Navegando por Assunto "Solos - Erosão"

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Acesso aberto (Open Access)
Análise comparativa entre uso e qualidade do solo na área do reservatório da UHE – Tucuruí com base nos atributos físicos e químicos
(Universidade Federal do Pará, 2018-12-21) RAMOS, Jaqueline Pinheiro; VILHENA, Karyme do Socorro de Souza; http://lattes.cnpq.br/3071495983880548
The construction of dams and their reservoirs generates a series of problems, among them, it is mentioned the erosions in the banks of the reservoirs. The soils forming the UHE-Tucuruí region are subject to different uses and occupations that over time have undergone changes with the seasonality of the lake and the increasing use of land, without considering the potentials and limitations of the soil. Some of these areas already show signs of degradation and erosion occurrence points are also identified. The present work seeks to determine the chemical and physical attributes for the evaluation of erodibility in soils located in the reservoir area of Tucuruí Hydroelectric Power Plant. With the selection of native forest, planting and pasture areas, the collected and deformed samples were collected to perform the chemical and physical tests at the Civil Engineering Laboratory of the Federal University of Pará at the Campus Universitário de Tucuruí. After obtaining the results of the physical and chemical properties of the soils can be prescribed the changes caused by the difference of their use and occupation, in the comparative between the areas, the established parameters showed the chemical degradation of the soil and the loss of nutrients that trigger the erosive processes. Multivariate analysis techniques were applied: Principal Component Analysis (PCA) and Hierarchical Grouping Analysis (HCA) to correlate the variables, the understanding of the data set was facilitated and the interrelation between the variables and samples became clearer, From these analyzes, it was possible to determine that the pasture area in the superficial layer is the one that most differs from the others, when considering all the attributes analyzed and the extracted samples, in addition, the multivariate analysis highlighted the information set, which variables are undergoing changes as a consequence of anthropic activity.
Acesso aberto (Open Access)
Aspectos sociais e naturais de um problema ambiental: um estudo na ilha da Coroa Comprida, Amazônia oriental
(Universidade Federal do Pará, 2012-09-28) BENTES, Erika Simone da Silva; IMBIRIBA, Breno Cesar de Oliveira; http://lattes.cnpq.br/7979656297541988; SANTOS, Sônia Maria Simões Barbosa Magalhães; http://lattes.cnpq.br/2136454393021407
The Amazon region is highlighted on the world stage not only for its biodiversity, it contains the largest rainforest in the world still existing, but also for its social diversity: the region contains distinct population groups. This paper discusses the problem of the social construction of environmental problem from the knowledge and the local perception of the phenomenon, supported by observation and interviews. The research develops the Island Coroa Comprida, mesoregion Salgado where a community made up mostly of fishermen, situated at the mouth of the river Urumajó under the direct influence of the Atlantic Ocean. This town has faced a long process of erosion that is declining because the territorial extension of the beach where the locals inhabit the island, causing its movement to other locations both along the river and to the outskirts of Augusto Corrêa. Of the approximately 400 families that originally inhabited the island, only 15 remain now and only due to lack of financial resources to travel. Residents who have already moved the island, went to several places: home of relatives in the county seat, to the village of Perimirim which was built 36 years ago to house the displaced exactly the Island in question, due to the erosion process that had begun since. Another portion of residents moved to the neighborhood Bom Jesus Near the center of the municipality. The last 15 residents await the end of the construction of 25 houses built by the City Hall to house the victims of the erosion process. Both fishermen as public managers interpret erosion as a "natural phenomenon", and no public policies for the population living in the territory and the destruction compulsory displacement. As this erosion is treated as a natural phenomenon, its effects are not included in current discussions on measurement of risk prevention and environmental protection of victims of environmental disasters.
Acesso aberto (Open Access)
Critérios operacionais para redução da contribuição de sedimentos gerados em pilhas de estéril
(Universidade Federal do Pará, 2018-11-14) COSTA, Glayce Wivyanne Oliveira; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Failure to construct and / or operate sterile piles can lead to significant environmental impacts due to the management of sediments from erosion processes, especially in the rainy season, making it necessary to prepare mitigation plans that take into account the behavior morphodynamic characteristics of the land, as well as the rate of sedimentation or the sediment load that can be incorporated into the watercourses during the different constructive stages of the structures, in order to guarantee the integrity of the flora around the enterprise, as well as to optimize the destination of the tailings and sediments within the space defined for the mining activities. In this sense, this study aims to analyze the process of sterile disposal and solids generation in iron ore sterile disposal cells from open pit mines, thus indicating operational criteria that subsidize the reduction of the contribution of sediment generated in batteries for the environment. In order to carry out this work, a Vale sterile stack was installed in the Mineral Province of Carajás, called PDE NW II, for which a documentary research and critical analysis of the main factors involved in the erosive dynamics of the structure was carried out. In this context, rainfall histories, soil cover classification, size and morphology of the contribution basin are included, as well as the quantification of sediment carried by the structure to downstream portions. The methodology used was efficient, mainly because it was able to correlate cause and effect, in the evaluation of the routines of implantation and operation of the piles, in order to make preventive actions intuitive, in order to minimize the contribution of sediment to the environment.
Acesso aberto (Open Access)
Estudo da erodibilidade de solos do reservatório da UHE Tucuruí
(Universidade Federal do Pará, 2019-10-30) SILVA, Lucas Manoel da; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378; ALENCAR JÚNIOR, Júlio Augusto de; http://lattes.cnpq.br/3663658632717465
The Tucuruí Hydroelectric Power Plant, besides being the 5th largest hydroelectric plant in the world in generating capacity, transfers electric power to several Brazilian states and, having a reservoir of 2,917 km², is strongly subject to erosion. Several studies report the occurrence of erosive features near the its reservoir, besides being constantly subjected to laminar erosive actions in its drainage areas. In this work we carried out bibliographical surveys, field checks and direct and indirect analyzes of the erodibility of samples of the main soils of the Tucuruí HPP reservoir. Indirect analyzes employed semiempirical formulations based on physical and geotechnical characteristics of the, and the direct ones tested undisturbed samples under runoff, exposure to gradual and total water immersion processes, and under intense sample remoulding levels for evaluations in the Tropical Compacted Miniature - M.C.T. It was possible to notice a significant increase in the reservoir territorial occupation, favoring the exposure to erosive processes, and that the samples classified as Pedisol as Ultisol and Yellow Latosol presented average erodibility rates, as 0.0392 and 0.0323 g / cm² / min / Pa and low levels of disaggregation, while Red Latosol presented low erodibility as 0.002 g / cm² / min / Pa, medium to high levels of disaggregation and expansions, in the MCT methodology. These conclusions indicate that the agricutural activity in the area must grow crops that maintain the surface coverage of the first soil areas, and the prevention of uses that may disrupt and damage the last soil.