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- Mestrado em Engenharia Civil: Dissertação, Projeto, Estágio. Anuário 2018Publication . Félix, Carlos; Abreu, Tiago; Jacob, Ângelo; Trigo, José Castro; Pinto-Faria, JoséO anuário 2018 – Dissertação, Projeto, Estágio reúne os resumos dos trabalhos da unidade curricular de Dissertação, Projeto ou Estágio (DIPRE) elaborados pelos estudantes finalistas do Mestrado em Engenharia Civil (MEC) do Instituto Superior de Engenharia do Porto, no ano letivo 2017/2018. Promove-se, deste modo, junto da comunidade técnica e científica, a contribuição do MEC-ISEP para a formação superior especializada, na área da Engenharia Civil. Os resumos estão organizados segundo as áreas de especialização em que se organiza o MEC, nomeadamente, Construções, Estruturas, Gestão da Construção e Infraestruturas, seguindo a ordem alfabética dos seus autores. Os correspondentes textos integrais, dos sessenta e oito trabalhos que constituem o presente Anuário 2018, estão disponíveis em http://recipp.ipp.pt Os temas abordados respondem às escolhas dos estudantes, mas também às necessidades de desenvolvimento sentidas pelos Docentes e pelas Empresas proponentes de estágios. Tais temas, na edição deste ano, são diversificados, ainda que sejam reveladores de um interesse crescente nas áreas da reabilitação do património, da inspeção e do reforço das construções e da sustentabilidade. O BIM continua a ser uma área que tem vindo a merecer uma atenção especial por parte de todos os envolvidos.
- Integrative Groundwater Studies in a Small-Scale Urban Area: Case Study from the Municipality of Penafiel (NW Portugal)Publication . Freitas, Liliana; Chaminé, Helder I.; Afonso, Maria José; Meerkhan, Helen; Abreu, Tiago; Trigo, José Filinto; Pereira, Alcides J. S. C.The occurrence of groundwater in urban hard rock areas is mostly controlled by secondary permeability caused by the fracturing degree and weathering grade. Vulnerability GIS-mapping, monitoring, and infiltration/recharge of water resources, and the delineation of the environmental protective background are key issues in evaluating, planning, managing, and decision-making for urban water systems. A small-scale urban area in Penafiel City was used as a case study. Historical and current scenarios were compared using hydrogeological GIS-based modelling. Water sources and potential contamination sources were mapped around the study area. Groundwater is mainly acidic, with a low mineralization and a Cl-Na to Cl-SO4-Na or Cl-Ca to Cl-SO4-Ca hydrogeochemical facies. Considering potential contamination sources, the moderate and the moderate-high classes dominate the area. The combined approach of the vulnerability indexes suggests that most of the area has a low to moderate vulnerability to contamination. The Infiltration Potential Index in urban areas (IPI-urban) indicates the prevalence of a low to moderate infiltration. Groundwater recharge evaluation indicates values < 2.3 mm/year and <60 mm/year for summer and winter scenarios, respectively. Finally, the investigation addresses insights for decision-makers for the appropriate planning and sustainable management of groundwater resources in small-scale urban areas.
- Evaluation of potential tidal impoundment energy systems in Ria de Aveiro, PortugalPublication . Rocha, João; Abreu, Tiago; Felgueiras, CarlosThe shelving of the seabed and funneling of the water by the estuaries is favorable for tidal impoundment technologies. In this work, the estimation of the tidal potential energy for Ria de Aveiro lagoon was achieved through the application of a model developed in the Delft3D software. This software can reproduce the hydrodynamics of this complex system and simulations were run to identify hot spots to retrieve gravitational potential energy. For the selected places, both power and annual energy were calculated. It was concluded that the tidal energy that can be extracted from Ria de Aveiro is considerable, justifying further studies to consider the accommodation of some type of tidal exploitation, in the foreseeable future.
