Browsing by Author "Silva-Afonso, Armando"
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- Contributions to the improvement of green roofs in Mediterranean climate, including rainwater harvestingPublication . Monteiro, Cristina; Calheiros, Cristina; Pimentel-Rodrigues, Carla; Silva-Afonso, Armando; Castro, Paula M. L.Green roofs (a type of construction that uses vegetation on the top of buildings) present the opportunity to contribute to the ecological sustainability of the urban environment in many ways, such as favouring the thermal performance of buildings and increasing humidity and contributing to CO2 sequestration in cities. On the other hand, rainwater harvesting is also important in urban areas, not only as a contribution for the global sustainability of buildings, through the increase of their water efficiency, but also to reduce flood peaks on public stormwater drainage systems. Green roofs and rainwater harvesting systems are technologies already known in the world, but for which there are a wide possibility of development and improvement, especially with regard to their adaptation to regional climates, such as the Mediterranean one. These technologies are particularly important in the Mediterranean basin, at risk of high water stress, and must be combined properly in view of the climate specificity. This paper describes the studies in this area conducted by Portuguese Catholic University/College of Biotechnology, in collaboration with ANQIP, a Portuguese Civil Society Association working on water efficiency in buildings, in terms of substrates, runoff coefficients and water quality collected in a pilot green roof. This study seeks to improve the basis for the design of rainwater harvesting systems in buildings with green roofs and a new expression is proposed for calculating monthly runoff coefficients under Mediterranean climate in extensive green roofs.
- Contributos para a adoção dos telhados verdes como tecnologia de retenção e aproveitamento de águas pluviaisPublication . Monteiro, Cristina; Calheiros, Cristina; Pimentel-Rodrigues, Carla; Silva-Afonso, Armando; Castro, Paula M. L.Os telhados verdes são uma solução arquitetónica que consiste na aplicação de substrato e vegetação sobre a cobertura impermeável de um edifício. A sua aplicação tem vindo a aumentar nos últimos anos, pelo facto de apresentar inúmeras vantagens, nomeadamente melhoria da qualidade do ar em áreas urbanas, promoção de ecossistemas nas cidades, redução do efeito “ilha de calor” e melhoria da eficiência tanto energética como acústica dos edifícios. Os telhados verdes reduzem também os caudais de ponta na drenagem pluvial, contribuindo para amortecer os picos de cheia em ambiente urbano, e são uma solução promissora para a melhoria da qualidade da água de escoamento, visando um posterior aproveitamento. Neste trabalho, desenvolveu-se um telhado verde experimental utilizando plantas aromáticas autóctones, com o objetivo de avaliar a qualidade da água da chuva após passagem por um substrato selecionado, bem como caracterizar o ciclo da água (escoamento, retenção, etc.) de forma a fornecer contributos para a expansão da aplicação deste tipo de tecnologias conjuntamente para o aproveitamento de águas pluviais em edifícios. Os principais resultados obtidos permitiram o desenvolvimento de um modelo referente à determinação do coeficiente de escoamento, bem como a caracterização da qualidade da água na perspetiva de posterior reutilização.
- Green roofs as a technology for rainwater retentionPublication . Monteiro, Cristina; Calheiros, Cristina; Pimentel-Rodrigues, Carla; Silva-Afonso, Armando; Castro, Paula M. L.Green roofs (GR) or living roofs are a technology of roof construction with a vegetation layer on the top of a building, which has a growing dissemination. Advantages include improvement of air quality in urban areas, generation of life ecosystems in urban cities and enhancement of both energetic and acoustic efficiency of buildings. Nowadays, they arise as potential solution for the improvement of the quality of stormwater runoff for later reuse, as well as rainwater retention in the urban scenario, decreasing water runoff. In that context the major goal of the present study is to establish a GR, with autochthonous aromatic species, aiming at evaluating the characteristics of rainwater runoff after crossing a selected substrate and its retention capacity, with a view to expand the technology application. The main outcomes allowed developing a model regarding the runoff coefficients and aspects of water quality and its reuse, promoting the development of GR technology and also the improvement of the design of rainwater harvesting systems in buildings with GR.
