Description: Understanding the distribution and structure of biotopes is essential for marine conservation according to international legislation, such as the European Marine Strategy Framework Directive (MSFD). The biotope ‘Sea Pen and Burrowing Megafuna Communities’ is included in the OSPAR list of threatened and/or declining habitats. Accordingly, the MSFD prescribes a monitoring of this biotope by the member states of the EU. In the German North Sea, however, the distribution and spatial extent of this biotope as well as the structuring of its benthic species inventory is unknown. We used an extensive geo-referenced dataset on occurrence, abundance and biomass of the benthic infauna of the south-eastern North Sea to estimate the distribution of the biotope and to characterize the associated infauna assemblages. Sediment preferences of the burrowing megafauna, comprising decapod crustaceans and echiurids, were identified and the core distribution areas of the burrowing megafauna were modelled using Random Forests. Clusters of benthic infauna inside the core distribution areas were identified by fuzzy clustering. The burrowing megafauna occurred on a wide range of sediments with varying mud contents. The core distribution area of the burrowing megafauna was characterized by elevated mud content and a water depth of 25–55 m. The analysis of the benthic communities and their relation to sedimentological conditions identified four infauna clusters of slightly varying species composition. The biotope type ‘Sea Pen and Burrowing Megafuna Communities’ is primarily located inside the paleo valley of the river Elbe and covers an area of 4980 km2. Dedicated monitoring will have to take into account the spatial extent and the structural variability of the biotope. Our results can provide a baseline for the evaluation of the future development of the environmental status of the biotope. The maps generated herein will facilitate the communication of information relevant for environmental management to authorities and policy makers.

Description: Offshore wind power generation requires large areas of sea to accommodate its activities, with increasing claims for exclusive access. As a result, pressure is placed on other established maritime uses, such as commercial fisheries. The latter sector has often been taking a back seat in the thrust to move energy production offshore, thus leading to disagreements and conflicts among the different stakeholder groups. In recognition of the latter, there has been a growing international interest in exploring the combination of multiple maritime activities in the same area (multi-use; MU), including the re-instatement of fishing activities within, or in close proximity to, offshore wind farms (OWFs). We summarise local stakeholder perspectives from two sub-national case studies (East coast of Scotland and Germany's North Sea EEZ) to scope the feasibility of combining multiple uses of the sea, such as offshore wind farms and commercial fisheries. We combined a desk-based review with 15 semi-structured qualitative interviews with key knowledge holders from both industries, regulators, and academia to aggregate key results. Drivers, barriers and resulting effects (positive and negative) for potential multi-use of fisheries and OWFs are listed and ranked (57 factors in total). Factors are of economic, social, policy, legal, and technical nature. To date, in both case study areas, the offshore wind industry has shown little interest in multi-use solutions, unless clear added value is demonstrated and no risks to their operations are involved. In contrast, the commercial fishing sector is proactive towards multi-use projects and acts as a driving force for MU developments. We provide a range of management recommendations, based on stakeholder input, to support progress towards robust decision making in relation to multi-use solutions, including required policy and regulatory framework improvements, good practice guidance, empirical studies, capacity building of stakeholders and improvements of the consultation process. Our findings represent a comprehensive depiction of the current state and key stakeholder aspirations for multi-use solutions combining fisheries and OWFs. We believe that the pathways towards robust decision making in relation to multi-use solutions suggested here are transferable to other international locations.

Description: In the field of risk evaluation and seismic hazard assessment, it is necessary to codify a great quantity of aspects of the so called knowledge and to supply an intelligent support for the not-well-defined problems (data uncertainty, lack of rigorous solution algorithms). The main feature of an expert system is to emulate effectively the behaviour of a human expert in a particular and defined field, enabling the final user to improve its decisional process and giving access to him to a knowledge base otherwise not clearly codified. From these general considerations the intention came to develop the prototype CZAR (Classificatore Zone A Rischio) that is an expert system reproducing the Italian seismic classification based on the definition of Seismic Hazard given by Progetto Finalizzato Geodinamica (PFG) of the Consiglio Nazionale delle Ricerche (CNR). The expert system built up on the commercial shell Nexpert Object is working on a personal computer through a graphic interface developed with the Graphical User Interface (GUI) of Window 3.0. This user friendly interface makes possible the choice of different procedures to estimate the hazard parameters and also allows the activation of the classification inferential process. The influence of different assumptions and strategies has been evaluated by a mathematical algorithm suggested by the general structure of the Bayes’ theorem. In this paper the prototype of the expert system has been applied to the data relating to Toscana region (central Italy) and the interactive evaluation of the maps furnishes a relative measure for discrepancies on seismic classification in the 2nd seismic category.

Description: Published

Description: 153-173

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: Nitrogen fixers, or diazotrophs, play a key role in the carbon and nitrogen cycle of the world oceans, but the controlling mechanisms are not comprehensively understood yet. The present study compares two paradigms on the ecological niche of diazotrophs in an Earth System Model (ESM). In our standard model configuration, which is representative for most of the state-of-the-art pelagic ecosystem models, diazotrophs take advantage of zooplankton featuring a lower food preference for diazotrophs than for ordinary phytoplankton. We compare this paradigm with the idea that diazotrophs are more competitive under oligotrophic conditions, characterized by low (dissolved, particulate, organic and inorganic) phosphorous availability. Both paradigms are supported by observational evidence and lead to a similar good agreement to the most recent and advanced observation-based nitrogen fixation estimate in our ESM framework. Further, we illustrate that the similarity between the two paradigms breaks in a RCP 8.5 anthropogenic emission scenario. We conclude that a more advanced understanding of the ecological niche of diazotrophs is mandatory for assessing the cycling of essential nutrients, especially under changing environmental conditions. Our results call for more in-situ measurements of cyanobacteria biomass if major controls of nitrogen fixation in the oceans are to be dissected.

