109 research outputs found

    Assessment of habitat and water quality of the Portuguese Febros River and one of its tributaries

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    A physical, chemical and biological characterisation of river systems is needed to evaluate their ecological quality and establish restoration programs. Aquatic benthic macroinvertebrates have proven to be among the most reliable and cost-effective assessment tools for water and habitat quality in streams throughout the world. During one year of seasonal surveys, the state of the Febros River and one of its tributaries, Jaca Creek, were evaluated in terms of habitat, physical, chemical and biological water quality, using benthic macroinvertebrates as ecological indicators. These watercourses suffer pollution from agriculture, industry and urban areas. Both watercourses were moderately to severely degraded, showing spatial and temporal variability in macroinvertebrate communities and water quality. The overall poor river conditions were particularly bad in the upper part of Jaca Creek, which is affected by industry. This upriver site showed higher temperatures, conductivity and dissolved solids than all other sites studied. The best conditions were found in the Gaia Biological Park area, where the habitat quality was evaluated to be high and biotic indices indicated excellent and good water quality in the spring and summer, respectively. However, even this site had biological indicator scores denoting severe degradation in autumn and winter. Macroinvertebrate diversity was low, with populations dominated by pollution-tolerant taxa like Chironomids, particularly in the summer and autumn samples. Abundances were mostly higher in the spring and lower in winter. Percentages of Ephemeroptera and Trichoptera (EPT) were low (totalling 31% on average), and Plecoptera was completely absent in the samples. The EPT percentage and the percentage of Chironomidae were related to temperature and Biochemical Oxygen Demand (BOD). In comparison to earlier studies, the Febros River improved in both habitat and biological quality. The present study should help to identify specific measures necessary to restore habitat and water quality to reference conditions.Para evaluar la calidad ecológica de un río y establecer programas de recuperación es necesaria una caracterización física, química y biológica de los sistemas fluviales. Los macroinvertebrados acuáticos bentónicos se encuentran entre las herramientas más fiables y efectivas para la estimación de la calidad del agua y los hábitats en aguas corrientes de todo el mundo. El estado del río Febros y uno de sus tributarios, la Ribeira de Jaca, han sido evaluados durante un año de controles estacionales en términos de hábitat y de la calidad física, química y biológica de sus aguas, mediante el uso de macroinvertebrados bentónicos como indicadores ecológicos. Estas cuencas fluviales están afectadas por la contaminación que procede de la agricultura, de la industria y de las áreas urbanas. Ambas corrientes de agua están de moderada a severamente degradadas, con variabilidad temporal y espacial de las comunidades de macroinvertebrados y de la calidad del agua. Las malas condiciones generales de la zona fluvial estudiada son especialmente aparentes en la parte alta de Ribeira de Jaca que está afectada por instalaciones industriales. Este punto presenta temperaturas, conductividades y sólidos disueltos más elevados que en los demás lugares estudiados. Las mejores condiciones se hallaron en el área del Parque Biológico de Gaia, donde el hábitat se puede evaluar como bueno y los índices bióticos indican que la calidad del agua es excelente y buena, respectivamente, durante la primavera y el verano. No obstante, incluso esta localización presenta valores de indicadores biológicos que apuntan a una severa degradación en otoño e invierno. La diversidad de macroinvertebrados es particularmente baja en las muestras de verano y otoño con poblaciones dominadas por taxones que toleran la contaminación, como los Chironomidae. Los valores de abundancia son generalmente más elevados en primavera y más bajos en invierno. El porcentaje de Ephemeroptera y Trichoptera (EPT) es bajo, alcanzando un 31% entre ambos grupos. Los Plecoptera se encuentran completamente ausentes en todas las muestras. El porcentaje EPT y de Chironomidae están relacionados con la temperatura y la Demanda Bioquímica de Oxígeno (BOD). La calidad de este hábitat y la de sus sistemas biológicos ha mejorado en relación con anteriores estudios. El presente trabajo debe ayudar a identificar las medidas específicas necesarias para recuperar la calidad del hábitat y de su agua hasta condiciones de referencia

    Artisanal salt production in Aveiro/Portugal - an ecofriendly process

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    Solar salinas are man-made systems exploited for the extraction of salt, by solar and wind evaporation of seawater. Salt production achieved by traditional methods is associated with landscapes and environmental and patrimonial values generated throughout history. Since the mid-twentieth century, this activity has been facing a marked decline in Portugal, with most salinas either abandoned or subjected to destruction, making it necessary to find a strategy to reverse this trend

