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- Permeable pavements – green infrastructures as a flood mitigation measurePublication . Afonso, Márcia Isabel Lopes; Almeida, Marisa S. Dinis; Fael, Cristina Maria SenaPermeable asphalt pavements have been one of the solutions used to increase the permeability of road pavements given the growing urbanization and climate change. The high porosity and permeability of surface layers with PA (porous asphalt) mixtures allows the water infiltration and, consequently, reduces superficial runoff and contributes to the recharge of underground aquifers. However, the infiltration capacity may be impaired by clogged pores with sediments. The double layer porous asphalt (DLPA) was developed to mitigate this effect. This is a key issue in the pavements’ service life. Information on the clogging processes in these layers is not yet well characterized. The study was carried out using a rainfall simulator in order to generate design storm events with a known intensity and duration. The experimental methodology adopted took into account different phases of evaluation of the infiltration capacity with two clogging cycles (500 and 1000 g m-2). The DLPA infiltration capacity was evaluated in the different phases after different precipitation events (100, 200 and 300 mm h-1). The results showed that, in general, the double layer porous asphalt has the capacity to drain the water, even after clogging and with lower voids content. The infiltration capacity was partially restored when subjected to simple maintenance.
- Flow-3D Modelling of the Debris Effect on Maximum Scour Hole Depth at Bridge PiersPublication . Mendonça, Inês Sofia Pereira; Canilho, Hugo Daniel Leitão; Fael, Cristina Maria SenaBridge foundations are frequently inserted in riverbeds constituted by alluvial material, being, therefore, subjected to scouring processes. Such phenomenon is aggravated during flood events due to the increase of water flow or due to the increase of the debris carried by the flow that can pile up along the bridge structural elements. The debris can partially obstruct bridge spans and accumulate near bridge piers and abutments, which will have consequences in terms of reduction of flow capacity and an increment of the maximum scour depth. The dimensions, shape and its location are characteristics that must be considered when predicting the scour depth. The present study aims at analyzing the effect of the debris on the maximum clear-water scour depth at cylindrical piers inserted in uniform sand, non-ripple forming sand, fully-developed turbulent flows in wide rectangular channel, using computational fluid dynamics software, Flow-3D. For this purpose, debris with a triangular and rectangular shape, floating and on the sand bed, were tested, using the k-ε RNG turbulence model and the numerical results were compared with those obtained experimentally. It was possible to verify that the floating debris gives greater scour hole depth and the debris on sand bed behave as scour countermeasure reducing the scour hole depth. Also, rectangular shaped debris seems to cause more scour near the structures than the triangular shaped ones, which also seemed beneficial to the scour hole, by reducing it. However, the results obtained computationally are significantly lower than those obtained experimentally.
- Water-Energy Nexus: Review of Literature in Management of Integrated Systems, Challenges and Opportunities. Case Study in Urban ContextPublication . Silva, Ana Rita Carriço; Santos, Fernando Charrua; Espírito Santo, António; Páscoa, J. C.; Fael, Cristina Maria SenaIn a society where Energy and Water walk side by side in practically all sectors of activity, it becomes necessary to analyze them from a productive, economic and sustainable point of view. From the extraction of mines and wells, to its treatment and transportation, and to the cooling systems of energy production, and despite being independently developed, managed and regulated, it is known that water needs energy and energy needs water. All these concerns, decision-making and the relationship between water and energy by itself create an opportunity to improve management in both sectors. There is an urgent need to consider all the assumptions and alternatives to improve the system and reduce energy consumption, which includes technological modifications and optimized resources management, leading to a more sustainable future. The increasing demand for energy and its exponential trend will have repercussions at all levels and will consequently increase the strain on freshwater resources with the most affected agricultural and industrial sectors. By improving the efficiency of water and energy use, there are positive repercussions that allow for substantial savings, especially where there is a lack of such resources. This article aims to address all these crucial issues related to energy and water in order to increase knowledge on the subject and to help promote alternatives for managing and developing integrated management systems and, consequently, for a rational use of both resources and a more sustainable future.
- Development of the Concept vs Prototyping: Implementation of a real scale Water-Energy Integrated SystemPublication . Silva, Ana Rita; Santos, Fernando Charrua; Espírito Santo, António; Páscoa, J. C.; Fael, Cristina Maria SenaCurrently, the concept of smart cities and renewable energy are more consolidated and developed. With each passing day, new technological advances are emerging within both themes. At the same time, the water sector has becoming increasingly demanding in terms of quality and compliance with all existing legislation. That said, it is understandable that both sectors and their management entities come together in search of more sustainable operations that go against the reduction of greenhouse gas emissions, decentralization of energy production and the improvement of efficiency, quality and use of resources. It is important to understand the synergies between water and energy to contradict what has been said so far about the increasing demand for energy, its exponential trend and the negative repercussions on freshwater resources. As such, this article aims to address the interconnection between both sectors to promote alternative scientific and technological improvements to the management and development of Integrated Water-Energy systems, while studying the dynamics between the theoretical development of the problem and the challenges of prototyping of such complex systems in real and urban context.
