ABSTRACT Identifying sediment sources is fundamental for protecting and improving soil and water quality. Conventional fingerprinting studies have often collected sediments at the overall watershed outlet only, resulting in an important spatial scale dependency. This study aimed to identify and to assess the delivery patterns of sediment sources within three priority sub-catchments (Sapocaji, Piedade and Minas) located in the downstream portion of the Ipojuca River watershed in Brazil. This research would build on understanding sediment sources in the studied watershed by elucidating source type contributions on a sub-catchment basis. Both bed and suspended sediment samples were collected in these sub-catchments, and two types of sources were sampled: surface and subsurface sources. A total of 21 geochemical tracers were measured. The tracers were evaluated for their conservation and discriminatory ability (Kruskal-Wallis test and linear discriminant analysis), and the best set of tracers was selected for source apportionment modeling using MixSIAR. Surface (i.e., sugarcane croplands) sources contributed the highest to suspended sediments in the Piedade and Minas sub-catchments. There was a difference in the quality of riverbank management, which helped explain contrasts in the importance of this source. Overall, sub-catchment-specific sediment control management measures, such as the revegetation of riparian forests, need to be implemented, mainly in the Sapocaji sub-catchment. These results underscore the importance of connectivity for surface source contributions. only dependency subcatchments sub catchments Sapocaji, (Sapocaji Brazil subcatchment catchment basis subcatchments, catchments, sampled 2 measured KruskalWallis Kruskal Wallis analysis, analysis , analysis) MixSIAR i.e., ie i e (i.e. croplands subcatchments. catchments. Overall subcatchmentspecific specific measures forests implemented subcatchment. catchment. i.e. (i.e i.e

Abstract The current level of anthropogenic impact on open water sources shows a decrease in the quality of surface runoff, a constantly growing volume of water withdrawal for economic purposes, exerting the greatest significant impact and damage on the hydrobiological resources of water sources. The processes of interaction between subjects of hydro-biocenosis force us to study the mechanisms of interaction between fish, water flow, and hydraulic structure (channel), including the optimization of elements of hydraulic structures that affect the environmental safety of a water source as a whole. We noted the main formation patterns of the structure of a turbulent flow and its interaction with a hydraulic structure (channel), such as the pulsating nature of the aquatic environment, heterogeneous structure, gradient nature, and vortex structure. We analyzed the advantages and features of the effect of three-dimensional flow-forming elements on the behavior of fish. We developed the design and method of designing a bottom flow-forming element for controlling the behavior of fish in a river flow, substantiated geometrical parameters, created an optimal layout of bottom flow-forming elements in artificial channels. We provided an assessment of the use of technical solutions for flow-forming elements of existing and reconstructed fish protection facilities. runoff purposes hydrobiocenosis hydro biocenosis channel, channel , (channel) whole environment threedimensional three dimensional flowforming forming parameters channels facilities (channel

Resumo O nível atual de impacto antropogênico em mananciais abertos indica uma diminuição na qualidade do escoamento superficial, um volume cada vez maior de captação de água para fins econômicos, exercendo o maior impacto e danos significativos sobre os recursos hidrobiológicos dos mananciais. Os processos de interação entre sujeitos da biocenose aquática nos obrigam a estudar os mecanismos de interação entre peixes, fluxo de água e estrutura hidráulica (canal), incluindo a otimização de elementos de estruturas hidráulicas que afetam a segurança ambiental de fontes de água como todo. Observamos os principais padrões de formação da estrutura de um escoamento turbulento e sua interação com uma estrutura hidráulica (canal), como a natureza pulsante do ambiente aquático, sua estrutura heterogênea, natureza gradiente e formação de vórtices. Analisamos as vantagens e características do efeito de elementos tridimensionais formadores de fluxo no comportamento dos peixes. Desenvolvemos o projeto e o método de projeto para um elemento formador de fluxo de fundo visando controlar o comportamento de peixes em um fluxo de rio, substanciamos parâmetros geométricos, criamos um layout otimizado para elementos formadores de fluxo de fundo em canais artificiais. Fornecemos uma avaliação do uso de soluções técnicas para elementos formadores de fluxo em instalações existentes e reconstruídas para a proteção de peixes. superficial econômicos canal, canal , (canal) todo aquático heterogênea vórtices rio geométricos artificiais (canal

Abstract Introduction: The diversity of fish species in the Amazonian foothills of Ecuador includes moderate-sized species adapted to living in fast flowing, well-oxygenated, stony-bed rivers. These species are still important for subsistence fishing. However, current studies of the ethnoichthyology of indigenous communities settled in the upper watersheds of the main Amazonian tributaries of Ecuador are still incipient. Objective: To characterize the ichthyological richness and the family fishing system of the Kichwa CEPLOA community, in the upper Ecuadorian Amazon. Methods: In 2020 we did a fish an inventory of in the Oglán river, mainly with cast net, and interviewed 18 community members about the family fishing system. Results: We recorded seventeen fish species, with a predominance of Characidae, Loricariidae and Cichlidae, all of them characteristic of well-conserved Amazonian foothill rivers. Local fishermen practice subsistence fishing with cast nets and hooks (mean 1,5kg of fish per catch). The anglers perceive a reduction in the diversity and abundance of fish fauna as well as in their sizes compared to the last decade, possible from the increase in fishing operations and the use of unsustainable catching techniques. Conclusion: The local 17 fish species are typical of well-preserved Amazonian foothill rivers. Local subsistence fishermen reported reduced diversity, abundance, and size of fish, attributed to increased fishing activities and unsustainable catching methods. Internal regulation may reduce the problem.

