S. Rafael
University of Aveiro
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Publication
Featured researches published by S. Rafael.
Science of The Total Environment | 2015
S. Rafael; L. Tarelho; A. Monteiro; E. Sá; Ana Isabel Miranda; C. Borrego; M. Lopes
The increase of the share of renewable energy in Portugal can be met from different sources, of which forest biomass residues (FBR) can play a main role. Taking into account the demand for information about the strategy of FBR to energy, and its implications on the Portuguese climate policy, the impact of energy conversion of FBR on air quality is evaluated. Three emission scenarios were defined and a numerical air quality model was selected to perform this evaluation. The results reveal that the biomass thermal plants contribute to an increment of the pollutant concentrations in the atmosphere, however restricted to the surrounding areas of the thermal plants, and most significant for NO₂ and O₃.
Science of The Total Environment | 2016
S. Rafael; Helena Martins; E. Sá; D. Carvalho; C. Borrego; M. Lopes
Different urban resilience measures, such as the increase of urban green areas and the application of white roofs, were evaluated with the WRF-SUEWS modelling system. The case study consists of five heat waves occurring in Porto (Portugal) urban area in a future climate scenario. Meteorological forcing and boundary data were downscaled for Porto urban area from the CMIP5 earth system model MPI-ESM, for the Representative Concentration Pathway RCP8.5 scenario. The influence of different resilience measures on the energy balance components was quantified and compared between each other. Results show that the inclusion of green urban areas increases the evaporation and the availability of surface moisture, redirecting the energy to the form of latent heat flux (maximum increase of +200Wm(-2)) rather than to sensible heat. The application of white roofs increases the solar radiation reflection, due to the higher albedo of such surfaces, reducing both sensible and storage heat flux (maximum reductions of -62.8 and -35Wm(-2), respectively). The conjugations of the individual benefits related to each resilience measure shows that this measure is the most effective one in terms of improving the thermal comfort of the urban population, particularly due to the reduction of both sensible and storage heat flux. The obtained results contribute to the knowledge of the surface-atmosphere exchanges and can be of great importance for stakeholders and decision-makers.
Science of The Total Environment | 2018
Paula Quinteiro; S. Rafael; Pedro Villanueva-Rey; Bradley G. Ridoutt; M. Lopes; Luís Arroja; Ana Cláudia Dias
The development of methods to assess the potential environmental impact of green water consumption in life cycle assessment has lagged behind those for blue water use, which are now routinely applied in industrial and policy-related studies. This represents a critical gap in the assessment of land-based production systems and the ability to inform policy related to the bio-economy. Combining satellite remote sensing and meteorological data sets, this study develops two new sets of spatially-differentiated and globally applicable characterisation factors (CFs) to assess the environmental impact of green water flows in LCA. One set of CFs addresses the impact of shifts in water vapour flow by evapotranspiration on blue water availability (CFWS) and the other set of CFs addresses moisture recycling within a basin (CFWA). Furthermore, as an additional and optional step, these two indicators are combined into an aggregated green water scarcity indicator, representing the global variability of green water scarcity. The values obtained for CFWA show that there are significant changes in green water flows that were returned to the atmosphere in Alaska (covered by open shrublands) and in some central regions of China (covered by grasslands and barren or sparsely vegetated land), where precipitation levels are lower than 10 mm/yr. The results obtained for CFWS indicate that severe perturbations in surface blue water production occur, particularly in central regions of China (covered by grasslands), the southeast of Australia (covered by evergreen broadleaf forest) and in some central regions of the USA (covered by grassland and evergreen needleleaf forest). The application of the green water scarcity CFs enables the evaluation of the potential environmental impact due to green water consumption by agricultural and forestry products, informing both technical and non-technical audiences and decision-makers for the purpose of strategic planning of land use and to identify green water protection measures.
