Propagação dos Fluxos de Sedimentos em suspensão do Rio Amazonas- Trecho Tamshiyacu (Peru) até Óbidos(Brasil)-Variabilidade Espacial e Temporal

The sediments flux in Amazon Basin have an important role on the aquatic biodiversity and richness in the floodplains because the nutrients and organic matter attached on suspended sediments are deposited in these zones. The suspended sediments have influence in the geomorphology of Amazon River too, because where they are deposited in zone of low turbulence new isle are create. The sediments flux have influence in the meandering movement and sometimes this movement can cause meanders to cutoff and create new lakes. These changes and richeness have influence in the Amazonian population. The Amazon Basin is considered in global terms as one of main source of suspended sediments of Atlantic Ocean, but the Andean region and foreland provide 90% of sedi- ments at the Amazon Basin. The aim of this study is to understand the spatial and temporal distribution of sediments flux in the Amazon River, therefore were select four gauging station located along of Amazon Riven from Peru to Brazil. In each gauging station was make superfi- cial samples each ten days and samples in the section in different times of hydrological period. Turbidity profiles and granulometry measuring were made too in each gauging station. In the Andean region, it is observed a relationship between the suspended sediments concentration and discharge, however, this relationship become a hysteresis in the plain especially in the Óbidos gauging station located at 870 km before of mouth. This result can be by the contribution of influx poor in suspended sediments from Guyanese and Brazilian shields. In 3000 km of long from Peru to Brazil plain, the suspended sediments is composed by two well defined types of suspended sediments: fine sediments (10-20 μm) and coarse sediments (100-250 μm). The percentage of each type of sediments in the main river is different during the hydrologic regime. Peak of fine sediments is observed in the same period of peak of rainfall (December to March) and peak of coarse sediments is observed in flood period (May to July). The Andean and sub-Andean basin gauging station show the coarse sediments in surface due to great turbulence and low depths. Therefore, this gauging station show a relationship between the suspended sediments concentration in surface and averagesuspended sediments concentration in section, with this relation is possible to calcu- late the suspended sediments flux. Hence the Peruvian basin provide 540 Mt year −1 . However in the Brazilian plain the context is different, the depth is from 40 to 100 m, becoming almost null the presence of coarse sediments in the surface. Therefore, cannot use the relationship between suspended sediments concentration in surface and average suspended sediments concentration in section. When the Óbidos gauging station is analysed, it found there is a relationship between suspended sediments concentration in surface and average of fine suspended sediments concentration. It is observed too, that there is the relationship between coarse suspended sediments concentration and discharge. Therefore, it is possible to calculate of suspended sediments flux using this two relationships. The Amazon River export 1100 Mt year − 1 of suspended sediments at Óbidos gauging station, of which 60% correspond at fine sediments flux and 40% to coarse sediments flux. It is observed that the suspended sediments are sensitivity of climate variability, generally El Niño events is associate with increase of fine suspended sediments and La Niña events increase a percentage of coarse sediments in Amazon River. It is using the turbidity for determinate of suspended sediments concentration, we use this technique due the high frequency in acquisition of data. However for use the turbidity is necessary the previous calibration. It was observed that the turbidity signal is an addition to the signal emitted by the particles in one sample and with this assumption the Rose model was used to separate the concentration signal obtained by the turbidity of these two types of sediments present in the Amazon River, fine particles and sand. Therefore, it was obtained the concentration profiles to fine sediments and the concentration profiles to the sand. It is observed during the rising period that the fine sediments profiles show a strong gradient, however in the flood periods this gradient reduce come a constant in all section. These results show that turbidity and Rouse model can be used for prediction of suspended concentration in Amazon River. Keywords: suspended sediNa bacia Amazônica, os fluxos de sedimentos