Resumen Introducción: La diversidad de especies de peces en las estribaciones amazónicas de Ecuador incluye especies de tamaño moderado adaptadas a vivir en ríos de lecho pedregoso, de rápido flujo y bien oxigenados. Estas especies siguen siendo importantes para la pesca de subsistencia. Sin embargo, los estudios actuales sobre la etnoictiología de las comunidades indígenas asentadas en las cuencas altas de los principales afluentes amazónicos de Ecuador aún son incipientes. Objetivo: Caracterizar la riqueza ictiológica y el sistema de pesca familiar de la comunidad Kichwa CEPLOA, en la Amazonia ecuatoriana alta. Métodos: En 2020 elaboramos un inventario de peces en el río Oglán, principalmente con redes de lanzamiento, y entrevistamos a 18 miembros de la comunidad sobre el sistema de pesca familiar. Resultados: Registramos 17 especies de peces, con predominio de las familias Characidae, Loricariidae y Cichlidae, todas características de ríos bien conservados en las estribaciones amazónicas. Los pescadores locales practican la pesca de subsistencia con redes de lanzamiento y anzuelos (promedio 1,5kg de pescado por captura). Los pescadores perciben una disminución en la diversidad y abundancia de la fauna de peces, así como en sus tamaños, en comparación con la última década, posiblemente debido al aumento de las operaciones de pesca y al uso de técnicas de captura insostenibles. Conclusión: Las 17 especies de peces locales son típicas de ríos bien conservados en las estribaciones amazónicas. Los pescadores locales de subsistencia informaron una reducción en la diversidad, abundancia y tamaño de los peces, atribuida al aumento de las actividades de pesca y a métodos de captura insostenibles. Una regulación interna podría reducir el problema.

Summary: The use of wastewater in agricultural irrigation contributes to improving soil productivity and solving water scarcity problems. However, problems of salinity and sodicity in the soil, toxicity to plants, and public health problems are generated. In the Pánuco River basin, which originates in the Valley of Mexico and flows into the Gulf of Mexico, is the Valle del Mezquital, where approximately 90,000 ha are irrigated with wastewater that arrives through various routes, including the Great Drainage Canal. A part of the water that is used for irrigation infiltrates and is incorporated into the bed of the Tula River, which flows into the Zimapán dam. From the Zimapán dam, the channel acquires the name of the Moctezuma River and in the lower part of the Pánuco River basin until it discharges into the Gulf of Mexico. The objective of this work was to evaluate the water quality along the channel of the Pánuco river basin through sampling, laboratory determinations and analysis through quality indices with agronomic criteria, and to compare the results of the upper part of the basin with the lower part. The results indicate that the wastewater that enters the Mezquital Valley has an impact along the entire channel, but to a greater extent in the upper part of the basin. In all the sample points, the water is classified as bicarbonate-sodium, the RSC index indicates that 96% of the sites present some type of irrigation restriction, the EC is not ideal in any of the points and the sodium adsorption ratio (SAR) evidences sodicity risks.

Resumen: El uso de aguas residuales en el riego agrícola contribuye a mejorar la productividad del suelo y a resolver los problemas de escasez del agua. Sin embargo, también se generan problemas de salinidad y sodicidad en el suelo, toxicidad para las plantas, y problemas de salud pública. En la cuenca del río Pánuco, que se origina en el Valle de México y desemboca en el Golfo de México, se encuentra el Valle del Mezquital, donde se riegan más de 90 000 ha con aguas residuales que llegan a través de diversas vías, entre ellas el Gran Canal del Desagüe. Una parte del agua que se utiliza para el riego se infiltra y se incorpora al cauce del río Tula, que desemboca en la presa Zimapán. A partir de la presa Zimapán, el cauce adquiere el nombre de río Moctezuma y en la parte baja de la cuenca río Pánuco hasta la descarga en el Golfo de México. El objetivo de este trabajo fue evaluar la calidad del agua a lo largo del cauce de la cuenca del río Pánuco mediante el muestreo, las determinaciones en laboratorio y el análisis mediante índices de calidad con criterios agronómicos, y comparar los resultados de la parte alta de la cuenca con la parte baja. Los resultados indican que las aguas residuales que se incorporan al Valle del Mezquital impactan a lo largo de todo el cauce, pero en mayor medida en la parte alta de la cuenca. En todos los puntos de muestreo el agua se clasifica como bicarbonatada-sódica, el índice de CSR indica que el 96% de los sitos presenta algún tipo de restricción para el riego, la CE no es idónea en ninguno de los puntos y la relación de adsorción de sodio (RAS) evidencia riesgos de sodicidad.

