5678 research outputs found
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Combinação do método da resistividade elétrica com registos contínuos de condutividade elétrica e de nível piezométrico num ensaio de recarga de aquífero
No full textNo âmbito do projeto MARSOL (http://www.marsol.eu/) foram realizados no Algarve diversos ensaios de gestão de recarga de aquíferos, com recurso a diferentes técnicas. Na presente comunicação apresentam-se os resultados de um desses ensaios, de injeção de água num poço, onde se colocou sal como traçador. Este ensaio foi monitorizado com recurso a perfis de resistividade elétrica e a sondas de registo contínuo da condutividade elétrica e da pressão, instaladas no poço onde foi feita a recarga e em furos e poços situados na sua vizinhança. Nos resultados obtidos destaca-se a deteção do retorno do traçador salino introduzido no poço e a determinação da direção de escoamento subterrâneo.4pDG/NGE
An index-based method for coastal-flood risk assessment in low-lying areas (Costa de Caparica, Portugal)
No full textThe coastal area of Costa de Caparica is an important territory representing one of the main affected areas by storms such as Hercules in 2013 and 2014. This paper propose a new coastal risk assessment to coastal floods, combining GIS-based inundation analysis over the last 35 years, coastal vulnerability model based on geological and physical variables and, valuation of surface' elements exposed to storms considering territorial and human components. Along with the methodology proposed for local scale, this paper points out strengths and weakness, comparing the results with another simple method to achieve coastal risk by floods. Based on this study, the paper identifies potential directions for future research contributing in management, rescue and safety decisions with local authorities.90-104ppVolume 144DHA/NPEOcean & Coastal Managemen
Windows from a Lisbon palace. Heritage values for sustainable construction
No full textWindows are an essential element of façades providing building identity. Windows are
also an important element for occupant’s wellbeing and to decrease energy demand
for heating, cooling ventilation and lighting. The recent development of material and
technological process changed the shape, size and functionality of windows. This
article describe the windows main characteristics from a Lisbon Palace, presenting
their technological solutions, performance and heritage value for sustainable
construction.10pDED/NAIC
Storm-induced marine flooding: lessons from a multidisciplinary approach
No full textThere is a growing interest for marine flooding related to recent catastrophic events and their unintended consequences in terms of casualties and damages, and to the increasing population and issues along the coasts in a context of changing climate. Consequently, the knowledge on marine flooding has progressed significantly for the last years and this review, focused on storm-induced marine submersions, responds to the need for a synthesis. Three main components are presented in the review: (1) a state-of-the-art on marine submersions from the viewpoint of several scientific disciplines; (2) a selection of examples demonstrating the added value of interdisciplinary approaches to improve our knowledge of marine submersions; (3) a selection of examples showing how the management of future crises or the planning efforts to adapt to marine submersions can be supported by new results or techniques from the research community. From a disciplinary perspective, recent progress were achieved with respect to physical processes, numerical modeling, the knowledge of past marine floods and vulnerability assessment. At a global scale, the most vulnerable coastal areas to marine flooding with high population density are deltas and estuaries. Recent and well-documented floods allow analyzing the vulnerability parameters of different coastal zones. While storm surges can nowadays be reproduced accurately, the modeling of coastal flooding is more challenging, particularly when barrier breaches and wave overtopping have to be accounted for. The chronology of past marine floods can be reconstructed combining historical archives and sediment records. Sediment records of past marine floods localized in back barrier depressions are more adequate to reconstruct past flooding chronology. For the two last centuries, quantitative and descriptive historical data can be used to characterize past marine floods. Beyond providing a chronology of events, sediment records combined with geochronology, statistic analysis and climatology, can be used to reconstruct millennial-scale climate variability and enable a better understanding of the possible regional and local long-term trends in storm activity. Sediment records can also reveal forgotten flooding of exceptional intensity, much more intense than those of the last few decades. Sedimentological and historical archives, combined with highresolution topographic data or numerical hindcast of storms can provide quantitative information and explanations for marine flooding processes. From these approaches, extreme past sea levels height can be determined and are very useful to complete time series provided by the instrumental measurements on shorter time scales. In particular, historical data can improve the determination of the return periods associated with extreme water levels, which are often inaccurate when computed based on instrumental data, due to the