em suspensão têm um papel importante na biodiversidade aquática e na riqueza das zonas inundadas, pois, os nutrientes e matéria orgânica que estão aderidos aos sedimentos são depositados nestas zonas. Os sedimen- tos influenciam na geomorfologia do curso do rio Amazonas ao serem depositados em zonas de menor velocidade, criando novas ilhas. O fluxo sedimentar tem a capacidade de influir na movimentação dos meandros e em certos casos até no desligamento destes, formando assim novos lagos. Estas mudanças e riquezas, têm influência direita nas po- pulações que moram na Amazônia. A bacia Amazônica é considerada como uma das principais fontes de sedimentos para o Oceano Atlântico em termos mundiais, porém, os Andes e as zonas sub-Andinas produzem aproximadamente o 90% desses sedimentos para a bacia Amazônica. Entender o a distribuição espacial e temporal dos fluxos sedimentários é o objetivo deste estudo, no qual foram escolhidas quatro estações de monitoramento de água e sedimento ao longo do rio Amazonas, desde o Peru até o Brasil. Para cumprir com este objetivo, foram feitas coletas superficiais a cada 10 dias em cada estação e amostragens distribuídos na seção em diferentes épocas do ano. Perfis de turbidez e amostragem para granulometria ao longo da seção também formaram parte do monitoramento. Na zona Andina, os fluxos de sedimentos em suspensão têm uma relação direita com os fluxos de água, no entanto, está relação se transforma em uma histereses ao se aproximar da planície, tornando-se bem marcada em Óbidos, localizada a 870 km antes da desembocadura. Atribui-se este resultado à contribuição de fluxos de água de tributários pobres em sedimentos provenientes principalmente dos Escudos Brasileiro e Guianês. Tanto na planície peruana quanto na planície brasileira, em aproximadamente uma longitude de 3000 km, observa-se que a concentração de sedimentos em suspensão está composta de dois tipos de granulometrias bem definidos: sedimentos finos (10-20 μm) e sedimentos grosseiros de tipo areias (100-250 μm). A porcentagem de cada tipo de sedimentos presente no curso principal está em função do regime hidrológico. Picos de concentração de sedimentos finos são presenciados nas épocas de máximas chuvas (Dezembro a Março) e picos de areias em época de cheia (Maio a Julho). Nas estações Andinas e sub-Andinas, a turbulência junto com as baixas profundi- dades permitem a ascensão de sedimentos grosseiros à superfície. Consequentemente,observa-se uma relação direita entre concentração de sedimentos em suspensão na su- perfície com a concentração de sedimentos média da seção, o que permite o cálculo de fluxos sedimentários, sendo que, a bacia peruana contribui com 540 Mt ano −1 . Na planície brasileira o contexto muda, onde as profundidades atingem de 40 á 100 m, tornando quase nula a presencia de areias na superfície. Está é, por tanto, a maior incerteza ao utilizar a relação da concentração de superfície com a média da secção. Analisando a estação de Óbidos constatou-se que existe uma relação direita entre a concentração de sedimentos da superfície e a concentração média de sedimentos finos da seção. Observou-se também que, a concentração média de sedimentos grosseiros da seção têm relação direita com a vazão. Esta diferenciação dos tipos de sedimentos per- mite o cálculo de fluxos do rio Amazonas, concluindo que 1100 Mt ano −1 de sedimentos são transportados para el Oceano Atlântico na estação de Óbidos, sendo que 60% cor- responde ao fluxo de sedimentos finos e 40% ao fluxo de areias. Observou-se que os sedimentos são sensíveis à variabilidade climática, em geral eventos El Niño estão rela- cionados com maiores quantidades de sedimentos finos e eventos La Niña incrementam a porcentagem de sedimentos grosseiros no rio Amazonas. Utilizou-se a turbidez para obter dados de concentração por ser uma medida de alta frequência, na qual, foram feitas curvas de calibração em função do diâmetro da partícula. Observou-se que o sinal de turbidez é uma adição do sinal emitido pelas partículas presentes em uma amostra, com esta premissa utilizou-se o modelo de Rouse para separar o sinal de concentração obtido pela turbidez dos tipos de sedimentos pre- sentes no rio Amazonas, partículas finas e areias. Deste modo conseguiu-se perfis de concentração para sedimentos finos e perfis de concentração para as areias. Observa-se que na época de enchente os perfis de concentração tem um gradiente bem marcado para os sedimentos finos, no entanto, em épocas de cheia o gradiente é governado pelas areias e os perfis de finos são verticais e constantes em toda a seção. Estes resultados indicam que, pode-se predizer perfis de concentração com base na turbidez em rios da Amazônia