ABSTRACT The study of the interaction between hydraulic structures in mobile bed river systems is complex because it involves sediment transport and dynamic changes in the boundary conditions, requiring the use of physical models. This article presents the procedure for the design and construction of a physical model of the reservoir and dam of the Small Hydroelectric Power Plant (SHPP) of Salto Paraopeba. In the design phase, computational modelling of sediment transport was used to reconstitute the primitive geometry of the river, and simulations of the flow regime and the transport capacity along the course of the river were also carried out; both results allowed to delimit the model extension. Considering the choice of scale and the similarity criteria between the model and the prototype, the use of a new alternative material was proposed, composed of crushed tire rubber particles, with a lower specific mass and a larger diameter than the prototype's sediment. In the construction phase, a new constructive method of the physical model was applied using fiberglass, the method presents constructive advantages, such as better representation of the morphology, lower weight, simple installation and uninstallation through modules, and simple and fast repairs, among others. conditions models SHPP (SHPP Paraopeba phase out extension prototype proposed particles prototypes s fiberglass advantages morphology weight modules repairs others

RESUMO O estudo da interação entre estruturas hidráulicas em sistemas fluviais de leito móvel é complexo pois envolve transporte de sedimentos e mudanças dinâmicas nas condições de contorno, sendo necessário o uso de modelos físicos. Este artigo apresenta o procedimento para o desenho e construção de um modelo físico do reservatório e da barragem da Pequena Central Hidroelétrica (PCH) de Salto Paraopeba. Na fase de desenho, foi utilizada a modelagem computacional de transporte de sedimentos para a reconstituição da geometria primitiva do rio, também foram realizadas simulações do regime do escoamento e da capacidade de transporte ao longo do curso do rio; ambos os resultados permitiram delimitar a extensão do modelo. Considerando a escolha da escala e os critérios de semelhança entre o modelo e o protótipo, foi proposto o uso de um novo material alternativo, composto por partículas de borracha de pneu trituradas, de massa específica menor e diâmetro maior do que o sedimento do protótipo. Na fase de construção, foi aplicado um novo método construtivo do modelo físico empregando fibra de vidro, o método apresenta vantagens construtivas como melhor representação da morfologia, menor peso, instalação e desinstalação simples mediante módulos, e reparações simples e rápidas, entre outras. contorno físicos PCH (PCH Paraopeba rio protótipo alternativo trituradas vidro morfologia peso módulos rápidas outras

Resumen El parámetro para delimitar las Áreas de Conservación Permanente del Código Forestal de 2012 es el borde del cauce del cauce regular y no su nivel más alto. El objetivo de este estudio es evaluar la pérdida de áreas protegidas, clasificadas en la categoría de APP de agua, debido al Código Forestal 2012 en el río Cabaçal. Los mapas de uso del suelo y cobertura vegetal para los años 2012 y 2018 se elaboraron utilizando tecnologías espaciales. La modificación del Código Forestal en 2012 provocó la pérdida del 90% del área anteriormente protegida por la de 1965, correspondiente al lecho hidrológico mayor del Cabaçal. río, especialmente en el curso bajo, ubicado en la llanura del Pantanal de Mato Grosso. Se concluyó que se removió la cubierta vegetal en las APPs para que se pudieran implementar usos urbanos y agrícolas, caracterizándolos como conflictos por la flexibilidad de la legislación ambiental. 201 alto protegidas agua Cabaçal espaciales 90 1965 bajo Grosso agrícolas ambiental 20 9 196 2 19 1

Abstract The parameter for delimiting Areas of Permanent Preservation (APPs) in the 2012 Forest Code is the edge of the regular stream bed, not its highest level. The objective of this study is to evaluate the loss of protected areas, framed the category of water APPs in the 2012 Forest Code, in the Cabaçal River. By means of spatial technologies, maps of vegetation cover and land use from 2012 and 2018 were prepared. The change in the Forest Code in 2012 caused the loss of 90% of the area previously protected by the 1965 Code, corresponding to the major waterbed of the Cabaçal River, especially in the lower course, located in the Pantanal plain of Mato Grosso. It was concluded that the vegetation cover in the Areas of Permanent Preservation was suppressed so that urban and agricultural uses could be implanted, characterizing them as conflict areas due to the flexibilization of the environmental legislation. (APPs 201 bed level River technologies prepared 90 196 course Grosso implanted legislation 20 9 19 2 1