    Estuarine hydrodynamic patterns and hydrokinetic energy production: The Douro estuary case study

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    Influenced by both marine and river flows, estuaries can present a high potential for hydrokinetic energy exploitation. In this study, the hydrokinetic energy production in the Douro estuary was evaluated through hydrodynamic numerical modelling. The model analysed the tide and river flow, reproduced the combined effects of these two factors on the main current velocity patterns, and identified the estuarine locations with the highest potential for energy exploitation. Given the river?s high variability caused by the precipitation patterns in the hydrographic basin area and the river?s torrential regime, several discharge scenarios were explored, combining spring and neap tides, and high and low river flows. The results revealed that the region with the highest potential is located in the upper part of the estuary, where the highest-velocity currents were achieved for mid-ebb tide conditions and strong river flows. It was also found that tides reinforce the hydrokinetic energy production during ebb tide, although they are not strong enough to produce high values of hydrokinetic energy, being the river flow the main forcing. This work demonstrates the relevance of choosing parametrized magnitudes that are not dependent on a specific equipment, as well as the importance of a proper characterization of the estuarine hydrodynamic patterns needed to optimize the hydrokinetic energy exploitation. ? 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Assessing the ecological status of fluvial ecosystems employing a macroinvertebrate multi-taxon and multi-biomarker approach

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    Biomarkers are recognised sensitive early-warning tools of biological effects in aquatic organisms. In this scope, the main aim of this study was to investigate the potential usefulness of a battery of biomarkers, evaluated in different benthic macroinvertebrate taxa, to discriminate aquatic ecosystems with different levels of ecological status and to provide further clues supporting environmental management. The study took place during the autumn of 2013 and the spring and summer of 2014, and the study cases were two Mediterranean rivers (Âncora and Ferreira rivers), differing in their ecological status. The biomarkers determined are widely employed and comprise a large set of biochemical responses: the activity of enzymes (cholinesterases, glutathione S-transferases, catalase and lactate dehydrogenase) and the levels of lipid peroxidation. They were assessed seasonally and in different macroinvertebrate taxa. Thirteen water physico-chemical parameters were also seasonally determined, and the concentration of seven organophosphorus pesticides and the percentage of 32 trace metals in sediments were determined in the spring. This is particularly useful for water management. Based on this, authorities can take actions to prevent further damage in the ecological status. Multivariate analyses showed distinct patterns of biological response for the Calopteryx spp., Chironomidae and Baetis spp. taxa. Calopteryx spp. and Chironomidae, in particular, showed distinct response patterns for the two rivers, which were fairly stable across seasons. This study sets the foundations for future cost-effective biomonitoring campaigns in Mediterranean rivers, allowing to establish historical data important to understand ecosystem evolution, as well as baseline levels of diagnostic biomarkers in informative macroinvertebrate taxa.The present study was supported by the Foundation for Science and Technology (FCT) through a PhDgrant attributed to Rodrigues C. R. (SFRH/BD/87695/2012) and apost-doc fellowship attributed to Cruz V. F. (SFRH/BPD/109153/2015) and by the Strategic Funding UID/Multi/04423/2019 through national funds provided by the FCT and European Re-gional Development Fund (ERDF), in the framework of the pro-gramme PT2020info:eu-repo/semantics/publishedVersio

    Linking short- to medium-term beach dune dynamics to local features under wave and wind actions: a northern portuguese case study