presence of gaps and too short time-series. Longterm numerical hindcast of tides and surges can also be used to provide the required time series for statistical analysis. Worst-case scenarios, used to define coastal management plans and strategies, can be obtained from realistic atmospheric settings with different tidal ranges and by shifting the trajectory of storms. Management of future crises and planning efforts to adapt to marine submersions are optimized by predictions of water levels from hydrodynamic models. Such predictions combined with in situ measurements and analysis of human stakes can be used to define a vulnerability index. Then, the efficiency of adaptation measures can be evaluated with respect to the number of lives that could be potentially saved. Numerical experiments also showed that the realignment of coastal defenses could result in water level reduction up to 1 m in the case where large marshes are flooded. Such managed realignment of coastal defenses may constitute a promising adaptation to storm-induced flooding and future sea level rise. From a legal perspective, only a few texts pay specific attention to the risk of marine flooding whether nationally or globally. Recent catastrophic events and their unintended consequences in terms of death and damages have triggered political decisions, like in USA after hurricane Katrina, and in France after catastrophic floods that occurred in 2010.151-184ppVolume 165DHA/NECEarth-Science Review
Soil-Aquifer Treatment as a passive solution to enhance treated wastewater quality
No full textWater scarcity episodes are being experienced in many parts of the Mediterranean Basin as a result of changes in rainfall intensity and duration, causing more intense extreme events, like droughts and river floods. Adaptive and innovative water management strategies, such as the storage of reclaimed water or excess water from different sources in Managed Aquifer Recharge (MAR) schemes, can greatly increase the groundwater availability and therefore help addressing water scarcity challenges. Besides, water quality can be improved during transport of the infiltrated water through the unsaturated and saturated zone, together with Soil-Aquifer-Treatment (SAT) systems, due to chemical and biological reactions, linking water reclamation, water reuse, and water resources management (González et al., 2015).
This paper presents the results of a DEMO scale experiment made in S. Bartolomeu de Messines (SBM) Waste Water Treatment Plant (WWTP), where SAT basin systems were built. The SAT systems aimed to improve the treated effluent water quality prior to its discharge in Ribeiro Meirinho, that later infiltrates in an important karstic aquifer along the river influent sections. The water quality enhancement was obtained using the soil's ability to reduce the concentrations of contaminants, namely pharmaceutical compounds and nutrients, through natural processes (e.g. particle retention, adsorption and biodegradation). Prior to this, soil-column experiments were conducted aiming to reproduce optimal SAT conditions using different soil mixtures as depuration media (Martins, 2016; Martins et al., 2016). The soil physico-chemical conditions were optimized in terms of permeability, organic matter content, and aerobic / anaerobic conditions. The results obtained showed an improvement of water infiltrated through SAT, for several pharmaceuticals and nutrients.
This research was carried out under MARSOL project (Demonstrating Managed Aquifer Recharge as a Solution to Water Scarcity and Drought), whose main objective was to demonstrate that MAR is a sound, safe and sustainable strategy that can be applied with great confidence and therefore offering a key approach for tackling water scarcity in Southern Europe.10pDHA/NR
Assessing intermodal freight transport scenarios bringing the perspective of key stakeholders
No full textThis paper extends the previous R&D project on the evaluation of intermodal freight transport scenarios (seamless multimodal logistic chains) centered in the Port of Sines in Portugal where a set of alternative investment options were compared: (i) maritime – maritime (short-sea-shipping); (ii) maritime-road; (iii) maritime-rail; (iv) maritime-rail-air. This paper aims to bring the perspective of key stakeholders gathered in a specific workshop and assesses the impact of their views in the evaluation of options. The impact analysis focuses on most critical operational and environmental variables, namely shipping speed and CO2 emissions.900-915ppEstudo realizado no âmbito de projeto de investigação financiado pela FCT (Investigadora responsável: Elisabete Arsenio G. Almeida, PhD pelo Institute for Transport Studies, Universidade de Leeds, Reino Unido). Estudo apoiado pela APS.25CDT/NPTSTransportation Research Procedi
Functional rehabilitation of heritage buildings based on reinforced concrete structural elements. Cultural/historic values and public utility to consider
No full textFor the definition of conservation and rehabilitation actions in buildings of heritage value, it is necessary to take into account the significant evolution processed in several functional aspects of these buildings. The complexity of the issues involved in conservation and repair of their construction elements and functional rehabilitation requires knowledge in several domains, in order to integrate, in an interdisciplinary and multidisciplinary way, the functional requirements that are needed to be considered.
