Dissertações em Oceanografia (Mestrado) - PPGOC/IG
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Navegando Dissertações em Oceanografia (Mestrado) - PPGOC/IG por Orientadores "EL-ROBRINI, Maâmar"
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Item Acesso aberto (Open Access) Análise multitemporal (1991-2021) da linha de costa (trecho Calçoene - Cabo Norte), costa atlântica do estado do Amapá.(Universidade Federal do Pará, 2023-08-21) SILVA, Rhuan Rodrigo Pereira e; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217The coastline (LC) is highly dynamic due to its geographic position adjacent to the mouth of the Amazon River estuary. This region is characterized by meteorological forcings, such as a semihumid equatorial climate, high rainfall (> 2,600 mm. year-1), winds (3 to 9 m. s-1), and extreme events (El Nino - 1997/1998 and 2015/2016; La Nina - 1999/2000 and 2010/2011). It is also influenced by hydrological forcings, including water and solid discharge from the Amazon River (175,000 m³ s-1 and 1,200 Mt. year-1, respectively), and oceanographic forcings, such as hyper-tides (up to 12 m), tidal currents (2 m. s-1), waves (up to 3 m in height), and currents (up to 3 m. s-1). This study aims to analyze the multitemporal variation of the LC between the mouths of the Calçoene and Sucuriju rivers, and at the Maracá-Jipioca Ecological Station, from 1991 to 2021. The methodology includes a literature review, acquisition of LANDSAT satellite images (1991, 2000, 2008, 2014, and 2021), LC vectorization, and the application of DSAS to quantify accretion (m) and erosion areas (m) of the LC, determine retreat and advance rates (m/year and m²/year) between the mouths of the Calçoene and Sucuriju rivers, and create change polygons at the Maracá-Jipioca Ecological Station. The study area experienced predominant erosive dynamics, with an average LC retreat of 12 m. year-1 and 1.4 km² of erosion in the Calçoene-Sucuriju stretch, and 2 km² of erosion at the Maracá-Jipioca Ecological Station with an annual average retreat of approximately 18 m. Due to erosive dynamics, the study area requires special attention from public managers to prevent any type of anthropic interference that could intensify this process.Item Acesso aberto (Open Access) Dinâmica espaço-temporal e pressões antrópicas em manguezais de RESEXs na costa atlântica paraense.(Universidade Federal do Pará, 2022-04-26) PEIXOTO, Herbert Junior Campos; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217The Atlantic Coast of Pará (ACP) is shelter of the most well-preserved mangrove belt in the world, where some of these areas are included in extractive reserves (RESEX), which provide the sustainable use of its natural resources by the local population. This commitment to sustainability has been gaining strength since the creation of the 2030 Agenda, which gave rise to the Ocean Decade, which seeks the sustainable and scientific development of marine and coastal resources. Thus, the objective of this study is to analyze the spatio-temporal variability of mangroves inserted in the RESEX of the PCZ. The adopted methodology consists of: (1) acquisition and processing of images from Landsat satellites (2) quantification and comparison of the mangrove areas of four RESEX (Mãe Grande de Curuçá, Mestre Lucindo, Mocapajuba and São João da Ponta). These analyzes were carried out using polygons, created from Landsat satellite images, which delimited the mangrove areas for a period of thirty-four years (1986 to 2020). Using the mapbiomas collection plugin, available in the QGIS software, it was possible to observe urban sprawl in the studied areas and their interaction with mangrove environments. To corroborate the results obtained, environmental data of suspended particulate matter (MPS) were used. The vegetation cover had the highest reduction value of 8,054 km² and maximum increase value of 14,825 km². It was possible to observe patterns of variation in the RESEXs, which showed similar trends, both in terms of loss and gain in area. Little change occurred in the mangrove areas in the innermost portions of the RESEXs. The suspended particulate material (SPM) transported in the region has SW NE direction. It was also possible to observe the growth of urban infrastructure in all municipalities where the RESEXs are located, with Marapanim and Curuçá showing the highest growth (4,642 km² and 4,797 km², respectively). However, most changes in mangrove cover occurred along the coastline, far from urbanized