Loading...
16 results
Search Results
Now showing 1 - 10 of 16
- Flood analysis with the standardized precipitation index (SPI)Publication . Guerreiro, Maria João; Lajinha, Teresa; Abreu, IsabelThe occurrence of flood spells is difficult to monitor and detect. However, there are some indices that permit to monitor hydrological and climatological conditions in river basins. The SPI (Standardized Precipitation Index) is one of those indices. Though the SPI was originally developed for drought detection and monitoring, it can also be applied to perceive wetter than normal conditions. This study pretends to characterize the relationship between the SPI and annual peak flow occurrences in the Tejo (Portugal) river basin and provide a tool for prediction of high flood risk. Results indicate that SPI satisfactorily explained the development of circumstances leading up to major peak flow events.
- Eco-physiological characterization of the macroinverterbate communities of a very disturbed urban stream (Rio Tinto, Portugal): How they survive?Publication . Jesus, Teresa Maria Gonçalves Moreira de; Monteiro, Álvaro; Guerreiro, Maria João; Abreu, Isabel; Amado, Ana; Costa, Miguel
- Comparative statistical analysis new urban road pavement versus conventional pavement of pervious concretePublication . de Oliveira, Evailton Arantes; Guerreiro, Maria João; Abreu, Isabel; Dinis, Maria Alzira PimentaThis research proposes a variation to pervious concrete pavement, in which a mixture of cement, aggregates and water includes calcium hydroxide additive (Ca(OH)2). This new approach focuses on two main environmental functions: increased permeability of urban soil favoring a decrease of total and peak runoff and resulting reduction of flood occurrence in the cities, and CO2 absorption from the atmosphere, contributing to reduction of the negative impacts caused by the observed increased greenhouse effect in the cities. A series of 40 conventional pervious concrete pavement samples and 30 specimens of the proposed urban pavement were tested in the laboratory for permeability, density, porosity and compression resistance, and monitored for CO2 absorption. Results show that there is an environmental benefit of CO2 sequestration when adding Ca(OH)2 to pervious concrete, but there is also a decrease in its compressive strength and permeability.
- Study of the effect of two wastewater treatment plants (WWTP’s) discharges on the benthic macroinvertebrate communities’ structure of the River Tinto (Portugal)Publication . Jesus, Teresa Maria Gonçalves Moreira de; Monteiro, Álvaro; Abreu, Isabel; Guerreiro, Maria JoãoThe Water Framework Directive (DQA-2000/60/ EC) establishes, as one of its main objectives, the achievement of good ecological status of water bodies and introduces the concept of "ecological status", which includes the study of a broad set of parameters and factors to determining the health of an ecosystem. This work is part of a project whose main objective is the rehabilitation of a small urban river in the north of Portugal, the Tinto river, that presents a high degree of environmental degradation. This work aims to study the effect of the two wastewater treatment plants (WWTP’s) discharges in the structure of the benthic macroinvertebrate communities. The study compares results (metrics and indices) obtained from the analysis of benthic macroinvertebrates samples collected in river sections upstream and downstream of the discharges of WWTP’s, between october 2015 and july 2017, and values of hydro-morphological and physico-chemical parameters. Although the benthic macroinvertebrate communities are very conditioned by the bad status of the Tinto river, in the sections downstream of the WWTP's the macroinvrtebrates communities present characteristics that indicate a higher degree of environmental disturbance.
- Indoor air quality in healthcare units - a systematic literature review focusing recent researchPublication . Fonseca, Ana; Abreu, Isabel; Guerreiro, Maria João; Barros, NelsonThe adequate assessment and management of indoor air quality in healthcare facilities is of utmost importance for patient safety and occupational health purposes. This study aims to identify the recent trends of research on the topic through a systematic literature review following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology. A total of 171 articles published in the period 2015–2020 were selected and analyzed. Results show that there is a worldwide growing research interest in this subject, dispersed in a wide variety of scientific journals. A textometric analysis using the IRaMuTeQ software revealed four clusters of topics in the sampled articles: physicochemical pollutants, design and management of infrastructures, environmental control measures, and microbiological contamination. The studies focus mainly on hospital facilities, but there is also research interest in primary care centers and dental clinics. The majority of the analyzed articles (85%) report experimental data, with the most frequently measured parameters being related to environmental quality (temperature and relative humidity), microbiological load, CO2 and particulate matter. Non-compliance with the WHO guidelines for indoor air quality is frequently reported. This study provides an overview of the recent literature on this topic, identifying promising lines of research to improve indoor air quality in healthcare facilities.
