Programa de Pós-Graduação em Geologia e Geoquímica - PPGG/IG

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2603

O Programa de Pós-Graduação em Geologia e Geoquímica (PPGG) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA) surgiu em 1976 como uma necessidade de desmembramento do então já em pleno desenvolvimento Curso de Pós-Graduação em Ciências Geofísicas e Geológicas (CPGG), instalado ainda em 1973 nesta mesma Universidade. Foi o primeiro programa stricto sensu de Pós-Graduação (mestrado e doutorado) em Geociências em toda Amazônia Legal. Ao longo de sua existência, o PPGG tem pautado sua atuação na formação na qualificação de profissionais nos níveis de Mestrado e Doutorado, a base para formação de pesquisadores e profissionais de alto nível. Neste seu curto período de existência promoveu a formação de 499 mestres e 124 doutores, no total de 623 dissertações e teses.

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Acesso aberto (Open Access)
Análise da dinâmica morfo-sedimentar da praia da Marieta – Ilha do Marco-Maracanã (NE do Pará)
(Universidade Federal do Pará, 2010-04-19) GUERREIRO, Juliana de Sá; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
This study aims the investigation of the morphological and sedimentological variations occurred in Marieta’s Beach- Marco Island (NE of Pará) during the rainy season (March) and rainyless season (November) of 2007, seeking to identify the main factors responsible by these variations. The Marieta’s beach has 3 km long, with NW-SE direction, and is supported by the sediments of the Barreiras Group, Post-Barreiras and the recent sediments that provide much of the sediment at the mouth of the estuary Urindeua. Topographic profiles were conducted in June in the following subdivisions Beach Marieta: Sector sandy spit - profiles I and II (tgβ = 0.0015); central section - profiles III, IV (tgβ = 0.0017) and NW sector - and V profiles VI (tgβ = 0.005). We applied the following morphological beach models: Inmam & Guza (1975), Sandy Spur -        in the rainy season         in the rainyless period, Sector Central -      12 in the rainy season        during rainyless. These results show a strong reflection with some dissipation, characterized as Intermediate Bar and Longitudinal with the NW sector, which indicated a Dissipative behavior during the two periods studied, According to Wright & Short (1984) had a whole beach Dissipative behavior during the two periods studied -       in the rainy season         in the less rainy period; And following Masselink & Short (1993) showed the profiles to be modified by tides, with dissipative bars RTR = 4 in the rainy season and RTR= 3.6 in the rainyless period. The beaches are predominantly covered by very fine sand, very well selected and moderately selected, with mesocurtic and platicurtic kurtosis and negative asymmetry at the supratidal zones during the rainy season and in areas of infratidal in the rainyless season in other areas of the beach Marieta were approximately symmetrical and positive asymmetries. The Marieta’s beach has been profiled morpho-sedimentary influenced by the displacement of the Convergence Zone Inter-Tropical (ITCZ) in the rainy season (1736.6 mm) and at rainless (2.4 mm). The speed of the wind was weaker during the rainy season with an average of 6.7 nodes while in the less rainy period the average speed was 11.3 knots with preferential direction NE, and therefore, buckled with higher energy (Hb = 1 , 5 m in the rainy season in March). Coupled with an amplitude of 5.5 m tide reaching the innermost areas of the beach. In the less rainy period, the waves were smaller, compared to the rainy season, which reached 1.2 m combined with an amplitude of 4.8 m tide. Through these parameters showed that the major changes in the beach profile were associated mainly to the interaction of the effects of winds, waves and tides, showing the strong relationship between the shape and orientation of the beach and the incidence of these agents.
Acesso aberto (Open Access)
Análise morfoestratigráfica do estuário do Rio Marapanim - NE do Pará
(Universidade Federal do Pará, 1998-12-20) SILVA, Cléa Araújo da; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The estuary of Marapanim River is developed on tertiary-quaternary sediments of Barreiras and Pós-Barreiras Formation. It is inserted on "Littoral of Rias" of Pará northeast, which from High Pleistocene was submitted to marine transgression that drowned coastal paleolines and, in the maximum of Holocene Transgression, reached the coastal plateau. This portion of coast is strongly influenced by dynamic macrotides (5,3m) and salt wedge with mear salinity of 8%0 (high tide — Marudazinho) and 3%0 (low tide — Marapanim). So that, on outer funnel (Marudá) the salinity is 35°/00, representing no influente of mouth river discharge. Geomorphology of the area is subdivided in three morphologic domains: (1) Coastal Plain, constituted by strand plain, paleodune, coastal dune, salt marsh, tidal flat (sand flat and mangrove swamp), recurved spit, lake and palco tidal creek; (2) Estuarine Plain, constituted by estuarine channel (subdivided in estuarine funnel segment, sinuous meandering segment, cuspidate meandering segment and upstream channel), tidal creek and floodplain (salt marsh and fresh water marsh) and; (3) Alluvial Plain constituted by meandering channel (chute cutoff), channel deposits (channel lag deposits), overbank deposits (natural levee, crevasse-splay deposits and floodplain) and channel-fill deposits. Fourteen morphostratigraphic units was identified: floodplain, levee, chute cutoff, fresh water marsh, mudflat, channel bar, point bar, strand plain, paleodune, coastal dune, recurved spit, sand flat and salt marsh. Six stratigraphic facies are also present: point bar sand and mud, marine sands, estuarine sand and mud, estuarine muds, fluvial sands and motled sand. Stratigraphical analysis permitted recognize stratigraphic sequences: Basal Marine Transgressive (Si) with fluvial, salt marsh and shoreface environments; Marine Regressive (S2) with fluvial, fresh water marsh, tidal flat, salt marsh and strand plain environments and; Recent Marine Transgressive (S3) with estuarine (channel bar and point bar) and littoral environments (recurved spit, strand plain and coastal dune). Geological evolution of the estuary of Marapanim River is associated with sea levei oscillations that occurred during progradation and regressive cycles on Later Holocene, which in the maximum of the Holocenic Transgression eroded the highland (coastal plateau). In stillstand sea levei conditions occurred marine regressive and mud flat progradation over marine sand deposits. In present time, sand sheets are deposited over mud ilat providing partia! filling in the mouth of estuary by sand bars.
Acesso aberto (Open Access)
Aplicação da modelagem hidrodinâmica na circulação do estuário do rio Maracanã (NE do Pará)
(Universidade Federal do Pará, 2017-10-16) BARBOSA, Leandro Patrick Ferreira; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The coastline of NE Pará presents a configuration cut and a large number of estuarine systems, very active with amplitudes of tide between 5-7m.In this region, is inserted the estuary of the river Maracanã - estuary of coastal plain and the type and mixed - with a length of 101 Km from igarapé the tube to the island of Cumaru. The profile of this is typically meandrante, low slope that allows runoff, and allows a pattern of drainage with large amount of water in several directions and an order of flow of 103 to 104 m3 s-1.This estuary likely a result of the system of macro-tides (> 4m), the semi-diurnal nature, with winds of influence (average of 6 m / s) and the tidal currents (mean of 69.53 cm / s). The climate is the type Am (Tropical Wet), which is characterized by being warm and humid (Climate Equatorial Amazon), with temperature between 25 ° C and 28 ° C and rainfall of 2,500 mm / year to 3,000 mm / year, and two distinct periods, a dry (June to November) and another rainy season (December to May). The work was aimed at the implementation of the hydrodynamic modeling the movement of the estuary of the river Maracanã (NE Pará), using as a modeling tool (Program Design SisBAHIA - Base Hidrodinâmica Environmental System), based on interpretation of the data collected in the field and experimental studies conducted in the laboratory. The methodological procedures consisted of three basic steps: bibliographical survey, work of field and laboratory. In the field, were performed: (1) a survey of semi-ecobatimétrico detail, employing is a Ecossonda DGPS / PLOTTER / SONAR FURUNO GP-1850 F, which were made transects ecobatimétricos cross-sectional and longitudinal in the estuary during the flood tide, ( 2) measurement of currents, tidal, to obtain measures of intensity and direction of currents in a point (00 ° 45187 'S and 47 ° 26712' W), over a period of continuous sampling of 8 days (preamar e) (baixamar 04/02/07 to 11/02/07), covering sizígia. To this end, it was used a Correntógrafo Falmouth Scientific 2D-ACM, (3) the monitoring of the vertical tide was based Marégrafos Orphimedes Brand OTTHidrometrie, which recorded the water level at the same time, near the mouth and the inner part of the estuary, for a period of 8 days continuous every 20 minutes. In the laboratory: (1) the data processing environment ecobatimétricos in Excel for correction in relation to the level of tide. Still, the Surfer was used for scanning the data input for the hydrodynamic model of the Program Sisbahia, (2) time series of the level of current and tide were subjected to routine data processing environment developed in Excel (3) For flow was conducted an estimate based on simple and rational.The data were then processed for analysis: (1) In implementation of the model, were gathered all the data collected in the study area and these data were supplied to the model within a predefined area, (2) For calibration of the model Adjustments were made in an attempt to merger of the data collected in the field and model, (3) the validation of the model, which was the accuracy of the results of the computational model in relation to its purposes, and the natural system that it represents, in order to reproduce the actual phenomena. Then put up the model pra "run", that is, the model will generate scenarios of ebb tide, flooding, and squaring sizígia. With this, could itself describe the patterns of movement of estuarine river Maracanã and understand the aspects of their complex hydrodynamics. Thus, it is obtained, maps featuring patterns of current averages upright over a cycle of the tide sizígia and quadrature (half ebb tide, half flood tide, estofa of preamar and estofa of baixamar). It was observed that during the tides of sizígia, the speeds are higher if compared with the tides, squaring. The geometry of the estuary is responsible for restricting the penetration of coastal waters and help to raise the tide inside of it. The results generated by the model were not equal to those measured in the field, because of the complexity of the area and the amount of data acquired.