areas. The analyzed mangroves remained in balance; however, disorderly urbanization can bring losses if there are no effective measures.Item Acesso aberto (Open Access) Evolução multitemporal (2010-2024) do canal de acesso do estuário do rio Amazonas (canal Norte - baía de Macapá - margem ocidental)(Universidade Federal do Pará, 2025-02-27) SILVA, Eduardo Pantoja da; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217The Amazon River, the world’s largest by water volume, has an average discharge of approximately 209,000 m³/s and exhibits a semidiurnal tidal range that varies from 0.3 m to 4 m during spring tides. Its vast watershed profoundly shapes the geomorphology of the Amazon Basin, driving sedimentary processes and directly affecting navigability. The economic importance of navigation within its estuary contrasts sharply with the challenges posed by both natural and anthropogenic alterations, which compromise the long-term stability of the channel. This dissertation analyzes the geomorphological evolution of the Amazon River’s northern channel and Macapá Bay from 2010 to 2024. It assesses the impacts of sedimentary dynamics on navigability and port management. The research methodology encompassed the analysis of bathymetric data, 38 Sentinel-1 radar scenes (captured between 2016 and 2024) processed via the Google Earth Engine platform, and historical hydrological records. Bathymetric processing was carried out in SURFER using the kriging method, while spatial analyses were performed with geostatistical tools in Python and QGIS. This included the delineation of sandbanks and the calculation of modification areas to identify erosion and deposition patterns. The study area is highly dynamic, influenced by tidal forces, river discharge, and sedimentation. These interacting processes drive the formation and migration of sandbanks and unstable channels, which directly affect bed depth and navigational safety. The findings indicate a reduction in the northern channel’s average depth from 26 m to 22 m, along with a noticeable east-northeastward migration. This shift is evidenced by erosion along the left bank and simultaneous deposition on the right bank. Three-dimensional analysis revealed that while the bed morphology was relatively homogeneous in 2011, by 2024 it had become more compartmentalized, reflecting a rate of change of 0.307 m per year. The study also highlights significant variations in the spatial extent of emerged areas within Macapá Bay. During El Niño years (2016, 2018, 2023), average accretion reached 8,326.93 km², whereas La Niña years (2017, 2020, 2021, 2022) experienced average erosion of -13,941.27 km². Linear regression analysis produced an adjusted R² value of 0.163, indicating that hydrological variability and human activity influence the region’s sedimentary dynamics. The observed geomorphological changes directly affect waterway management and the Santana port complex, underscoring the need for effective strategies to ensure ongoing navigability. Remote sensing has proven invaluable for monitoring these dynamic transformations, offering strategic insights to enhance port infrastructure planning and ensure the long-term sustainability of navigation in the region. This research reinforces the necessity of continuous monitoring and integrated hydrodynamic planning to maintain navigational safety and logistical efficiency. The combined use of geoprocessing and bathymetric techniques enables more accurate planning and the implementation of measures to mitigate sedimentation impacts, thereby preserving the viability of inland waterway transport. Ultimately, the results provide essential support for managing navigation in the Amazon River’s northern channel, promoting enhanced efficiency and safety.Item Acesso aberto (Open Access) Evolução multitemporal da linha de costa (1972-2040) do município de Soure, Ilha do Marajó (Amazônia - Brasil)(Universidade Federal do Pará, 2021-11-11) MENEZES, Rafael Alexandre Alves; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217Exogenous agents that act in the Coastal Zone (ZC) act as morphological modelers of the CoastLine (LC) and this action modifies the erosive and accretive scenario of the LC over time. To assess these temporal changes in the ZC, remote sensing (SR), from orbital remote sensors, is an opening that makes it possible to identify these variations, where the main objective around the world is the management and protection of these coastal areas. Thus, the present composition aims to present the evolution of the LC line during the period 1972-2020 (48 years) and estimate the evolution of the LC for the years 2030 and 2040 in the ZC of the Soure municipality, located in the northeastern part (NE) of the Marajó island (Pará-Eastern Amazon), inserted in the Pará Estuarine Coastal Zone (ZCEP), conditioned by the hydrodynamics of the South channel of the Amazon River and by the estuary of the Pará River. A set of 6 images from a time series of the satellite were acquired: Landsat 1 (MSS) from 1972 and 1994 (bands 7.6.5 and 5.4.3, respectively), Landsat 5 (TM) from 1985, 2004, 2009 ( bands 5.4.3), with a spatial resolution of 30m, and Landsat 8 (OLI) 2020 (bands 6.5.4.8), with a spatial resolution of 15 m after the fusion of band 8 (panchromatic), being obtained from the USGS (United States Geological Survey) site, all already georeferenced and geoprocessing techniques for: a) LC delimitation: where it was created from semi-automatic methods combined with manual methods, using the normalized water difference index (NDWI) technique; b) DSAS version 5.0 (v5.0), being used to compose the LC analysis hrough this tool: NSM, EPR and LRR, version v5 brings the Kalman Filter, which was used to calculate the future estimate in the LC for the years 2030 and 2040. As a result, it was identified that in sectors I and II (southern channel of the Amazon River), accretion predominates, in sector III (Maguari Cape) it is where it obtained the highest accretion rates, and in sector IV the accretion process predominates with a tendency erosive, sector V erosion predominates. These data are linked to the total number of 654 transects comprising an average distance of 214.4 m, where the mean retreat is indicated with a negative rate of - 179.5 m and a positive rate of 451.9 m. For the years 2030 and 2040, the trend is that this process will continue, where the greatest coastal retraction, around 271.46 m, will be in the Northeast (NE) (sector II), and a CL advance of 625.26 m in sector III.Item Acesso aberto (Open Access) Morfodinâmica da praia do Caripi (Barcarena/Pará - Amazônia Oriental) através do experimento da aerofotogrametria com drone.(Universidade Federal do Pará, 2023-08-22) VITELLI, Aline de Castro; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217Item Acesso aberto (Open Access) Sedimentação recente e palinologia do Talude Continental Superior Amazônico-Maranhão(Universidade Federal do Pará, 2025-04-24) AZEVEDO, Gabriela Miranda de; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217The continental slope off the Amazonas, coast of Pará is a geologically complex region, influenced by tectonic phenomena and sedimentary processes associated with the proximity of the Amazon River mouth. The Amazon River discharges approximately 5.7 × 10¹² m³ of water per year and 1.2 × 10³ m³·s⁻¹ of solid load. The continental slope displays a diverse sedimentary cover distribution, which varies regionally depending on the origin of the sediment sources. Few studies (in sedimentology, palynology, and paleontology) have been conducted on the continental slope of the northern region. The main objective of this study is to analyze the sedimentological characteristics (grain size distribution, calcium carbonate content/CaCO₃, organic matter/OM, and organic carbonate/OC) and investigate the occurrence of fertile sediments in the sediment cover of the upper continental slope off Pará, based on two core samples (T66 and T144). The methodology involved: (1) Bibliographic research on scientific databases; (2) Acquisition of sub-surface core samples using a piston corer; (3) Macroscopic description of cores (color, stratigraphic arrangement, and sediment analysis) and core subsampling; (4) Grain size analysis of the sampled layers, including separation of the silt/clay fraction; (5) Quantification of OM and CaCO₃ contents; (6) Selection of fertile samples for palynological analysis. The results indicate that the sediments are predominantly muddy, with a dominance of coarse silt fraction. They are mostly well-sorted, with approximately symmetrical skewness and platykurtic kurtosis. OM content in the cores ranged from 10.64% to 24.42%, with an average of 16.39% (T66) and 10.64% to 24.42% with an average of 16.39% (T144). Preliminary palynological investigation confirms the presence of pollen grains in the samples. The sediments from the continental slope off Pará consist of a mixture of allochthonous and autochthonous material, with the occurrence of palynomorphs.