Roberto Lima Barcellos

An integrated GIS for sedimentological and geomorphological analysis of a lagoon environment. Barra de Cananéia inlet region, (Southeastern Brazil)

The aim of this work is to use GIS integration data to characterize sedimentary processes in a SubTropical lagoon environment. The study area was the Cananéia Inlet estuary in the southeastern section of the Cananéia Lagoon Estuarine System (CLES), state of São Paulo, Brazil (25°03′S/47°53′W). The area is formed by the confluence of two estuarine channels forming a bay-shaped water body locally called “Trapandé Bay”. The region is surrounded by one of the most preserved tracts of Atlantic Rain Forest in Southwestern Brazil and presents well-developed mangroves and marshes. In this study a methodology was developed using integrated a GIS database based on bottom sediment parameters, geomorphological data, remote sensing images, Hidrodynamical Modeling data and geophysical parameters. The sediment grain size parameters and the bottom morphology of the lagoon were also used to develop models of net sediment transport pathways. It was possible to observe that the sediment transport vectors based on the grain size model had a good correlation with the transport model based on the bottom topography features and Hydrodynamic model, especially in areas with stronger energetic conditions, with a minor contribution of finer sediments. This relation is somewhat less evident near shallower banks and depositional features. In these regions the organic matter contents in the sediments was a good complementary tool for inferring the hydrodynamic and depositional conditions (i.e. primary productivity, sedimentation rates, sources, oxi-reduction rates).

Depositional evolution in a estuarine lagoonal system under a port influence in Northeastern Brazil

ABSTRACT Martins, S. E. M; Barcellos, R. L; Flores-Montes, M. J. and França, E. J. 2016. Depositional evolution in a lagoonal estuarine system under a port influence in Northeastern Brazil. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 83–87. Coconut Creek (Florida), ISSN 0749-0208. The Holocene evolution reconstruction corroborates to understand sediment dynamics and, recent anthropogenic environmental changes; in addition, may subsidize the future prospects of its development. The aim of this work is to elaborate a historical comparative analysis of the total organic matter content (TOM), calcium carbonate (CaCO3) and grain size variation in a estuarine environment and adjacent inner shelf area under influence of Recife Port (8°03′S/34°53″W), Northeastern Brazil. Two sediment cores were collected (Jun/2013), one (1.26m long) in the inlet of the estuarine system (T2E); and another (1.30m long) in a sheltered area of a breakwater adjacent to the estuary mouth (T3E). The sedimentation rate, measured based on breakwater building (1909), was 1.18 cm.year−1 in T3E and 0.81 cm.year−1 in T2E. The cores presented preservation of structures indicative of waves and currents processes, such as erosive surfaces, linsen bedding, flaser bedding, and wavy bedding, environment features of shallow platform. Both cores presented variations in sediment composition with an essential carbonate sandy base ranging upward to a terrigenous mud on their tops. The change in sediment composition indicates environmental changes such as the increase in the sediment suspension concentrations, directly influenced by changes in coastal engineering in the Recife Port. The results indicate how important local rivers sediments input and estuarine processes are to deposition features in the estuarine lagoonal system, like the mud trapping and preservation in the inner shelf shallow areas adjacent to the Recife Port.

Seasonal and Intraseasonal Variability of Wave Climate on the NE Brazilian Coast using a Nautical Radar System

ABSTRACT Silva, A.C.; Bezerra, C.S.; Barcellos, R.L.; Araújo, M.; Bouchonneau, N. and Manso, V., 2016. Seasonal and intraseasonal variability of wave climate in the NE Brazilian coast by using Nautical Radar System. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 927–931. Coconut Creek (Florida), ISSN 0749-0208. This paper presents a study about wave climate acting on the Northeast coast of Brazil (Recife, Pernambuco) from the use of X-band nautical radar, which runs through the emission of electromagnetic waves and receives the signal by backscattering the sea surface. The main objective of this work is to obtain information about the wave acting on this coast, by analyzing significant height, period and direction of the incident waves, which will be helpful to generate a solid database for future coastal measures, engineering works of contention for coastal and marine protection. Data were obtained from polar images of X-band nautical radar, from April 2010 to April 2011. By analysing the results, it was possible to observe the joint occurrence of waves wind sea and swell in the region of study. Wind sea waves occur predominantly at 90° - 135°, with higher values at the end of September (3.9 m). Swell waves were more frequent during June, October and December 2010, and February and March 2011. Moreover, we observed a change in direction of the waves and decrease in wave heights along the inner shelf of the coast, caused by variation in bathymetry and the presence of sandstone reefs. The results of this study demonstrated great efficiency in acquiring the physical parameters of waves through the X-band nautical radar system, proving to be an efficient tool for measuring physical parameters of waves in coastal regions.