Sedimentary flow quantification of the amazon basin of Peru

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Recursos HídricosEl presente estudio, trata sobre la cuantificación del flujo sedimentario, el grado de incertidumbre en las metodologías empleadas y la variabilidad temporal de los flujos líquidos y sólidos. Para este trabajo se consideró 8 estaciones hidrológicas y sedimentarias de la cuenca amazónica peruana, tres en el pie de monte y cinco en la llanura, sobre los ríos, Marañón, Huallaga, Ucayali, Amazonas, El Tigre y Napo. El período de observación es del 2004 a 2009. Para la determinación de flujo de sedimentos en suspensión, se utilizó muestreos superficiales recolectados cada diez días por una persona del lugar, además de los datos de caudal sólido, obtenidos en campañas de campo realizadas cada tres meses. La evaluación de los flujos sedimentarios se realizó a través de dos metodologías de cálculo, una de interpolación de los datos de concentraciones especializados cada diez días y la otra de extrapolación, mediante de la relación caudal líquido vs caudal sólido. El cálculo de la carga de fondo se fundamentó en el perfil de concentraciones de Rouse y el perfil de velocidades. Se muestra por primera vez la utilización del perfil de Rouse y la turbiedad como una herramienta para el análisis espacial, para los ríos amazónicos peruanos. Para el período establecido y con un total de 1 547 muestras, se determinó que la cuenca amazónica peruana transporta 629*106 ± 36% t/año de sedimentos en suspensión al año, y un caudal de 36 000 m3/s. El río Ucayali aporta la mayor cantidad de sedimentos con 61.2%, la cuenca del río Marañón 30.4% y la cuenca el Napo 8.4%. En el pie de monte el río Marañón conduce 162 106 ± 24% t/año, el río Huallaga 81 106 ± 19% t/año, y el río Ucayali 239 106 ± 12% t/año. Se observa una fuerte variabilidad temporal tanto en caudales líquidos como sólidos, sobre todo en los ríos de montaña, que se atenúa con forme se acerca a la planicieThe present study deals with the quantification of sedimentary transport, the degree of uncertainty in the methodologies employed, and the temporal variability of the liquid flow and sedimentary transport. In this study, we considered 8 hydrological and sedimentary stations in the Peruvian Amazonian River basin, three on the piedmont and five in the plain, specifically on the Marañón, Huallaga, Ucayali, Amazon, Tigre and Napo rivers. The period of observation is from 2004 until 2009. For the determination of the suspended sediments flow, surface samplings were collected every ten days by a local person, in addition to the collection of sedimentary transport data, obtained during field campaigns made every three months. The evaluation of the sedimentary flows was made through two methodologies of calculation; one of interpolation of the data of concentrations obtained every ten days and the other of extrapolation, using the relation between liquid flow versus sediment transport. The calculation of the bottom load was based on the Rouse´s concentration and velocity profiles. For the first time, Rouse´s profile and the turbidity profile were used as a tool of spatial analysis for the Peruvian Amazonian rivers. For the period of study and with a total of 1 547 samples, we determined that the Peruvian Amazonian River basin transports 629*106 ± 36% t year-1 of sediments in suspension, and a liquid flow rate of 36 000 m3s-1. The Ucayali River contributes the greatest amount of sediments with 61.2%, the Marañon River Basin with 30.4%, and the Napo River Basin with 8.4%. At the piedmont, the Marañon river transports 162*106 t year-1 (± 24%), the Huallaga river 81*106 t year-1 (± 19%) and the Ucayali river 239*106 t year-1(± 12%). Large temporal variability in liquid as well as sediment fluxes is observed, mainly in the mountain rivers, which is attenuated approaching the plainTesi

Calidad de servicio y la satisfacción de los clientes de una empresa de representaciones y distribuciones en Jaén

La presente investigación tuvo por objetivo determinar como la calidad de servicio influye en la satisfacción de los clientes de una empresa de representaciones y distribuciones en Jaén. Fue de enfoque cuantitativo, tipo descriptiva y diseño no experimental. La muestra fue de 100 colaboradores considerando en este caso toda la población. El estudio concluyó que el 89 % de los clientes encuestados indicaron que el personal está bien presentado, que los ambientes de la empresa son atractivos, están ordenados y son de fácil acceso, que los precios son los adecuados, que el personal se dedica atender especialmente al cliente, cumplen con el horario y que la atención es rápida. Además, el 91 % de los clientes encuestados manifestaron que el personal muestra dominio del producto, que está dispuesto a solucionar problemas, que brinda y sugiere alternativas de solución. El 88 % de los clientes encuestados expresaron que el personal de cada sección conoce los productos, que la empresa ofrece variedad productos para elegir de acuerdo a las necesidades, que el personal explica los beneficios y bondades de los productos, que siempre encuentran en cantidad y calidad lo que necesitan y que siempre hay una persona disponible para atenderlo

Performance of Regional Climate Model Precipitation Simulations Over the Terrain-Complex Andes-Amazon Transition Region