Resumo O parâmetro para delimitação das Áreas de Preservação Permanentes (APPs) do Código Florestal de 2012 é a borda da calha do leito regular do curso d’água e não o seu nível mais alto. O objetivo deste estudo é avaliar a perda de áreas protegidas, enquadradas na categoria das APPs hídricas, em virtude do Código Florestal de 2012, no rio Cabaçal, MT Por meio das tecnologias espaciais, foram elaborados mapas de cobertura vegetal e uso da terra de 2012 e 2018. A mudança do Código Florestal em 2012 ocasionou perda de 90% de área anteriormente protegida pelo de 1965, correspondente ao leito maior hidrológico do rio Cabaçal, especialmente no baixo curso, situado na planície do Pantanal mato-grossense. Concluiu-se que a cobertura vegetal nas Áreas de Preservação Permanente foi suprimida para que os usos urbano e agropecuário fossem implantados, caracterizando-as como de conflitos devido à flexibilização da legislação ambiental. (APPs 201 dágua d água alto protegidas hídricas Cabaçal espaciais 2018 90 1965 matogrossense. matogrossense mato grossense. grossense mato-grossense Concluiuse Concluiu se implantados caracterizandoas caracterizando as ambiental 20 9 196 2 19 1

Abstract The appropriation and use of a hydrographic basin by society is a historical process, necessary and, above all, a generator of environmental problems that greatly alter the quality of water. One of the problems related to water quality is eutrophication. Many aquatic ecosystems have suffered from this problem, which consists of large inputs of Phosphorus and Nitrogen introduced into the riverbed, for example, through domestic and/or industrial effluents. This context of change in water quality by human action triggers the significant growth of phytoplanktonic and phytobenthic organisms, thus causing an imbalance in the dynamics of the aquatic ecosystem, as well as damage to society. In this context, this study aimed to evaluate the Trophic State of the Paraíba do Meio River and understand the unfolding and influences of society's relationship with the river and how this relationship has contributed to the eutrophication process. The materials and methods were based on: data acquisition of chemical and physical parameters from campaigns carried out monthly during the hydrological year of 2013; flow and precipitation data; adequate sanitary sewage data; laboratory analyses; determination of the Trophic State Index by the TRIX Model. It was evidenced that due to the varied anthropic activities that occurred in the hydrographic basin in question, with the significant introduction of nutrients such as Phosphorus and Nitrogen in the river bed, during the hydrological year of 2013, the Paraíba do Meio river presented different stages of eutrophication that range from mesotrophic to eutrophic. process all problem riverbed example andor or effluents organisms ecosystem societys s on 2013 analyses Model question bed eutrophic 201 20 2

Resumo A apropriação e uso de uma bacia hidrográfica, pela sociedade, é um processo histórico, necessário e, sobretudo, gerador de problemas ambientais que alteram, sobremaneira, a qualidade da água. Um dos problemas relacionados à qualidade da água é a eutrofização. Muitos ecossistemas aquáticos tem padecido desse problema que consiste em grandes aportes de Fósforo e Nitrogênio introduzidos no leito de rios, por exemplo, por meio de efluentes domésticos e/ou industriais. Esse contexto de alteração da qualidade da água pela ação humana desencadeia o crescimento significativo de organismos fitoplanctônicos e fitobentônicos, provocando assim, um desequilíbrio na dinâmica do ecossistema aquático, bem como prejuízos também para a sociedade. Nesse contexto, este estudo teve como objetivo avaliar o Estado Trófico do Rio Paraíba do Meio e compreender os desdobramentos e influências da relação da sociedade com o rio e como tal relação tem contribuído para o processo de eutrofização. Os materiais e métodos pautaram-se em: aquisição de dados de parâmetros químicos e físicos de campanhas realizadas mensalmente durante o ano hidrológico de 2013; dados de vazão e precipitação; dados de esgotamento sanitário adequado; análises laboratoriais; determinação do Índice de Estado Trófico pelo Modelo TRIX. Evidenciou-se que devido as variadas atividades antrópicas que ocorreram na bacia hidrográfica em questão, com a introdução significante de nutrientes como Fósforo e Nitrogênio no leito do rio, durante o ano hidrológico de 2013, o rio Paraíba do Meio apresentou diferentes estágios de eutrofização que variam do mesotrófico ao eutrófico. histórico sobretudo alteram sobremaneira rios exemplo eou ou industriais fitobentônicos assim aquático pautaramse pautaram se 2013 precipitação adequado laboratoriais TRIX Evidenciouse Evidenciou questão eutrófico 201 20 2

Resumen: El objetivo de este trabajo fue establecer la influencia que ejerce la granulometría del lecho del río, la forma de la pila de un puente y los parámetros hidrológicos en la profundidad de socavación, a partir de un modelo físico. Para el desarrollo experimental se empleó un suelo granular proveniente de río al que se le realizaron ensayos de laboratorio para determinar la distribución del tamaño de las partículas, empleando materiales cuya clasificación, según el sistema unificado de clasificación de suelos (USCS, por sus siglas en inglés) es SP (arena mal gradada), SW (arena bien gradada), SP-SC (arena mal gradada con arcilla). Adicionalmente, se realizó un análisis estadístico con el fin de determinar las diferencias significativas entre cada una de las variables y su influencia en dicho proceso. Se encontró que existe una fuerte relación entre la forma de la pila, el caudal y la granulometría, con las características hidrodinámicas del flujo cuando pasa por las pilas, así como en la profundidad de socavación.