Acesso aberto (Open Access)
Aplicação do modelo hidrodinâmico no estuário do rio Caeté (NE do Pará)
(Universidade Federal do Pará, 2007-10-17) ABREU, Marcelo Wanderley Matos de; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The northern coast of Brazil is trimmed by a big and complex hydrographic net, where the main river is the Amazon. This river, as well as others smaller, flow into in the Atlantic Ocean finalist the estuaries, that are frequently defined like a stretch of the river, where occurs the interaction of the ocean and fluvial waters (transition zone). The Caeté estuary is inserted at the northeast of Pará (00º43’18" – 00º04’17" S and 46º32’16" – 46º55’11" W) that suffers influence of macro-tides and semi-diurnal with medium amplitude of 5,6 m, coastal currents (mean velocity approximately 0,75 m/s), waves of 0,7 m and Trade winds that possess NE preferential direction with medium speed of 6 m/s. That estuary is situated in a tropical region of humid climate, with annual medium temperature of 27ºC and elevated precipitation with annual medium of 2500 mm/year. In this area, are also showed, the existence of seasons with distinct characteristics: rainy (December to May), dry (June to November) and intermediate. The estuary of the Caeté river is a tide-dominated estuary (as regards the physical process), that forms an extensive coastal plain (as regards the coastal geomorphology) and well mixed (as regards waters circulation).The hydrodynamic circulation in estuary is considered as an important trial and it has a lack of studies in this area until today, principally in the North’s region of Brazil, where still have a few the studies of estuarine modeling. So, for this work were adopted the use of the hydrodynamic model with the Modeling program called SisBAHIA (Environmental Hydrodynamics Base System), aiming the observation of the general aspects of the hydrodynamic circulation in different phases of tide (high tide, low tide, flood and ebb tide) in the Caeté estuary (PA) and like this validate, through the modeling, the facts (current, tides and amplitude of tide) collected in the estuary. The methodology was performed in two phases,( fieldwork and laboratory). The phase of fieldwork consisted of: (1) hoist bathymetric, linked to the Research’s Project of the SET PROGRAM/ CT-Hidro that utilized a cartographic base previously digitalized, having like base a satellite image LANDSAT-ETM+7, beyond a digital ecobatymetric and a DGPS (Differential Global Positioning System); (2) records of elevation of the sea level, through the fixation of two digital tide predictors Orphimedes OTT-Hydrometric, located in the Maguary city, where was observed daily values to each 20 minutes during 7 consecutive days with results varying of a minimum of 0,01 m to a maximum one of 5,08 m and of 0,42 to 5,18 in the point situated in the bridge about the hole of the Maguary and in the Bacuriteua city, respectively; and (3) measure the speed of the shackles utilizing a current predictor Falmouth 2D YMCA in a point inside the model, that stayed coupled to the boat during seven consecutive days and that presented values for the currents varying of a minimum of 2,95 cm/s to a maximum one of 154,59 cm/s. In the laboratory’s phase, was carried out the trial of calibration between the facts of the model with the measurements taken in the fieldwork. They were generated simulations of the hydrodynamics conditions during the flood, ebb tide, half tide flood, half tide ebb tide, and the high value of high tide and low tide, and in the neap and spring tides. Through those simulations were generated superficial maps of currents to see the different standards of circulation.
Acesso aberto (Open Access)
Aspecto geoquímicos do material particulado da pluma estuarina do rio Amazonas: fatores que controlam as interações com as águas oceânicas
(Universidade Federal do Pará, 2000-02-10) PEREIRA, Simone Baía; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The geochemical aspects addressed in this investigation are the determination of the chemical composition of the material in suspension in coastal waters under the influence of the mouth of the Amazon River, indicating the possible location of the source of suspended material, as well as the influences that it suffers along the continent transition -ocean. X-ray diffraction analysis indicated the predominance of kaolinite, illite and quartz clay minerals over the other identified inorganic components, observing the presence of chlorite, sometimes as a subordinate mineral in some samples, sometimes as a trace, and smectite in trace grades, which, like chlorite, is also present as a subordinate mineral. The centesimal mineralogical composition of the particulate material was estimated, associating the analytical results with X-ray diffraction data, using stoichiometric calculation, based on the scientific literature. The results obtained through the stoichiometric calculation confirm the tendency shown by the diffractograms. It is observed that the dominant clay minerals are kaolinite (maximum in 51.19%), associated with high levels of aluminum, distinguishing the dominance of this clay mineral in the sample in which this fact occurs, and illite (maximum in 42.43%) associated At high levels of potassium, when this clay mineral dominates the samples, the presence of iron and titanium colloids was also admitted. The content and nature of the organic matter associated with suspended sediments were evaluated, using elemental analysis for carbon, nitrogen and hydrogen, thermogram records and absorption spectra in the infrared region. In the sediments, organic compounds predominate (clay minerals, silica, iron colloids), with organic matter always having a content below 3.6%. Therefore, in interpreting the records of absorption spectra in the infrared region, the most intense bands are related to the dominant clay minerals in the material, that is, the illite and kaolinite mixture. Bands related to chemical bonds in clay minerals dominate in the infrared spectra. The clear and intense vibration band of the Si-O stretching, which extends from 1200 to 1000 cm-1, with its most significant developments around 1180 and 1034 cm-1, is well representative of structures of the illite and kaolinite types. And there is still a clear band, with weak folds around 950 to 915 cm-1, related to the Al-OH bond; bands around 790-800, 750-780, 640-690 cm-1; or in the range of 400 - 600 cm-1, the intense absorption bands recorded in the range of 4000 - 3400 cm-1, with their various developments, related to the bonds with hydroxyl, –OH, so common in clay minerals and an intense and average band recorded around 1640 cm-1 corresponding to the angular deformation of the HOH bond, a characteristic of constitutive water present in clay minerals. The infrared absorption spectra of humic and fulvic acids from different sources are similar but not identical. The (subtle) differences are the result of brief changes in their compositions. Perhaps the most interesting feature of the spectrum of humic acids is the appearance of intense and broad absorption bands related to the stretching vibrations of the C=O bond of several organic functional groups (carboxylic acids and their derivatives, aldehydes, ketones), in the range from 1709 to 1715 cm-1 and vibrations of aromatic compounds around 1600 to 1613 cm-1. The bands recorded around 1698 to 1701 cm-1 and around 1400 cm-1 indicate the presence of carboxyl and carbonyl groups. The most interesting aspects of the recorded spectra concern the appearance of clear (but weak) absorption bands in the range of 2959-2885 cm-1, attributed to methylene groups –CH2- of hydrocarbons; and the presence of a weak (but clear) band around 1385 cm-1 referring to the carboxyl and/or carbonyl groups. Leading to the conclusion that it is humic material present in organic matter from leaching and drainage of typical Amazonian soils, such as podzolic and latosolic. Elementary organic carbon contents range from 1.27% to 2.05%, while nitrogen contents range from 0.03% to 0.13%. These contents produce high C/N ratios (minimum 12.7% and maximum 68.3%) of material rich in cellulose decomposition products of vegetable origin. The integration of data from the chemical analysis of suspended matter with physical-chemical parameters of coastal waters and the variation in phosphorus levels (minimum of 0.06% to maximum of 0.71%, expressed in P2O5), associated with salinity variation (minimum of 24.31‰ and maximum of 39.19‰), used as limiting parameters, defined the existence of three characteristic zones of origin of suspended material: one predominantly terrigenous, one transitional and one predominantly oceanic biogenic.
