Aplicação de índices espectrais na avaliação do aporte de sedimento aos reservatórios das Usinas Hidrelétricas Itumbiara e Batalha (Brasil)

In this work, two spectral indexes were implemented using Landsat images, the Normalized Difference Water Index (NDWI) for the delimitation of the water mirror and the Normalized Difference Turbidity Index (NDTI) to evaluate the sediment contribution to the reservoirs of the hydroelectric power plants Itumbiara and Batalha, located on the borders of the states of Goiás and Minas Gerais. The acquisition and processing were carried out in the Google Earth Engine platform and the post-processing in the QGIS software. The NDTI was applied to the reservoirs considering the variation in water level between the dry and rainy seasons in 2020. The highest concentration of turbidity in the Itumbiara reservoir occurred in September, and the lowest in June. August was the month with the highest turbidity concentration and July the lowest in the Batalha reservoir.En este trabajo se implementaron dos índices espectrales utilizando imágenes Landsat, el Índice de Diferencia de Agua Normalizada (NDWI) para la delimitación del espejo de agua y el Índice de Turbidez de Diferencia Normalizada (NDTI) para evaluar el aporte de sedimentos a los embalses de las centrales hidroeléctricas Itumbiara y Batalha, ubicadas en los límites de los estados de Goiás y Minas Gerais. El NDTI se aplicó en los embalses considerando la variación del nivel del agua entre las épocas seca y lluviosa de 2020. La mayor concentración de turbiedad en el embalse de Itumbiara se presentó en septiembre y la menor en junio, siendo agosto el mes con mayor concentración de turbidez y julio con la menor en el embalse de Batalha.Dans ce travail, deux indices spectraux ont été implémentés à l'aide d'images Landsat, le Normalized Difference Water Index (NDWI) pour la délimitation du miroir d'eau et le Normalized Difference Turbidity Index (NDTI) pour évaluer la contribution des sédiments aux réservoirs des centrales hydroélectriques. Itumbiara et Batalha, situées aux confins des états de Goiás et Minas Gerais. Le NDTI a été appliqué dans les réservoirs en tenant compte de la variation du niveau d'eau entre les saisons sèche et pluvieuse de 2020. La plus forte concentration de turbidité dans le réservoir d'Itumbiara s'est produite en septembre et la plus faible en juin. Dans le réservoir de Batalha, août étant le mois avec la plus forte concentration de turbidité et la plus faible en juillet.In questo lavoro sono stati implementati due indici spettrali utilizzando immagini Landsat, il Normalized Difference Water Index (NDWI) per la delimitazione dello specchio d'acqua e il Normalized Difference Turbidity Index (NDTI) per valutare il contributo dei sedimenti ai serbatoi delle Centrali Idroelettriche Itumbiara e Batalha, situate ai confini degli stati di Goiás e Minas Gerais. L'acquisizione e l'elaborazione sono state effettuate nella piattaforma Google Earth Engine e la post-elaborazione nel QGIS. L'NDTI è stato applicato nei bacini considerando la variazione del livello dell'acqua tra la stagione secca e quella piovosa del 2020. La più alta concentrazione di torbidità nel bacino di Itumbiara si è verificata a settembre, e la più bassa a giugno. Nel bacino di Batalha, agosto è il mese con la più alta concentrazione di torbidità e il più basso a luglio.Neste trabalho foram implementados dois índices espectrais utilizando imagens Landsat, o Índice da Diferença Normalizada de Água (NDWI) para delimitação do espelho d’água e o Índice de Turbidez por Diferença Normalizada (NDTI) para avaliação do aporte de sedimentos aos reservatórios das Usinas Hidrelétricas Itumbiara e Batalha, localizadas nas divisas dos estados de Goiás e Minas Gerais. A aquisição e o processamento foram realizados na plataforma Google Earth Engine e o pós-processamento no software QGIS. O NDTI foi aplicado nos reservatórios considerando a variação do nível de água entre as estações seca e chuvosa de 2020. A maior concentração de turbidez no reservatório de Itumbiara se deu em setembro, e a menor em junho. Já no reservatório de Batalha, sendo agosto o mês com maior concentração de turbidez, e a menor em julho

The Mitigation Potential of Buffer Strips for Reservoir Sediment Yields: The Itumbiara Hydroelectric Power Plant in Brazil

Soil erosion and deposition mechanisms play a crucial role in the sustainability of both existing reservoirs and newly planned projects. Soil erosion is one of the most important factors influencing sediment transport yields, and, in the context of existing reservoirs, the surrounding watersheds supply both runoff and sediment yield to the receiving water body. Therefore, appropriate land management strategies are needed to minimize the influence of sediment yields on reservoir volume and, hence, the capacity of power generation. In this context, soil erosion control measures such as buffer strips may provide a practical and low-cost option for large reservoirs, but need to be tested at the catchment scale. This paper represents a study case for the Itumbiara hydroelectric power plant (HPP) in Brazil. Four different scenarios considering radially planted buffer strips of Vetivergrass with widths of 20 m, 40 m, 100 m and 200 m are analyzed. A semi-distributed hydrological model, SWAT, was used to perform the simulations. Results indicate a reduction of sediments transported to the reservoir of between 0.2% and 1.0% per year is possible with buffer strip provision, and that this reduction, over the life of Itumbiara HPP, may prove important for lengthening the productivity of the plant

Historical streamflow series analysis applied to furnas HPP reservoir watershed using the SWAT model

Over the last few years, the operation of the Furnas Hydropower Plant (HPP) reservoir, located in the Grande River Basin, has been threatened due to a significant reduction in inflow. In the region, hydrological modelling tools are being used and tested to support decision making and water sustainability. In this study, the streamflow was modelled in the area of direct influence of the Furnas HPP reservoir, and the Soil and Water Assessment Tool (SWAT) model performance was verified for studies in the region. Analyses of sensitivity and uncertainty were undertaken using the Sequential Uncertainty Fitting algorithm (SUFI-2) with a Calibration Uncertainty Program (SWAT-CUP). The hydrological modelling, at a monthly scale, presented good results in the calibration (NS 0.86), with a slight reduction of the coefficient in the validation period (NS 0.64). The results suggested that this tool could be applied in future hydrological studies in the region of study. With the consideration that special attention should be given to the historical series used in the calibration and validation of the models. It is important to note that this region has high demands for water resources, primarily for agricultural use. Water demands must also be taken into account in future hydrological simulations. The validation of this methodology led to important contributions to the management of water resources in regions with tropical climates, whose climatological and geological reality resembles the one studied here

Analysis of Average Temperatures And Trends In Brazil: Applying CUSUM Graphic from 2000 to 2014

In recent decades the temperature trends are being confirmed earlier. To determine the temperature changes in Brazil, analysis of annual trends and seasons was carried out based on daily data from 187 weather stations, covering the period from 2000 to 2014. Trends were confirmed using the Cumulative Sum Chart, a method that notices the changes in series faster than others. The modeling of temperature was obtained by Multiple Regression and using Cluster Analysis, and through this it was possible to group weather stations. The observed trends confirmed oscillations in cooling, heating and, in some cases, cooling followed by heating. These main trends presented during the study period were from -15 to 0 in latitude. The region with the highest confirmation of inversions in temperature was the North, then Northeast. Heights below 500 meters presented higher trends. Regarding the seasons, autumn contributed significantly to the trends.Nas últimas décadas as tendências de temperatura estão se confirmando mais rapidamente. Para determinar as mudanças de temperatura no Brasil foi realizada análise das tendências anuais e por estações do ano tendo por base dados diários de 187 estações meteorológicas, abrangendo o período de 2000 a 2014. As tendências foram confirmadas com a utilização do Gráfico de Soma Acumulativa, este método percebe as alterações em séries mais rápido que outros. A modelagem da temperatura foi obtida por Regressão Múltipla e com a Análise de Cluster foi possível agrupar Estações Meteorológicas. As tendências observadas confirmam oscilações de resfriamento, aquecimento e em alguns casos de resfriamento seguido de aquecimento. As principais tendências apresentadas no período estudado foram a partir de -15 até 0° na latitude. A região com maior confirmação de inversões na temperatura foi o Norte, seguida do Nordeste. Em altitude abaixo de 500 metros é onde apresentou maior tendência. Quanto às estações do ano, o outono contribuiu significativamente com as tendências

Assessing nature exposure: a study on the reliability and validity of a Portuguese version of the nature exposure scale

IntroductionEngaging with nature has been widely acknowledged for its positive impact on well-being. Traditionally, assessments of nature exposure focus on estimating green space exposure and outdoor time. However, the Nature Exposure Scale (NES) offers a unique approach by evaluating the quality of nature experiences, encompassing both deliberate and spontaneous encounters.MethodsThis study aimed to assess the validity and reliability of the NES in the context of Portugal. Exploratory Factor Analysis (PCA) and Confirmatory Factor Analysis (CFA) were employed to examine the underlying structure of the scale. Additionally, reliability assessments, along with tests of convergent and divergent validity, were conducted. Data were collected from a sample of 558 adults and 241 adolescents between 2016 and 2018.ResultsThe findings revealed strong internal consistency of the NES, supported by acceptable correlation values and robust factor loadings within a unidimensional model. The scale effectively predicted variations in nature exposure across diverse professional activities.DiscussionIn summary, the 4-item NES emerged as a reliable tool for assessing nature exposure in various settings, effectively bridging a gap in the Portuguese context. The scale demonstrated potential for cross-cultural research and was particularly adept at predicting nature exposure in different professional contexts. The results suggest that the NES can enhance our understanding of the impact of nature on well-being in diverse cultural settings.ConclusionThe study underscores the reliability of the NES in assessing nature exposure in Portugal, paving the way for further exploration in Portuguese-speaking regions. The scale holds promise for advancing research on the relationship between nature and well-being, contributing valuable insights across different cultural contexts

USO DE SOLUÇÃO DE CAL PARA MITIGAÇÃO DE PROCESSOS EROSIVOS EM UM SOLO DA UHE DE ITUMBIARA

O presente estudo tem como objetivo geral estudar e propor uma alternativa, por meio da aplicação de solução de cal sobre o solo, para mitigação dos processos erosivos em margens de reservatórios. A região que foi selecionada pertence à Usina Hidrelétrica de Itumbiara. Foram realizados os ensaios de Inderbitzen, Desagregação, Microscopia Eletrônica de Varredura, Difração de Raio X e Granulometria a laser em amostras de solos estabilizados com concentrações de cal de 1%, 2% e 4% e tempos de cura de 1, 7, 28 e 56 dias. Verificou-se que o tratamento aumentou a resistência do solo quanto a erodibilidade superficial e à estabilidade estrutural. Em relação à erodibilidade superficial, a concentração da solução de cal de 1% se mostrou adequada. No entanto, para que se tenha um ganho na estabilidade estrutural é necessário concentração da solução de cal superior a 2% e tempo de cura maior que 28 dias. Sendo assim, o tratamento do solo por meio da aplicação de solução de cal apresenta-se como uma boa técnica na prevenção aos processos erosivos laminares

Neurobehavioral and Antioxidant Effects of Ethanolic Extract of Yellow Propolis

Propolis is a resin produced by bees from raw material collected from plants, salivary secretions, and beeswax. New therapeutic properties for the Central Nervous System have emerged. We explored the neurobehavioral and antioxidant effects of an ethanolic extract of yellow propolis (EEYP) rich in triterpenoids, primarily lupeol and β-amyrin. Male Wistar rats, 3 months old, were intraperitoneally treated with Tween 5% (control), EEYP (1, 3, 10, and 30 mg/kg), or diazepam, fluoxetine, and caffeine (positive controls) 30 min before the assays. Animals were submitted to open field, elevated plus maze, forced swimming, and inhibitory avoidance tests. After behavioral tasks, blood samples were collected through intracardiac pathway, to evaluate the oxidative balance. The results obtained in the open field and in the elevated plus maze assay showed spontaneous locomotion preserved and anxiolytic-like activity. In the forced swimming test, EEYP demonstrated antidepressant-like activity. In the inhibitory avoidance test, EEYP showed mnemonic activity at 30 mg/kg. In the evaluation of oxidative biochemistry, the extract reduced the production of nitric oxide and malondialdehyde without changing level of total antioxidant, catalase, and superoxide dismutase, induced by behavioral stress. Our results highlight that EEYP emerges as a promising anxiolytic, antidepressant, mnemonic, and antioxidant natural product

Clinical Manifestations and Complications of Children With COVID-19 Compared to Other Respiratory Viral Infections: A Cohort Inpatient Study From Rio de Janeiro, Brazil

IntroductionThe coronavirus disease-2019 (COVID-19) clinical manifestations in children and adolescents are diverse, despite the respiratory condition being the main presentation. Factors such as comorbidities and other respiratory infections may play a role in the initial presentation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aims to describe the epidemiological aspects, clinical, and laboratory manifestations of pediatric patients admitted to a tertiary pediatric hospital in Rio de Janeiro, diagnosed with COVID-19, and compare these with other viral conditions during the first year of the SARS-CoV-2 pandemic.MethodsAll patients under 18 years of age that were admitted with upper airway infection were enrolled and followed up for 30 days. The main dependent variable was the laboratorial diagnosis of SARS-CoV-2, and independent variables were studied through logistic regression.ResultsA total of 533 patients were recruited, and 105 had confirmed SARS-CoV-2 infection. Detection of other viruses occurred in 34% of 264 tested participants. Six patients died (two in SARS-CoV-2 infected group). The variables independently associated with COVID-19 were older age (OR = 1.1, 95% CI = 1.0–1.1), lower leukocytes count at entry (OR = 0.9, 95% CI = 0.8–0.9), and contact with suspected case (OR = 1.6, 95% CI = 1.0–2.6). Patients with COVID-19 presented higher odds to be admitted in an intensive care unit (OR = 1.99, 95% CI = 1.08–3.66).ConclusionsEven during the SARS-CoV-2 pandemic, several other respiratory viruses were present in admitted pediatric patients. Variables associated with COVID-19 infection were older age, lower leukocytes count at entry, and a domiciliary suspect contact. Although patients with COVID-19 were more frequently admitted to ICU, we did not observe higher mortality in this group