Regional climate models (RCMs) are widely used to assess future impacts associated with climate change at regional and local scales. RCMs must represent relevant climate variables in the present-day climate to be considered fit-for-purpose for impact assessment. This condition is particularly difficult to meet over complex regions such as the Andes-Amazon transition region, where the Andean topography and abundance of tropical rainfall regimes remain a challenge for numerical climate models. In this study, we evaluate the ability of 30 regional climate simulations (6 RCMs driven by 10 global climate models) to reproduce historical (1981–2005) rainfall climatology and temporal variability over the Andes-Amazon transition region. We assess spatio-temporal features such as spatial distribution of rainfall, focusing on the orographic effects over the Andes-Amazon “rainfall hotspots” region, and seasonal and interannual precipitation variability. The Eta RCM exhibits the highest spatial correlation (up to 0.6) and accurately reproduces mean annual precipitation and orographic precipitation patterns across the region, while some other RCMs have good performances at specific locations. Most RCMs simulate a wet bias over the highlands, particularly at the eastern Andean summits, as evidenced by the 100%–2,500% overestimations of precipitation in these regions. Annual cycles are well represented by most RCMs, but peak seasons are exaggerated, especially at equatorial locations. No RCM is particularly skillful in reproducing the interannual variability patterns. Results highlight skills and weaknesses of the different regional climate simulations, and can assist in the selection of regional climate simulations for impact studies in the Andes-Amazon transition zone

APRENDIZAJE COOPERATIVO Y LAS DIFICULTADES EN LA ENSEÑANZA DE LOS ESTUDIANTES DE NIVEL BÁSICO SUPERIOR

En las últimas décadas se ha venido a instaurar la necesidad del estudio de nuevos métodos activos e innovadores, como el aprendizaje cooperativo, que admitan a los educandos la posibilidad de obtener capacidades para su mejora personal, afectiva y social, en la que puedan ser participantes activos de los procesos educativos. En la presente investigación se hace énfasis sobre la viabilidad del aprendizaje cooperativo en el abordaje de las dificultades que se presentan en la enseñanza de los estudiantes del nivel básico superior, destacando diferentes circunstancias, examinando para ello un extenso número de trabajos y escritos de investigación que se encuentran en revistas periódicas, que describen prácticas aplicadas en diferentes períodos pedagógicos. Por ello, basados en la referida indagación, se destaca que el aprendizaje cooperativo es un método apropiado para superar las dificultades en la enseñanza de una disciplina, ya que favorece el fortalecimiento de las aptitudes y habilidades, optimizando el rendimiento académico de los alumnos, sin que se considere una especifico período educativo o alguna asignatura en cuestión

On the relationship between suspended sediment concentration, rainfall variability and groundwater: An empirical and probabilistic analysis for the Andean Beni River, Bolivia (2003-2016)

Fluvial sediment dynamics plays a key role in the Amazonian environment, with most of the sediments originating in the Andes. The Madeira River, the second largest tributary of the Amazon River, contributes up to 50% of its sediment discharge to the Atlantic Ocean, most of it provided by the Andean part of the Madeira basin, in particular the Beni River. In this study, we assessed the rainfall (R)-surface suspended sediment concentration (SSSC) and discharge (Q)-SSSC relationship at the Rurrenabaque station (200 m a.s.l.) in the Beni Andean piedmont (Bolivia). We started by showing how the R and Q relationship varies throughout the hydrological year (September to August), describing a counter-clockwise hysteresis, and went on to evaluate the R-SSSC and Q-SSSC relationships. Although no marked hysteresis is observed in the first case, a clockwise hysteresis is described in the second. In spite of this, the rating curve normally used (SSSC = aQb) shows a satisfactory R2 = 0.73 (p < 0.05). With regard to water discharge components, a linear function relates the direct surface flow Qs-SSSC, and a hysteresis is observed in the relationship between the base flow Qb and SSSC. A higher base flow index (Qb/Q) is related to lower SSSC and vice versa. This article highlights the role of base flow on sediment dynamics and provides a method to analyze it through a seasonal empirical model combining the influence of both Qb and Qs, which could be employed in other watersheds. A probabilistic method to examine the SSSC relationship with R and Q is also proposed. © 2019 by the authors

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Propagation of suspended sediment flux in the Amazon river from Tamshiyacu gauging station in Peru to Obidos gauging in Brazil : spatio-temporal variability

