Abstract
In a climate change context, changes in extreme sea-levels rather than changes in the mean are of particular interest from the coastal protection point of view. In this work, extreme sea-levels in the Baltic Sea are investigated based on daily tide gauge records for the period 1916-2005 using the annual block maxima approach. Extreme events are analysed based on the generalised extreme value distribution considering both stationary and time-varying models. The likelihood ratio test is applied to select between stationary and non-stationary models for the maxima and return values are estimated from the final model. As an independent and complementary approach, quantile regression is applied for comparison with the results from the extreme value approach. The rates of change in the uppermost quantiles are in general consistent and most pronounced for the northernmost stations.

Abstract
Many animal species, during their life cycles, can select specific food elements that meet the special and unique metabolic needs of crucial stages such as growth, gonad maturation or larvae production and brooding. The objective of this study was to analyze the seasonal phytoplankton composition in the stomach contents of the freshwater mussel Anodonta cygnea in order to determine whether it was capable of selecting food seasonally and which were its preferences. Specimens and water samples were collected monthly from Barrinha de Mira lagoon in the northwest of Portugal during one year. From the microalgae composition found in the water and stomach content samples, Chlorophyta presented a clear predominance, followed by Cryptophyta and Bacillariophyta in water samples, and Bacillariophyta and Cyanobacteria in stomach contents. Although mussels ingested algae in a pattern very similar to its abundance in the natural habitat, in some periods specific groups were preferred even if they were present in very low concentrations in the environment. Thus, these animals are capable of selecting food by its specific characteristics and this selectivity may be associated with its physiological cycle, mainly with the reproductive cycle. Namely, the large relative abundance (ratio stomach/environment) peak of blue green algae that co-occur with gamete development covering two other smaller peaks: one of Bacillariophyta that co-occurs with gametogenesis restart and the other of Chlorophyta at the end. In addition, a significant peak of Cryptophyta co-occurs with growth and glochidia brooding periods.

Abstract
This work addresses the rock matrix strength comparative analysis on rocky coasts. A coastal geoengineering integrated system for rocky coast assessment was proposed and applied in two fissured granitic key-sites in NW Iberia (NW Portugal, and Galicia). The main stages of the study comprise six steps: (i) high-resolution aerial imagery survey; (ii) visual inspection and systematic monitoring; (iii) applied field datasheet; (iv) in situ evaluation; (v) scanline survey; (vi) coastal geosciences engineering GIS based mapping. The Schmidt Hammer and Equotip tester were applied to measure the rebound and hardness, respectively, in rocky platforms, geoforms and coastal boulders. Moreover a detailed description of discontinuities and a geologic-geotechnical evaluation in the rocky platforms was performed. The current rock project is of great interest especially to highly dynamic coastal areas. This approach evolving geomorphic processes, geoengineering issues and geomechanical testing assessment contributes to support coastal management/planning.

Abstract
This work deals with the problem of assessing armourstone structures focusing on strengthening the combination of geo-marine techniques and geotechnical properties. The research has two main purposes: (i) to establish an integrative coastal geo-engineering approach for better assessment of the hydraulic structures; and (ii) to draw attention to the importance of quarry evaluation in order to improve armourstone quality and durability. Several studies have demonstrated the relevance of a holistic approach to coastal design issues. The suggested approach couples GIS-based mapping with geo-engineering techniques assessment along five pilot sectors of the Espinho coastal system in Northwestern Portugal. This investigation allowed us to propose zoning a coastal structure according to its degree of deterioration, geomechanical properties and geomaterial status. Replacement of the primary armour layer in only selected sections or components of the structure will reduce the cost of maintenance, repair and reinforcement work. All the gathered data about the preservation status of the armour layer and the quarry inventory have been compiled in a powerful GIS geo-database. The paper argues for the wider use of combination of coastal geo-engineering and GIS analysis in planning the monitoring and/or maintenance of marine works using armourstone.

Abstract
In this article, an algorithm to identify LPV State Space models for both continuous-time and discrete-time systems is proposed. The LPV state space system is in the Companion Reachable Canonical Form. The output vector coefficients are linear combinations of a set of a possibly infinite number of nonlinear basis functions dependent on the scheduling signal, the state matrix is either time invariant or a linear combination of a finite number of basis functions of the scheduling signal and the input vector is time invariant. This model structure, although simple, can describe accurately the behaviour of many nonlinear SISO systems by an adequate choice of the scheduling signal. It also partially solves the problems of structural bias caused by inaccurate selection of the basis functions and high variance of the estimates due to over-parameterisation. The use of an infinite number of basis functions in the output vector increases the flexibility to describe complex functions and makes it possible to learn the underlying dependencies of these coefficients from the data. A Least Squares Support Vector Machine (LS-SVM) approach is used to address the infinite dimension of the output coefficients. Since there is a linear dependence of the output on the output vector coefficients and, on the other hand, the LS-SVM solution is a nonlinear function of the state and input matrix coefficients, the LPV system is identified by minimising a quadratic function of the output function in a reduced parameter space; the minimisation of the error is performed by a separable approach where the parameters of the fixed matrices are calculated using a gradient method. The derivatives required by this algorithm are the output of either an LTI or an LPV (in the case of a time-varying SS matrix) system, that need to be simulated at every iteration. The effectiveness of the algorithm is assessed on several simulated examples.

Abstract
The Geophysical Institute of the University of Porto (IGUP) constitutes an important pillar in the scientific and technological culture, developed over more than a century in the city of Porto. A strategic plan for its recovery has been recently developed. In terms of instruments there are currently some instruments related to seismology, meteorology and radiation, which are directly related to the measurement of variables involved in the estimation of seismic hazard and risk, meteorological hazards and radiological hazards. Thus IGUP has the potential to become a center for research in the field of Natural Hazards that in turn may contribute to studies, data and parameters for civil society and the scientific community. The Recovery that is already underway in seismic station, previously included as PTO in the world network known as Worldwide Standardized seismographic Network (WWSSN), can help achieve the implementation of a complex research in seismology and simultaneously acknowledging the geopolitical importance of this stations records. With the current work we intend to show a brief analysis of a few previously unknown seismic records, relating to Soviet nuclear explosions, as well as a few aspects of the the digital signal conversion adaptation of the previous 1960s analogue equipment.