Abstract: The objective of this work was to establish the influence of river bed granulometry, bridge pile shape, and hydrologic parameters on scour depth based on a physical model. For the experimental development, granular soil from a river was used and laboratory tests were carried out to determine the particle size distribution using materials whose classification, according to the Unified Soil Classification System (USCS), is SP (poorly graded sand) SW (well-graded sand), SP-SC (poorly graded sand with clay). In addition, a statistical analysis was performed to determine the significant differences between each of the variables and their influence on the process. It was found that there is a strong relationship between the shape of the pile, flow rate, and granulometry, with the hydrodynamic characteristics of the flow as it passes through the piles, as well as the scour depth.

BACKGROUND Malaria remains common among native Amazonians, challenging Brazil′s elimination efforts. OBJECTIVES We examined the epidemiology of malaria in riverine populations of the country′s main hotspot - the upper Juruá Valley in Acre state, close to the Brazil-Peru border, where Plasmodium vivax accounts for > 80% of cases. METHODS Participants (n = 262) from 10 villages along the Azul River were screened for malaria parasites by microscopy and genus-specific, cytochrome b (cytb) gene-based polymerase chain reaction. Positive samples were further tested with quantitative TaqMan assays targeting P. vivax- and P. falciparum-specific cytb domains. We used multiple logistic regression analysis to identify independent correlates of P. vivax infection. FINDINGS Microscopy detected only one P. vivax and two P. falciparum infections. TaqMan assays detected 33 P. vivax infections (prevalence, 11.1%), 78.1% of which asymptomatic, with a median parasitaemia of 34/mL. Increasing age, male sex and use of insecticide-treated bed nets were significant predictors of elevated P. vivax malaria risk. Children and adults were similarly likely to remain asymptomatic once infected. MAIN CONCLUSIONS Our findings are at odds with the hypothesis of age-related clinical immunity in native Amazonians. The low virulence of local parasites is suggested as an alternative explanation for subclinical infections in isolated populations.

Resumo Objetivo Nosso objetivo foi descrever a estrutura e os padrões espaciais da comunidade zooplanctônica em um pequeno sistema fluvial brasileiro (sub-bacia do rio Paranaíba) e avaliar o papel de um meandro na dinâmica dessa comunidade. Métodos Amostras de zooplâncton foram coletadas em pontos localizados em um meandro e no leito do rio Aporé durante os períodos chuvoso e seco. Coletamos essas amostras na superfície e fundo de duas zonas diferentes (litorânea e canal). Para cada período hidrológico, a análise de variância foi conduzida para determinar as diferenças na riqueza de espécies e abundância do zooplâncton entre os diferentes pontos (longitudinal), zonas (lateral) e profundidades (vertical). A análise de cluster foi realizada para avaliar a similaridade na composição de espécies. Além disso, uma análise de correspondência canônica foi usada para selecionar as variáveis ambientais que melhor explicaram a variação nos dados de abundância do zooplâncton. Resultados Registramos 152 espécies: 70 de rotíferos, 53 de amebas testáceas, 20 de cladóceros e 9 de copépodes. Observamos mudanças na riqueza de espécies e abundância do zooplâncton ao longo do eixo longitudinal do rio tanto no período chuvoso quanto no seco. No entanto, não detectamos nenhuma mudança lateral ou vertical nesses atributos. A análise de cluster também indicou que as maiores diferenças na composição de espécies estavam no eixo longitudinal do rio. A variabilidade longitudinal do zooplâncton foi associada principalmente a influência de um meandro a montante, bem como a mudanças na velocidade de fluxo d’água, turbidez e concentrações de sólidos suspensos à jusante. Conclusões Nossos resultados demonstraram a importância de uma heterogeneidade de características hidrológicas como fator estruturante da comunidade zooplanctônica no rio Aporé. Assim, destacamos a relevância de ações para proteger e manter as características naturais desses ambientes.

Abstract Aim Our objective was to describe the structure and spatial patterns of the zooplankton community in a small Brazilian river system (Paranaíba River sub-basin) and evaluate the role of an oxbow lake in the dynamics of this community. Methods Zooplankton samples were collected from sites located in an oxbow lake and the Aporé River bed during the rainy and dry seasons. We collected these samples from the surface and bottom levels of two different zones (littoral and channel). For each hydrological season, analysis of variance was conducted to determine the differences in species richness and abundance of zooplankton among different sites (longitudinal), zones (lateral), and depths (vertical). Cluster analysis was performed to assess the similarity in species composition. In addition, a canonical correspondence analysis was used to select the environmental variables that best explained the variation in zooplankton abundance data. Results We recorded 152 species: 70 rotifers, 53 testate amoebae, 20 cladocerans, and 9 copepods. We observed changes in the species richness and abundance of zooplankton along the longitudinal axis of the river in both the rainy and dry seasons. However, we did not detect any lateral or vertical changes in these attributes. Cluster analysis also indicated that the greatest differences in species composition were in the longitudinal axis of the river. The longitudinal variability of zooplankton was mainly associated with the influence of an upstream oxbow lake, as well as the changes in water flow velocity, turbidity, and concentrations of suspended solids downstream. Conclusions Our results demonstrate the importance of a heterogeneity of hydrological characteristics as a structuring factor of the zooplankton community in the Aporé River. Thus, we highlight the relevance of actions to protect and maintain the natural characteristics of these environments.

