Browsing by Author "Paz, Maria Catarina"
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- Assessing soil salinity dynamics using time-lapse electromagnetic conductivity imagingPublication . Paz, Maria Catarina; Farzamian, Mohammad; Paz, Ana Marta; Castanheira, Nádia Luísa; Gonçalves, Maria Conceição; Santos, Fernando MonteiroLezíriaGrandedeVilaFrancadeXira,locatedinPortugal,isanimportantagriculturalsystemwhere soil faces the risk of salinization due to climate change, as the level and salinity of groundwater are likely to increase as a result of the rise of the sea water level and consequently of the estuary. These changes can also affect the salinity of the irrigation water which is collected upstream of the estuary. Soil salinity can be assessed over large areas by the following rationale: (1) use of electromagnetic induction (EMI) to measure the soil appar- ent electrical conductivity (ECa, mS m−1); (2) inversion of ECa to obtain electromagnetic conductivity imaging (EMCI) which provides the spatial distribution of the soil electrical conductivity (σ,mSm−1); (3) calibration process consisting of a regression between σ and the electrical conductivity of the saturated soil paste extract (ECe, dS m−1), used as a proxy for soil salinity; and (4) conversion of EMCI into salinity cross sections using the obtained calibration equation. In this study, EMI surveys and soil sampling were carried out between May 2017 and October 2018 at four locations with different salinity levels across the study area of Lezíria de Vila Franca. A previously developed regional calibration was used for predicting ECe from EMCI. Using time-lapse EMCI data, this study aims (1) to evaluate the ability of the regional calibration to predict soil salinity and (2) to perform a preliminary qualitative analysis of soil salinity dynamics in the study area. The validation analysis showed that ECe was predicted with a root mean square error (RMSE) of 3.14 dS m−1 in a range of 52.35 dS m−1, slightly overesti- mated (−1.23 dS m−1), with a strong Lin’s concordance correlation coefficient (CCC) of 0.94 and high linearity between measured and predicted data (R2 = 0.88). It was also observed that the prediction ability of the regional calibration is more influenced by spatial variability of data than temporal variability of data. Soil salinity cross sections were generated for each date and location of data collection, revealing qualitative salinity fluctuations related to the input of salts and water either through irrigation, precipitation, or level and salinity of groundwater. Time-lapse EMCI is developing into a valid methodology for evaluating the risk of soil salinization, so it can further support the evaluation and adoption of proper agricultural management strategies, especially in irrigated areas, where continuous monitoring of soil salinity dynamics is required.
- Avaliação da profundidade das raízes das árvores e do nível piezométrico no Jardim Botânico de LisboaPublication . Mendes, Maria Paula; Falcão, Ana Paula; Afonso, Nuno; Esteves, Miguel; Paz, Maria CatarinaO Jardim Botânico de Lisboa (JBL) foi estabelecido em meados do século XIX, e acolhe cerca de 18.000 espécies de plantas de todo o mundo. Neste jardim existem árvores, que dada a sua raridade, não se conhece a profundidade média dos seus sistemas radiculares. Num lote adjacente ao JBL, localizado a cotas mais elevadas, vão-se proceder a obras que envolvem escavações, sendo necessário estabelecer algumas condições de referência nos dois canteiros mais próximos, nomeadamente, os níveis freáticos para os semestres húmido e seco. Existe também a necessidade de se avaliar se a profundidade das raízes das árvores plantadas nesses canteiros pode chegar ao nível freático. Para dar resposta a estes dois objectivos foram utilizadas técnicas de geofísica. Especificamente, a tomografia de resistividade eléctrica (ERT) e o geo-radar (GPR). O ERT permitiu a aferição da profundidade das raízes das árvores e o GPR foi utilizado para o mapeamento do nível freático. A metodologia aplicada permitiu estabelecer que: (1) a profundidade média do sistema radicular varia aproximadamente entre 2,5 e 3,0 metros e; (2) as raízes das árvores podem atingir o nível freático durante os semestres húmidos e secos.
