Navegando por Assunto "Rio Xingu"

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Acesso aberto (Open Access)
Análise geoecológica como subsídio ao planejamento ambiental da sub-bacia hidrográfica do igarapé ambé, Altamira-PA
(Universidade Federal do Pará, 2021-08-27) LOBATO, Alexandre Augusto Cardoso; PAULA, Éder Mileno Silva De; http://lattes.cnpq.br/8647718165947306; https://orcid.org/0000-0002-6895-2126; BORDALO, Carlos Alexandre Leão; http://lattes.cnpq.br/1253955182585852
Although the Amazon Biome has an incalculable value for the balance and maintenance of life on the planet, in recent years it has suffered from the construction of controversial infrastructure works, in particular the opening of highways and construction of hydroelectric plants, such as the BR-230 Highway (Transamazônica) and the Belo Monte Hydroelectric Power Plant, as happened in the Xingu River hydrographic basin, which caused and can still entail several modifications at different spatial scales, mainly at the local level. Therefore, it is extremely important to understand the functioning of these landscapes and their tendencies towards changes arising from human activities, thus providing subsidies to plan environmentally sustainable uses. Adopting the concept of hydrographic basins as a physical-territorial unit for measuring socio-environmental impacts and the geoecology of landscapes as a methodology for systemic environmental analysis, this research aims to study the operation and changes caused by the opening of the Transamazon Highway and its construction of the Belo Monte Hydroelectric Complex in the Igarapé Ambé hydrographic sub-basin which has its territorial extension cut by the aforementioned highway and is located within the Direct Influence Area (AID) and the Directly Affected Area (ADA) of the Belo Monte Hydroelectric Complex and that drain the urban area of the city of Altamira in the State of Pará. The analyzes show that 45% of the SBHA's landscapes are with active morphogenetic processes and 29% are with moderate environmental vulnerability and in a fragile stage of ecodynamic balance, which shows the importance of thinking about alternative uses for these landscapes.
Acesso aberto (Open Access)
Explorando a biodiversidade do rio Xingu: apresentação e validação de um novo equipamento de amostragem de DNA ambiental
(Universidade Federal do Pará, 2024-04-29) BAHIANA, Bruno Gonçalves; KEPPELER, Friedrich Wolfgang; GIARRIZZO, Tommaso; http://lattes.cnpq.br/5889416127858884
Knowledge and monitoring of biodiversity are key elements for defining actions and initiatives focused on nature conservation and restoration. However, monitoring techniques are generally expensive and time-consuming, which complicates efforts to identify and manage biological diversity. In this sense, it is essential to investigate new fast, non-invasive and low-cost methods that can provide reliable and robust results and information, highlighting, in this context, approaches based on the use of environmental DNA (eDNA). eDNA is a complex mixture of genetic material originating from entire organisms or parts of them, present in environmental matrices, which can be, for example, soil, water or sediment. This project presents a prototype of a simple and low-cost equipment to obtain eDNA sampling, aiming to explore the richness and composition of the ichthyofauna in the Fish Transposition System of the Belo Monte Hydroelectric Power Plant (HPP), located in the middle course of the Xingu River, a hyperdiverse river located in the Amazon Brazilian. To this end, a new and affordable piece of equipment was manufactured for passive collection of genetic material (eDNA) using a metal structure and two PVC tubes. A flow meter was attached to one of the tubes and two rolls of gauze were firmly attached to the other tube. From the samples, which were collected every two hours over a 24-hour period, a species inventory was generated using a combination of fish-specific molecular markers (Tele02 12S). To validate the equipment and the proposed methodology, the temporal variation in the richness and composition of the fish fauna detected with eDNA were compared with those recorded during monitoring using the Video-Image System located at the exit of the STP. The results indicate that the method was efficient and sampled 100% of the ichthyofauna orders that were recorded in monitoring with SVI, but the similarity between the two methods reduced as taxonomic specificity increased. This result can be explained by the low representation of Xingu species in existing genomic libraries. In this sense, eDNA is a promising approach with great potential to become a valuable tool for studying and monitoring the composition of fish in highly diverse tropical freshwater rivers with affordable costs and minimal impacts on organisms and habitats, but which, in this At the moment, more basic research is needed so that it can replace and/or complement traditional sampling methods.