Acesso aberto (Open Access)
Avaliação e aplicação de dados de sensores remotos no estudo de ambientes costeiros tropicais úmidos, Bragança, norte do Brasil
(Universidade Federal do Pará, 2000-11-17) SOUZA FILHO, Pedro Walfir Martins e; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The study site is situated in the Cretaceous Bragança-Viseu coastal basin. The holocenic evolution of this area is marked by muddy progradation over a submerging coast, where is developed one of the most mangrove system of the world, with almost 6,000 km2. This research has showed that orbital remote sensing data can provide excellent geologic and coastal land use information. The SAR RADARSAT-1 imageries represent a powerful tool to understand the coastal processes in the wet tropical environments, mainly in the mangrove coasts. This fact is related to microwave radiation can be interpreted for Amazon coastal zone mapping and monitoring, because SAR image constitutes in the unique source of data with all-weather remote sensing capability, in response to difficulty to get optical images in the Amazon, due to all-time cloud cover. Landsat TM imageries are excellent data sources to integration with RADARSAT-1. They present a good performance in coastal environments discrimination. The remote sensing data integration allow a synoptic view of the area and provide geobotanic (relation between coastal environment and vegetation) and multitemporal information. In addition to integrated data, geographic information system (GIS) combines different data sets and simultaneously interprets the spatial and temporal relationship between various coastal environments. This way, GIS allows for a more comprehensive, accurate and easier interpretation of a geomorphologic mapping under an organizational philosophy to control data towards use the information to coastal zone management. The application of remote sensing data in the tropical coastal studies was used in different approaches. In relation to spatial and temporal variability of the shoreline, this study has revealed that during the Holocene, the coastal plain is marked by a muddy progradation. However, from the analysis of the remote sensing images were possible investigate the shoreline variability under long (1972-1998) and short (1985-1988, 1988-1990, 1990-1991) term, which is characterized by shoreline retreat, probably due to climatic changes, such as El-Niño and La-Niña events. These climatic events control the rainfall along the coastal zone, where severe erosional period (1985- 1988) are coupled with high precipitation rate (> 4,000 mm/yr.). From the point of view of the spatial analysis of the coastal changes, the mangroves constitutes one of the most environments to be analyzed by remote sensing images, as in the electro-optical spectrum due to their high reflectance in the infrared, as in the microwave due to their rough surface responsible for high backscattering. Therefore, mangroves have showed to be an excellent geologic indicator to detect and to quantify short and long-term morphological coastal changes. To conclude, remote sensing data integration, GIS and auxiliary fieldwork data present a fundamental role to the integrated coastal zone management, environmental risk assessment, local characterization of the study sites, base maps upgrading and information dissemination for public consultation, which are all significant factors in this decision-making process.
Acesso aberto (Open Access)
Avaliação multitemporal da dinâmica costeira da Praia do Pescador: Bragança (Norte do Brasil)
(Universidade Federal do Pará, 2001-11-26) SILVA, Marcos Gleidson Lima da; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
Acesso aberto (Open Access)
Caracterização geomorfológica estratigráfica e geoquímica da Planície Costeira do município de Itarema-CE.
(Universidade Federal do Pará, 2011-09-01) PEREIRA, Lamarka Lopes; FREIRE, Geoerge Satander Sá; http://lattes.cnpq.br/6803944360256138; 6803944360256138; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; 5707365981163429
The Itarema coastal plain, situated at the western coast of Ceará, in the area dominated by the Cenozoic sedimentary cover. This thesis shows the geomorphological, sedimentological and geochemical features of this coastal plain. The Itarema coastal plain is subdivided in two major morpho-structural units: pre-coastal ¨plateaus¨ and coastal plain, that is subdivided into lithostratigraphic units, lagoon plain, tidal plain with and without mangroves, marine and fluvial plain, mobile and fixed dunes, beach ridges, tidal channels, sand bars and beaches. The supply and sediment transport in the area are closely linked to the climatic, meteorological and oceanographic conditions. The sedimentary, stratigraphy, geomorphological and geochemical data have been defined: (1) five lithological units: Lagoon Deposits, dune deposits, eolianits deposits, beach deposits and alluvial deposits and (2) seven lithofacies: mud sandy, mud, Sand mud, fine sand, medium sand, thick sand, conglomeratic sand-clay with different characteristics which have been drawn through the lateral and vertical correlations, thus allowing the interpretation of depositional paleoenvironments related to the evolution of the Itarema Coastal Plain. The analysis of the lithological units allowed the reconstruction of the processes indicative of a transgressive sucession prograded during which the lagoon-barrier system was installed on the system of alluvial fans, the bus of small streams, forming the lagoon plain, it was also noted that the lagoon has undergone changes in their size both by progradation of the barrier and subsequently by the deposition of sediments within the same wind. The Itarema coastal plain presents physiographic features of an coastal promontory or embaiments of central nuclei as a spiral, that would have provided the evolution to the current environment and the current model of coastline with beaches of the barrier beach-type and suggests that is occurring repetition in the construction of comparative morphology morphogenetic active in the region's past.
Acesso aberto (Open Access)
Caracterização morfossedimentar durante o ano de 2007 das praias estuarinas da ilha de Cotijuba (Baía do Marajó) no estado do Pará.
(Universidade Federal do Pará, 2008-08-22) OLIVEIRA, Gheisa Karla Martins de; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The Cotijuba Island located at 90 km from the mouth of the Pará river is embedded in a tidal zone of the river, where the salinity is zero, and conductivity average is 65.70 μ S. The island belonging to the municipality of Belém is located 33 km of this, with 15 km2 of size and elongated shape in NE-SW direction. The island is supported by: (1) Barreiras sediments, outcroping in the form of exposed cliffs and platforms of abrasion, on the west side, (2) Pós Barreiras sediments, which are above and separated by a erosional surface (SÁ, 1969 apud SANTOS, 1996) and (3) Recent sediments (mangroves, marine terraces, bars and beaches). The study of sedimentmorph characterization of the morpho-sedimentary estuarine beaches of Saudade and Vai-quem-quer during the year 2007 (January, March and August), showed clear seasonal changes of these beaches. They were executed topographical profiles: nine on the beach of Saudade and twelve on the beach of Vai-quem-quer using a Total Station, in addition to the sediments collection. The beach of Saudade is 800 m length and is located on the southern island, with high topographic gradient ranging from tg d = 0,030 to tg d = 0,286. In the northern part of the island is the beach Vai-quem-quer with 1 km in length, which has a gradient topographic trivial compared to the beach of Saudade, ranging from tg d = 0069 to tg d = 0143. Have been applied on these beaches the morphological models of Guza & Inmam (1975), Wright & Short (1984) and Masselink & Short (1993) prepared for ocean beaches. Through the parameters used the beach showed state reflective of Saudade (b = 0.10 to 2.38) and longshore bar and runnel (b = 2.70 to 12.90), during the rainy season and only reflective (b = 0.05 to 1.84), during the dry season of Guza & Inmam (op. cit.). By the measure of Wright & Short (op. cit.) behaved the beach itself as refletiva (g = 1.08 and 0.86 in January and March, respectively, and in August g = 0.43) in the two periods. The beach of Vai-quem-quer presented by the measure of Guza & Inmam (op. cit.) states dissipativo (b = 20.05 to 31.28) and longshore bar and runnel (b = 9.21 to 18.23), in the rainy season. In the dry season, showed the states reflective (b = 1.61 to 2.46) and longshore bar and runnel (b = 2.63 to 3.44). For the parameter of Wright & Short (op. cit.) was classified as dissipative (g = 4.12) in January; longshore bar and runnel (g = 2.64) in March, and terrace of low tide (g = 2.38) in August. The parameter of RTR Masselink & Short (1993) stated that in January the beach of Saudade was influenced by waves and tides (RTR = 5.2) and in March by tides (RTR = 14.5). Already the beach of Vai-quem-quer either in January was influenced by waves (RTR = 2.15) and in March by waves and tides (RTR = 4.80). In the dry period, the two beaches were influenced by waves and tides (RTR = 10.5 and 3.16 for the beach of Saudade and Vai-quem-quer, respectively). The beaches are mostly covered by sand average (65%), moderately selected (59%), with kurtosis mesocúrtica (53%) and asymmetry negative (54%) on the beach of Saudade and approximately symmetrical (43%) on the beach of Vai-quem-quer. There was evidence of seasonality through profiles of acression and erosion, respectively, in dry and wet periods. On the beach of Saudade erosion occurred during the rainy season and acression, during the dry period. This beach has been divided into two sectors: North and South Sector. The South did not present major changes, however in the North Sector was developing a system of ridge and runnel and this has been intense variations with the changes of measures zones of intertidal and supratidal. On the beach of Vai-quem-quer either there was no notable changes during the rainy season. However, in the dry period was noticed acression in zones of upper intertidal and supratidal due to wind influence on the sediments that are at dried in this period. The characterization of the morphosedimentary estuarine beaches of Saudade and Vai-quem-quer is influenced by the Intertropical Convergence Zone (ITCZ), in the rainy season. It intensifies the winds in this period, which reached maximum speed of 7.5 m/s and preferential NE direction, and consequently, formed waves with higher energy (Hb = 1.3 m in January on the beach of Vai-quem-quer) and contributed to the beach erosional process. In addition to the high tides (Hm = 2.9 m in March) who achieved the most internal of these beaches.
Acesso aberto (Open Access)
Dinâmica dos parâmetros abióticos na zona de mistura do estuário do rio Paracauari, ilha do Marajó-Pa
(Universidade Federal do Pará, 2009-09-09) MONTEIRO, Sury de Moura; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
This paper evaluate the seasonal (2008) and longitudinal dynamics of abiotics parameters in water column in the mixing zone of the estuary of Paracauari River (Marajo Island-PA). This estuary is located in the eastern portion of the Marajo island – PA, and it is influenced by a wet tropical climate, with annual average temperature of 27oC, rainfall of 2.566 mm/year with two distinct seasons of rainy (that occurs from December to May and less rainy from July to November); and presents a system from meso to macrotide (3 to 5 m), half-day time. Three campaigns were carried out using a mesh of 15 stations distributed over the estuary, and a fixed station at the mouth of the river during a half of a tidal cycle. The campaigns were carried: rainy (March), intermediate (June) and less rainy (September). Were measured in situ physicochemical parameters, temperature, pH, OD, salinity, CE and TDS using a multiparameter, transparency through Secchi disc and collected water samples for laboratorial analysis of the nutrients through methods spectrophotometer and MPS by the gravimetric method. In the fixed station, the analytical results are due to the variation of the tide, in general, with a sinusoidal behavior, with the exception of water temperature which ranged to the time of gathering. As rainy, intermediary and less rainy period, pH, OD and PO4 3- had a direct proportion to the variance of tide, the highest indexes occurred during flood tides. The CE, TDS and salinity, during the rainy period, was maximum during low tide; during the intermediary and less rainy the maximum value occurred in the tide floods, due penetration of marine waters. The NO3 -, NO2 – and Si(OH)4, however, observed minimum concentrations during flood tide periods analysed, as the marine waters are impoverished these compounds. For MPS maximum values were observed during the ebb tide and the minimum during flood tide in the rainy, intermediate and less rainy periods, but the transparency analysis did not provide a direct proportion to the change of the tide, but with time of gathering. The analytical results of samples collected along the estuary of the river Paracauari showed that the estuarine waters do not have large seasonal variations in the concentrations of the studied parameters. The water temperature has been constant, 28.70°C average with 1.5°C variation in three periods, confirming the homogeneity of the thermal waters. The pH was acid with averaging 5,87 and 6,77 during the rainy period and intermediary, respectively, and alkaline during the period less rainy (7,37) reflecting the influence of marine waters in the estuary. The transparency of these waters is 10 cm averaging, during the rainy period as a result of the large suspended solids load (order 93,72 mg/l), which produces a dirty aspect in the region; already during the intermediary and less rainy, the concentration of suspended solids was 37,19 and 15,18 mg/l, respectively, causing higher transparencies, around 43 cm. The concentration of OD showed that estuarine waters there is low levels during the rainy and intermediary period, with 3,11 and 4,32 mg/L, average levels, respectively, and high level during rainy season (average 6,30 mg/l). All dissolved nutrients analyzed showed high average levels during the rainy period due to natural dump from adjacent areas, averages values: NO2 - 0,08 μM/l; NO3 - 6,52 μM/l; n-ammoniacal 0,46 μM/l; PO4 3- 0,89 μM/l; and Si(OH)4 60,14 μM/l. In the intermediate and less rainy period, there is a significant reduction in these average levels, particulary in the mouth, where there is greater influence of marine waters. The CE, TDS and salinity showed an expressive seasonal variation, with respective minimum values during the rainy period of 256 μS/cm, 125,66 mg/l and 0,12, maximum in less rainy of 11002 μS/cm, 5505,03 and 6,18, and in all of these periods the highest value occurred in the mouth, where there is a marine water influence. Longitudinal changes in parameters analyzed in the Paracauari River estuary are controlled mainly by dump from rivers, precipitation, wind and tide. Which allows you to suggest that this estuary is influenced by continental waters during the rainy and intermediary period, and oceanic during the less rainy, which the ocean waters penetrate in the estuary around 40 km from the mouth. Keywords: Estuary, Paracauari River, Nutrients, meso and macro-tidal, seasonal variation, the mixing zone, Marajo, Island of the (PA).
Acesso aberto (Open Access)
Estratigrafia holocênica morfodinâmica atual da planície costeira da Ilha de Algodoal e Marudá
(Universidade Federal do Pará, 1996-11-08) SANTOS, Valdenira Ferreira dos; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The Coastal Plain of Algodoal and Marudá Island is located on the Bragantina Platform, on the coast of "rias" in the NE of the State of Pará. This plain is limited by the Coastal Plateau, built on Tercio-Quaternary sediments of the Barreiras and Post-Barreiras Formation. Geomorphologically, the Coastal Plain of Ilha de Algodão and Marudá was compartmentalized into 7 morphogenetic units: estuarine channel, beach-dune cords, tidal flat, beach, dunes, salt marshes and "cheniers". This subdivision reveals the existence of a beach-dune string system concomitant with a tidal flat system. The stratigraphic studies allowed the identification of 9 morphostratigraphic units: beach-dune ridges, paleodunes, coastal dunes, beach, supratidal plain, intertidal plain, sandy tidal bar, tidal bar and saline marsh; which in part are related to the morphogenetic units of the plain. 10 stratigraphic facies were also defined: intertidal mud, sand from tidal excavation channels, sand and mud from bars, supratidal plain mud, sand and marine mud, estuarine mud, marine sand, bioturbated silty clay, undifferentiated sediments and sand. mottled. The integration of morphological and stratigraphic data allowed the identification of two stratigraphic sequences: transgressive sequence (S1) with estuarine and beach facing environments and ; regressive sequence (S2) characterized by a beach-dune string system, interdigitated with a tidal flat system. These sequences point to an evolution of this plain within a transgressive-regressive cycle that probably started at the end of the Late Pleistocene. The morphodynamic analysis indicates that the system has been constantly modified in the last 19 years. Waves and tides are the major erosional agents that act in restricted sectors of the coastal plain, while the biggest changes result from coastal accretion to the NE of Algodoal and Marudá Islands. The results of this work show the influence of hydro and aerodynamic parameters (tides, waves, currents, wind and weather), sea level variations and sediment input as preponderant factors in the evolution of the system.
Acesso aberto (Open Access)
Estudo da morfodinâmica sazonal e quantificação de transporte sedimentar costeiro nas praias de Fortalezinha e Princesa, Algodoal/Maiandeua (nordeste do estado do Pará)
(Universidade Federal do Pará, 2015-02-03) SILVA, Paulo Victor Magno; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
Understanding the processes responsible for the morphodynamics of the coastal environments and sediment transport is necessary considering that such processes play an important role in the formation and stabilization of the beach. The coastal zone is a complex, dynamic and unstable range in which is subject to continuous changes generated by coastal morphodynamic processes such as winds, waves, tides and tidal currents. This Master thesis shown the morphodynamics and transport measurement of sediment in macrotidal on the Princesa and Fortalezinha beaches (Pará coast). These beaches are part of the sandy plains, around the Algodoal/ Maiandeua island (Maracanã city), being inserted in the Salgado Atlantic Coast of Pará. Two data collection campaigns were conducted: (i) in the dry season (15 - 19/10/2012) and; (ii) in the rainy season (13 - 16/03/2013). To analyze the morphological variation of these beaches and its erosive trends and / or accretion, were executed 8 topographic profiles (4 in each beach). At the same time the survey of profiles, sediment samples and measurements of hydrodynamic parameters (waves and currents) were performed. To quantify the coastal sediment transport were used two methods: (1) “traps” for aeolian sediment transport in each profile, and (2) “portable traps” for longitudinal transport in the surf zone, over three different sectors of the beaches. These beaches are composed predominantly of fine and well selected sand. The beaches exhibited low slope (<2 °) for the two periods. In the dry period was observed on the Princesa beach one well developed bar-rip in the middle intertidal zone, characteristic of dissipative beaches, while in the rainy season occured loss of sediment in this area, allowing the exposure of a muddy terrace (paleomangrove) in the central sector. In general, the Princesa and Fortalezinha beaches are subject to a semidiurnal macrotidal regime. The active winds have preferred direction of E in less rain season and NE in the rainy season period, with sliding dominant waves of low period and NE direction. The coastal currents have preferred NW direction, with variations during the tidal cycle. The active winds have preferred direction E in less rainy period and NE in the rainy season. During the dry season the beaches have intermediate characteristics beaches, with Ω between 4.322 to 4.579 on the Princesa beach and 4.074 to 4.668 in the Fortalezinha beach. During the rainy season were characterized as dissipative, with Ω ranging from 5,088 to 6,763 values on the Princesa beach and 5.790 to 6.174 on the Fortalezinha beach, with only the NE sector of the Princesa beach with intermediate characteristics. The Princesa beach evolved from ultradissipative beach state (7 5)(rainy period). However, the Fortalezinha beach had its status as an intermediary with low-water channel-bar system (3 5), in the rainy season. On the beaches is bidirectional longitudinal transport however in the rainy season the beach was characterized as dissipative and no bars (3 5). On the beaches is bidirectional longitudinal transport, with resulting NW. The direction of the longitudinal current and longshore drift is influenced, respectively, by the direction and intensity of the trade winds from the NE (dry season) and tidal currents (rainy season). The aeolian transport is a function of the intensity and duration of winds and rains mainly, however, in the dry season this is high due to strong winds, and the lack of rain makes the sediments of less cohesive swash zone and easier to be transported. The coastal dynamics on the beaches is influenced by the adjacent drainages (rivers and tidal channels) especially during the ebb tide. During the rainy season, the Marapanim and Maracanã rivers flow is high, due to increased rainfall in the headwaters of rivers, increasing the export of continental sediments (silt and clay) for the coastal region, and are incorporated into coastal drift and deposited in beaches during times of low energy, along with sandy sediments mainly from adjacent continental shelf by tidal currents.
Acesso aberto (Open Access)
Estudo morfoestratigráfico e sedimentológico dos depósitos holocênicos da planície costeira de Maracanã – NE do Pará
(Universidade Federal do Pará, 2007-03-15) CARVALHO, Charles de Almeida; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The Maracanã Coastal Plain is located in the northeastern part of the Para State where there are some coastal rias. This place is over tertiary sediments of the Barreiras and Pirabas Formations as well as is over quaternary sediments of the Pos-Barreiras. The Maracana Coastal Plain is influenced by an macrotidal regime (amplitude > 4 m). The Maracana Coastal Plain is characterized by three different geomorphologic domains: (1) Coastal Upland that presents active and inactive cliffs, and platforms of abrasion build in the laterites of Barreiras Formation as well as outcrop of the limestone from Pirabas Formation; (2) Coastal Plain that presents coastal dune fields and palaedunes, beach, mud-tide flat (mangrove), sandy plain, edd-tide delta, beach ridge plain and lakes; (3) Estuarine Plain which presents estuarine funnel, tidal channel and floodflat. In the Maracana Coastal Plain were identified nine morfostratigraphic units: (1) mud-tidal flat, (2) point bar, (3) Sandy plain, (4) dune, (5) paleodune, (6) beach, (7) ebbtide delta, (8) beach ridge plain, and (9) lake. These morfostratigraphic units are associated to three stratigraphic facies: (1) sand facies and point bar mud facies (sandy and muddy) that show alternate layers of greenish gray mud and light gray sand; (2) sea sand facies located over infratide mangrove that it has light olive gray and yellowish gray sands; (3) estuarine mud-sand facies that mean a variable thicking alternate layers with dark gray mud or greenish gray mud. In the Maracana Coastal Plain were characterized three depositional sequences: (1) Basal Transgressive Marine Succession S1, (2) Regressive Marine Succession S2 and (3) Transgressive Marine Succession S3. S1 show mid-large sand in its base (tidal channel) so that following by dark mud with high concentrations of organic matter (sand-silty clay). In these base, the sand is in moderate selection, but to top the sand is fine to middle size and it’s negative asymmetry. Distribution of the mineral clay was homogeneous (kaolinite = 45 %, ilite = 37 % and smectite = 18 %). Heavy minerals show larger concentration in the sandy facies, but the relative amount these minerals increased upward which owing zircon (35 %), staurolite (28 %), epidote (9 %) and cianita (11 %) presences. This sequence of sediments marks an estuarine mud, sea sand and seamud depositions during marine transgressive period. S2 is constituted by thin-very thin, well selected, near asymmetric sand that could be classified as clay-sand sediment. The mineral clay is represented by slight increase of the smectite as well as a decrease of the kaolinite in top sequence. The main heavy mineral located in the point bar are staurolite (44 %), zircon (39 %) and tourmaline (9 %) while there are zircon (39 %) and staurolite (27 %) contents at bottom sequence. This sequence was build during a marine regressive period from coastal upland so that consist the progradational deposits over sequence S1. The sequence S3 corresponds to unit of dunes, barrier-arrow beach, sandy and muddy bars. Coastal dune deposits show some crossing stratification to slow slope and thin layer of mud. Beach deposits show crossing stratus in low angle. Sandy bars presents a full structure with some bioturbation. The contents of sand are well selected and it has quartz as main mineral. The amount of heavy mineral was lower at top layer. Composition and texture of heavy mineral provide a rounding shape of the sediments because it has been transported, reworked and it was suffering a strong abrasion. In the Maracana Coastal Plain, grain size and mineral distribution are homogeneous being not possible to determine a clear edge between stratigraphic sequences either continental contribution or sea sediment source. There are so many morphologic features (cheniers, paleochannel, paleodelta) and some stratigraphic characteristics that suggest an occurrence of sea level oscillations as well as a migration in the shoreline position. The presence of transition environment deposits (tide flat) show some stratigraphic evidence in the study area. The Maracana Coastal Plain and the northeastern coastal area of the Para State (Bragança, Salinopolis and Marapanim) are over actual transgression event (large sandy plain and beach presences).