- Temporal variability of precipitation indices at a raingauge station in PortugalPublication . Guerreiro, Maria João; Abreu, Isabel; Lajinha, TeresaO objectivo deste estudo é avaliar variações nos índices de precipitação (precipitação total,intensidade, frequência, duração de dias secos e dias húmidos), que possam ser afectados por alterações climáticas numa estação udométrica, chouto, no período de 1912-2007. Nessa estação não se observam variações significativas na precipitação anual no último século,o aumento de precipitação que se observa em outubro é compensado pela diminuição da precipitação em março. em outubro verifica-se um aumento de dias húmidos consecutivos e em março uma diminuição dos mesmos e um aumento de dias secos consecutivos. The objective of this study is to provide insight on variations of precipitation indices (total precipitation, intensity, frequency, duration of wet and dry spells), that may be affected by climate change at a local raingauge station, chouto, in the period of 1912-2007. While no significant changes in precipitation totals were observed annually within the last century,the precipitation increase observed in the month of october is compensated by a precipitation decrease in march. Also in october, there has been an increase in the length of wet spells, whereas a decrease of these is observed in march, which also shows an increase in length of dry spells.
- Study of the effect of two WWTP’s discharges on benthic macroinvertebrate communities structure of the river Tinto (Portugal)Publication . Jesus, Teresa Maria Gonçalves Moreira de; Monteiro, Álvaro; Guerreiro, Maria João; Abreu, IsabelA diretiva quadro da água (DQA-2000/60/EC ) estabelece como um dos objetivos principais a obtenção de um bom estado ecológico das águas e introduz o conceito de “estado ecológico” de um ecossistema o que inclui o estudo de um amplo conjunto de parâmetros e fatores na determinação da saúde de um ecossistema. Este trabalho é parte de um projeto cujo principal objetivo é a reabilitação de um pequeno rio do norte de Portugal, que corre ao longo de uma área urbana e que apresenta um elevado nível de degradação ambiental e tem como objetivo estudar o efeito das descargas de duas estações de tratamento de águas residuais (ETAR’s) na estrutura das comunidades de macroinvertebrados bentónicos do rio Tinto. O estudo compara resultados (métricas e índices) obtidos a partir da análise de amostras de macroinvertebrados bentónicos recolhidas em troços do rio a montante e a jusante das descargas das ETAR’s entre outubro de 2015 e setembro de 2017 e alguns valores parâmetros hidro-morfológicos e físico-químicos. Os resultados permitem verificar que apesar de as comunidades de macroinvertebrados bentónicos se encontrarem muito condicionadas pelo estado mau estado ecológico geral do rio Tinto, nas áreas a jusante das ETAR’s as mesmas apresentam-se ainda mais perturbadas.
- Environmental implications of CO2 absorption by pervious concrete pavement in urban roadsPublication . Oliveira, Evailton Arantes; Guerreiro, Maria João; Abreu, Isabel; Dinis, Maria Alzira PimentaThis research deals with a new material, made from conventional pervious concrete, but with the addition of two components in its mixture, calcium hydroxide (Ca(OH)2), to improve its carbon dioxide (CO2) absorption properties from the atmosphere, and Scrap Tyre Tubes (STT), a rubber waste from used tyres of vehicle (motorcycles and cars), which makes the new material lighter and contributes to urban sustainability by reusing industrial waste automotive. Conventional pervious concrete has a main property that benefits the environment, which is natural from its porous structure, which is the permeability of the urban pavement, which allows the drainage of rainwater from the urban pavement to the underground, contributing to the reduction of flooding in cities through the infiltration of water into the groundwater. This research sought to improve conventional pervious concrete through additives in its mix to create a new porous material, more efficient at sequestering CO2 from the atmosphere, lighter and reusing rubber waste from used tyres. The porosity of conventional pervious concrete makes this material ideal for carbon dioxide (CO2) sequestration due to the ease of CO2 penetration into its internal structure pore network, which interacts with cement and other additives, which by means of a chemical reaction called carbonation, absorbs CO2 from the atmosphere to form calcium carbonate (CaCO3) in its internal structure, which is an excellent environmental benefit for the materials used in the manufacture of urban pavements, as it makes the urban pavement contribute directly for air quality and for the control of pollution emanating from motor vehicles traveling on urban roads. In this investigation were performed laboratory tests of compressive strength and permeability, because