Besides their important ecological role in flowing waters, blackflies (Diptera: Simuliidae) may pose medical and veterinary risks. For seventeen months, we surveyed the blackflies of ten localities across the Aures Mountains, in the Saharan Atlas, Algeria, and recorded eight taxa (i.e. species, species groups or species complexes). High altitude sites were dominated by the Simulium ornatum (Meigen, 1818) group, whereas sites located on the southern slope of the Aures Mountains were occupied by the eurytopic Simulium velutinum (Santos Abreu, 1922) complex and the thermophilic, pollutant-tolerant Simulium ruficorne Macquart, 1838 'A' morphotype. Co-inertia analysis was used to determine the relationship between a species' abundance and habitat types. The co-inertia analysis revealed a likely co-structure between blackfly assemblages and measured environmental descriptors (water temperature, conductivity, current velocity, bed width, etc.) in sampled habitats. This confirmed the importance of altitude as a driver of blackfly distribution. Our results also showed that there has been an increase in anthropogenic pressures on the vulnerable freshwater biota of the Aures Mountains.

EXTENDED ABSTRACT A sedimentological study of the prograding area of the Paraná River delta (PRD) is here presented with the aim of characterizing the deposits related to the last ~100 yr. of paleoenvironmental evolution and to contribute to facies models of bayhead deltas. Delta deposits are the result of the interaction of various processes and factors (principally hydrological characteristics, waves, tidal action, type and volume of sedimentary discharge, water depth, sea level, climate) that disperse the sediments transported to the river mouth (Wright, 1977). The Paraná River, together with the contribution of the Uruguay River, develops a bayhead delta into the Río de la Plata (RdP) estuary (Fig. 1a). The delta constitutes an extensive plain with a very low gradient, lined by numerous fluvial channels of diverse hierarchy, and a series of distributary mouth bars with a lobate morphology (Figs. 1c, 2). It is a fluvial-dominated delta, regulated by the hydrological regime of its drainage basin and modulated by the estuary dynamics (Iriondo, 2004; Cavallotto et al., 2005). This bayhead delta has a drainage area of 3.000.000 km2. The Paraná river supplies 160 million tons of sediment per year to the delta mouth, with ~145 million tons of suspended sediments (30% clays, 60-65% silts and 5-10% sands) and 15 million tons of sands as bottom load (Sarubbiet al., 2004). In the Uruguay River, the suspended load reaches 7 million tons per year of sediments, with a higher contribution of sandy bottom sediments (Urien, 1972). Several studies revealed a high-constructive dynamic for the Paraná river delta during the last decades, with progradation rates of 30 to 70 m per year since AD 1818 (Soldano, 1947; Codignotto and Marcomini, 1993; Pittau et al., 2007; Leal, 2011; Medina and Codignotto, 2013). In particular, the study area grew an average of 42-45 m per year between AD 1933-2016 (Marcomini et al., 2018; Fig. 3). The PRD is placed at a temperate zone of southern South America, under a subhumid, mesothermal climate (periods 1981-1990 and 1991-2000; National Meteorological Service, 1992, 2003). Winds are mainly from the northeast and the southeast quadrants (Simionato and Vera, 2002), and are the main forcing of the RdP estuary circulation (Moreira et al., 2016). The estuary experiences a microtidal regime and the wave energy in the inner estuary is low (in average lower than 0.6 m high) and local (Moreira, 2016). Strong southeasterly wind (sudestada), that can last several days, triggers storm surges in the estuary and extensive floods in coastal areas (Seluchi, 1995). On the opposite, when ebb tides are accompanied by intense northeasterly winds, a very low water level happens (Simionato et al., 2004). Fitogeographically, the PRD belongs to the Neotropical region, and the vegetation is strongly influenced by the landscape and the hydrologic regime (Kandus et al., 2006). At the subaerial deltaic plain, plant communities are characterized by riparian forest along the levees and graminoid type plants in the interior, while bulrush colonizes the proximal subaqueous delta (Fig. 4d). Materials and methods include a geomorphologic-temporal evaluation, in-situ survey and sampling of surficial sediments and sediment cores in the lower subaerial and proximal subaqueous delta plains (34° 26’S, 58° 30’ W; Fig. 3), accompanied by lab determinations and then facies analysis. Surficial sediments were sampled with a Snapper dredge and the sediment cores were extracted using 2.5 inches PVC tubes. Grain size was measured with a Malvern Mastersizer Hydro 2000 laser analyzer, after pretreatment to eliminate organic content by soaking samples in hydrogen peroxide solution (H2O2) and rinsed with distilled water. The textural results were statistically processed and evaluated following the Folk and Ward (1957) protocols (Table 1). Due to the common presence of heterolithic sediments and in order to obtain an improved interpretation of the relationship between grain size distribution and sedimentary