Le bassin amazonien est considéré au niveau mondial comme l'un des principaux apports de sédiments à l'Océan Atlantique. Comprendre la distribution spatiale et temporelle des flux sédimentaires est l'objectif de cette étude pour laquelle on a choisi quatre stations hydrométriques de suivi réparties tout au long de l'Amazone depuis sa formation au Pérou jusqu'à environ 800 km de son embouchure au Brésil (Óbidos). Pour atteindre cet objectif, on a mis en place pour chaque station un échantillonnage décadaire en surface et une exploration totale de leur section à différentes périodes de l'année. Des profils de turbidité et des échantillons pour la granulométrie sur toute la section faisaient également partie de ce suivi. Sur les stations andines et sub-andines, la turbulence de l'écoulement jointe aux faibles profondeurs permet l'ascension de sédiments grossiers vers la surface. Par conséquent, on observe une relation directe entre la concentration de sédiments en suspension de surface et la concentration moyenne dans la section, ce qui permet un calcul simple des flux sédimentaires et d'arriver à une valeur de 540 Mt/an pour qui concerne l'apport du basin péruvien de l'Amazone. Dans la plaine brésilienne, le contexte change, les profondeurs moyennes se situent entre 40 et 100 m de telle sorte que la présence de sable en surface est quasi nulle. Cependant, l'analyse des résultats à la station d'Óbidos montre qu'il existe une relation directe entre la concentration de sédiments de surface et la concentration moyenne de sédiments fins dans la section alors que la concentration moyenne de sédiments grossiers dans la section est, elle, em relation directe avec le débit liquide. En différenciant ainsi le calcul suivant ces deux types de sédiments, on arrive à une valeur de flux de 1100 Mt/an transitant par Óbidos, dont 60% correspond au flux des sédiments fins et 40% aux grossiers. On a utilisé la turbidité pour par courbes de calibration em funtion da granulometrie parvenir aux valeurs de concentration. On a utilisé le modèle de Rouse pour différencier le signal de concentration obtenu avec la turbidité résultat du signal de le deux types de sediment. On a constaté que les granulométries en présence sont les mêmes tout au long du régime hydrologique mais que ce sont les proportions de chacune d'entre elles qui varient. Aussi a-t-on abouti à des profils de concentration pour sédiments fins et des profils pour sédiments grossiers. En montée de crue, les profils de concentration présentent un gradient bien marqué pour les sédiments fins, alors qu'en période de crue ce gradient est contrôlé par les sables et les profils de fines sont alors verticaux et constants sur toute la section. Ces résultats montrent qu'il est possible de prédire, en Amazonie, les profils de concentration à partir de la turbidité.The sediments flux in Amazon Basin have an important role on the aquatic biodiversity and richness in the floodplains because the nutrients and organic matter attached on suspended sediments are deposited in these zones. The aim of this study is to understand the spatial and temporal distribution of sediments flux in the Amazon River, therefore were select four gauging station located along of Amazon Riven from Peru to Brazil. In each gauging station was make superficial samples each ten days and samples in the section in different times of hydrological period. Turbidity profiles and granulometry measuring were made too in each gauging station. In the Andean region, it is observed a relationship between the suspended sediments concentration and discharge, however, this relationship become a hysteresis in the plain especially in the Óbidos gauging station located at 870 km before of mouth. This result can be by the contribution of influx poor in suspended sediments from Guyanese and Brazilian shields. In 3000 km of long from Peru to Brazil plain, the suspended sediments is composed by two well-defined types of suspended sediments: fine sediments (10-20 µm) and coarse sediments (100-250 µm). The percentage of each type of sediments in the main river is different during the hydrologic regime. Peak of fine sediments is observed in the same period of peak of rainfall (December to March) and peak of coarse sediments is observed in flood period (May to July). The Andean and sub-Andean basin gauging station show the coarse sediments in surface due to great turbulence and low depths. Therefore, this gauging station show a relationship between the suspended sediments concentration in surface and average suspended sediments concentration in section, with this relation is possible to calculate the suspended sediments flux. Hence the Peruvian basin provide 540 Mt year -1. However in the Brazilian plain the context is different, the depth is from 40 to 100 m, becoming almost null the presence of coarse sediments in the surface. Therefore, cannot use the relationship between suspended sediments concentration in surface and average suspended sediments concentration in section. When the Óbidos gauging station is analysed, it found there is a relationship between suspended sediments concentration in surface and average of fine suspended sediments concentration. It is observed too, that there is the relationship between coarse suspended sediments concentration and discharge. Therefore, it is possible to calculate of suspended sediments flux using these two relationships. The Amazon River export 1100 Mt year-1 of suspended sediments at Óbidos gauging station, of which 60% correspond at fine sediments flux and 40% to coarse sediments flux. It is observed that the suspended sediments are sensitivity of climate variability, generally El Niño events is associate with increase of fine suspended sediments and La Niña events increase a percentage of coarse sediments in Amazon River. It is using the turbidity for determinate of suspended sediments concentration, we use this technique due the high frequency in acquisition of data. However for use the turbidity is necessary the previous calibration. It was observed that the turbidity signal is an addition to the signal emitted by the particles in one sample and with this assumption the Rose model was used to separate the concentration signal obtained by the turbidity of the two types of sediments present in the Amazon River, fine particles and sand. Therefore, it was obtained the concentration profiles to fine sediments and the concentration profiles to the sand. It is observed during the rising period that the fine sediments profiles show a strong gradient, however in the flood periods this gradient reduce come a constant in all section. These results show that turbidity and Rouse model can be used for prediction of suspended concentration in Amazon River