- A bibliometric analysis of the plastic wastePublication . Paz, Maria Catarina; Serralha, F. N.; Carriço, Nelson
- Combining of MASW and GPR Imaging and Hydrogeological Surveys for the Groundwater Resource Evaluation in a Coastal Urban Area in Southern SpainPublication . Alcalá, Francisco Javier; Martínez-Pagán, Pedro; Paz, Maria Catarina; Navarro, Manuel; Pérez-Cuevas, Jaruselsky; Domingo, FranciscoThis paper conceptualizes and evaluates the groundwater resource in a coastal urban area hydrologically influenced by peri-urban irrigation agriculture. Adra town in southern Spain was the case study chosen to evaluate the groundwater resource contributed from the northern steep urban sector (NSUS) to the southern flat urban sector (SFUS), which belongs to the Adra River Delta Groundwater Body (ARDGB). The methodology included (1) geological and hydrogeological data compilation; (2) thirteen Multichannel Analysis of Surface Waves (MASW), and eight Ground Penetrating Radar (GPR) profiles to define shallow geological structures and some hydrogeological features; (3) hydrogeological surveys for aquifer hydraulic definition; (4) conceptualization of the hydrogeological functioning; and (5) the NSUS groundwater resource evaluation. All findings were integrated to prepare a 1:5000 scale hydrogeological map and cross-sections. Ten hydrogeological formations were defined, four of them (Paleozoic weathered bedrock, Pleistocene littoral facies, Holocene colluvial, and anthropogenic filling) in the NSUS contributing to the SFUS. The NSUS groundwater discharge and recharge are, respectively, around 0.28 Mm3 year−1 and 0.31 Mm3 year−1, and the actual groundwater storage is around 0.47 Mm3. The groundwater renewability is high enough to guarantee a durable small exploitation for specific current and future urban water uses which can alleviate the pressure on the ARDGB.
- Comparison of electromagnetic induction and electrical resistivity tomography in assessing soil salinity: Insights from four plots with distinct soil salinity levelsPublication . Paz, Maria Catarina; Castanheira, Nádia Luísa; Paz, Ana Marta; Gonçalves, Maria Conceição; Santos, Fernando Monteiro; Farzamian, MohammadElectromagnetic induction (EMI) and electrical resistivity tomography (ERT) are geophysical techniques measuring soil electrical conductivity and providing insights into properties correlated with it to depths of several meters. EMI measures the apparent electrical conductivity (ECa, dS m−1) without physical contact, while ERT acquires apparent electrical resistivity (ERa, ohm m) using electrodes. Both involve mathematical inversion to obtain models of spatial distribution for soil electrical conductivity (σ, mS m−1) and electrical resistivity (ρ, ohm m), respectively, where ρ is the reciprocal of σ. Soil salinity can be assessed from σ over large areas using a calibration process consisting of a regression between σ and the electrical conductivity of the saturated soil paste extract (ECe, dS m−1), used as a proxy for soil salinity. This research aims to compare the prediction abilities of the faster EMI to the more reliable ERT for estimating σ and predicting soil salinity. The study conducted surveys and sampling at four locations with distinct salinity levels in Portugal, analysing the agreement between the techniques, and obtained 2D vertical soil salinity maps. In our case study, the agreement between EMI and ERT models was fairly good in three locations, with σ varying between 50 and 500 mS m−1. However, this was not the case at location 4, where σ exceeded 1000 mS m−1 and EMI significantly underestimated σ when compared to ERT. As for soil salinity prediction, both techniques generally provided satisfactory and comparable regional-level predictions of ECe, and the observed underestimation in EMI models did not significantly affect the overall estimation of soil salinity. Consequently, EMI demonstrated an acceptable level of accuracy in comparison to ERT in our case studies, supporting confidence in utilizing this faster and more practical technique for measuring soil salinity over large areas
- Construção de um sistema de modelos para simulação computacional da limitação natural de pragasPublication . Paz, Maria Catarina; Barreira, Raquel; Amaro, Luís; Sousa, José Paulo; Benhadi-Marín, Jacinto; Rasko, Mykola; Silva, António Alves da; Alves, Joana; Mina, Ruben; Chuhutin, Andrey; Duan, Xiaodong; Topping, Christopher John; Santos, Sónia A.P.A limitação natural de pragas é um serviço de ecossistema que deve ser promovido nos sistemas agrícolas, já que pode ser usada como alternativa, ou complementarmente, à aplicação de pesticidas. Consiste no consumo das pragas pelos seus inimigos naturais e pode ser promovida através do estabelecimento de componentes paisagísticas que forneçam, a estes inimigos das pragas, alimento alternativo e refúgio, para além da aplicação de práticas agrícolas sustentáveis. No