Acesso aberto (Open Access)
Geoquímica dos sedimentos superdiciais de fundo do Estuário do Rio Maracanã, NE do Pará
(Universidade Federal do Pará, 2006-04-05) DELFINO, Smaily Bastos; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The Maracanã estuary is located in the northeastern of Pará State, within the Extraction Marine Reserve (Law 9.985/00), which has as primary goal to the sustainable use and conservation of the renewable ressources, protecting living conditions and the culture of the population, which consists of fisherman, small seliers and the local community. Due to its environmental characteristics, this area represents an important pole for the regional development. In this work, one of the aims was to search a geochemical formality to an interpretation of analytical results related to the geochemistry of the superficial sediments of the estuary of Maracanã bottom in order to determine the amount of heavy metais (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) of the granulometry with smaller fractions than 0,64 tem by atomic absorption spectrometry, to obtain the current inexistent background leveis. In the Maracanã estuary, it was registered much more silt-clay fraction than sand fraction, besides mineralogical similarity that indicates presence of kaolinite, illite and smectite. The amount of organic matter (MO) (5,4±0,70%) in sediments was homogeneously distributed. The pH didn't vary much, only between weakly acid (6,48) and weakly alkaline (7,13). Heavy metais - 1) in Maracanã river estuary cadmium concentrations were under of the equipment detection limit (0,009 ppm); 2) Cobalt varied from 46 to 55 ppm (50,97 ± 2,31 ppm) in total fraction, and from 5 to 7 ppm (6 ± 0,37 ppm) in bio-available fraction; 3) Cromo varied from 126 to 152 ppm (140,33±6,56 ppm) in total fraction and from 17 to 24 ppm (20,73±1,7 ppm) in bio-available fraction; 4) Copper varied from 17 to 21 ppm (18,97±1,19 ppm) in total fraction and from 6 to 9 ppm (7,0 ± 0,69 ppm) in bio-available fraction; 5) Iron varied from 3,4 to 4,6 % (4,14± 0,24 %) in total fraction and from 1,5 to 1,9 % (1,66± 0,1 %) in bio-available fraction; 6) Manganese varied from 293 to 545 ppm (423,53±74,63 ppm) in total fraction and from 168 to 499 ppm (335,1±91,3 ppm) in bio-available fraction; 7) Nickel varied from 44 to 53 ppm (48,77 ± 2,27 ppm) in total fraction and from 7 to 9 ppm (8,03±0,56 ppm) in bio-available fraction; 8) Lead varied from 42 to 48 ppm (45,63±1,69 ppm) in total fraction and from 14 to 17 ppm (15,13±0,78 ppm) in bio-available fraction; 9) Zinc varied from 72 to 85 ppm (78,83±3,44 ppm) in total fraction and from 26 to 32 ppm (29,43±1,65 ppm) in bio-available fraction. Concentration values of the bio-available heavy metal analyzed are smaller than those VGQS (Guide-Value of Sediment Quality), established by the "Canada Environmental Agency" (AAC) and the "National Oceanic and Atmospheric Administration"(NOAA), indicating that it should rarely occur bad effect on local biota. Considering that the area is an extraction reserve and that were not found evidence of anthropic contamination associated with the heavy metais, neither in their total fractions nor in their bio-available fractions in the Maracanã estuary, it is possible to consider that the data obtained from both analyzed geochemical fractions of heavy metais represent a value dose to the characteristical background of the region. Therefore, the Maracanã estuary is a reference cite to study the biogeochemistry and ecotoxicoiogy of the sediments of similar environments in Coastal of the Pará State. Besides that, the data obtained in this work can provide a subside for future geochemical and environmental surveys in the area, once that concentration ranges and reference values for many heavy metais that are present in the bottom sediments of this estuary were established.
Acesso aberto (Open Access)
Hidrologia e biomassa fitoplanctônica do sistema flúvio-estuarino do rio Arari (Ilha de Marajó-PA).
(Universidade Federal do Pará, 2010-08-19) ALVES , Igor Charles Castor; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
Este trabalho objetiva a avaliação do comportamento hidroquímico do sistema flúvioestuarino (parte superior) do rio Arari (Ilha de Marajó-PA). Foram avaliados os seguintes parâmetros físicos e químicos: temperatura, Material Particulado em Suspensão (MPS), Sólidos Totais (ST), Sólidos Totais Orgânicos (ST Orgânicos), Sólidos Totais minerais (ST Minerais) condutividade elétrica, profundidade do disco de Secchi, variação da maré, pH, oxigênio dissolvido, nitrato, nitrito, N-amoniacal, fosfato (PID), silicato e Biológico: Clorofila-a. Coletas simultâneas de águas superficiais foram realizadas em dois períodos distintos: chuvoso e menos chuvoso de 2009 de hora em hora durante 12 horas, sempre em condições de marés de sizígia em três estações fixas assim distribuídas: Uma na foz do rio Arari (trapiche da Vila de Santana do Arari) outra estação localizada no trapiche da cidade de Cachoeira do Arari e uma no trapiche da Fazenda Murutucú a meio caminho entre a foz e a cidade de Cachoeira do Arari. Os parâmetros obtidos foram analisados por métodos de estatística descritiva e multivariada, Análise de Componentes Principais (ACP) e Cluster. Através das análises estatísticas, foram observadas diferenças significativas entre os períodos estudados, o que demonstra uma grande influência dos diversos fatores ambientais como descarga fluvial, turbulência, precipitação e marés na dinâmica dos processos que ocorrem no rio Arari. A ilha do Marajó apresenta topografia suave, com altitudes que não atingem 20 metros. O Planalto do Baixo Amazonas é constituído por sedimentos terciários da formação Barreiras/Pós-Barreiras. No município de Cachoeira do Arari predominam os tipos de vegetação: Floresta Densa de Terra Firme, Campos Cerrados, Campos Altos e Campos Baixos. O clima da margem leste da Ilha de Marajó é classificado como clima do tipo “A” definido como clima tropical chuvoso. Na bacia hidrográfica do rio Arari a média pluviométrica anual é em torno de 2500 mm. Esta bacia posiciona-se na região de campos e totaliza 864 km2. A temperatura das águas do rio Arari foi característica de um ambiente tipicamente tropical e variou de 28,59°C no período chuvoso a 29,88°C no menos chuvoso. Os valores de condutividade elétrica, máximo de 233 μS.cm-1, revelam que este rio não recebe influência salina, o que caracteriza o rio Arari como um sistema predominantemente de água doce durante ambos os períodos. Durante o período chuvoso o rio Arari recebe contribuições de material alóctone, principalmente na forma orgânica, resultante da decomposição da vegetação das áreas alagadas, essa distribuição foi confirmada pelos valores da fração orgânica dos sólidos totais que representaram 61% dos sólidos totais, os outros 39% representam a fração mineral. A profundidade do disco de Secchi foi em média 28 cm no período chuvoso e 15 cm no menos chuvoso. Os menores valores de OD (mediana de 3,64 mg.L-1) ocorreram no período chuvoso e no menos chuvoso foi de 4,25 mg.L-1). As formas mais reduzidas de nitrogênio (nitrito e N-amoniacal) predominam durante o período chuvoso (mediana de 0,32 μmolol-1 e 18,1 μmol.L-1), por outro lado, quando as concentrações de OD aumentam no período menos chuvoso a nitrificação é favorecida, e a concentração de nitrato aumenta (mediana de 24,98 μmol.L-1). Concentrações elevadas de N-amoniacal no rio Arari ocorreram em ambos os períodos, com o máximo 41,67 μmol.L-1 12 vezes maior que o mínimo 3,33 μmol.L-1 registrado no período menos chuvoso. Os valores de fosfato neste trabalho foram inferiores a 2 μmol.L-1 durante o ano, com mediana de (0,32 μmol.L-1) no período chuvoso e de (0,46 μmol.L-1) no menos chuvoso. O silicato apresentou comportamento semelhante ao do fosfato, os valores foram maiores no período menos chuvoso, com mediana de 33,7 μmol.L-1 no período chuvoso e 75,88 μmol. L-1 no menos chuvoso. Observou-se uma variação sazonal da clorofila a no rio Arari, as condições mais favoráveis para atividade fotossintética ocorreram no período chuvoso (mediana de 17,4 mg.m-3), quando foi registrada a maior profundidade de penetração do disco de Secchi (máximo de 55 cm), por outro lado durante o período menos chuvoso esse valor diminui consideravelmente (máximo de 15cm) e apesar do incremento nas concentrações de nutrientes a clorofila a diminui, isso revela que a disponibilidade de luz é o principal fator limitante da produtividade primária no rio Arari. A ACP e os gráficos de Box mostraram que para a maioria dos parâmetros estudados, no período chuvoso a grande descarga de água do rio Arari promove a mistura das águas a longo do rio, dessa maneira é pouco intensa a diferença entre as águas, por exemplo, da foz (estação Santana) com Cachoeira do Arari. Por outro lado durante o período menos chuvoso ocorre uma divisão do rio de acordo com as três estações estudadas, as águas apresentam características distintas, com valores característicos para cada região do rio, além de padrões de distribuição espacial, com gradientes crescentes ou decrescentes de acordo com o parâmetro em questão.
Acesso aberto (Open Access)
Identificação e caracterização das massas d´água da Plataforma Continental do Maranhão, durante os períodos seco (Novembro, 1997) e chuvoso (Junho 1999)
(Universidade Federal do Pará, 2007-10-26) PONTES, Paulo Henrique Parente; KAMPEL, Milton; http://lattes.cnpq.br/0063119667740811; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The Maranhão Continental Shelf (MCS) between the mouths of Gurupi and Parnaíba rivers is 203 km wide on the occidental coast and 72 km from Tubarão Bay toward southeast. The Maranhão coast is distinct: there are Maranhenses Reentrances in the Northwest; the dunes coast in the eastern side, being separated by the Golfão Maranhense, where the Mearim river, whose discharge is about 770 m3/s, discharges its fresh water. Other small rivers like Gurupi, Maracaçumé, Turiaçu, Itapecuru and Parnaíba discharge fresh water on the shore. The parameters of temperature, salinity and density were used to identify and characterize the water masses during dry season (november, 1997) and rainy season (june, 1999) in order to study seasonal variability of the local water masses. Images of Sea SurfaceTemperature (SST) obtained from Advanced Very High Resolution Radiometer (AVHRR) from NOAA satellites were used to observe its variation and verify some oceanographic features. The time series of monthly averages of images from AVHRR Pathfinder of SST with 4 km resolution (from 1985 to 2001), obtained from Instituto Nacional de Pesquisas Espaciais (INPE), was used to study the temporal and spatial SST variability through the calculation of climatological mean and its monthly SST changes in three points of the MCS to see if there are substantial changes in the features of the MCS waters during El-Niño/La-Niña seasons, since those phenomena can provoke (or not) great changes in the superficial water masses and in the local circulation. During the dry season (1997), it was observed that only Tropical Water, which is a water mass occurred, proving that at this season the continental water does not act on the MCS. However, during rainy season (1999) there were Coastal Water, Mixture Water, Tropical Water and South Atlantic Central Water. The Coastal Water is a water mass that comes from the rivers that discharge in the MCS. Mixture Water is a mixture of oceanic and continental water. So the presence of these two masses in the MCS proves that continental water occurred in the field of study during that period. The MCS water masses have the following physical characteristics: (i) Tropical Water: salinity over 36, temperature between 26,6° and 28,7°C and density between 23 kg/m³ and 23,8 kg/m³, which during the dry season occurs since the surface until more than 60 m of depth, while during rainy season it only occurs 40 km from the coast, from the surface until deeper 60 m; (ii) Coastal Water: salinity under 33, temperature between 28° and 29,4°C and density between 19 kg/m³ and 21,4 kg/m³, it occurs along 10km from the coast being also found from the surface until 28 m; (iii) Mixture Water: has salinity values between 33 and 36, temperature between 25,8º and 28,75ºC and density between 21,8 kg/m3 and 23,8 kg/m3 , and can be observed until 60 km from the coast along surface until 60 m; (iv) South Atlantic Central Water has salinity between 35,6 and 36, temperature under 18ºC and density between 23,9 kg/m3 and 25,8 kg/m3 that can be found 31 km from the coast and over 50 m depth. In the MCS, the AVHRR/NOAA images has shown low variation the SST field over the MCS. In November, 1997 maximum SST variation was 2,5ºC (minimum of 27°C and maximum of 29,5ºC) almost the same data obtained in situ where the maximum of SST was 28,6°C and minimum of 27,1°C. In the images of june, 1999, the oscillation of this parameter was between 27° and 29°C, similar to the data obtained during the ocean cruse of the same year that were of 27,4°C (minimum) and 29,2ºC (maximum). The graphics of SST anomaly in three different geographical sites of the MCS show a slight SST anomaly oscillation during the 1997/98 El-Niño event. The SST anomaly is higher in the MCS during 1998, which is between this work’s oceanographic expeditions. Therefore there was no significant influence of this phenomenon on the water masses of the MCS temperature characteristics during the data acquisition period. The occurrence of different water masses in the MCS region is related mainly to the seasonality on the area of study, which presents larger estuarine influence during the rainy season and little or no influence during the dry period, as can be confirmed through the predominance of oceanic waters (Tropical Waters) during the dry period and the presence of coastal waters and mixture water in the rainy season, determining clearer water stratification.
Acesso aberto (Open Access)
Influência da sazonalidade sobre as águas estuarinas dos furos da ilha de Colares (baía do Marajó)
(Universidade Federal do Pará, 2014-12-17) GUIMARÃES, Robledo Hideki Ebata; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The characterization of surface and interstitial waters in estuaries is critical to unravel the environmental conditions, environmental quality and seasonal changes, which may occur in smaller space such as the hole in the island of Colares. This work aims to show the influence of seasonality in estuarine waters in the north and south of the mouth of the hole island of Colares and the contribution of pore waters to surface waters. The physical and chemical parameters and nutrients are included: rainfall (IP), temperature, salinity, pH, electrical conductivity, total dissolved solids, suspended particulate matter, dissolved oxygen, Secchi depth, nitrate, nitrite, N-ammonia, phosphate, silicate and sulfate. The determination of these parameters occurred simultaneously in each mouth of the hole necklaces over a tidal cycle (13 hours) in rainy (04/10/2013) and drier (10/05/2013) periods. The results show that seasonality affects abiotic conditions of estuarine waters bore the island of Colares and deduces that P1 is the most important factor to effect the changes of physical and chemical parameters, and especially the higher charge mobility, availability and distribution of dissolved nutrients, which were found in higher concentrations in the rainy season. Although the nutrients nitrate and N-ammonia were considered very high at the mouth North, possibly related to the influence of anthropogenic activities. However were considered within the limits established by CONAMA Resolution 357/05. Mouth occurred in South pH levels outside the standard stipulated by Resolution CONAMA, but the phenomenon was considered natural since in this specific is distant from anthropogenic activities. In less rainy period the N-ammonia was found to be absent in mouth North and South. The mangrove was considered as a source of salinity, silicate and sulfate to surface waters.
Acesso aberto (Open Access)
Mapeamento Plani-Altimétrico da microrregião do Salgado paraense a partir de procedimentos fotogramétricos
(Universidade Federal do Pará, 1995-03-31) PEREIRA, Silvio Wigwam Mendes; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The Coastal Microregion of Salgado Pará is characterized by a low topographic gradient controlled by paleopavements (stone layers) and lateritic crusts, having its model developed in Cenozoic units (Pirabas and Barreiras Formations) and Quaternary (Post-Barriers and recent sediments). From a geographic and geomorphological point of view, this area is subdivided into two geosystems: in resistasia of regressive character, with geomorphogenesis associated with anthropic activities of continental domain; and, marginal-mosaic with resistasia and biostasis responsible for the morpho-environmental susceptibility of the coastal domain. The photogrammetric and morphotopographic mapping of the Coastal Microregion of Salgado Paraense allowed the elaboration of eleven topographic maps (systematic and non-systematic) suitable for morpho-environmental studies. An integrated photogrammetric system of a 1st order analog stereo-returner (universal type) - Topocart-D/Zeiss and Orthophot-E/Zeiss differential optical transformer was used to make the maps, aided by other cartographic systems such as interpretoskop-C/Zeiss, aerosktchmaster /Zeiss and ST-4/Wild stereomicrometer. The modeling of the data arranged in four levels of stereotopographic density, showed the photogrammetric capacity of Topocart-D, and the mapping alternatives for the Coastal Microregion of Salgado Paraense. a predominantly transgressive system with localized regressive pulses. These processes are also indicated by the morphodynamic changes of the geofacies, whose morphotopographic correlations allowed the compartmentalization of the Coastal Microregion of Salgado Paraense in the NE, SW and E topographic domains, which encompass the morphological domains of esplanade, coastal plain and estuarine plain. The fluvial-coastal systems of Japerica-Primavera-Quatipuru, Pirabas-Inajá, Arapepó-Urindeua and Maracanã-Caripi characterize the NE, SW and E domains. dissected developed in lateritic crusts, in which concave amphitheaters of springs (catchment basins) and erosive levels are inserted; the coastal plain, which corresponds to the coastal portions directly influenced by the ocean, is characterized by beaches, active and inactive cliffs, active and degraded mangroves, platforms of laterite blocks and mobile and degraded dune cords; and, the estuarine plain is formed by estuaries filled with mud and sand banks, generally degraded dunes, active and inactive cliffs, elliptical to elongated hills, trapezoidal “strained”, saline wetlands with a lot of organic matter, pre-salt, peripheral igapós and penelagos in the form of double-bottomed saucers. In the SW topographic domain: the esplanade shows a flat-shaped relief with a table top and erosive levels, controlled by paleopavements, the relief also being characterized by valleys in the “◡” shape and springs of the dale and thalweg types; the coastal plain exhibits narrow oceanic beaches with curved ends (spits), inter-dune fields, active and inactive cliffs, leterite block platforms, abrasion platforms and oceanic mangroves; and, the estuarine plain encompasses unfilled estuaries and partially filled estuaries. Topographic domain E, encompasses only the esplanade (also controlled by paleopavements) and estuarine plain compartments, and belongs to an independent morphotopographic system, featuring a single interfluvial corridor. The esplanade shows normal short and convex slopes, inserted in multidirectional drainage patterns; and, the estuarine plain is bordered by active and inactive large cliffs. This estuarine plain has numerous underwater and subaerial indents formed by blocks of laterite and kilometric lateral mangroves penetrating into transverse valleys in the E-W direction.