Acesso aberto (Open Access)
Hidrodinâmica, transporte e proveniência sedimentar no baixo rio xingu e sua importância como “Tidal River” amazônico
(Universidade Federal do Pará, 2022-07-14) MEDEIROS FILHO, Lucio Cardoso de; LAFON, Jean Michel; http://lattes.cnpq.br/4507815620234645; ASP NETO, Nils Edvin; http://lattes.cnpq.br/7113886150130994
This research is based on the investigation of the processes (geological and hydrodynamic) that govern the recent evolution of a large tributary of the lower Amazon, the Xingu River. The aim was to investigate its aspects of sedimentary evolution and hydrological flows, from already consolidated data on the filling of its ria and how its patterns of transport and sediment trapping, its seasonal and tidal effects have been established, in addition to understanding the role of the Amazon River as a regulator in the dynamics of its tributary. Hydrodynamic measurements of flow, velocity and water level along with bottom sediment and MPS samples were collected at 3 annual seasons (February, June and November). The results provided support for the investigation of the Xingu-Amazonas interaction and the evolution of the bottom morphology of the lower Xingu. The results suggest a filling of the ria both by the Xingu River, forming a prominent headwater delta, and the Amazon River, where tidal variations transport sediments upstream in the Xingu River. On the other hand, large areas in the central part of the ria indicate muddy sedimentation. Elementar geochemistry allowed us to trace part of the history of sediments and source rocks, together with the analysis of immobile elements (Al, Ti, Zr, Hf, Th) and rare earth elements (REE) because they are poorly fractionated during weathering processes. and they are concentrated in the bottom sediments to the detriment of the dissolved fraction of the rivers. The deposits preserved in the lower Xingu River, despite draining cratonic regions in higher areas, confirm that the bottom material is derived from heterogeneous sources with predominantly intermediate igneous compositions and that they underwent important recycling during fluvial transport. The hydrodynamic modeling allowed to indicate the fluvial discharge as the most relevant forcing for the muddy deposition dynamics in the Xingu estuary. From a numerical model, it was possible to extrapolate the flow and transport dynamics beyond the open boundaries, that is, the central portion of the ria, elucidating the interaction mechanism between river and tidal discharge and the associated sedimentary dynamics. The determination of the amplitudes and phases of the tidal components, whether of purely astronomical origin or resulting from shallow waters, as well as the average level and the hourly discharge proved to be fundamental for the understanding of the governing processes.
Acesso aberto (Open Access)
Investigação do limite entre domínios geocronológicos da região do médio Rio Xingu, sudeste do Cráton Amazônico
(Universidade Federal do Pará, 2005-11-03) MONTEIRO, Pablo Condurú; MACAMBIRA, Moacir José Buenano; http://lattes.cnpq.br/8489178778254136
The Central Amazon Province (PAC), the oldest portion of the Amazon Craton, is admitted as a domain of Archean evolution. This domain, cratonized from the Paleoproterozoic onwards, would be bordered by successive Proterozoic geochronological provinces (2.25 to 0.9 Ga), such as the Maroni-Itacaiúnas Province, progressively younger towards the southwest of the craton. The CAP is divided into two blocks: Carajás and Xingu-Iricoumé, whose boundaries are poorly defined. Today, it is known that the Carajás block has its evolution reported to the Arqueano. The Xingu-Iricoumé block lacks data to characterize its evolution. The general objective of this dissertation is the characterization of the crustal evolution and the evaluation of the boundary between the Central Amazon Province (Carajás or Xingu-Iricoumé blocks) and the Maroni-Itacaiúnas in an area in the middle course of the Xingu River (PA) through geochronological studies. and isotopic geochemistry of igneous and orthometamorphic bodies. To achieve this, we resorted to: construction of a cartographic base through data obtained in previous surveys and in a field campaign; individualization of different types of rocks; determination of crystallization and mantle extraction ages of different igneous rocks and protoliths of metamorphic rocks, as well as the metamorphism that affected them, through the application of Pb-Pb methods in zircon and Sm-Nd in whole rock and garnet. The petrographic studies and field features made it possible to define, within the work area, eight main rocky domains, which are: inequegranular granodiorites, gneisses (enderbitic, tonalitic and peraluminous), charnochites, enderbites, migmatitic gneisses, Iriri-type volcanics, Maloquinha-type granites and, finally, Parauarí-type granodiorite. A set of 19 isotopic data was generated by the Pb-Pb methods in zircon (6) and Sm-Nd total rock and garnet (13), in 13 samples of 6 units. These data aim to bring new geochronological references to the key units and establish a chronology for the events that occurred in the area. The Pb-Pb ages in zircon for the units in the middle Xingu region allowed us to define that they were formed in a short time interval of less than 40 Ma (2.07 - 2.11 Ga). The Sm-Nd isotopic results in whole rock indicated T(DM) model ages with values within the Archean in the range of 2.60 to 3.09 Ga. Thus, the studied rocks were originated by the regeneration of older continental crust, at least 500 Ma, but reaching values of up to about 1.0 Ga. The application of the Sm-Nd method in the garnet-total rock pair of a leukomonzogranitic injection in gneisses indicated an age of 1962 ± 15 Ma, interpreted as the minimum age of the peak of the metamorphism that affected the region. The dataset presented shows that in the studied region there was a Paleoproterozoic magmatism of varied composition linked to a tectonic-thermal event of regional expression – the Transamazonian Cycle. With this, it is confirmed that the region falls within the Maroni-Itacaiúnas Geochronological Province, as previously raised by several authors, and its boundary with the PAC must be in the south of the studied area.