This article focuses attention on the buildings classified as cultural heritage as well as buildings not included in this classification, but which present relevant cultural/historical value or public utility. In both cases targeting the set of buildings that are specifically based on structural concrete elements associated to infill or resistant masonry walls.
Relevant aspects of the overall performance of referred heritage buildings are here presented, in particular of their walls and confining elements, concerning the different basic requirements and the other functional requirements.12pCD/C
Concrete block tracking in breakwater models
No full textThe protection of harbours in coastal areas, that are exposed to the action of the sea waves, is made by breakwaters. During the phase of design of new breakwaters or the rehabilitation of existing ones, the evaluation of effectiveness of the shape and of the protective elements to save the harbour, 3D scale models are built inside wave basins or wave flumes. In the testing phase, water waves are generated, and the resulting impact on the breakwater model is periodically evaluated to study the hydraulic and structural behaviour under predefined sea-wave conditions. This study proposes a methodology to estimate displacements of concrete blocks of the outer layer, also called protection layer, of rouble-mound breakwater models. These blocks are placed in the areas where it is expected that action of the waves is stronger. The combination between the 3D information of a point cloud survey and the visual information of a digital image is a key factor for estimate the spatial location of the geometric centre of the blocks. The location of a block centre point, at different instants, gives its spatial displacement. The equipment used for data acquisition tests were a Kinect V2 sensor and a digital camera, with which were obtained the main data sets for this work: RGB imagery and 3D Point Clouds. The data collected by this allowed the generation of point clouds (X, Y and Z) and orthomosaics, both fundamental for the determination of displacements of the blocks. Indeed, displacements detection results from the determination of the spatial coordinates of the several locations of the Geometric Centre of each block, which is in fact the main outcome of this study. It is expected to serve as a contribution to the laboratory teams working at the Harbours and Maritime Structures Division of the Department of Hydraulics and Environment.12pComunicação de acesso livre na InternetDBB/NG
Bingo project: climate change and the groundwater component of the water cycle
No full textClimate change is bound to impact the water cycle and water availability, compounding the sustainable
management of its quantity and quality. Groundwater is bound to suffer the impacts of climate change, coupled
with those of land use changes, population and its lifestyles evolution. Climate change studies normaly have a 50
to 100 years horizon, which is a challenge for decision makers, who usually rely on relatively short therm data
and projections to implement their management policies. BINGO Project tries to address this gap, by providing
information of climate change impacts, including those of extreme events, on the water cycle for the short-tomedium
term. Climate change impacts on groundwater rely on mathematical modeling, using recharge
projections obtained from the climate forecasts of the Regional Climate Models set up for Europe. Sea level
change is also a component of this analysis and its ensuing impacts of saltwater intrusion on the coastal and
estuarine areas of Aluviões do Tejo and Bacia do Tejo-Sado/Margem Esquerda aquifers.4pDHA/NR
Performance of expanded high-density cork agglomerates
No full textPrototype boards of high-density expanded cork agglomerates (230 and 290 kgm−3) were produced and tested for tensile strength (before and after moisture resistance cyclic tests), hardness, thermal conductivity, and reaction to fire. Increases in tensile strength and dimensional stability were observed with the increase in density. No significant change in thermal conductivity was noticed. The application of a varnish resulted in a noticeable increase in hardness for the higher-density cork agglomerate. Reaction to fire was improved from class Efl to class Cfl. The improvement of properties of expanded cork agglomerates from densification can enhance their application in the building sector.04016198-1-04016198-6pp.29DE/NCEJournal of Materials in Civil Engineerin