outcomes, the multimedia material, the organization of the final seminar in Brussels, the newsletters are expected to further increase the dissemination of the project results to coastal community, authorities and potential end users, including the public at large.

List of Websites:
All project official deliverables, multimedia material, publications and the decision support system are accessible through the project website: