Análise Morfométrica Da Bacia Hidrográfica Do Rio Subaé, Bahia, BrasilMorphometric Analysis River Basin Of Subaé, Bahia, Brasil

A análise morfométrica permite investigar as interações entre os processos físicos e as formas do relevo de uma bacia, sob a ótica quantitativa, fornecidas pelas geotecnologias. Dentre essas geotecnologias se destaca o uso de técnicas de Geoprocessamento, a partir do software ArcMap® 10.2, que possibilita a geração de mapas de hierarquia fluvial, declividade e hipsometria, entre outros. Objetivou-se, neste estudo, calcular, a partir dos mapas gerados, os dados morfométricos da bacia hidrográfica do rio Subaé, visando ao entendimento da morfodinâmica de sua paisagem. Foram estudados, padrões de drenagem, densidade hidrográfica e densidade de drenagem, gradiente de canais e relação de relevo, bem como a delimitação da própria bacia. O padrão de drenagem apresentouse sob a forma dendrítica, com área de drenagem de 559.23 km² e perímetro de 167.56 km, constatando-se que a bacia possui forma alongada, com densidade de drenagem regular, com relevo ondulado a suavemente ondulado, com potencial de escoamento e não susceptível às enchentes. AbstractThe morphometric analysis allows to investigate the interactions among the physics process and the forms of the relief of an watershed, on a quantitative perspective, provided by geotechnologies. Among these geotechnologies stands out the use of Geoprocessing techniques, from software ArcMap® 10.2, which allow the generation of maps of fluvial hierarchy, slope and hypsometry, among others. The objective of this study is calculated, from of the generated maps, the morphometric data of the watershed of the Subaé river, for understanding of the morphodinamic of its landscape. They were studied drainage pattern, hydrographic density and drainage density, channel gradient and relief relation, and the delimitation of the own bowl. The pattern of drainage shown in the dendritic form, with the drainage area of 559,23 km² and perimeter of 167,56 km. Noting that the watershed have elongated shape, with the regular drainage of density, with wavy relief to gently rolling relief, with potential flow and not susceptible to floodin

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR, browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters. Finally we briefly discuss on the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, and touch on communication and outreach activities, the consortium organisation, and finally on the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. (abridged).Comment: 48 pages, 29 figures, Accepted for publication in Experimental Astronomy with minor editin

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory. Athena is a versatile observatory designed to address the Hot and Energetic Universe science theme, as selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), X-IFU aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over a hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR (i.e. in the course of its preliminary definition phase, so-called B1), browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters, such as the instrument efficiency, spectral resolution, energy scale knowledge, count rate capability, non X-ray background and target of opportunity efficiency. Finally, we briefly discuss the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, touch on communication and outreach activities, the consortium organisation and the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Poland, Spain, Switzerland, with additional contributions from the United States and Japan.The French contribution to X-IFU is funded by CNES, CNRS and CEA. This work has been also supported by ASI (Italian Space Agency) through the Contract 2019-27-HH.0, and by the ESA (European Space Agency) Core Technology Program (CTP) Contract No. 4000114932/15/NL/BW and the AREMBES - ESA CTP No.4000116655/16/NL/BW. This publication is part of grant RTI2018-096686-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This publication is part of grant RTI2018-096686-B-C21 and PID2020-115325GB-C31 funded by MCIN/AEI/10.13039/501100011033

Transfert d´espèces chimiques au travers d´un sol cultivé avec du maïs et du tournesol et irrigué avec des effluents d´eaux usées

Estudos atuais sobre uso de efluente na agricultura buscam sustentabilidade dos sistemas agrícolas irrigados. O presente trabalho teve como objetivo caracterizar a hidroquímica de um Latossolo cultivado e irrigado com efluente de esgotos domésticos, no município de Lins (SP). Foram cultivados 2 ciclos de milho e 2 ciclos de girassol. O monitoramento consistiu nas análises químicas de Na+, K+, Ca2+, Mg2+, Cl-, SO42-, NO3-, NH¬4+ e carbono orgânico dissolvido, na solução do solo (16 amostragens) e no solo (3 amostragens), além da caracterização da hidrodinâmica no solo, entre 0 e 200 cm de profundidade. Apesar de ter observado intensa nitrificação do NH4+ nos primeiros centímetros do solo irrigado com efluente, os valores de nitrato não foram superiores do que no caso de uma adubação nitrogenada mineral. A irrigação tanto com efluente como com água sódica potável promoveu rápida percolação da água até 0,75-1,00 m, acompanhada de um aumento das concentrações iônicas e de uma sodificação nesta profundidade. Consequentemente, ocorreu decréscimo da condutividade hidráulica K(θ) e aumento da retenção de água h(θ), resultando num decréscimo dos fluxos de água do solo. Demonstrou-se a importância do estabelecimento das curvas K(θ) e h(θ) do solo irrigado para obter balanço hídrico e químicos corretos, principalmente no caso do Na+, Mg2+ e matéria orgânica.Les études actuelles portant sur lutilisation agricole des effluents sintéressent à la durabilité de sistèmes agricoles irrigués. Lobjectif de ce travail fut de caractériser lhydrochimie dun Latossolo cultivé e irrigué avec de leffluent issu des eaux usées de la municipalité de Lins (SP). Deux cycles de maïs et deux cycles de tournesol furent cultivés, durant lesquels furent analysées les teneurs de Na+, K+, Ca2+, Mg2+, Cl-, SO42-, NO3-, NH¬4+ et de carbone organique dissous, dans la solution du sol (16 échantillonages) et dans le sol (3 échantillonages), de 0 à 200 cm; une détermination parallèle de hydrodynamique du sol fut également realisée. Malgré lintense nitrification du NH4+ dans les premiers centimètres du sol, les valeurs de nitrate nont pas dépassé les valeurs obtenues dans le cas dune fertilization azotée. Lirrigation utilisant aussi bien de leffluent que de leau sodique potable a suscité une percolation rapide de leau jusquà 0,75-1,00 m, accompagnée de laugmentation des concentrations ioniques et dune sodification à cette profondeur. Par conséquent, une diminution de la conductivité hydraulique K(θ) et une augmentation de la rétention de leau h(θ) furent observées, résultant en une diminution des flux deau dans le sol. Limportance de la determination des courbes K(θ) e h(θ) dans le sol irrigué fut démontrée afin dobtenir des bilans hydriques et chimiques corrects, principalement dans le cas du Na+, du Mg+ et de la matière organique

REDUCING THE GAP BETWEEN FIELD AND LABORATORY X-RAYS FLUORESCENCE ANALYSIS

International audienceSoil samples preparation methods for X-ray fluoresence analysis diverge between different studies. An official method is described in US-EPA 3200, but many authors do not follow this recommendation and propose adaptation according to the specificity of the analyzed matrix. Furthermore, XRF analysis is supposed to be rapid and precise for in situ mapping or lab bench measurements. The succession of preparation procedures can delay the acquisition of results: if the duration of samples preparation is equivalent or superior to a standard total acid-extraction procedure, the use of the XRF method can be questionable.Portable XRF devices (pXRF) are typically designed for in situ mapping. However, researchers frequently collected and analyzed soil samples back home in their laboratory, for different reasons: (1) need to investigate deeper soil horizons, (2) reduction of time-consumingfield analysis (soil sampling can actually be faster than XRF analysis), (3) comfort and safety reasons (i.e. weather conditions), (4) requirement of extra analyses, etc.... As the soil samples are supposed to represent the field conditions, the correlation between field results and laboratory results is decisive.The first experiments in this study aimed at optimizing the analyzing time and ensure measurement quality: (1) calibrations using different organic and mineral reference materials, (2) effect of time measurement on calibration. Then, we focused on the effects of sample preparation of XRF measurements, by comparing different procedures: (a) Directly from field, (b) after drying, (c) after sieving 2 mm, (d) after grinding at 6m/s, until 180 microns (80mesh), (e) after burning at 550oC (elimination of organic matter). We confirmed that a 2 min time measurement is sufficient for accurate and precise pXRF results. As expected, a strong effect of the organic matter appears during the analysis. We could distinctly model two calibration curves using two groups of certified references material: 8 mineral samples (soils and sediments) and 19 organic samples. Within the second group, we included aquatic plants, lichen, peat, leaves and coal samples. The slope of the calibration curve is three to four times attenuated in these organic samples, so specific calibration according to soil matrix is mandatory. Concerning the preparation procedure, most of the elements (40 of 50 elements) presented a low variability (8% variability.Burning of the sample at 550oC does not change the chemical composition (which must be corrected due to the loss of organic matter). Surprisingly, even the 2mm sieving does not significantly modify the XRF measurements. Finally, we observe that fine grindind (<180 μm)provides results far from the real field values, probably because the procedure generates metal-rich fine particles that can accumulate at the bottom of the capsule where the XRF measurement is made. We conclude that the preparation of the samples should be minimal to avoid laboratory bias. This makes the XRF scans faster, which is the main purpose of this type of analysis and allows to get closer to the real conditions of the field

Hydrogeochemistry of the Subaé River Impacted by Lead Smelting Activities, Bahia State, Brazil: Geochemical Characterization and Fluxes of Metals

International audienceThe Subaé river watershed is considered one of the most critical Pb-impacted environments in Brazil and around the world, due to pollutant dispersion during 33 years of lead ore purification in Santo Amaro da Purification. Severe damages have been reported in biota and population, which depends on the Subaé river watershed quality for agriculture, fishing, and shellfish harvesting. This study aims to understand the geochemical characteristics and dynamics of the river close to the former Pb smelter. The river was sampled at eight sites upstream and eight sites downstream the smelter, near the estuary in the Todos os Santos Bay, six times during a year. Immediate analyses were performed by multiprobe. Major ions were measured by chromatography, dissolved metals by ICP-OES in the filtrated samples (0.45 μm), and particulate metals > 0.45 μm by EDX spectrometry. The ions Na⁺ and HCO3⁻ are dominated in the river. Most of the samples (47.6%) were classified as sodic, due to oceanic saline intrusion during tide. Despite the high pollution caused by the smelter from 1960 to 1993, still observed in the surrounding soils, dissolved and particulate metals in the river remained low in all sites during the entire year. Only Cu presented some concentration above the threshold of the Brazilian regulations. The discharge of metals by the river into the Todos os Santos Bay appears to be low for Pb and Zn (2.2 and 14.3 kg km⁻¹ year⁻¹, respectively), but higher for Cu comparatively to other worldwide bays

Irrigation with domestic wastewater: a multivariate analysis of main soil changes Irrigação com água residuária doméstica: análise multivariada das principais mudanças no solo