- Green Roofs as a tool to promote water efficiency in buildingsPublication . Monteiro, Cristina; Calheiros, Cristina; Pimentel-Rodrigues, Carla; Silva-Afonso, Armando; Castro, Paula M. L.
- Green roofs as contributors for water management schemes within urban areas : a pilot study in PortoPublication . Monteiro, Cristina; Calheiros, Cristina; Pimentel-Rodrigues, Carla; Palha, Paulo; Silva-Afonso, Armando; Castro, PaulaWater scarcity is an issue of worldwide concern and a holistic approach to water management is needed to overcome the potential threats that climate change brings to water availability and security in many parts of the globe. Societal and economic challenges need to be addressed when implementing technological solutions to environmental problems. The fact that green areas in the cities have been reduced and replaced by impervious buildings and paved streets has caused a number of problems, such as an increase in the amount of stormwater runoff discharged into the public drainage system. Green roof (GR) structures promote several ecosystem services and can counteract such effect and contribute to manage stormwater floods within city settlings, at the same time allowing for their storage for later reuse by collecting some of the rainwater into the growing substrate and reducing the runoff into the public drainage system (Schroll et al., 2011), and these advantages can be enhanced with the installation of a system of rainwater harvesting in the buildings. At the same time, Mediterranean countries are among those with high risk of water stress and rainwater harvesting in buildings can be a measure to promote water use efficiency. The present research study shows an example of established GRs at a pilot scale in the city of Porto (fig 1) (Monteiro et al., 2016). Different growing substrates and aromatic plants species were used to evaluate the runoff coefficients applicable to our Mediterranean climate, in order to assess the GR capacity for rainwater runoff delay. This contributes to improve the basis for the design of rainwater harvesting systems in buildings with GR in Mediterranean climate, particularly in regard to runoff coefficients and aspects of water quality and its reuse.
- The impact of green roofs (GR) runoff in storm water quality and quantityPublication . Santos, Cristina; Monteiro, Cristina M.; Matos, Cristina; Briga-Sá, Ana; Silva-Afonso, Armando; Pimentel-Rodrigues, Carla
- The impact of green roofs (GR) runoff in storm water quality and quantityPublication . Santos, Cristina; Monteiro, Cristina; Matos, Cristina; Briga-Sá, Ana; Silva-Afonso, Armando; Pimentel-Rodrigues, CarlaNature-based solutions are being worldwide implemented in highly impermeabilized city centres, due to the environmental benefits they generate and their contribution to urban sustainability and resilience, especially regarding stormwater management issues. The impact of Nature-based Solutions in the surrounding environment where they are set up, considering all the environmental aspects they have an effect on, with a special focus on stormwater management, is a fundamental aspect that must be addressed before promoting their large-scale implementation. In this scope, this study intended to address the influence of Green Roofs (GR) on rainwater quality and quantity, based on scientific experimental studies published worldwide. The compiled results show that GR dimensions, GR composition of the different layers and plant species used, amongst other characteristics, have a major influence on the quality and quantity of the rainwater downstream. In some reported cases, the quality of the drained rainwater resulted worst and for some conditions, the effect on rainwater retention was minimal, contrary to what was expected. The factors that resulted in these inconveniences are well defined and must be minimized in future GR construction and maintenance. GR are key elements to make resilient cities and thus, a clear understanding of their operation is fundamental to avoid water degradation and minimize potential impacts of malfunctioning of these structures. Furthermore, it is essential to choose the best combination of GR materials regarding water retention, to set GR systems adapted to local climate conditions and the present climate change scenario, with high performance in water management, to help urban areas dealing with extreme precipitation events, avoiding thus the consequent floods and economic damages that arise.