Description: This document defines and prioritises the key objectives of dissemination of REFLECT and details the steps to be taken during the project’s lifetime in order to achieve maximum impact and reach relevant audiences. It also sets the framework to facilitate communication among Consortium members, and between the Consortium and stakeholders or the general public.

Description: The analysis of damage on buildings affected by an earthquake allow to trace back to the defects of the structural system and the imperfections of the constructive elements with reference to the best or worst behaviour in case of seismic action. As a matter of fact the tendency of buildings to be damaged, also defined as seismic vulnerability, is strictly connected with their geometric-constructive characteristics. The damage appears as "effect" of the phenomenon that has its "cause" in the seismic action. Once the characteristics of the system are defined, it is possible to reconstruct the 'cause-effect' relation between seismic action and damage. These relations can be obtained through survey of damage caused by recent earthquake. However this methodology reveals a series of problems. The various quantities applied must be expressed with indices that allow to synthesize complex and articulated scenarios exhaustively; although the damage is a quantity that can be directly assessed by description, it is difficult to measure, as its quantification should be representative for all aspects connected with it (physical, economic, functional, social, etc.). The level of the seismic action must be expressed by a parameter that is an index of the event's destructive capacity and in direct correlation with mechanical quantities (acceleration, velocity, energy, etc.). The vulnerability is an entity able to characterize the more or less accentuated predisposition of the structures to suffer damages independently from the intensity and direction of the seismic action. In this work, subjects concerning seismic action and vulnerability shall not be dealt with, as they have already been investigated in previous works [see Grimaz S., 1992 - Cella F. 1994 and 1995]; in the following the problem of damage quantification shall therefore be explored.

Description: Published

Description: 83-103

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: Introduced bioengineering organisms may fundamentally change native coastal ecosystems by modifying existing benthic habitat structures and thereby habitat-specific species interactions. The introduction of the Pacific oyster Magallana gigas into the sedimentary coastal area of the south-eastern North Sea and its preferred settlement on native blue mussel shells caused a large-scale shift from monospecific Mytilus edulis beds to current mixed reefs of mussels and oysters. To investigate whether the newly developed biotic habitat affects the occurrence of associated native key organisms and their ecological functions, we studied the long-term density trajectory of the gastropod Littorina littorea and its grazing activity on barnacles attached to Pacific oyster reefs in the northern Wadden Sea. We found no significant correlation between oyster and snail densities on blue mussel beds in the last two decades, which spans a time-period from the beginning of Pacific oyster establishment to today's oyster dominance. A manipulative field experiment revealed that snail density significantly affects the recruitment success of barnacles Semibalanus balanoides on oyster shells with the highest number of barnacle recruits at snail exclusion. Thus, density and grazing activity of the snail L. littorea may control barnacle population dynamics on epibenthic bivalve beds in the Wadden Sea. This interspecific interaction was already known for blue mussel beds before the oyster invasion and, therefore, we conclude that despite the strong modifications that non-native ecosystem engineers cause in native biotic habitats, the ecological functions of associated key species can remain unchanged.

Description: The studies urban areas directed at the definition of seismic risk, raise the problem of the seismic vulnerability assessment of construction properties that require the estimation of the tendency to damage of a plurality of buildings. Very often one comes upon buildings that have been constructed in former epochs without the use of seismic codes and generally built in masonry. The leads to the search for procedures for vulnerability assessment, based on the rapid acquisition of information on existing buildings, which must furnish a sufficiently reliable assessment of the seismic damageability, generally without the possibility to refer to very sophisticated models. In previous works, assessments of seismic vulnerability have been effected using surveys transferred on National Project for Seismic Prevention (GNDT) sheets (Zonno and Ducarme, eds, 1992). These works have been realized using capes systems in order to treat with the uncertainty of the data. However, the analyses that only refer to GNDT sheets, are limited to single buildings, ideationally understood as isolated. An alternative and maybe complementary attempt is to assess the vulnerability of buildings in a global structural context using Geographic Information Systems to mapping the urban system, integrated with the surveys transferred on COOT sheets. The main characteristics of the building and the structural context, indices of a major or minor damageability, have been individuated, but it is difficult to define a rapid procedure for the assessment of seismic vulnerability. The idea was to use an expert system to codify a basis of the presently acquired knowledge and to apply it automatically on the basis of the results obtained by processes of space analyses calculated by GIS. On the basis of the data obtained with GNDT sheets, the vulnerability of the building can be assessed independently from the structural context (intrinsic vulnerability). The availability of data on the space distribution of the adjoining buildings permits an assessment on the effective vulnerability that takes into account the influence of the structural context. With relation to other works effected on the argument, the proposed system automatically assesses a large quantity of geocoded data either in geometry and in the structure of the components. In particular, in this work the seismic vulnerability assessment of the buildings is effected through the Geographic Information Systems PC Arc-Info connected with the Expert System Shell Nexpert Object, starting from the methods used by the GNDT of the National Council for Research (CNR) (Benedetti and Petrini, 1984; Baldi and Corsanego, 1987) and integrating the effects of anisotropics of the structural behaviour and context (Grimaz, 1992-93).

Description: Published

Description: 105-128

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica