Definição dos ecossistemas dependentes de águas subterrâneas nos planos de bacia do sul de Portugal

Quando pela primeira vez, por volta de 2010/2011 se colocou a questão da definição das áreas onde os ecossistemas estariam dependentes de águas subterrâneas, e entendendo-se por “ecossistemas dependentes de águas subterrâneas” os ecossistemas que dependem, em todo ou em parte de águas subterrâneas e que seriam irrevogavelmente afetados em caso de afetação da quantidade ou qualidade das águas subterrâneas, tornou-se necessário criar mecanismos para rapidamente se conseguirem identificar esses sistemas ecológicos. Para esse fim, foram em primeiro lugar, com base em dados de níveis freáticos de águas subterrâneas, identificadas as áreas onde as águas subterrâneas se situariam próximo da superfície do solo. Depois foram usados modelos conceptuais, onde estes existiam, para determinar as zonas onde havia hipóteses de haver ascensão de água subterrânea. Finalmente, foram identificadas áreas onde condições hidrogeológicas locais permitiriam a sustentação de ecossistemas com caraterísticas específicas (lagoas temporárias, por exemplo). As áreas identificadas foram então comparadas com as zonas protegidas classificadas em Portugal (Rede Natura 2000, Parques e Reservas Nacionais, etc.). Curiosamente, verificou-se de imediato uma grande coincidência entre as áreas identificadas no estudo e as áreas protegidas já definidas, mostrando que as áreas ecologicamente importantes já o eram por razões também ligadas às águas subterrâneas. Depois avançou-se para uma análise mais ecológica, com base em dados pré-existentes, e recorrendo a uma equipa pluridisciplinar. Por esta via foram identificados sistemas em linhas de água ou ligados a lagos e sistemas terrestres, de que resultou toda a cartografia final dos ecossistemas dependentes de águas subterrâneas dos planos de bacia no sul de Portugal

Decision-support groundwater modelling of managed aquifer recharge in a Coastal Aquifer in South Portugal

The Vale do Lobo sector of the Campina de Faro aquifer system in the Algarve (Portugal) is at risk of seawater intrusion. Managed Aquifer Recharge (MAR) is being considered to avoid groundwater quality deterioration. Numerical modelling was undertaken to assess the feasibility of several proposed MAR schemes. Although some data is available, many aspects of system behaviour are not well understood or measured. We demonstrate the use of a structurally simple but parametrically complex model for decision-making in a coastal aquifer. Modelling was designed to facilitate uncertainty reduction through data assimilation where possible, whilst acknowledging that which remains unknown elsewhere. Open-source software was employed throughout, and the workflow was scripted (reproducible). The model was designed to be fast-running (rapid) and numerically stable to facilitate data assimilation and represent prediction-pertinent uncertainty (robust). Omitting physical processes and structural detail constrains the type of predictions that can be made. This was addressed by assessing the effectiveness of MAR at maintaining the fresh-seawater interface (approximated using the Ghyben-Herzberg relationship) below specified thresholds. This enabled the use of a constant-density model, rather than attempting to explicitly simulating the interaction between fresh and seawater. Although predictive uncertainty may be increased, it is outweighed by the ability to extract information from the available data. Results show that, due to the limit on water availability and the continued groundwater extraction at unsustainable rates, only limited improvements in hydraulic heads can be achieved with the proposed MAR schemes. This is an important finding for decision-makers, as it indicates that a considerable reduction in extraction in addition to MAR will be required. Our approach identified these limitations, avoiding the need for further data collection, and demonstrating the value of purposeful model design.info:eu-repo/semantics/publishedVersio

In-channel managed aquifer recharge: a review of current development worldwide and future potential in Europe

Managed aquifer recharge (MAR) schemes often employ in-channel modifications to capture flow from ephemeral streams, and increase recharge to the underlying aquifer. This review collates data from 79 recharge dams across the world and presents a reanalysis of their properties and success factors, with the intent of assessing the potential of applying these techniques in Europe. This review also presents a narrative review of sand storage dams, and other in-channel modifications, such as natural flood management measures, which contribute to the retardation of the flow of flood water and enhance recharge. The review concludes that in-channelMARsolutions can increase water availability and improve groundwater quality to solve problems a ecting aquifers in hydraulic connection with temporary streams in Europe, based on experiences in other parts of the world. Therefore, to meet the requirements of the Water Framework Directive (WFD), in-channel MAR can be considered as a measure to mitigate groundwater problems including saline intrusion, remediating groundwater deficits, or solving aquifer water quality issues.European Union (EU) 814066info:eu-repo/semantics/publishedVersio

Evaluation of GRACE data for water resource management in Iberia: a case study of groundwater storage monitoring in the Algarve region

Study region: Iberia, Algarve basin, South Portugal. Study focus: This study evaluates the performance of several GRACE products in Iberia using the closure of the water budget. Then, it focusses on the Algarve region and explores the potential of GRACE as a tool of quantitative groundwater monitoring capable of bridging gaps in the existing ground-based network. Monthly data from GRACE, ancillary datasets from E-OBS, GLEAM, GRUN and ERA5, and groundwater level measurements from 12 karst-porous aquifers in the Algarve basin (5000 km2) are analyzed from 2004 to 2014. New Hydrological Insights for the Region: When considering the closure of the water budget at the Iberian scale, GRACE Mascon solutions perform remarkably well and better than the products based on spherical harmonics. When considering only the Algarve region, the results are similar to the ones obtained for Iberia, but the GRACE solution that performs the best is the average of the CSR and JPL Mascon products. In spite of the Algarve’s extremely small area when compared to the GRACE footprint, the satellite is capable of capturing the regionally averaged seasonal and deseasonalized variations in observed groundwater storage (correlation between GRACE-derived and regionally averaged ground-based measurements is 0.82). For the first time ever at the regional Algarve scale, bounds are placed on the aquifer’s storage properties which vary from 3.65 × 10 3 to 4.92 × 10 2.FCT: UIDB/50019/2020 -IDLinfo:eu-repo/semantics/publishedVersio

Arquitectura intempestiva. Permanência. Acontecimento: Debilidade, Contingência, Disponibilidade

Sendo a Arquitectura Intempestiva definida, por Ignasi de Solà-Morales, como "a queque nasce da intempérie de qualquer sistema de princípios, de tradições, e de códigoslinguísticos"1, o que se pretende, nesta dissertação, é simultaneamente construir eexpor uma perspectiva que persegue a ideia de uma arquitectura sem regras ou leisimutáveis, disponível para se reinventar a cada experiência, totalmente livre numaaproximação às realidades onde intervém, considerando, para tal, o projecto enquantoexperiência - abertura ao desconhecido, disponibilidade para se deixar surpreender(emocionar) pelas circunstâncias, por aquilo que nelas existe de silêncio, que não sedeixa fixar através da linguagem enquanto puro sistema de signos.A estrutura divide-se em cinco momentos que corresponderam sensivelmente àsdiferentes fases do trabalho: o primeiro momento parte da interpretação da crisedo Movimento Moderno enquanto crise do pensamento da Idade Clássica, paraconsiderar a dimensão da arte enquanto abertura de sentido, através da resistênciaaos sistemas universais, e da atenção ao concreto, ao múltiplo, ao singular; osegundo momento descreve uma aproximação à noção de arquitectura intempestiva,ou débil, considerando o minimalismo como redução ao mínimo da produção desentido, através da aproximação experimental e fenomenológica, e considerando ostrês exemplos mencionados por Solà-Morales - Álvaro Siza, Tadao Ando, FrankGehry -; numa tentativa de evitar uma definição fixa dessa ideia de arquitectura,o quarto momento vem introduzir três perturbações, três Projectos de arquitecturacontemporânea - Smiljan Radic, Lacaton & Vassal, Selgascano -, onde a condiçãoexperimental se concentra em tipos diferentes de operações, sem deixar, com isto, desugerir outras formas de debilidade; por fim, o quinto e último momento coloca-se, porsua vez, como um retorno à origem de algumas das inquietações que impulsionarama construção desta narrativa: um exercício de projecto no primeiro ano (2013), outrodurante o período de elaboração da dissertação (2017), e uma relação gradualmenteconstruída com o projecto da Faculdade de Arquitectura da Universidade do Porto,de Álvaro Siza (entre 2012 e 2018).Being the Untimely Architecture defined, by Ignasi de Solà-Morales, as "that whichis born from the turmoil of any system of principles, traditions, and linguisticcodes"1, what is intended in this dissertation is to simultaneously build and expose aperspective that pursues the idea of an architecture without immutable rules or laws,available to reinvent itself in each experiment, totally free to approach the realitieswhere it intervenes, considering, to this end, the project as experience - openness tothe unknown, willingness to be surprised (affected) by the circumstances, by what inthem exists only as silence, that which can't be fixed trough language as a pure systemof signs.The structure is divided in five moments that corresponded approximately to thedifferent phases of the work: the first moment starts from the interpretation of thecrisis of the Modern Movement as a crisis of the thinking of the Classical Age, toconsider the dimension of art as opening of meaning, through resistance againstuniversal systems, and attention to the concrete, the multiple, the singular; thesecond moment describes an approach to the notion of untimely or weak architecture,regarding minimalism as reduction to a minimum of production of meaning, throughan experimental and phenomenological approach, and regarding three examplesmentioned by Solà-Morales - Álvaro Siza, Tadao Ando, Frank Gehry -; in anattempt to avoid a static definition of this idea of architecture, the fourth momentintroduces three disturbances, three Projects of contemporary architecture - SmiljanRadic, Lacaton & Vassal, Selgascano -, in which the experimental condition focuseson different types of operations, while suggesting also other forms of weakness; finally,the fifth and final moment is a return to the origins of some of the anxieties thatpropelled the construction of this narrative: a project exercise in the first year (2013),another during the period of dissertation (2017), and a relationship gradually builtwith the project of the Faculty of Architecture of the University of Porto, by ÁlvaroSiza (between 2012 and 2018)