- Inter- and intra-annual variability of wave energy in Northern mainland Portugal: Application to the HiWave-5 projectPublication . Silva, Kássio; Abreu, Tiago; Oliveira, Tiago C.A.Ocean wave energy capacity has been pointed out as one of the unexplored renewable energy sources to help reach net zero carbon emissions by 2050, contributing to meeting the European Green Deal targets. However, despite the broad range of wave energy converter technologies already developed in a sustainable and economic model, there is still a lack of structured projects with high performance beyond the prototype stage. This paper investigates the potential for large-scale electricity production by the innovative HiWave-5 project in Aguçadoura (on the Northern coast of mainland Portugal). Wind–wave data (1950–2020) from the ERA5 reanalysis model are used to estimate inter- and intra-annual wave energy variability in Aguçadoura. ERA5 data is compared with field wind–wave data recorded between 2012–2019 near the study area. A mean wave power resource of 25.84 kW/m is obtained, for a possible device capture equal to 119.45 kW, despite a considerable intra-annual variability (ranging between 8.03 and 47.57 kW/m) and inter-annual variability (between 18.29 and 35.47 kW/m). Results show that local wave conditions do not substantially compromise the absolute performance of the device, given its survival limitations to adverse conditions. Considering a Levelized Cost of Energy of around €60/MWh, an annual investment of €62 885 is estimated, tending to meet targets for large sustainable electricity generation with the exponential growth expected until 2030, aided by the increase of devices in an energy farm concept. Wave power resources estimated using ERA5 data can underestimate about 7.20% values obtained with the wave buoy data.
- Analysis of Nonlinear Wave Parameters on Ofir Sandy Beach (NW Portugal)Publication . Abreu, Tiago; Silva, Paulo A.; Baptista, Paulo; Pais-Barbosa, Joaquim; Fernández-Fernández, Sandra; Ferreira, Caroline; Matos, JoãoThe characterization of wave transformation processes in the nearshore is of paramount importance when it comes to assessing storm and flooding impacts, sediment transportation and deposition, harbors safety or design of coastal protective structures. This study analyzes nonlinear wave parameters on Ofir sandy beach. This beach is located along the northwest Portuguese coast which is a highly energetic coast exposed to waves generated far away in the Atlantic Ocean. Despite the existence of rocky outcrops in the nearshore and intertidal zones at the study site, reducing the wave energy that reaches the beach, the study site exhibits pronounced erosive processes. Field observations of six near-bottom pressure records collected at the intertidal zone help to characterize the evolution of wave nonlinearities which are directly associated with sediment transport mechanisms. Data results show that there is an interrelation between the characteristics of the waves and the local morphology. It is also possible to ascertain, more clearly, the level of asymmetry present in the waves propagated at different depths, contributing to a better understanding of the local morpho-hydrodynamics.
- Coastal management risk analysis of an embayed beach in Majorca islandPublication . Abreu, Tiago; Parreño-Mas, Benjamín; Pinto-Faria, JoséCoastal erosion affects many coastlines around the world. This is a serious problem for the Balearic Islands, located at the western Mediterranean Sea, since the economy of the region largely relies on tourist activities along the sandy coastline. Therefore, coastal management strategies are required, particularly, in anthropized coasts as it is the case of Cala Millor beach (north-eastern Mallorca). A risk analysis for this micro-tidal sandy beach is performed in this paper. It is recognized that the beach suffers a persistent loss of sediments since its natural balance was changed due to anthropic activities that took place in that Spanish coast in the 1960s. Some solutions can be adopted to solve this problem, but it is important to be aware that, close to the shore, the seabed is covered by a native vegetation known as Posidonia Oceanica. This seagrass meadow plays an important role in this coastal system, being responsible by the lamination of the waves through energy dissipation, which are inextricably linked to coastal morphology. Therefore, any solution needs to address local specificities, and its consequent potential impact must be incorporated into the coastal risk management process. This study analyzes the failure modes identified according to the failure modes and effects analysis/failure mode, effects and criticality analysis, proposing a set of recommendations, in order to mitigate the occurrence of failure modes and to minimize risks.
- Nearshore Bathymetry Retrieval from Wave-Based Inversion for Video ImageryPublication . Santos, Diogo; Abreu, Tiago; Silva, Paulo A.; Santos, Fábio; Baptista, PauloA wavelet-based method for bathymetry retrieval using a sequence of static images of the surface wave field, as obtained from video imagery, is proposed. Synthetic images of the water surface are generated from a numerical Boussinesq type model simulating the propagation of irregular waves. The spectral analysis is used to retrieve both wave periods and wavelengths by evaluating the spectral peaks in the time and spatial domains, respectively. The water depths are estimated using the linear dispersion relation and the results are validated with the model’s bathymetry. To verify the proposed methodology, 2D and 3D simulations considering effects of wave shoaling and refraction were performed for different sea conditions over different seafloors. The method’s ability to reproduce the original bathymetry is shown to be robust in intermediate and shallow waters, being also validated with a real case with images obtained with a shore-based video station. The main improvements of the new method compared to the consideration of a single image, as often used in Satellite Derived Bathymetry, is that the use of successive images enables the consideration of different wave periods, improving depth estimations and not requiring the use of subdomains or filters. This image processing methodology shows very positive results to provide bathymetry maps for shallow marine environments and can be useful to monitor the nearshore with high time- and space-resolution at low cost.
