Navegando por Assunto "Watersheds"
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Item Acesso aberto (Open Access) Análise da vulnerabilidade ambiental da sub-bacia do Jaurucu – Brasil Novo Pará(Universidade Federal do Pará, 2022-08-29) FREITAS, Jaylim Reis de; VELOSO, Gabriel Alves; http://lattes.cnpq.br/9757471213923099; https://orcid.org/0000-0002-3655-4166The overall objective of this study is to analyze the environmental vulnerability of the Jaurucu sub-basin and to understand how land cover and land use changes between 1990 and 2020 affect the loss of its landscape potential and its geoecological and socioeconomic features, including the pattern of encroachment of environmental systems. . , possibilities and limits of use and the impact on spatial changes. To achieve the desired goals, the theoretical and methodological foundations of the earth system approach, the theory of ecological dynamics, the concepts of landscape, land system and stability of the environmental system were chosen; The concepts of risk and vulnerability were introduced to avoid confusion when understanding these concepts. The research used techniques and methodological procedures as theoretical and methodological support for mapping environmental systems, assumptions by Bertrand (2004), Sotchava (1977), Tricart (1977), Monteiro (2000), Souza (2000) and others. The cartographic products were created with the support of geographic information systems (GIS). The environmental vulnerability analysis was adapted by applying the methodology of Crepani et al. proposed method. Persons. (2001), Grigio (2003), Tagliani (2003), Costa et al. (2006), Oliveira and Mattos (2014), based on Tricart (1977). Field work has been performed to verify the generation of land cover and land cover maps using MapaBiomas, vulnerability determinations are calculated using the grid calculation tool from algebraic equations crossing data in the GIS environment. Therefore, creating a sustainable development plan requires planning and analysis of the environment. Understanding vulnerable environments and the systems used within them helps with territory planning.Item Acesso aberto (Open Access) Análise do comportamento da precipitação e da vazão em bacias hidrográficas Amazônicas(Universidade Federal do Pará, 2016-03-14) HACHEM, Bruno Penna; FERNANDES, Lindemberg Lima; http://lattes.cnpq.br/4641468846318922The aim of this study was to analyze the behavior of precipitation and flow in two river regions of the state of Pará, where Northern Corridor and Coast Northeast Atlantic. Both have the same rainfall and physical properties of the bowls are similar, being different only in regard to level and vegetable preservation area. For this study, we used 7 gauged stations and 7 rainfall in the Northern Corridor and 6 fluviometric 6 and rainfall in Costa Northeast Atlantic. After collecting the data in HIDROWEB, they were organized in Microsoft Excel spreadsheets software for application of Mann Kendall and Spearman tests, which stated that there is no trend in the series analyzed (α=5%). Was detected that the density of fluviometric and rainfall stations is low , according to the thresholds established by WMO. The Pearson correlation coefficients showed up "strong" between precipitation and flow of the areas studied, which also suffer influence of climatic phenomena (El Niño and La Niña). It was possible to consider that in the most preserved region, the time lag between the maximum rainfall and the maximum flow rate averaged two months, while the region with greater human action this time was an average of 1 month.Item Acesso aberto (Open Access) Aplicação da RUSLE a uma pequena bacia hidrográfica da Amazônia(Universidade Federal do Pará, 2013-09-26) SANTOS, Diego Benvindo Oliveira; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808The Amazon is experiencing severe changes due to anthropogenic activities, among which the transformation of forested land into areas for agricultural use stand out, intensifying erosion processes. Erosion, especially the drag of particles by runoff, causes a reduction of soil fertility impairing agricultural productivity and impacting the quality and quantity of surface water resources, a fact compounded by strong rainfall and naturally poor soils in the region. In this context, knowledge of erosion processes, such as through the use of mathematical models for predicting soil loss helps in determining management practices for sustainable use of natural resources. This study aimed to evaluate the applicability of the empirical model RUSLE (Revised Universal Soil Loss Equation) in the region, which considers the