processes, extreme member (EM) analysis (after Paterson and Heslop, 2015) was applied to identify subpopulations (parametric curve-fitting applying the Weibull distribution; Fig. 5). EM modelling of the studied deposits was guided by geologic criteria and examined in terms of sediment availability and transport-deposition processes, including particle trapping due to bulrush vegetation (a common process in the PRD). The textural characterization by means of ME results a convenient technique to interpret mixed sediments like the here studied. Particularly, it can be useful when the sediment sample are acquired with dredges or augers, methods that produce the loss of sedimentary structures but demand less time and logistics than to extract cores. Sediment cores were described in terms of grain-size, sedimentary structures, color (Munsell, 2000), biological remains, mass magnetic susceptibility (SM, using a Bartington MS2B sensor) and percentage of LOI550 and LOI950. The time constrain for the core successions (ca. 1915-2017) was inferred by means of two main elements: correlation with a sediment core extracted about 15 km to the north of our study area and dated using radionuclide dating (210Pb and 137Cs) by (Schuerch et al., 2016) and the presence and depth of shells of Corbícula fluminea (Table 2), invader bivalve first recorded in the RdP estuary by ca. 1970 (Ituarte, 1981). The vertical growth rate of 1.52 cm per year (since year 1960) estimated for that core, that shows a comparable thickness and grain-size trend and represents a similar subaqueous delta subenvironment (Schuerch et al., 2016), was used in the here study sediment cores (Table 3). In a couple of studied cores there is some inconsistency between the two elements, possibly due to a higher rate of sedimentation. Besides, it is important to notice these estimations are relative age that have a degree of uncertainty due to these organisms not necessary may appear in all the sampled sites. The inferred relationships of grain-size subpopulations and sediment transport-deposition, the analysis of the sediment cores (Figs. 6,7) and the evaluation of the geomorphological setting of surficial and core samples, allow proposing a series of lithofacies (Table 2) and facies associations (Table 4). Core location in a time series of aerial photograph and Google Earth® images (Fig. 3) and previous delta models and concepts (mainly those by Wright and Coleman, 1973; Coleman and Wright, 1975; Wright, 1977; Orton and Reading, 1993) were applied in the facies analysis. Principally, the theoretical model of friction-dominated effluents proposed by Wright (1977) can be applied to the PRD, developed in a shallow basin (inner estuary is less than 4 m deep; Urien, 1972; Fig. 2) that promotes turbulent bed friction. The distributary mouth bars are laterally extensive (several km2), with very low slope (Fig. 4a-c) and crossed by shallow tidal channels. Bars are made up of massive or horizontal laminated beds forming heterolithic beds (sandy and muddy silt) and few fine-very fine sand and silty sand (bar crest) (Facies association F1, Table 4; Figs. 6, 7). This is interpreted as quick accumulation of tractive sediments, due to friction at the shallow river mouth, and then reworked by semidiurnal tidal currents and exceptional storm surges and accompanied by settling of fines from suspension. Once these shoals are stabilized by bulrush vegetation the sedimentation is dominated by suspension and particle trapping by vegetation (Fig. 4d), with eventual very low currents. Finally, the bar becomes an island of the lower subaerial delta plain, dominated by accumulation from flooding events. During this final stage clayey silt and silty clay, with the largest values of LOI550 of all core sediments, are deposited by flooding from the distributary channels (Facies association F5). Facies association F2 represents high energy deposition of sand and silty sand, usually with shells, due to exceptional storm surges or fluvial flooding. Deposits of interdistributary bays (Fig. 4e), included in facies association F4, are dominated by horizontal and heterolithic laminated, clayed silt with low LOI550 (Figs. 6,7). Deposits of subaqueous distributary channel (Fig. 4f) are fine-very fine sand and silty sand interlayered with silt and muddy silts with heterolithic laminations (Facies association F3a, Figs. 6,7). In core D11-T2 a succession with interbedded fine-very fine sand and sandy silt-silt with inclined heterolithic stratification (HIS) was identified (Facies association F3b, Fig. 7), and interpreted as subaqueous channel deposits, developed next to distributary bars (Fig. 3e). The textural characterization by means of ME proves to be a convenient technique to interpret mixed sediments like the here studied. Particularly, it can be useful when the sediment sample are acquired with dredges or augers, methods that produce the loss of sedimentary structures but demand less time and logistics than to extract cores. The proposed lithofacies and facies association will allow to systematize the sedimentological studies of the DRP and research of prograding deposits of bayhead deltas fed by big rivers with a sandy silt load.