entanto, o delineamento de uma estratégia eficaz de limitação natural de pragas está dependente da caracterização detalhada dos comportamentos dos animais que fazem parte dessa cadeia trófica, nomeadamente, das pragas e dos seus predadores, o que pode ser feito através de simulações computacionais. Neste contexto, e no âmbito do projeto OLIVESIM, estamos a construir um sistema de modelos para simular a biologia e o comportamento de duas espécies de artrópodes (1) a mosca-da-azeitona, Bactrocera oleae (Rossi), praga chave da oliveira, e (2) a aranha de solo, Haplodrassus rufipes (Lucas), um dos potenciais predadores da praga, e as suas interações com a paisagem selecionada para realizar este estudo, localizada na região de Trás-os-Montes (Mirandela, Portugal) e caracterizada fundamentalmente por olival tradicional. Para isso, está a ser utilizado o sistema ALMaSS (Animal, Landscape and Man Simulation System), que recebe inputs diários de variáveis climáticas e também de ações de gestão agrícola, e que é calibrado com dados sobre abundância quantitativa e qualitativa de animais. Neste simpósio focamo-nos nestes dois modelos, mostrando também o estado atual deste trabalho.
- Construção de um sistema de modelos para simulação computacional da limitação natural de pragasPublication . Paz, Maria Catarina; Barreira, Raquel; Amaro, Luís; Sousa, José Paulo; Benhadi-Marín, Jacinto; Rasko, Mykola; Silva, António Alves da; Alves, Joana; Mina, Rúben; Chuhutin, Andrey; Duan, Xiaodong; Topping, Christopher John; Santos, Sónia A.P.
- Detailed detection of active layer freeze–thaw dynamics using quasi-continuous electrical resistivity tomography (Deception Island, Antarctica).Publication . Farzamian, Mohammad; Vieira, Gonçalo; Santos, Fernando A. Monteiro; Tabar, Borhan Yaghoobi; Hauck, Christian; Paz, Maria Catarina; Bernardo, Ivo; Ramos, Miguel; Angel de Pablo, MiguelClimate-induced warming of permafrost soils is a global phenomenon, with regional and site-specific vari- ations which are not fully understood. In this context, a 2- D automated electrical resistivity tomography (A-ERT) sys- tem was installed for the first time in Antarctica at Decep- tion Island, associated to the existing Crater Lake site of the Circumpolar Active Layer Monitoring – South Program (CALM-S) – site. This setup aims to (i) monitor subsurface freezing and thawing processes on a daily and seasonal basis and map the spatial and temporal variability in thaw depth and to (ii) study the impact of short-lived extreme meteoro- logical events on active layer dynamics. In addition, the feasi- bility of installing and running autonomous ERT monitoring stations in remote and extreme environments such as Antarc- tica was evaluated for the first time. Measurements were re- peated at 4 h intervals during a full year, enabling the detec- tion of seasonal trends and short-lived resistivity changes re- flecting individual meteorological events. The latter is impor- tant for distinguishing between (1) long-term climatic trends and (2) the impact of anomalous seasons on the ground ther- mal regime. Our full-year dataset shows large and fast temporal resis- tivity changes during the seasonal active layer freezing and thawing and indicates that our system setup can resolve spa- tiotemporal thaw depth variability along the experimental transect at very high temporal resolution. The largest resis- tivity changes took place during the freezing season in April, when low temperatures induce an abrupt phase change in the active layer in the absence of snow cover. The seasonal thaw- ing of the active layer is associated with a slower resistivity decrease during October due to the presence of snow cover and the corresponding zero-curtain effect. Detailed investiga- tion of the daily resistivity variations reveals several periods with rapid and sharp resistivity changes of the near-surface layers due to the brief surficial refreezing of the active layer in summer or brief thawing of the active layer during win- ter as a consequence of short-lived meteorological extreme events. These results emphasize the significance of the con- tinuous A-ERT monitoring setup which enables detecting fast changes in the active layer during short-lived extreme meteorological events. Based on this first complete year-round A-ERT monitor- ing dataset on Deception Island, we believe that this sys- tem shows high potential for autonomous applications in re- mote and harsh polar environments such as Antarctica. The monitoring system can be used with larger electrode spacing to investigate greater depths, providing adequate monitoring at sites and depths where boreholes are very costly and the ecosystem is very sensitive to invasive techniques. Further applications may be the estimation of ice and water contents through petrophysical models or the calibration and valida- tion of heat transfer models between the active layer and per- mafrost.