Propagação dos Fluxos de Sedimentos em suspensão do Rio Amazonas- Trecho Tamshiyacu (Peru) até Óbidos(Brasil)-Variabilidade Espacial e Temporal

The sediments flux in Amazon Basin have an important role on the aquatic biodiversity and richness in the floodplains because the nutrients and organic matter attached on suspended sediments are deposited in these zones. The suspended sediments have influence in the geomorphology of Amazon River too, because where they are deposited in zone of low turbulence new isle are create. The sediments flux have influence in the meandering movement and sometimes this movement can cause meanders to cutoff and create new lakes. These changes and richeness have influence in the Amazonian population. The Amazon Basin is considered in global terms as one of main source of suspended sediments of Atlantic Ocean, but the Andean region and foreland provide 90% of sedi- ments at the Amazon Basin. The aim of this study is to understand the spatial and temporal distribution of sediments flux in the Amazon River, therefore were select four gauging station located along of Amazon Riven from Peru to Brazil. In each gauging station was make superfi- cial samples each ten days and samples in the section in different times of hydrological period. Turbidity profiles and granulometry measuring were made too in each gauging station. In the Andean region, it is observed a relationship between the suspended sediments concentration and discharge, however, this relationship become a hysteresis in the plain especially in the Óbidos gauging station located at 870 km before of mouth. This result can be by the contribution of influx poor in suspended sediments from Guyanese and Brazilian shields. In 3000 km of long from Peru to Brazil plain, the suspended sediments is composed by two well defined types of suspended sediments: fine sediments (10-20 μm) and coarse sediments (100-250 μm). The percentage of each type of sediments in the main river is different during the hydrologic regime. Peak of fine sediments is observed in the same period of peak of rainfall (December to March) and peak of coarse sediments is observed in flood period (May to July). The Andean and sub-Andean basin gauging station show the coarse sediments in surface due to great turbulence and low depths. Therefore, this gauging station show a relationship between the suspended sediments concentration in surface and averagesuspended sediments concentration in section, with this relation is possible to calcu- late the suspended sediments flux. Hence the Peruvian basin provide 540 Mt year −1 . However in the Brazilian plain the context is different, the depth is from 40 to 100 m, becoming almost null the presence of coarse sediments in the surface. Therefore, cannot use the relationship between suspended sediments concentration in surface and average suspended sediments concentration in section. When the Óbidos gauging station is analysed, it found there is a relationship between suspended sediments concentration in surface and average of fine suspended sediments concentration. It is observed too, that there is the relationship between coarse suspended sediments concentration and discharge. Therefore, it is possible to calculate of suspended sediments flux using this two relationships. The Amazon River export 1100 Mt year − 1 of suspended sediments at Óbidos gauging station, of which 60% correspond at fine sediments flux and 40% to coarse sediments flux. It is observed that the suspended sediments are sensitivity of climate variability, generally El Niño events is associate with increase of fine suspended sediments and La Niña events increase a percentage of coarse sediments in Amazon River. It is using the turbidity for determinate of suspended sediments concentration, we use this technique due the high frequency in acquisition of data. However for use the turbidity is necessary the previous calibration. It was observed that the turbidity signal is an addition to the signal emitted by the particles in one sample and with this assumption the Rose model was used to separate the concentration signal obtained by the turbidity of these two types of sediments present in the Amazon River, fine particles and sand. Therefore, it was obtained the concentration profiles to fine sediments and the concentration profiles to the sand. It is observed during the rising period that the fine sediments profiles show a strong gradient, however in the flood periods this gradient reduce come a constant in all section. These results show that turbidity and Rouse model can be used for prediction of suspended concentration in Amazon River. Keywords: suspended sediNa bacia Amazônica, os fluxos de sedimentos