Archive | 2018
Vera Rodrigues; S. Rafael; Sandra Sorte; Sílvia Coelho; HélderRelvas; Bruno Vicente; Joana Leitão; M. Lopes; Ana IsabelMiranda; C. Borrego
Green infrastructures play an essential role in urban planning, namely with their potential to reduce the impact from air pollution episodes together with extreme weather events. This chapter focuses on the assessment of green infrastructures’ benefits on current and future microclimate and air quality patterns in Porto’s urban area (Portugal). The effects of green infrastructures on flow dynamics are evaluated for the baseline scenarios by means of numerical and physical simulations, using the computational fluid dynamics (CFD) model VADIS and the wind tunnel of the University of Aveiro. The baseline morphological (BM) scenario focuses on the current morphological characteristics of Porto’s urban area, while a baseline green (BG) scenario comprises the replacement of built-up areas by green areas and parks. In addition, the benefits of green infrastructures on air quality are assessed for the baseline and under future climate scenarios. The air quality simulations focus on particulate matter, one of the most critical air pollutants with severe impacts on human health. For the BM scenario, the simulated concentrations are compared with hourly averaged PM10 concentrations measured during a weekday at the air quality station located within the study domain.
Environmental Research | 2017
S. Rafael; Helena Martins; Martinho Marta-Almeida; E. Sá; Sílvia Coelho; A. Rocha; C. Borrego; M. Lopes
&NA; Climate change and the growth of urban populations are two of the main challenges facing Europe today. These issues are linked as climate change results in serious challenges for cities. Recent attention has focused on how urban surface‐atmosphere exchanges of heat and water will be affected by climate change and the implications for urban planning and sustainability. In this study energy fluxes for Greater Porto area, Portugal, were estimated and the influence of the projected climate change evaluated. To accomplish this, the Weather Research and Forecasting Model (WRF) and the Surface Urban Energy and Water Balance Scheme (SUEWS) were applied for two climatological scenarios: a present (or reference, 1986–2005) scenario and a future scenario (2046–2065), in this case the Representative Concentration Pathway RCP8.5, which reflects the worst set of expectations (with the most onerous impacts). The results show that for the future climate conditions, the incoming shortwave radiation will increase by around 10%, the sensible heat flux around 40% and the net storage heat flux around 35%. In contrast, the latent heat flux will decrease about 20%. The changes in the magnitude of the different fluxes result in an increase of the net all‐wave radiation by 15%. The implications of the changes of the energy balance on the meteorological variables are discussed, particularly in terms of temperature and precipitation. Graphical abstract: Figure. No caption available. HighlightsAssessment of energy fluxes behaviour under past period and medium‐term climate change projection.Evaluation of climate change at urban scale.Meteorological variables alters the partitioning of the energy fluxes.Changes in the partition of the annual energy balance are found between the two analysed periods.Increase in the magnitude of sensible and storage heat fluxes.
Artificial Intelligence Review | 2015
S. Rafael; Helena Martins; C. Borrego; M. Lopes
Notwithstanding the increasing number of studies on vulnerability, there has been relatively little research focused specifically on urban vulnerability to climate change. The different lineages explored offer insights into the factors that control urban vulnerability to climate change and weather extremes effects, providing a framework to consider resilience. A new vulnerability paradigm is emerging as a useful tool for city decision-makers to analyse how their city should seek to adapt to the anticipated impacts of climate change. In the scope of the project CLICURB (Urban atmospheric quality, climate change and resilience) urban vulnerability is explored with respect to recent climate change and the relations between the concepts of vulnerability, resilience and adaptive capacity. This review and analysis contributes to the understanding of, and the general agreement amongst research communities, about the definition of these key concepts with respect to the climate change literature in urban areas.
International Journal of Environmental Impacts: Management, Mitigation and Recovery | 2018
C. Borrego; S. Rafael; Vera Rodrigues; A. Monteiro; Sandra Sorte; Sílvia Coelho; M. Lopes
Cities are home of about 70% of the European population, and it is expected that by 2050 this number will be achieved around the world. As a result, cities are facing important challenges related to pressures induced by changes on urban metabolism and by climate change (CC) effects. Understanding the key factors determining the vulnerability of a city provides a framework to consider resilience. These issues become more and more relevant since changes in urban structure and metabolism together with CC will start affecting atmospheric emissions, urban air quality and consequently human health. Cobenefits of an urban air quality and CC approach need to be further addressed taking into consideration that CC creates both risks and opportunities. Therefore, an integrated assessment of the interaction between resilience factors and CC effects, and its influence on the urban microclimate and air quality, is required to better adapt to future climate. This knowledge is fundamental to support policy makers and stakeholders helping them to choose the best strategies to manage resources, to mitigate extreme weather events and to predict air pollution episodes. This article offers a systematic review on CC impacts in cities, providing some adaptation strategies and suggesting future research topics.