Unilateral optic neuritis as a presentation of neurobrucellosis

Neurobrucellosis manifesting as optic neuritis is a rare disease in childhood. We report a case of neurobrucellosis in a 11 year old girl leading to visual impairment and headache. Physical examination revealed mild oedema of right tibiotarsic joint and optic neuritis. Investigations showed CSF pleocytosis and a Brucella serum agglutination titer of 1/640. Complete reversal of the symptoms was observed after appropriate antibiotic treatment. To our knowledge only four cases of neurobrucellosis manifesting with visual impairment in childhood are previously reported in literature

Environmental and landscape rehabilitation: case study for fresh stone treatment on big dams

The construction of big dams usually cause a severe environmental change at a local level, producing a considerable visual impact that must be remedied and the disturbed area must be rehabilitated and recovered, approaching the landscape prior to the dam construction. In this work, several assays were tested, with the purpose of finding a treatment for fresh cut granite that could be used as a general rock treatment for visual impact of fresh excavated rocks. Some organic mixtures were tried, using autochthonous lichens and moss, as well as chemical treatments, like acid or paint. Granite blocks were selected and five different treatments were applied to cover the fresh granitic blocks and trigger their colonization and aging. The experiment has been established on two groups of blocks, one submitted to irrigation three times a week and the other without irrigation. Each treatment had two repetitions per group. Two blocks for control were also established in each group to interpret the gaps of variation in comparison to the treated blocks. All the stone blocks were maintained in a greenhouse, with controlled temperature and humidity. The monitoring of the treatment was done by taking pictures every 20 days, that were analyzed using RGB color characteristics and parameters that shows the evolution of pigmentation of the blocks. The results of this study show that three or at least two out of the five tested treatments are recommended to use in the disturbed areas. Irrigation can be more useful for the first two to three weeks after treatmentsinfo:eu-repo/semantics/submittedVersio

Optimized exploitation of aquifers: application to the Querenca-Silves aquifer system

A great deal of optimization models have been developed to support aquifer planning and management with the goal of arriving at the best decisions in relation to the number and siting of infrastructures to be built and how to operate them. A mixed-integer multi-objective linear model has been taken from the literature to define the best decision for the development of the aquifer of Querenca-Silves (Portugal). It identifies efficient solutions for the location and design of pumping stations and their catchment area to supply a given number of demand centers, without disregarding the effect of groundwater management on the piezometric surface of aquifers and the many facets of groundwater management. The multi-objective model includes two objectives: (1) the minimization of aggregate water elevation height, and (2) the minimization of aggregate water transport length, weighted by the flows conveyed from the facilities to the centers. The effect of groundwater extraction on the piezometric surface of the aquifer is modelled with a response matrix method, with the establishment of maximum drawdown to prevent over-exploitation

Quantifying and modelling the contribution of streams that recharge the Querenca-Silves aquifer in the south of Portugal

The water balance of the mesocenozoic aquifers of the Algarve, in the south of Portugal has traditionally been estimated considering only direct ("autogenic") recharge from rainfall occurring in the area of the aquifers. Little importance has been attributed to so-called allogenic recharge, originating from streambed infiltration from runoff generated outside the aquifers, particularly in the Palaeozoic rocks to the north where runoff is high. The Querenca-Silves (QS) aquifer is the most important aquifer of the region both for irrigation and public water supply. Several important and sensitive surface/groundwater ecotones and associated groundwater dependent ecosystems exist at the springs of the natural discharge areas of the aquifer system. A numerical flow model has been in constant development over the last few years and currently is able to reproduce the aquifer's responses to estimated direct recharge and abstraction for the years 2001-2010. However, recharge calculations for the model do not take into account allogenic recharge infiltration along influent reaches of streams. The quantification of allogenic recharge may further improve the assessment of water availability and exploitation risks. In this paper an attempt is made to quantify the average annual contribution of allogenic recharge to the QS aquifer, based on monitoring data of the principal water courses that cross the aquifer system. Significant uncertainties related to surface runoff generated within the aquifer area, as well as areal recharge were identified and the consequences for the optimization of spatial distribution of transmissivity in the groundwater flow model are also addressed