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SUMMARY: The Vale do Ribeira region has a large extension of Brazilian Atlantic Forest, and in most cities, low environmental impact activities predominate, such as sand mining. Sand mining has been trying to adapt their industrial activities to low environmental impact, aiming at the protection of permanent preservation areas (PPAs) of riparian forests. The objective of this work was to conduct a case study focused on monitoring and initial growth of forest species by 18 months. This study was performed in a riparian forest site on the Ribeira de Iguape River, Registro, state of São Paulo, Brazil, in a PPA with extraction of river bed sand. Forest species height, stem diameter and mortality index, and rainfall were evaluated in the period. Non-pioneer species accounted for 42.7 % of the forest, while pioneer species accounted for 53.1 %. These proportions are in accordance with local legislation, which establishes a lower limit of 40 % in planting for both groups. Drought periods and leaf-cutting ants at the beginning of growth stages contributed to a higher mortality index and irregular development of some species, however, even during such adversities, forest species indicated resistance to these conditions. Pioneer species had more important development, with emphasis on Senna multijuga, Alchornea triplinervia, Citharexylum myrianthum and Trema micranta, these species must be taken into consideration during the first stages of a project which aims at recovering degraded areas in riparian forests of Atlantic Forest.

RESUMEN: La región de Vale do Ribeira tiene una gran extensión de selva Atlántica brasileña, y en la mayoría de las ciudades predominan las actividades de bajo impacto ambiental, como la minería de arena de río. La extracción de arena ha estado tratando de adecuar sus actividades con menor impacto ambiental, apuntando a la protección de áreas de preservación permanente (APP). El objetivo fue realizar un estudio de caso con enfoque en el monitoreo y crecimiento inicial de especies forestales hasta 18 meses. Este estudio se realizó en un bosque ribereño del río Ribeira de Iguape, municipalidad de Registro, estado de São Paulo, Brasil, en una APP con extracción de arena de lecho de río. Se evaluó la altura de las especies forestales, el diámetro del tallo, el índice de mortalidad y la precipitación en el período. Las especies no pioneras tuvieron una proporción del 42,7 % del total y las pioneras el 53,1 %; las proporciones están de acuerdo con la ley local. Los períodos de sequía y las hormigas cortadoras de hojas al inicio del crecimiento de las especies contribuyeron para o mayor índice de mortalidad y al desarrollo irregular de algunas especies, sin embargo, incluso las adversidades, las especies forestales indican resistencia en estas condiciones. Las especies pioneras tuvieron mayores desarrollos, con énfasis en Senna multijuga, Alchornea triplinervia, Citharexylum myrianthum y Trema micranta. Estas especies deben ser tomadas en consideración al inicio del proyecto de recuperación de área degradada en bosque ribereño de selva atlántica.

The flow pattern and bed shear stress are important factors to determine the scour potential regions in river bridges. This study has developed a 3D numerical model to simulate the flow around bridge abutments in a compound channel, and study the simultaneous effects of the bridge skew angle and contraction ratio (i.e. the roadway embankment length normal to the flowto the floodplain width) on the velocity distribution and the bed shear stress. After the model performance was verified, 13 cases were considered with different skew angles and contraction ratios. The results showed that the flow was more complex around the flow-splitting embankment than around the flow-guiding one, because of the flow-roadway embankment confrontation. At a zero skew angle, an increased contraction ratio increased the velocity around both abutments significantly; velocity increased by 67% and 40% when the contraction ratio rose from 0.25 to 0.50 and from 0.50 to 0.75, respectively. This velocity increase around the flow-splitting embankment was also visible for 15°, 30° and 45° angles; unexpectedly, the increase was less for the 45° angle than for the other cases. A shear stress study around the flow-guiding embankment showed that in all three cases an increased skew angle reduced the maximum shear stress mildly at contraction ratios of 0.25 and 0.50, and severely at 0.75. The trend of the maximum shear stress variations around the flow-splitting embankment was different for different contraction ratios - at a contraction ratio of 0.25 it was the highest at 45°, but for contraction ratios of 0.50 and 0.75, the maximum was 30°.

ABSTRACT In this work, the influence of the Manning roughness coefficient is studied on the flood areas of the Yanuncay river due to the ocurrence of extreme flows. A hydraulic model was used in varied and permanent regimes, with different flows and values of the coefficient n that represents the dynamic bed resistance to the transit of the avenue. Among the main results, it was evidenced that, by increasing the dynamic resistance coefficient (n), the flood area is increased non-linearly, which ratifies the care that should be taken when adopting a value for this parameter in a hydraulic model.

RESUMEN En este trabajo se estudia el impacto del coeficiente de rugosidad de Manning en las áreas de inundación del río Yanuncay debido al paso de caudales extremos. Para esto, se utilizó un modelo hidráulico en régimen variado y permanente, con diferentes caudales y valores del coeficiente n, que representa la resistencia dinámica del cauce al tránsito de la avenida. Entre los principales resultados se evidenció que, si se aumenta el coeficiente de resistencia dinámico (n), el área de inundación se incrementa no linealmente, lo que ratifica el cuidado que se debe tener a la hora de adoptar un valor para este parámetro en un modelo hidráulico.