em suspensão têm um papel importante na biodiversidade aquática e na riqueza das zonas inundadas, pois, os nutrientes e matéria orgânica que estão aderidos aos sedimentos são depositados nestas zonas. Os sedimen- tos influenciam na geomorfologia do curso do rio Amazonas ao serem depositados em zonas de menor velocidade, criando novas ilhas. O fluxo sedimentar tem a capacidade de influir na movimentação dos meandros e em certos casos até no desligamento destes, formando assim novos lagos. Estas mudanças e riquezas, têm influência direita nas po- pulações que moram na Amazônia. A bacia Amazônica é considerada como uma das principais fontes de sedimentos para o Oceano Atlântico em termos mundiais, porém, os Andes e as zonas sub-Andinas produzem aproximadamente o 90% desses sedimentos para a bacia Amazônica. Entender o a distribuição espacial e temporal dos fluxos sedimentários é o objetivo deste estudo, no qual foram escolhidas quatro estações de monitoramento de água e sedimento ao longo do rio Amazonas, desde o Peru até o Brasil. Para cumprir com este objetivo, foram feitas coletas superficiais a cada 10 dias em cada estação e amostragens distribuídos na seção em diferentes épocas do ano. Perfis de turbidez e amostragem para granulometria ao longo da seção também formaram parte do monitoramento. Na zona Andina, os fluxos de sedimentos em suspensão têm uma relação direita com os fluxos de água, no entanto, está relação se transforma em uma histereses ao se aproximar da planície, tornando-se bem marcada em Óbidos, localizada a 870 km antes da desembocadura. Atribui-se este resultado à contribuição de fluxos de água de tributários pobres em sedimentos provenientes principalmente dos Escudos Brasileiro e Guianês. Tanto na planície peruana quanto na planície brasileira, em aproximadamente uma longitude de 3000 km, observa-se que a concentração de sedimentos em suspensão está composta de dois tipos de granulometrias bem definidos: sedimentos finos (10-20 μm) e sedimentos grosseiros de tipo areias (100-250 μm). A porcentagem de cada tipo de sedimentos presente no curso principal está em função do regime hidrológico. Picos de concentração de sedimentos finos são presenciados nas épocas de máximas chuvas (Dezembro a Março) e picos de areias em época de cheia (Maio a Julho). Nas estações Andinas e sub-Andinas, a turbulência junto com as baixas profundi- dades permitem a ascensão de sedimentos grosseiros à superfície. Consequentemente,observa-se uma relação direita entre concentração de sedimentos em suspensão na su- perfície com a concentração de sedimentos média da seção, o que permite o cálculo de fluxos sedimentários, sendo que, a bacia peruana contribui com 540 Mt ano −1 . Na planície brasileira o contexto muda, onde as profundidades atingem de 40 á 100 m, tornando quase nula a presencia de areias na superfície. Está é, por tanto, a maior incerteza ao utilizar a relação da concentração de superfície com a média da secção. Analisando a estação de Óbidos constatou-se que existe uma relação direita entre a concentração de sedimentos da superfície e a concentração média de sedimentos finos da seção. Observou-se também que, a concentração média de sedimentos grosseiros da seção têm relação direita com a vazão. Esta diferenciação dos tipos de sedimentos per- mite o cálculo de fluxos do rio Amazonas, concluindo que 1100 Mt ano −1 de sedimentos são transportados para el Oceano Atlântico na estação de Óbidos, sendo que 60% cor- responde ao fluxo de sedimentos finos e 40% ao fluxo de areias. Observou-se que os sedimentos são sensíveis à variabilidade climática, em geral eventos El Niño estão rela- cionados com maiores quantidades de sedimentos finos e eventos La Niña incrementam a porcentagem de sedimentos grosseiros no rio Amazonas. Utilizou-se a turbidez para obter dados de concentração por ser uma medida de alta frequência, na qual, foram feitas curvas de calibração em função do diâmetro da partícula. Observou-se que o sinal de turbidez é uma adição do sinal emitido pelas partículas presentes em uma amostra, com esta premissa utilizou-se o modelo de Rouse para separar o sinal de concentração obtido pela turbidez dos tipos de sedimentos pre- sentes no rio Amazonas, partículas finas e areias. Deste modo conseguiu-se perfis de concentração para sedimentos finos e perfis de concentração para as areias. Observa-se que na época de enchente os perfis de concentração tem um gradiente bem marcado para os sedimentos finos, no entanto, em épocas de cheia o gradiente é governado pelas areias e os perfis de finos são verticais e constantes em toda a seção. Estes resultados indicam que, pode-se predizer perfis de concentração com base na turbidez em rios da Amazônia