- Influence of a Bubble Curtain Device on Microplastics DynamicsPublication . Santos, César Augusto Vaz; Camacho, E. A. R.; Silva, André; Fael, Cristina Maria SenaAir bubble curtains have been applied to a wide range of situations, from the attenuation of underwater noise, debris control, and containment of suspended sediment to the reduction in saltwater intrusion. This work conducts a preliminary numerical study on the influence of a bubble curtain device on microplastic dynamics. Simulations are conducted with a two-phase unsteady model, and the trajectories of the microplastic particles are computed with the Discrete Phase Model (DPM). Particles are injected upstream of the bubble curtain, and their transport is analyzed under different flow conditions. Results show that the ratio between the water velocity and the air injection velocity can significantly impact the efficiency of the device in directing the particles toward the surface. Furthermore, a higher degree of turbulent mixing is seen for lower water velocities. This study highlights the intricate flow behavior, and the need for a deeper understanding of other variables such as the microplastic size and concentration and the geometry of the air injection system.
- Clear-water scour at submerged pile groupsPublication . Galán, Álvaro; Simarro, Gonzalo; Fael, Cristina Maria Sena; Cardoso, António HelenoAccurate estimates of the scour depth around submerged pile groups are important in river engineering for a number of reasons, however, the literature on this issue is scarce. This study introduced an experimental campaign of 48 long-duration clear water experiments at submerged and skewed pile groups composed of cylindrical elements under steady flow. The effects of the skew angle, submergence ratio and pile group configuration on the equilibrium scour depth were investigated. The experimental scour depths were compared with the results from the HEC-18 empirical method and a modification of it to take into account a wide range of submergence ratios was proposed. Further, a new formulation to estimate the equilibrium scour depth at submerged pile groups was introduced with good agreement for the tests under consideration. Some considerations about the most employed characteristic lengths used to normalize the equilibrium scour depth were made.
- Repensar os pavimentos urbanos face ao impacto das mudanças climáticasPublication . Fael, Cristina Maria Sena; Almeida, Marisa S. Dinis; Afonso, MárciaAs alterações climáticas, nomeadamente as mudanças dos padrões de precipitação, têm sofrido uma forte aceleração e a tendência é que se tornem mais frequentes e intensos acarretando riscos como inundações e secas. Fazem-se sentir ao nível da qualidade da água superficial e subterrânea, na biodiversidade e ecossistemas territoriais e dos solos para agricultura. Os pavimentos betuminosos permeáveis, pelas suas propriedades de elevada permeabilidade e porosidade, apresentam-se eficazes no que diz respeito à redução da taxa de escoamento superficial e ao aumento da infiltração da água para o solo.
- Characterization of the Skid Resistance and Mean Texture Depth in a Permeable Asphalt PavementPublication . Afonso, Márcia Isabel Lopes; Almeida, Marisa S. Dinis; Fael, Cristina Maria SenaRoad pavements need a deep characterization of the surface layer, with which the vehicles have direct contact and, therefore, must provide security to the users. The use of permeable asphalt pavements (PAP) with porous layers has provide obvious advantages in reducing runoff and the rainwater infiltration into the soil or for storage. However, the study of the interaction between the pavement surface layer and the tire rubber requires additional tests in terms of texture and friction, since they are important parameters for the design, construction, management, maintenance and roads safety. Considering the application of a PAP in a parking lot, the study objective was to characterize in the field the pavement surface in terms of mean texture depth (MTD) and skid resistance (Pendulum test value, PTV). The methods used were the volumetric technique by the patch test and the pendulum test, according to EN 13036-1 and EN 13036-4, respectively. The double layer porous asphalt (DLPA) at the surface is characterized by having a structure with high voids content that led to results of clearly rougher macrotexture and good skid resistance. The normalized limit values were met, however, a very strong correlation between MTD and PTV was not observed. A comparison was also made with porous surfaces of other studies and it was found that porous asphalt has a good behaviour at the start of construction which may tend to improve in the long term. From the study, it is concluded that the PAP presents good performance of the surface layer, providing road safety to users.
- Qualitative approach for assessing runoff temporal dependence through geometrical symmetryPublication . Zazo, Santiago; Macian-Sorribes, Hector; Fael, Cristina Maria Sena; Martín, Ana María; Molina, Jose-Luis; Pulido-Velazquez, ManuelCurrently, noticeable changes in traditional hydrological patterns are being observed on the short and medium-term. These modifications are adding a growing variability on water resources behaviour, especially evident in its availability. Consequently, for a better understanding/knowledge of temporal alterations, it is crucial to develop new analytical strategies which are capable of capturing these modifications on its temporal behaviour. This challenge is here addressed via a purely stochastic methodology on annual runoff time series. This is performed through the propagation of temporal dependence strength over the time, by means of Causality, supported by Causal Reasoning (Bayes’ theorem), via the relative percentage of runoff change that a time-step produces on the following ones. The result is a dependence mitigation graph, whose analysis of its symmetry provides an innovative qualitative approach to assess time-dependency from a dynamic and continuous perspective against the classical, static and punctual result that a correlogram offers. This was evaluated/applied to four Spanish unregulated river sub-basins; firstly on two Douro/Duero River Basin exemplary case studies (the largest river basin at Iberian Peninsula) with a clearly opposite temporal behaviour, and subsequently applied to two watersheds belonging to Jucar River Basin (Iberian Peninsula Mediterranean side), characterised by suffering regular drought conditions.
- Pavimentos Betuminosos PermeáveisPublication . Almeida, Marisa S. Dinis; Afonso, Márcia Isabel Lopes; Fael, Cristina Maria SenaAs alterações climáticas têm conduzido a padrões de precipitação mais elevados e frequentes, causando um aumento instantâneo das águas pluviais que acarretam riscos como inundações.
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