- Determination of baseline groundwater levels for tree conservation in urban historical botanical gardens using Applied GeophysicsPublication . Paz, Maria Catarina; Falcão, Ana Paula; Garcia, César Augusto; Esteves, Miguel; Afonso, Nuno; Mendes, Maria PaulaHistorical botanical gardens hold a significant place in cultural heritage. They serve as interpretive repositories of past botanical knowledge and practices, showcase plant collections cultivated over centuries, provide space for the emergence of new ecologies, offer numerous human well-being benefits, and supply vital regulating ecosystem services, which are especially important in urban areas. Nowadays, however, plants within urban historical botanical gardens can be at risk due to urban development. Therefore, it is crucial to achieve a comprehensive understanding of these spaces to help implement protective measures and support proper urban planning of the surrounding areas. This study investigates the subsurface of the Botanical Garden of Lisbon (JBL), which is subject to nearby construction works that may alter groundwater flow and depth. We employed a methodology designed for minimal on-site disturbance and high adaptability to the spatial constraints typical of these spaces. Two non-invasive applied geophysical techniques were used: electrical resistivity tomography (ERT) and ground-penetrating radar (GPR). Our main objectives were: (1) to assess groundwater levels in the construction area and establish the piezometric surface, and (2) to determine if tree roots reach the saturated zone, establish a groundwater baseline, and suggest protective measures. The establishment of the piezometric surface and the delimitation of the root zone, extending up to 3.0 m in depth, revealed that tree roots can access groundwater levels. This finding underscores the critical need for vigilant monitoring and management of groundwater levels during excavation activities, as decreased lateral groundwater contributions from the excavation area can adversely affect groundwater levels of trees in the plant beds. These findings and methodology can be applied to urban botanical gardens worldwide, as many of these gardens face similar challenges due to urbanization and environmental changes.
- Determination of baseline groundwater levels for tree conservation in urban historical botanical gardens using Applied GeophysicsPublication . Paz, Maria Catarina; Falcão, Ana Paula; Garcia, César Augusto; Esteves, Miguel; Afonso, Nuno; Mendes, Maria PaulaHistorical botanical gardens hold a significant place in cultural heritage. They serve as interpretive repositories of past botanical knowledge and practices, showcase plant collections cultivated over centuries, provide space for the emergence of new ecologies, offer numerous human well-being benefits, and supply vital regulating ecosystem services, which are especially important in urban areas. Nowadays, however, plants within urban historical botanical gardens can be at risk due to urban development. Therefore, it is crucial to achieve a comprehensive understanding of these spaces to help implement protective measures and support proper urban planning of the surrounding areas. This study investigates the subsurface of the Botanical Garden of Lisbon (JBL), which is subject to nearby construction works that may alter groundwater flow and depth. We employed a methodology designed for minimal on-site disturbance and high adaptability to the spatial constraints typical of these spaces. Two non-invasive applied geophysical techniques were used: ground-penetrating radar (GPR) and electrical resistivity tomography (ERT). Our main objectives were: (1) to assess groundwater levels in the construction area and establish the piezometric surface, and (2) to determine if the tree-root zones reach the saturated zone, establish a groundwater baseline, and suggest protective measures. The establishment of the piezometric surface and the delimitation of the tree-root zone, extending up to 3.0 m in depth, revealed that tree-root zones can reach groundwater levels. This finding underscores the critical need for vigilant monitoring and management of groundwater levels during excavation activities, as decreased lateral groundwater contributions from the potential excavation site can adversely affect groundwater levels in the plant beds. These findings and methodology can be applied to urban botanical gardens worldwide, as many of these gardens face similar challenges due to urbanization and environmental changes.
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