Irrigation with treated domestic sewage wastewater (TSE) is an agricultural practice to reduce water requirements of agroecossystems and the nutrient load impact on freshwaters, but adverse effects on soil chemical (salinization, sodification, etc.) and soil physical properties (alteration in soil porosity and hydraulic conductivity, etc.) have been reported. This study aimed to define some relationships among these changes in an Oxisol using multivariate analysis. Corn (Zea mays L.) and sunflower (Helianthus annuus L.) were grown for two years, irrigated with TSE. The following soil properties were determined: Ca2+; Mg2+; Na+; K+ and H + Al contents, cationic exchangeable capacity (CEC), sum of bases (SB), base saturation (V), texture (sand, silt and clay), macro-, micro-, and cryptoporosity (V MA, V MI and V CRI), water content at soil saturation (&#952;S) and at field capacity (&#952;FC), residual water content (&#952;R), soil bulk density (d s), water dispersed clay (WDC) and saturated hydraulic conductivity (K SAT). Factor analysis revealed the following six principal factors: Fine Porosity (composed of Na+; K+; WDC, &#952;R, &#952;RFC, and V CRI); Large Porosity (&#952;S, d s, V MA, Vs); Soil CEC (Ca2+; Mg2+; CEC, SB, V); Soil Acidity (H + Al); and Soil Texture (factors 5 and 6). A dual pore structure appears clearly to the factors 1 and 2, with an apparent relationship between fine porosity and the monovalent cations Na+ and K+. The irrigation (with potable sodic tap water or sewage wastewater) only had a significant effect on Fine Porosity and Large Porosity factors, while factors 3 and 4 (Soil CEC and Soil Acidity) were correlated with soil depth. The main conclusion was a shift in pore distribution (large to fine pores) during irrigation with TSE, which induces an increase of water storage and reduces the capacity of drainage of salts.<br>A irrigação com águas residuárias tratadas (ART) é uma técnica utilizada na agricultura para reduzir as necessidades hídricas e o impacto da carga de nutrientes nos mananciais, porém vários efeitos negativos já foram registrados nas propriedades químicas (salinização, sodificação, etc.) e físicas do solo (alteração na porosidade e condutividade hidráulica do solo, etc.). Este estudo teve como objetivo definir, por meio de uma análise multivariada, inter-relações entre essas mudanças em um Latossolo onde foram cultivados durante dois anos milho (Zea mays L.) e girassol (Helianthus annuus L.), irrigando com ART. Foram analisados: teores de Ca2+; Mg2+; Na+; K+ e H + Al, capacidade de troca catiônica (CTC), soma das bases (SB), saturação por bases (V), textura (areia, silte e argila), macro-, micro- e criptoporosidade (V MA, V MI e V CRI), umidades na saturação (&#952;S) e na capacidade de campo (&#952;CC), umidade residual (&#952;R), densidade aparente do solo (d s), argila dispersa em água (ADA) e condutividade hidráulica em meio saturado (K SAT). A análise revelou os seguintes seis fatores principais. Porosidade fina (composto por Na+; K+; WDC, &#952;R, &#952;CC e V CRI), Porosidade larga (&#952;S, d s, V MA, Vs), CTC do solo (Ca2+; Mg2+; CCC, SB, V), Acidez do solo (H + Al) e Textura do solo (fatores 5 e 6). Uma estrutura de porosidade dupla apareceu claramente nos fatores 1 e 2, mostrando relações nítidas entre Porosidade fina e os cátions monovalentes Na+ e K+. O efeito da irrigação (utilizando água encanada sódica potável ou ART) foi somente significativo para os fatores Porosidade fina e Porosidade Larga, enquanto os fatores 3 e 4 (CTC do solo e acidez do solo) foram correlacionados com a profundidade do solo. A conclusão principal é a mudança da distribuição dos poros do solo durante a irrigação com ART (poros grossos para poros finos), o que leva ao aumento do armazenamento da água no solo e à redução da drenagem dos sais

Soil Chemistry after Irrigation with Treated Wastewater in Semiarid Climate

ABSTRACT Soil irrigation using treated wastewater in the Brazilian semiarid region is a promising practice as this area currently faces water scarcity and pollution of water resources by domestic sewage. The aim of this study was to evaluate the use of treated wastewater in drip irrigation and its effect on the chemistry of soil cultivated with squash (Cucurbita maxima Duch.) Coroa IAC and to verify whether there was an increase in soil salinity under a semiarid climate. The experiment was conducted for 123 days on a farm close to the sewage treatment plant, in a randomized block design with five treatments and four replications. The treatments consisted of two irrigation water depths (100 and 150 % of the evapotranspiration), two applications of gypsum to attenuate wastewater sodicity (0 and 5.51 g per plant), and a control treatment with no application of wastewater or gypsum. During the experiment, treated wastewater and soil gravitational water, at a depth of 0.40 m, were collected for measurement of Na+, K+, Ca2+, Mg2+, NO−3, NH4+, Cl− , alkalinity, electrical conductivity, pH and sodium adsorption ratio. At the end of the experiment, soil samples were collected at depths of 0.00-0.10, 0.10-0.20, and 0.20-0.40 m; and pH, total N, organic C, exchangeable cations and electrical conductivity of the saturation extract (CEs) were analyzed. Besides an increase in pH and a reduction in total N, the irrigation with wastewater reduces soil salinity of the naturally salt-rich soils of the semiarid climate. It also led to soil sodification, in spite of the added gypsum, which indicates that irrigation with wastewater might require the addition of greater quantities of gypsum to prevent physical degradation of the soil