Air Quality, Atmosphere & Health | 2018
Bruno Vicente; S. Rafael; Vera Rodrigues; Helder Relvas; Mariana Vilaça; João Teixeira; Jorge Bandeira; Margarida C. Coelho; C. Borrego
Urban mobility accounts for 38 and 19% of nitrogen oxide (NOx) and particulate matter (PM) emissions at European urban areas, respectively. Despite of all the technological development around automobile industry, urban areas are still facing problems related to exposure to high levels of air pollutants. Increasing the accuracy of both emissions and air quality modelling from road traffic is a key-issue for the management of air pollution in road transport sector. This study assessed the influence of using different road traffic emission models on the accuracy of air quality modelling with street-level resolution, having as a case study an urban area located on the centre region of Portugal. Two emission models, with different complexity levels regarding the ability to characterise the traffic dynamics were analysed, namely, transport emission model for line sources (TREM) and vehicle-specific power (VSP), based on data obtained in an experimental campaign. To perform the air quality simulations, the pollutant dispersion in the atmosphere under variable wind conditions (VADIS) model was used and two pollutants were analysed: NOx and PM10. The results showed that the magnitude of PM10 and NOx concentrations were result of a conjoint influence of traffic dynamics and meteorological conditions. Comparison between measured and modelled data showed that the VADIS model could track the evolution of NOx levels, for both emission models considered, displaying a high correlation (> 0.8) between traffic-related NOx emissions and NOx concentrations. For PM10, VADIS model is more sensitive to the differences in the emissions calculation; however, it was observed that the traffic-related PM10 emissions accounts 1.3–8.4% to the PM10 concentration levels at the study area.
Air Quality, Atmosphere & Health | 2018
Sílvia Coelho; S. Rafael; S. Silva; M. Pinho; L. Tarelho; M. Lopes
The increased knowledge and awareness of the impacts of climate change on global environment and its linkage to the greenhouse gases emissions (GHG) has resulted in an expansion of a set of European policies during the past decades. Since the energy sector is one of the major contributors of GHG emissions, the need to mitigate the climate change impacts has led to a diversification of the world’s energy mix, promoted by an increased demand for renewable energy sources. The Portuguese government considers the use of biomass for pellet production as a key factor to accomplish the national goals established in the energy strategy for renewable energy sources. However, few studies have evaluated the potential impact of this type of bioenergy on air quality. In this context, a case study was selected to estimate the atmospheric emissions of the pellet energy supply chain in Portugal. A comparison of both pellet and forest biomass residue energy supply chain in terms of atmospheric emissions was performed. Results show that the pellet production is the process with the largest contribution to CO2e and SOx emissions (with a contribution higher than 90%); the domestic combustion is mainly responsible for total suspended particle and CO emissions; NOx is a result of both production and combustion processes, and non-methane volatile organic compound is a result of the forest exploitation. Compared with the forest biomass residue energy supply chain, the pellet energy supply chain produces higher atmospheric emissions.
Artificial Intelligence Review | 2017
Sílvia Coelho; Joana Ferreira; Vera Rodrigues; S. Rafael; C. Borrego; M. Lopes
Air pollution has become a growing concern in the past few years, with an increasing number of acute air pollution episodes in many cities worldwide. Ozone (O3) is a powerful oxidising agent and one of the air pollutants of most concern in Europe. Source apportionment modelling provides valuable information on the contributions of different source sectors and source regions to ozone concentrations. This information can be useful in designing air quality management strategies and in understanding the potential benefits of reducing emissions from a particular source category. In the present work, the Comprehensive Air Quality Model with Extensions (CAMx), with its Ozone Source Apportionment Technology (OSAT), was applied over Amsterdam Region, Netherlands, for the period of 8th to 12th July 2010, when high concentration of ozone were measured in several air quality monitoring stations in the region of Amsterdam. The contributions of different source categories and the NOx/VOC limitation to the ozone formation were quantified. Results indicated a great influence of transboundary transport on the O3 simulated concentrations. The OSAT tool revealed that this is the main factor affecting O3 levels in the area of study, followed by VOC emissions from solvent use and NOx emissions from industry and other sources not individually analysed. O3 formation is slightly more NOx limited than VOC limited.