Programa de Pós-Graduação em Geofísica - CPGF/IG
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2355
O Programa de Pós-Graduação em Geofísica da UFPA (CPGF) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA). Foi o segundo no Brasil a formar recursos humanos em Geofísica em nível de pós-graduação stricto sensu. Criado em 1972, funcionou até 1992 junto com os Cursos de Pós-Graduação em Geoquímica e Geologia.
Navegar
Navegando Programa de Pós-Graduação em Geofísica - CPGF/IG por Linha de Pesquisa "HIDRODINÂMICA DE ESTUÁRIOS"
Agora exibindo 1 - 5 de 5
- Resultados por página
- Opções de Ordenação
Item Acesso aberto (Open Access) Caracterização física do estuário do rio Mojuim em São Caetano de Odivelas - PA(Universidade Federal do Pará, 2015-02-25) ROCHA, Adriano Santos da; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The present study has as objective describe the hydrodynamics, hydrologic and morphological aspects, of estuary of Mojuim River, it is localized in São Caetano de Odivelas city –PA (Salgado Paraense),it is analyzing the variations that happen according sea cycle seasonality (rain regime).The hydrologic and hydrodynamics data was collected in two seasonal period in 2014:March,it corresponds to rainy period (~500 mm)and September, it corresponds to dry period (~100 mm),both during tide of syzygy. The bathymetric survey happened only in the rainy period and it was realized with an echo sounder in a sampling grid with 116 spaced cross profile of 200m.In the estuarine channel,it was defined a section where it was realized profiles of strength measurement and current intensity and output, with ADCP, and in three fixed stations,right bank (RB), center(C),and left bank (LB)it was realized collections of conductivity and turbidity with a CDT and an OBS, in the water column. The pattern of tidal and the salinity they were also obtained with a pressure sensor and conductivity fixed in the LB during 56 days in the rainy period and 57 days in dry ones. The estuarine is shallow (4,5 m of average depth) and it is restrained by a regime of semidiurnal macrotidals. During a tidal cycle the salinity increases in the floods and decreases in the ebb tide in both seasonal periods. Turbidity increases in the floods and it decreases in the ebb tide of the rain period and the value measured in the center (C) is double found in the banks. In the dry period, the salinity was higher to rainy period (average 20 and 8, respectively) .This estuarine presents well mixed; it is vertically homogeneous in the rainy period and highly stratified in the dry. The flood flows occur predominantly at the center section, while the ebb flows predominate in the RB, in the two situations the highest intensity of the current occurs in the rainy season. The estuary is an importer in the two periods, however, more entering in the rainy period (resulting transport of 95,87 m³/s) .These data correspond to the first information on the hydrological and hydrodynamics characteristics of the estuary and they can support further studies in the region.Item Acesso aberto (Open Access) Caracterização hidrodinâmica do Furo da Laura (Rio Guajará-mirim), Amazônia Oriental(Universidade Federal do Pará, 2014-12-01) FERNANDES, Aldo Rafael Pascoal; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471Preserve our coastal and estuarine environments are of great importance to local and regional development, as these environments are located most cities and serve as a cradle for several specimens, despite these environments gather information and know their characteristic and seasonal patterns are important aspects. In this context, Laura hole (Rio Guajará-Mirim), transitional estuarine environment and important role in the economic and social framework for coastal communities, cities and surroundings, serves as one of the main routes of fishing inputs to the state. The Hole Laura is a water body adjacent to Marajó Bay, has two connections to the same and is under their direct influence, is located at coordinates UTM 22M, 796169-830035 W and S 9880864-9916228 through it were held three oceanographic, dry season (October 2013), the rainy season (February 2014) and dry (August 2014), this important stream with use of equipment for measurement of geophysical parameters in the region bathymetry, hydrodynamic, tide variation and salinity. There was in possession of these parameters the hydrodynamic behavior, classification and tidal range, phase difference between ebb and flood, salinity trend in the stream in response to the Marajó Bay, besides the identification of morphological features characteristics and seasonal analysis these changes in the collection of sections 1 and 2 pre-established, as well as mapping and preparation of a bathymetric map of the study area.Item Acesso aberto (Open Access) Modelagem hidrodinâmica 2DH no furo de Laura - Nordeste Paraense(Universidade Federal do Pará, 2016-05-23) LOPES, Matheus Santiago; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The estuarine environments are widely studied over the past decades due to its social, environmental and economic importance. For example, the strategies to contain oil spill are based on hydrodynamic modeling research. The application of numerical models to predict and analyze circulation patterns inside coastal water bodies is growing in the country. In northern Brazil the use of those models is still experimental. In this work was used the software SisBaHia to implement, calibrate and validate a hydrodynamic model to the water body “furo da Laura” (FL), located on Guajara-Mirin river, on the coastal region of northeastern Pará. The model was