Acesso aberto (Open Access)
Objetos entre contextos e significados: as coleções etnográficas do Museu Paraense Emílio Goeldi entre 1894 e 1905
(Universidade Federal do Pará, 2021-07-30) COELHO, Matheus Camilo; SANJAD, Nelson Rodrigues; http://lattes.cnpq.br/9110037947248805; https://orcid.org/0000-0002-6372-1185
This study aims to investigate the process of musealization of ethnographic collection placed in the Museum Paraense Emílio Goeldi (MPEG), named Lauro Sodré (1897), Henri Coudreau (1898), Frei Gil Vilanova (1902) and Koch-Grünberg (1905). Not only centered in the collector’s protagonism but comprehending the collection processes as a polysemic practice, this research intent to comprehend its role in social and political context, interests of the museums, their scientific agenda, trajectory and conceptions of the producing communities and collectors, the collaboration and circulation networks on Amazon region.. The four collections are relevant to Curt Nimuendaju Technical Reserve Ethnographic Collection at the Goeldi Museum due to their acquisitions during a restructuring and reorganization period, and also, in a way, represent three distinct contexts of collecting indigenous artefacts in Amazon at the end of 19th century and 20th century beginning, led by a French explorer, a Dominican missionary, and a German ethnologist. Their study certainly allows us to analyse how different political and social contexts, religious, philosophical, cultural, scientific thoughts and the relationships between indigenous peoples and collectors acted in objects selection and rejection that make up the aforementioned collections.
Acesso aberto (Open Access)
Palm community transitions along a topographic gradient from floodplain to terra firme in the eastern Amazon
(Instituto Nacional de Pesquisas da Amazônia, 2015-03) SALM, Rodolfo Aureliano; PRATES, Anderson Sousa; SIMÕES, Nadson Ressyé; FEDER, Lisa
Palms show clear niche segregation patterns along topographic gradients in tropical forests, with some species associated to terra firme and others to seasonally flooded areas. The aim of this study was to quantitatively describe the fine-scale spatial variation within a palm community, tracking the changes in species' abundance along environmental gradients associated with a perennial stream the eastern Amazon. The study of palm communities was based on 60 forest plots in which all adult palms were counted. We found a total of 566 palms in a community containing 11 species. Furthermore, we found a significant separation in the palm community between seasonally-flooded and terra firme forests. We found a gradient with various densities of the three most abundant palm species within the first 100 m away from the flooded area. Other species were located exclusively in the terra firme forest. The abundance of the six most common species were distributed in relation to humidity gradients from floodplains to terra firme, with palm distribution from the most flood-tolerant to the least flood-tolerant palm species as follows: Euterpe oleracea, Attalea phalerata and Socratea exorrhiza (species with floodplain affinity), Astrocaryum gynacanthum, Astrocaryum aculeatum, Attalea maripa (species with terra firme affinity).
Acesso aberto (Open Access)
Redes e vigilância no Xingu: a reconfiguração do território ribeirinho
(Universidade Federal do Pará, 2022-04-29) BAITELLO, Clara Bezerra de Menezes; HERRERA, José Antônio; http://lattes.cnpq.br/3490178082968263; https://orcid.org/0000-0001-8249-5024
This work examines how the construction of the Belo Monte Hydroelectric Dam at Xingu River, in Altamira city, Pará state is transforming the relationship between ribeirinhos, riverine people, and their traditional territories. Before the dam, the riverine people maintained relative territorial and social-economic autonomy. Since the construction of Belo Monte, the State and private companies are abusing their power in an attempt to gain territorial control and influence local dynamics. Subsequently, land-use planning in the region is changing. Previously organized by the ribeirinhos according to their own rules and subsistence needs, the land is now regulated by new private actors, impacting and altering the nature and purpose of the communities’ traditional activities. In order to conduct this analysis, I use the dialectical method due to its ability to analyze the contradictions of the territory.