these are the most important properties of conventional permeable concrete that make this building material a porous pavement that can be used on urban roadways, these properties are essential for the new pervious concrete material, were also CO2 volume monitoring in contact with specimens of conventional pervious concrete and specimens of new material, because this environmental benefit of CO2 absorption from the atmosphere is very important for the control of air quality in large metropolis, which have high levels of pollution that affect the life of urban citizens, causing respiratory diseases in old and children. In this research, 40 conventional pervious concrete were manufactured with limestone aggregate, to serve as a control group in the statistical analysis and 10 specimens of the new material of pervious concrete also were manufactured with proportions of 1:0.5:4 (cement:Ca(OH)2:pebble), factor water/cement (w/c) of 0.30, with 5% STT in mix, because the proportion of SST in the mix defines how much waste tyre waste can be reused in the manufacture of this new material. The STT is a non-biodegradable material that occupies a lot of urban space, so it harms the environment and the quality of life of the urban citizen, an alternative to reuse STT in the mix of new pervious concrete material is a very important sustainable solution to modern cities around the world due to the progressive annual increase of this waste tire rubber from automotive industries. In this research the results of the tests served to compare compression and permeability, as well as monitoring the absorption of CO2 from the atmosphere of the different groups. The results of the compressive strength and permeability tests and CO2 volume monitoring were analyzed statistically for normality and the t-Student test. This analysis showed that the improvement of environmental properties harms the physical properties of the new material with compressive strength of 1.25 MPa, permeability of 7.00 mm/s and 5% of STT in the mix of new material of the pervious concrete, however, this new permeable concrete material can be used in non-structural works, such as garden pavement, pedestrian sidewalks, finishes to beautify buildings and condominium facades, etc., due to the environmental benefits it produces and cannot be neglected.
- Considerations on the monitoring of water quality in urban streams: a case study in PortugalPublication . Guerreiro, Maria João; Abreu, Isabel; Monteiro, Álvaro; Jesus, Teresa Maria Gonçalves Moreira de; Fonseca, AnaMonitoring water quality in urban stream is of utmost importance for water resources managers, who are pressured to optimize monitoring schemes in order to reduce costs. The present study aims to use the results of a 2-year-long water quality monitoring pro- gram of an urban stream in Portugal to identify improve- ment opportunities. The urban stream under study was subjected to wastewater treatment plants effluent dis- charges, leachates from a major sealed landfill, low- class housing effluents, and nonpoint sources of pollu- tion. Contributing watersheds are mostly artificial sur- faces and agricultural land, which irrigate directly from the river. River water quality was evaluated on 11 sam- pling locations for 24 months from October 2013 to September 2015. The present paper describes statistical analysis of the results obtained for 12 physicochemical parameters in order to optimize the monitoring scheme. Cluster analysis detected a seasonal variation in the water quality and a spatial pattern based on the major point sources of pollution. A factor analysis showed that the parameters that mostly contribute to water quality assessment in this urban river are alkalinity, ammonia, electrical conductivity, pH, temperature, and dissolved oxygen. Results suggest that the monitoring efforts— and associated costs—may be reduced by decreasing monitoring frequency, sampling points, and monitored parameters. The statistical analysis described in this study may be replicated in other water quality monitor- ing programs, providing useful and important informa- tion for the systematic and iterative assessment of the adequacy of water quality sampling programs towards a sustainable management of water quality surveillance.
- Variação anual e mensal de parâmetros meteorológicos na região do Algarve, PortugalPublication . Guerreiro, Maria João; Abreu, Isabel; Barros, MarisolProcedeu-se à análise estatística da evolução temporal das variáveis meteorológicas temperatura, precipitação e evaporação na região do Algarve. Usaram-se dados de quatro estações meteorológicas com mais de 49 anos de registos simultâneos. Observaram-se alterações significativas da precipitação no mês de Março, da temperatura média em Março e Dezembro e da evaporação em todos os meses do ano. Apreciou-se o impacto destas alterações na utilização das variáveis em modelos hidrológicos.