calibrated with previous data about surface elevation and current speed collected in three periods: dry season of 2013, rainy season of 2014 and dry season of 2014. The flood and ebb tide flow occurs simultaneously in two entrances that the FL presents. The goal was to locate the barotropic convergence and its seasonal variation. It was simulated one month during the rainy season (February) and one month during the dry season (August). It was simulated a lagrangian transport with particles released in Sol bay with an analysis of its horizontal dispersion. The convergence sites were found nearby the south entrance of the FL and the divergence sites have a spatial variation due the tide cycle. The particles released in the Sol bay tend to leave the modeling domain and don’t penetrate the FL, but they contribute with the erosion and sedimentation process that occurs in coast of the Colares Island.Item Acesso aberto (Open Access) Modelagem matemática do sistema estuarino dos rios Mojuim e Mocajuba (Pará-BR)(Universidade Federal do Pará, 2016-02-29) SANTOS, Arthur Souza dos; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The estuaries of Mojuim and Mocajuba rivers are located in the eastern sector of the Amazon Coastal Zone and represent a peculiar and complex environment. They are connected by several channels and are receive influence of the Bay of Marajó and the Atlantic Ocean. The following research aims to implement a hydrodynamic model based on a flexible grid on the of Mojuim and Mocajuba rivers estuarine system; and to analyze the hydrological and hydrodynamic characteristics of the upper estuary of these rivers. The methodology involves the use of D-Flow Flexible Mesh pack a get simulate hydrodynamics patterns into the domain that covers the Mojuim Mocajuba rivers, the canals connecting these rivers, part of the mouth of the Bay of Marajó and the adjacent tidal flats. It was also performed an "in situ" systematic data collection, in which parameters of flow, salinity, turbidity and water level were analyzed during a tidal cycle in sites located at the upper estuary of Mojuim and Mocajuba rivers. In the Mojuim river two seasonal campaigns were made in two different sites and in the Mocajuba river only one campaign were made in the rainy season, however, a tide station was installed in this location that operated for 25 weeks. Part of the sample data were used as input to the hydrodynamic model. The upper estuary of Mocajuba river presented a macrotidal regime with maximum height of 5.8m recorded. In the Mojuim river, a gradual attenuation of the tidal wave is noticeable and, in the collection point and in the upper estuary a one-way flow discharge during the rainy season was observed. A different hydrodynamic pattern between the two rivers was also observed, with ebb speed more intense than floods and their hydrological properties directly influenced by the tide fluctuation. Finally a hydrodynamic model in flexible grid was implemented and calibrated in the researched area, where initial and boundary conditions were assigned, as well as adjustments to the border forcing. The model generated a good representation of the estuary conditions, showing acceptable tidal and hydrodynamic pattern when compared with the "in situ" measurement, once the error between the measured data and modeled data related to the water level were less than 5%, and errors related to transportation are lower than 15%.Item Acesso aberto (Open Access) Utilização da sísmica de reflexão rasa no estudo da morfodinâmica de rios na região amazônica(Universidade Federal do Pará, 2014-09-29) FURTADO, Camila da Cunha; VIZEU, Roberto; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471The main idea of this research is identify and characterize morphodynamic phenomena present on the lay of the Pará river and foz of the Tocantins river, this area comprises from the Bocas bay unto east portion of the Marajó island. It is a region where exists scarcity of information and data about constitution and morphology of the lay, there is necessity to search new knowledge. Sediment samples from the bottom of the river were collected with the assistance of a Van Veen sampler, 181 (one hundred eighty-one) samples submitted to macroscopic analysis aiming to identify the type of material which composes the bottom. With the data of hydrodynamic modeled assistance was possible to connect the patterns of bottom forms with the sort of sediment which composes the lay and the prevailing hydrodynamic in the local. Based on the seismic data, was possible to identify and map the sonographic patterns in 15 types of echoes, classified in four categories. The less frequent echo types are the ones which present very irregular lays and little or no acoustic signal penetration. Specially the C1 type characterized by diffraction hyperbolas presence and the D1 type which treat responses arising from large deposits of sediments, found just in two forms of acoustic. The most significant bottom forms were identified on the stretch where the Canaticu river flows to Pará river where the principal canal width decreases from 8km to 4km in upper depth to 20m. The adhibition geophysical methods (acoustics), by the use of the Sub-Bottom profiler SB-0512, enable the knowing of the bottom forms, as well as its dimensions that those submerged forms show over the studied region. The way how this region’s lay sets itself and the dimensions that those corps reach can affect the sailing on some river’s stretch, as well as it can affect future civilian building. Therefore, this work opens ways to future more appropriate investigations on the issues mentioned above.