interaction between the rain energy, soil and topography characteristics, as well as the uses and management practiced. This research applied the RUSLE in the upper basin of the Igarapé da Prata stream, with an approximate area of 37 km², located in the municipality of Capitão Poço, Pará, Brazil, approximately 160 km from the capital Belém, in Pará Northeast region. This research also consisted in the construction of a geo-referenced database made from public sources; such data passed through adaptations for insertion into the environment of the ArcGIS to quantify the parameters of RUSLE, which when combined allowed the generation of a map of soil loss for the study area. The small upper basin of Igarapé da Prata presented soil loss values ranging between 0.004 and 72.48 t/ha year, with an average value of 5.12 and a standard deviation of 6.97, where approximately 12% of its total area presents environmental risks due to erosive processes.Item Acesso aberto (Open Access) Fundamentos para o planejamento e gestão metropolitanos por ilhas e bacias hidrográficas: uma alternativa para região metropolitana de Belém(Universidade Federal do Pará, 2007) SENA, Lucinda Freitas de Assis; LIMA, José Júlio Ferreira; http://lattes.cnpq.br/5176390429456548This dissertation does a reflection on the absence of an effective planning system and administration of the Metropolitan Area of Belém (RMB), fundamental to set out their mutual municipal districts problems. It is a work that besides doing such reflection, he suggests fundaments to contribute to the construction of a planning proposal and administration of RMB, with base in the adaptation certain instruments instituted by the National Politics of Hydric Resources, Law number. 9.433/97. This adaptation was possible starting from the understanding and identification of the hydrographic structure of the territory of RMB that, associated to the administration instruments adopted by the referred Law, it resulted in institutional and technical instruments that use of the metropolitan hydrographic basins as strategic units of planning and administration and for the use of principles of democratic participation in the solution of the problems of interest of the municipal districts of that area.Item Acesso aberto (Open Access) Modelo vazão-velocidade para avaliação de potencial hidrocinético(Universidade Federal do Pará, 2018-05-25) CRUZ, Josias da Silva; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808The Brazilian hydrological information network provides daily flow data; however, daily velocity information is not available in historical series. The inventory of river velocities is important for many applications, and one of them is the study of hydrokinetic potential, including downstream of hydroelectric plants. Therefore, the work proposes a model called Flow-Velocity that determines the average daily velocity, the geometric form and the distribution of the logarithmic velocity profile of the cross section of rivers from daily flow data. The model was initially applied in a small river basin with flow data and the validation was performed using the mean square error (RMSE), the relative mean square error (RRMSE), the standard deviation of observation (RSR) and the percentage of bias PBIAS. Subsequently, the model was applied to the river basins of the Amazonas, São Francisco and Paraná rivers (Brazil's largest basins), using the highest and lowest flows in the historical series. The highest and lowest average speed found in the Amazon River was 2.27 ms-1 and 0.735 ms-1 in the Óbidos cross-section for a flow of 266 897 m³s-1 and 72 480 m³-1, respectively. The main contributors to the Amazon River, with the exception of the Trombetas, Madeira and Xingu rivers, present average daily speeds below 2 ms-1 for the flood period, but in the dry season the average daily speeds of all are below 0.5 ms-1. The São Francisco river, in the transversal sections studied along its length, presents velocities between 3.09 ms-1 to 1.68 ms-1 for the period of flood and in the period of drought the speeds are between 0,44 ms-1 to 0,12 ms-1. In the Paraná River, velocities are between 2.17 ms-1 to 1.50 ms-1 and 0,59 ms-1 to 0,12 ms-1 for the greater and smaller flow, in due order. It was verified that the Amazon river has hydrokinetic potential that can be explored all year round. In the São Francisco basin, it is only in the period of higher flows that there is potential for the installation of hydrokinetic turbines, similar to the Paraná river basin. Of course, at points in rivers where there are hydroelectric plants, this assessment should change due to the dispatch of power plants.