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    Many coasts suffer from prevailing erosion, with them being particularly vulnerable to predicted climate change impacts, threatening coastal ecosystems, their services, infrastructures and populations. Understanding coastal morpho-sedimentary dynamics is thus essential for coastal management. However, coastal vulnerability may differ locally, depending on exposure/protection and local geological and morpho-hydrodynamical features, suggesting that a local approach to erosion risk assessment is needed to identify and understand local patterns. Digital elevation models of a 14 km long coastal stretch in northern Portugal that were extracted from aerial surveys obtained between November 2008 and February 2019 were analysed to quantify changes in shoreline position and sediment budgets, both for the whole study area and for distinct beach segments. The observed dynamics were subsequently analysed by considering prevailing wave and wind intensities and directions. Overall and during the decade analysed, the beach–dune system of the studied stretch slightly increased in volume (0.6%), although the shoreline retreated (by 1.6 m on average). Temporal variability in coastal dynamics was observed at all of the temporal scales considered—from seasons to 5-year periods—with them being related to variability in ocean and wind patterns. There was a trend from accretional to erosional conditions, with the first 5-year period showing a mean increase in the beach–dune system’s volume of 0.6% and a mean shoreline progradation of 1.5 m, followed by 5-years with 0.0% volume change and 3.1 m shoreline retreat. Locally, the dynamics were very variable, with shoreline dynamics ranging from 24.0 m regression to 51.5 m progradation, and sediment budgets from 213.8 m3 loss to 417.0 m3 gain, per segment and for the decade. Stretches with relatively stable morphologies and others with erosional or accretional trends were found, depending on the beach type, shoreline orientation and the presence of defence structures. Rocky beaches were the least dynamic and sandy beaches the most dynamic, with mean shoreline position changes of 0.0 m and −3.4 m, respectively, and mean sediment budgets of −1.1 m3 and −2.9 m3 per linear meter of coastline, respectively, for the studied decade. The observed dynamics showed how local conditions interacted with meteo-ocean conditions in shaping local morpho-sedimentary dynamics, stressing the importance of a local approach to coastal erosion monitoring and risk assessment.European Union MarRISK project: Adaptación costera ante el Cambio Climático: conocer los riesgos y aumentar la resiliencia (0262_MarRISK_1_E) through EP INTERREG V A España-Portugal (POCTEP) program and the project INNOVMAR-Innovation and Sustainability in the Management and Exploitation of Marine Resources (NORTE-01-0145-FEDER-000035, within Research Line ECOSERVICES), supported by NORTE 2020, under the PORTUGAL 2020 Partnership Agreement, through the ERD

    Hydrodynamic Model Ensembles for Climate Change Projections in Estuarine Regions

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    In the current context of climate change, understanding the effects of the changing conditions on estuaries is of utmost importance to protect populations and ecosystems. Given the diversity of impacts depending on the region, there is a need for local and dedicated studies to understand and mitigate the risks. Numerical models can provide forecasts of extreme floods and sea-level rise (SLR). However, they can present inaccuracies. In this work, the ensemble technique was applied to improve the numerical modeling forecasting for estuaries by considering scenarios of extreme river flow discharges (EFDs) and SLR scenarios for 2050 and 2100. The simulations were performed for two different estuarine regions in northern Portugal, and the superensemble was constructed with the results of two different numerical models. The results differed per estuary, highlighting the importance of a local approach. For the Douro estuary dynamics, the results showed that for the EFD, the effects of the SLR were not noticeable, indicating that, in this estuary, the river component was more important than the maritime component. In contrast, the Minho estuary dynamics were found to be affected by the SLR along the whole estuarine region, indicating a maritime influence and a worsening of the flood conditions for future scenarios

    Numerical modeling tools applied to estuarine and coastal hydrodynamics: a user perspective

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    Estuarine and coastal areas have been intensively studied given their complexity, ecological, and societal value and the importance of their ecosystem services. Estuarine and coastal management must be based on a sound characterization of these areas, which is achievable complementing the comprehensive field measurements with numerical models solutions. Based on a detailed comparison between two close-by, but extremely different, Portuguese estuaries (the Douro and Minho estuaries), this chapter intends to discuss how accurately numerical modeling tools can provide relevant information for a variety of coastal zones. They can be very useful for various applications in the planning and management fields, such as coastal and infrastructures protection, harbor activities, fisheries, tourism, and coastal population safety, thus supporting an effective and integrated estuarine and coastal management, which must consider both the safety of the populations and the sustainability of the marine ecosystems and services. In particular, the capacity of the numerical models to give a detailed characterization of morpho-hydrodynamic processes, as well as assess and predict the effects of anthropogenic interventions, extreme events and climate change effects, are presented.This research was partially supported by the Strategic Funding UID/Multi/ 04423/2013 through national funds provided by FCT—Foundation for Science and Technology and European Regional Development Fund (ERDF). This contribution has also been funded by project EsCo-Ensembles (PTDC/ECI-EGC/30877/2017), co-funded by NORTE2020, Portugal 2020, and the European Union through the ERDF, and by FCT through national funds

    Hydro- and morphodynamic impacts of sea level rise: The Minho estuary case study

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    The understanding and anticipating of climate change impacts is one of the greatest challenges for humanity. It is already known that, until the end of the 21st century, the mean sea level (MSL) will rise at a global scale, but its effects at the local scale need to be further analyzed. In this context, a numerical modelling tool and a methodological approach for the river Minho estuary (NW of the Iberian Peninsula) are presented, to predict possible consequences of local MSL rise, considering the greenhouse emission scenarios RCP 4.5 and RCP 8.5. Hydrodynamic and morphodynamic impacts were analyzed considering several driving factors, such as tides, sea level rise, storm surge, wave set-up, and different river flood peak discharges, taking into account their probabilities of occurrence. The model was calibrated using in-situ data and a data assimilation tool, the OpenDA, which automates this process, allowing to reach reliable results in a considerably short time when compared with traditional techniques. The results forecast that the predicted MSL rise will reduce the flow velocity magnitude and the sediment transport into the coastal platform but will aggravate the inundation risks along the estuarine banks. In the worst scenario (RCP 8.5) the water level near the river mouth of the estuary is expected to rise 0.20 m for 50 years return period ocean water rising, and 0.60 m for 100 years return period. It was also possible to identify that floods are the most important driver for the sediment transport along the estuary, while the tide effect in the morphodynamics is restricted to the downstream estuarine region. This work demonstrated the importance of the numerical modelling tools to better understand the effects of climate change at local scales through the representation of the estuarine hydrodynamic pattern evolution for future climate scenarios.This research was partially supported by the Strategic Funding UID/Multi/04423/2019 through national funds provided by FCT—Foundation for Science and Technology and European Regional Development Fund (ERDF). This contribution has also been funded by the European Union MarRISK project: Adaptación costera ante el Cambio Climático: conocer los riesgos y aumentar la resiliencia (0262_MarRISK_1_E), through the EP INTERREG V A España-Portugal (POCTEP) program. The authors want also to acknowledge the contract funds provided by the project EsCo-Ensembles (PTDC/ECI-EGC/30877/2017), co-financed by NORTE 2020, Portugal 2020 and the European Union through the ERDF, and by FCT through national funds

    Coastal erosion: a northern-portuguese case study

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    Ponencia presentada en: XII Congreso de la Asociación Española de Climatología celebrado en Santiago de Compostela entre el 19 y el 21 de octubre de 2022.[EN]Coasts are socio-economically and ecologically highly important, yet vulnerable zones. Increasing pressure from human activities, like tourism, growing settlements and development of infrastructures, as well as climate change impacts, such as predicted sea-level rise and intensification of extreme climate, are likely to increase coastal vulnerability. Coastal Zone Management requires thus an evaluation of coastal dynamics, vulnerability and risks. The present work studied the morpho-sedimentary dynamics of the Northern-Portuguese Atlantic coast, between Caminha and Espinho. Digital terrain and surface models, derived from LiDAR and aerial photography survey data, collected in 2011, 2017 and 2018, were used to assess beach and dune morphology and to quantify morphodynamics. Coastal dynamics was analysed considering the types of beaches found in the region, being predominantly sandy beaches, sandy beaches with rocky outcrops, pebble and rocky beaches and dominant wind and wave conditions.[ES]Las áreas costeras son zonas de gran importancia socioeconómica y ecológica, pero a su vez son muy vulnerables. La vulnerabilidad de estas áreas puede aumentar con la creciente presión de las actividades humanas, como el turismo, el crecimiento de las zonas urbanas y el desarrollo de infraestructuras, así como con los impactos del cambio climático, como el aumento previsto del nivel del mar y la intensificación de extremos climáticos. Por lo tanto, es importante evaluar la vulnerabilidad y los riesgos para promover una gestión eficaz e integrada de las zonas costeras. El presente trabajo estudió los riesgos de erosión para la costa atlántica del norte de Portugal, entre Caminha y Espinho. Para evaluar la morfología de playas y dunas, y para cuantificar los procesos morfodinámicos, se utilizaron modelos digitales de terreno y de superficie, derivados de LiDAR y también datos de campañas de fotografía aérea, para los años 2011, 2017 y 2018. Se analizó la dinámica costera considerando los tipos de playas que se encuentran en la región, siendo predominantemente playas arenosas, playas arenosas con afloramientos rocosos, cantos rodados y playas rocosas, y también las condiciones predominantes de viento y oleaje.This research was partially supported by the Strategic Funding UIDB/04423/2020 and UIDP/04423/2020 through national funds provided by FCT—Foundation for Science and Technology and European Regional Development Fund (ERDF). This work was further funded by the European Union MarRISK project: Adaptación costera ante el Cambio Climático: conocer los riesgos y aumentar la resiliencia (0262_MarRISK_1_E), through EP INTERREG V A España-Portugal (POCTEP) program, and by the project EsCo-Ensembles (PTDC/ECI-EGC/30877/2017), co-financed by NORTE 2020, Portugal 2020 and the European Union through the ERDF, and by FCT through national funds
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