- Mestrado em Engenharia Civil: Dissertação, Projeto, Estágio. Anuário 2017Publication . Félix, Carlos; Abreu, Tiago; Jacob, Ângelo; Trigo, José Castro; Pinto-Faria, JoséA presente publicação, reúne os resumos de todos os trabalhos da unidade curricular de Dissertação, Projeto, Estágio (DIPRE) do Mestrado em Engenharia Civil do Instituto Superior de Engenharia do Porto, na sua edição de 2016/2017, organizados segundo as áreas de especialização em que se organiza o MEC, nomeadamente, Construções, Estruturas, Gestão da Construção e Infraestruturas, seguindo a ordem alfabética dos seus autores. Pretende-se deste modo promover e difundir estes trabalhos, e os resultados que têm vindo a ser alcançados, junto da comunidade técnica e científica.
- From engineering geosciences mapping towards sustainable urban planningPublication . Chaminé, Helder I.; Teixeira, José; Freitas, Liliana; Pires, Ana; Silva, Rui S.; Pinho, Telma; Monteiro, Rosália; Costa, Ana Lúcia; Abreu, Tiago; Trigo, José Filinto; Afonso, Maria José; Carvalho, José MartinsMaps are of key topical importance in urban geoscience and engineering practice, mainly in field data synthesis and communication related to a number of fields, such as geomatic techniques, applied geology and geomorphology, engineering geology, soil and rock geotechnics, slope geotechnics, subsurface site geotechnical investigations, urban hydrology, hydraulics and sanitation, coastal zones management, urban geoarcheology and heritage, planning and land use. The value of preparing engineering geoscience maps and plans specificallyfor urban engineering purposes are still a challenging task, particularly to end-users and planners. Nowadays, the application of Geographic Information Systems to geosciences and engineering has become more common. This paper emphasises the importance of an accurate ground field survey and inventory at several scales, GIS mapping and databases, and integrated multidisciplinary urban studies as useful tools to support a sustainable land use planning. Some selected sites are highlighted to demonstrate the importance of urban mapping for land use planning. Thus, in this study the significance of a smart urban geoscience approach is stressed.
- Retrieval of nearshore bathymetry from Sentinel-1 SAR data in high energetic wave coasts: The Portuguese case studyPublication . Santos, Diogo; Fernández-Fernández, Sandra; Abreu, Tiago; Silva, Paulo A.; Baptista, PauloThe ability to derive bathymetry using remote sensing techniques enables rapid and cost-efficient mapping of large coastal areas. This contribution focuses on the application of both fast Fourier transform (FFT) and wavelet spectral analysis to obtain satellite-derived bathymetry maps of the nearshore, from freely available and easily accessible Sentinel-1 synthetic aperture radar (SAR) data with 10 m pixel resolution. For this purpose, an extension of 220 km of the Portuguese west coast is analyzed using six satellite images obtained during the years 2018, 2019 and 2020. This extension allows to assess the applicability to coastal sectors with distinct geomorphological constraints. The peak wave periods corresponding to the acquisition of these images approximately range between 11 and 16 s. The spectral analysis is carried to estimate the water depths in near-shore water regions from the observed wavelength patterns. This signature of the sea surface, reflected in the variations of the wavelengths, is captured by the satellite images, making it possible to infer the underlying bathymetry. The bathymetric estimates obtained from both methodologies are compared with data extracted from the Coastal Nautical Charts provided by the Portuguese Hydrographic Institute. Wavelet image processing methodology shows very positive results, particularly extending the depth inversion limits of the FFT methodology, allowing to obtain bathymetric data for the entire shoaling zone where the wavelength patterns are visible. The achieved results also highlight that both FFT and wavelet methodologies are dependent from the seabed slope. For gentle slopes, the inferred depths from 2018 SAR images lead to relative errors between 2.5 and 20% when compared with the observed isobaths (10, 20 and 30 m). For steeper slopes, the errors are generally greater than 20% and increase with depth. The capabilities of the wavelet methodology to map shallow marine environments for high energetic coasts seems promising, regarding research purposes and management interventions.