Acesso aberto (Open Access)
Morfodinâmica costeira e o uso da orla oceânica de Salinópolis (Nordeste do Pará)
(Universidade Federal do Pará, 2014-12-15) RANIERI, Leilanhe Almeida; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The morphodynamic aspects related to erosion or accretion of the coastline are some of the topics analyzed in the management of coastal zones being discussed around the world in order to monitor and protect these zones. This thesis aims to analyze the behavior of the coastal morphodynamics of the Salinópolis, relating to the use of ocean margin. The study area was compartmentalized into three sectors: Western (Corvina and Maçarico beaches), Center (Farol Velho beach) and Eastern (Atalaia beach). The methodology consisted of: (a) acquisition and processing of multi-temporal images (1988-2001-2013) of the Landsat 5 TM, 7 ETM and 8 OLI; (b) application of interviews/questionnaires with bathers, (c) acquisition of field data during the rainy season (April 26th, 27th and 28th, 2013) and less rainy (045.5) prevailed at these beaches, but with the occurrence of the the longshore bar and trough state (4.7 <Ω <5.5) in the western sector. The macrotidals in the study area showed maximum height of 5.3 m (Center Sector during the less rainy season) and a minimum of 4 m in the same sector during the rainy season. The longshore currents were more intense in the eastern sector (> 0.45 m / s) during the two seasons of the year. The wave heights were also higher in the eastern sector (maximum of 1.05 m during the flood tide in the less rainy season) and wave periods were shorter (<4.5 s) in the western sector. The mean grain size obtained from sediments collected on the beaches had more frequent scale between 2.6 to 2.8 phi, indicating the predominance of fine sand. The predominant degree of sorting of sediment was 0,2 to 0,5 phi (very well sorted and well sorted), and asymmetry was positive (0.10 to 0.30) and nearly symmetrical (-0.10 to 0.10). The degree of kurtosis ranged from very platykurtic (<0.67) to very leptokurtic (1.50 to 3.00). Sediment accretion events were observed of the rainy season to less rainy season. From 07/22/1988 to 08/28/2013 (25 years) also predominated accretion, where the average linear advancement of the coastline was 190.26 m. The average linear retreat obtained for the entire study area was -42.25 m. The eroding areas are point: currencies from the beaches of Corvina and Maçarico, and Farol Velho and Atalaia. Portable traps indicated a greater quantity of sediment transported longitudinally in the less rainy season (minimum 280 g/m3: flood, west sector; maximum 1098 g/m3: ebb, east sector). In the traps applied in the swash zone, the balance of sediment entering and leaving the beaches was lower in the center sector (minimum 80 g/m3: ebb, maximum 690 g/m3: flood; less rainy season). The coastal sediment movement is derived mainly from effect of the tides, which are oriented toward the direction of the ebb and flow of the estuary crossing the coast. The data indicate the longshore transport of sediment from the Atalaia island and Sampaio River to the west sector and the beaches margins.
Acesso aberto (Open Access)
Morfodinâmica da praia estuarina do Cajuúna, Soure, Marajó – Pará
(Universidade Federal do Pará, 2016-06-08) BITTENCOURT, Lorena Amaral; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The Cajuúna beach is located in the municipality of Soure (0 ° 37 '41,971 "S - 48 ° 28' 56,980" W and 0 ° 38 '54,888 "S - 48 ° 29' 6.867" W), on the eastern shore of the Marajó island (Pará state). This beach is cut by tidal channels (one in the middle and two at the ends), and is influenced by meteorological parameters (wind, rain, thunderstorms), hydrological (water and solid discharge of Pará estuary) and hydrodynamic (waves, tidal currents). The aim of this work is to identify the morphodynamics of estuarine Cajuúna beach through seasonal analysis, may clarify questions about which morphological features are characteristic during the rainy and less rainy periods; which the textural changes of the sediments; which most forcing this change in the transport and distribution of sediments and with what intensity and preferred direction they are transported. There were two field campaigns: during the rainy periods of equinoctial tide (04/01/2014) and less rainy (11/23/2014). The beach stretches for 4 km, your lenght reaches about 100-489m, was applied 7 topographic profiles with equidistance of 300 m. The beach was divided into three sectors: profiles A and B - Sector 1, profiles, C, D and E - sector 2, F and G profiles - sector 3. The sediment samples were collected from: (1) timely measurement longitudinal transport in the surf zone (traps) and (2) over topographical profiles, adopting morphological zonation (Souza Filho et al., 2003). Still, waves and currents data acquired in the surf zone. The sediment samples were subjected to analysis and classified according to Folk and Ward's method (1957), Shepard diagrams (1954) and Pejrup (1988). Besides these were produced morphometric parameters: Sedimentary volume variation (Vv), declivity of praial face (β), width of the beach (Yb), coefficient of shoreline change (CVYb), Speed decanting of sedimentary particles (Ws ) beach morphodynamic state (Ω) Dean (1973) and the relative variation of the tide (RTR – Relative Tide Range) Davies and Hayes (1984), suggested by Masselink and Short (1993). The results show that the Cajuúna beach is composed of sediments ranging from fine sand (< 2 to 3 Φ) to very thin (< 3 to 4 Φ) with a good degree of selection (0.35 to 0.50 Φ) very well selected (<0.35 Φ) to moderately selected (from 0.50 to 1.00 Φ) in less rainy season. The asymmetry remained approximately symmetrical tending to positive values (0.10 to 0.30 Φ), very positive (from 0.30 to 1.00 Φ) and negative (-0.30 to -0.10 Φ) and kurtosis predominant in both periods was leptokurtic (1.11 to 1.50 Φ), hooting for very leptokurtic (1.50 to 3.00 Φ), mesokurtic (0.90 to 1.11 Φ) and platykurtic (0.67 to 0.90 Φ). This beach had a positive balance of the sediment volume during the rainy season (lower volume 134 m³ / m higher volume 955 m³ / m) to the less rainy (lower volume 74 m³ / m higher volume 1,567 m³ / m), and growing, with the exception in sector 2 which is the decrease in sediment volume (136 m³ / m in the rainy season to 74 m³ / m in less rainy). The Cajuúna beach remains wider in the rainy season; the coefficient of variation of shoreline was also higher in this period; however the sectors 1 and 3 were larger in the less rainy season (sheltered areas). This beach had low slope (<2.0 °) in both periods, related to the presence of fine sediments. Prevailed morphodynamic state (Ω) intermediate in both periods; Terrace Low Sea (TLS) in the rainy season and variation between Terrace Low Sea and Bank Cusp Beach (BCB) in less rainy season. The RTR classified as intermediate beach in less rainy and wet seasons, with wave-tide interaction (RTR < 7), occurring variation in the least rainy season, a reflective classification, dominated by wave with RTR < 3. In the surf zone, the fine sand fraction (< 3 to 4 Ф) was dominant in rainy periods (up to 74.27g) and less rainy (maximum 562.61g) during ebb tides in the sector 2; the silt remained high fraction (100g), even surpassing the dominant fraction in the less rainy season; and the clay had the lowest amount in both periods (minimum of 0.27g and maximum 23,48g). The incidence angle of the waves varies from NW (rainy season) to NE (less rainy season). The largest wave height was recorded during the ebb tide in both periods (1,074 m - rainy season and 2.94 m - less rain). The wind speed was more intense during the flood in the rainy season (8.4 m/s), and the ebb in less rainy season (10.3 m/s). The intensity of tidal currents was higher during the flood in rainy seasons (0.73 m/s) and less rain (0.35 m/s). Various features such as ridges and troughs, paleomangrove soils, dunes, sand spit and canals occur in the Cajuúna beach are formed and / or seasonally modified by weather forcings, hydrological and hydrodynamic. Understanding the morphodynamics of the Cajuúna beach is important, due to his strategic location above the beaches of the eastern part of the Marajó island, suffers influence of the waters of Pará mouth, and is part of an Environmental Protection Area Despite the implementation of a Coastal Management Plan, in some parts of the Northeast region of Pará ; to date, the Marajó Island does not have a methodology and set to the prognosis and monitoring of coastal erosion . Given these shortcomings , it is necessary to determine how the rising sea level is affecting the eastern margin of Marajó Island . This study makes contribution the Organization of the Amazon Cooperation Treaty Organization, the project " Adaptation to Sea Level Rise in the Amazon Delta " which aims to assess the impact of rising sea level caused by global climate change on island environments Marajó (Eastern and Northern margins).

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