Propagation des flux de sédiments en suspension sur l'Amazone de Tamshiyacu (Pérou) à Obidos (Brésil) : variabilité spatio-temporelle

The sediments flux in Amazon Basin have an important role on the aquatic biodiversity and richness in the floodplains because the nutrients and organic matter attached on suspended sediments are deposited in these zones. The aim of this study is to understand the spatial and temporal distribution of sediments flux in the Amazon River, therefore were select four gauging station located along of Amazon Riven from Peru to Brazil. In each gauging station was make superficial samples each ten days and samples in the section in different times of hydrological period. Turbidity profiles and granulometry measuring were made too in each gauging station. In the Andean region, it is observed a relationship between the suspended sediments concentration and discharge, however, this relationship become a hysteresis in the plain especially in the Óbidos gauging station located at 870 km before of mouth. This result can be by the contribution of influx poor in suspended sediments from Guyanese and Brazilian shields. In 3000 km of long from Peru to Brazil plain, the suspended sediments is composed by two well-defined types of suspended sediments: fine sediments (10-20 µm) and coarse sediments (100-250 µm). The percentage of each type of sediments in the main river is different during the hydrologic regime. Peak of fine sediments is observed in the same period of peak of rainfall (December to March) and peak of coarse sediments is observed in flood period (May to July). The Andean and sub-Andean basin gauging station show the coarse sediments in surface due to great turbulence and low depths. Therefore, this gauging station show a relationship between the suspended sediments concentration in surface and average suspended sediments concentration in section, with this relation is possible to calculate the suspended sediments flux. Hence the Peruvian basin provide 540 Mt year -1. However in the Brazilian plain the context is different, the depth is from 40 to 100 m, becoming almost null the presence of coarse sediments in the surface. Therefore, cannot use the relationship between suspended sediments concentration in surface and average suspended sediments concentration in section. When the Óbidos gauging station is analysed, it found there is a relationship between suspended sediments concentration in surface and average of fine suspended sediments concentration. It is observed too, that there is the relationship between coarse suspended sediments concentration and discharge. Therefore, it is possible to calculate of suspended sediments flux using these two relationships. The Amazon River export 1100 Mt year-1 of suspended sediments at Óbidos gauging station, of which 60% correspond at fine sediments flux and 40% to coarse sediments flux. It is observed that the suspended sediments are sensitivity of climate variability, generally El Niño events is associate with increase of fine suspended sediments and La Niña events increase a percentage of coarse sediments in Amazon River. It is using the turbidity for determinate of suspended sediments concentration, we use this technique due the high frequency in acquisition of data. However for use the turbidity is necessary the previous calibration. It was observed that the turbidity signal is an addition to the signal emitted by the particles in one sample and with this assumption the Rose model was used to separate the concentration signal obtained by the turbidity of the two types of sediments present in the Amazon River, fine particles and sand. Therefore, it was obtained the concentration profiles to fine sediments and the concentration profiles to the sand. It is observed during the rising period that the fine sediments profiles show a strong gradient, however in the flood periods this gradient reduce come a constant in all section. These results show that turbidity and Rouse model can be used for prediction of suspended concentration in Amazon River.Le bassin amazonien est considéré au niveau mondial comme l'un des principaux apports de sédiments à l'Océan Atlantique. Comprendre la distribution spatiale et temporelle des flux sédimentaires est l'objectif de cette étude pour laquelle on a choisi quatre stations hydrométriques de suivi réparties tout au long de l'Amazone depuis sa formation au Pérou jusqu'à environ 800 km de son embouchure au Brésil (Óbidos). Pour atteindre cet objectif, on a mis en place pour chaque station un échantillonnage décadaire en surface et une exploration totale de leur section à différentes périodes de l'année. Des profils de turbidité et des échantillons pour la granulométrie sur toute la section faisaient également partie de ce suivi. Sur les stations andines et sub-andines, la turbulence de l'écoulement jointe aux faibles profondeurs permet l'ascension de sédiments grossiers vers la surface. Par conséquent, on observe une relation directe entre la concentration de sédiments en suspension de surface et la concentration moyenne dans la section, ce qui permet un calcul simple des flux sédimentaires et d'arriver à une valeur de 540 Mt/an pour qui concerne l'apport du basin péruvien de l'Amazone. Dans la plaine brésilienne, le contexte change, les profondeurs moyennes se situent entre 40 et 100 m de telle sorte que la présence de sable en surface est quasi nulle. Cependant, l'analyse des résultats à la station d'Óbidos montre qu'il existe une relation directe entre la concentration de sédiments de surface et la concentration moyenne de sédiments fins dans la section alors que la concentration moyenne de sédiments grossiers dans la section est, elle, em relation directe avec le débit liquide. En différenciant ainsi le calcul suivant ces deux types de sédiments, on arrive à une valeur de flux de 1100 Mt/an transitant par Óbidos, dont 60% correspond au flux des sédiments fins et 40% aux grossiers. On a utilisé la turbidité pour par courbes de calibration em funtion da granulometrie parvenir aux valeurs de concentration. On a utilisé le modèle de Rouse pour différencier le signal de concentration obtenu avec la turbidité résultat du signal de le deux types de sediment. On a constaté que les granulométries en présence sont les mêmes tout au long du régime hydrologique mais que ce sont les proportions de chacune d'entre elles qui varient. Aussi a-t-on abouti à des profils de concentration pour sédiments fins et des profils pour sédiments grossiers. En montée de crue, les profils de concentration présentent un gradient bien marqué pour les sédiments fins, alors qu'en période de crue ce gradient est contrôlé par les sables et les profils de fines sont alors verticaux et constants sur toute la section. Ces résultats montrent qu'il est possible de prédire, en Amazonie, les profils de concentration à partir de la turbidité