Modern sedimentary processes and seasonal variations of organic matter in an urban tropical estuary, Jaboatão River (PE), Brazil

ABSTRACT Barcellos, R.L., Flores-Montes, M.J., Alves, T.M.F. and Camargo, P.B. 2016. Modern sedimentary processes and seasonal variatios of organic matter in a urban tropical estuary, Jaboatão River (PE) Brazil. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 38–42. Coconut Creek (Florida), ISSN 0749-0208. The aim of this research is to evaluate the environmental conditions in the Jaboatao River estuarine system (8°14′S/34°55′W), by studying sedimentary organic matter, which may provide information about anthropogenic influence in this tropical mesotidal estuary. The catchment area is 442 km2 with a population estimated at 500,000 inhabitants, and is characterized as an urban coastal plain estuarine system. Thirty surface sediment samples were collected in November-2010 (dry season) and May-2011 (rainy season). Results indicated that the adjacent sediments from continental shelf are sandy, moderately sorted and bioclastic (74.8%CaCO3), differing from estuarine sediments, which although sandy (silty-sand) are lithoclastic (17.4%CaCO3) and poorly sorted. The predominance of sand observed in both seasons is due to the small length of the river (75km) and to the low supply of mud sediments, since its drainage basin is located mostly on sandy coastal plain. Carbon and nitrogen contents indicates a sensitive seasonal variation with large ranges, varying from 0.03–8.51% and from 0.00–0.54%, respectively, with higher contents prevailing in the inner portions of the estuary and gradually decreasing towards the shelf. The organic matter origin, according to the C/N ratios and δ13C values reflected the occurrence of marine organic matter in shelf samples (C/N<7.0/δ13C>-20.0‰PDB). However, the estuary terrigenous organic matter proportion increases upward (C/N>15.0). The δ13C values are typical of C4 higher plants (−27.0‰PDB) and domestic sewage mix (−26.7‰PDB), ranging from −28.0 to −25.9‰PDB and indicating evidences of urban pollution in Jaboatão estuarine sediments.

Determination of geochemical background values on a tropical estuarine system in a densely urban area. Case study: Capibaribe estuary, Northeastern Brazil

This study aims to infer the background values of several metals in the Capibaribe estuary and to identify the likely impact of anthropic activities during 200-years of sedimentation. Two cores were sampled, with subsamples at intervals of 2cm. Sedimentation rates and metal concentrations were analyzed. The Al-normalized method was used to infer the background values, and to identify anthropic influences, the enrichment factor, the contamination factor and the geoaccumulation index were employed. The background values showed concentrations for Mn of 292.2, for Co of 10.4, for Ni of 22.3, for Cu of 60.8, for Zn of 105.5, for As of 106.0, for Pb of 52.9 (all in mgkg-1) and for Fe of 2.7%, The higher values, mainly for As, Zn and Pb, are associated with the influence of the Barreiras Formation. The geogenic inputs are significantly greater than the anthropic activities, masking the contamination.

INFLUÊNCIA DA MARÉ NA VARIABILIDADE SEDIMENTAR DA BARRA DE CATUAMA, ILHA DE ITAMARACÁ, PERNAMBUCO-BRASIL

Um estudo sobre a dinâmica e composicao sedimentar foi realizado na barra norte do canal de santa Cruz (07°41’S/34°50’W), que separa a Ilha de Itamaraca do continente. O objetivo deste trabalho foi analisar a influencia da mare na estrutura sedimentar, sendo realizadas coletas em um transecto transversal, durante um ciclo semidiurno de mares sizigia. As amostras foram coletadas em tres pontos equidistantes (ST1, ST2 e ST3), durante uma baixa-mar e uma preamar. Foram realizadas analises de Carbonato de calcio (CaCO3), materia orgânica total (MOT) e granulometria. Os resultados da analise granulometrica sofreram tratamento estatistico para obtencao do grau de selecao, diâmetro medio, classificacao e composicao sedimentar. Foram executadas tambem analises estatisticas de correlacao (Spearman) com os parâmetros de CaCO3, MOT, diâmetro medio e percentual de areia. Os resultados mostraram que na estacao proxima ao continente, ST1, o material sedimentar nao apresentou nenhuma alteracao em sua composicao, aumentando apenas os teores de CaCO3 e de MOT (21% a 24%; 1,37% a 1,87% respectivamente) durante a baixa-mar. Na ST2 os teores de CaCO3 e MOT tambem aumentaram durante a baixa-mar (13,9% a 40,5%; 1,80% a 2,03% respectivamente), enquanto o sedimento varia apenas no grau de selecao (de moderado a pobremente selecionado). A ST3, proxima da ilha, teve um decrescimo de todos os parâmetros analisados em relacao a preamar, visto que o CaCO3 caiu de 17,2% para 8,6%, a MOT caiu de 1,30% para 1,23%, assim como o grau de selecao que foi de moderado a pobremente selecionado e a granulacao que foi de areia grossa para media. As analises de correlacao (Spearman) indicaram relacao significativa entre o teor de CaCO3 e MOT (rs= 0,72) e uma relacao nao significativa desses teores com o diâmetro medio e a fracao areia. Conclui-se que embora a granulometria nao apresente uma variacao intermareal consideravel, a mare e a hidrodinâmica dos estuarios adjacentes atuam como agentes controladores na deposicao da materia orgânica e do carbonato. Uma vez que as correntes marinhas com direcao sul-norte deslocam o material para norte durante a subida da mare e a hidrodinâmica dos rios carreiam esse material para o sul, fazendo com que a ST2 seja uma area de by-pass de sedimentos, que precisamente e o eixo do canal e o ponto medio do transecto de estudo.

Mangroves – Captured By The Keen Eye Of A 17th Century Landscape Painter

Artists and scientists alike came across unfamiliar landscapes and strikingly strange fauna and flora when they embarked for the ‘colonies’. In the 17th and 18th centuries curiosity for the exotic developed into direct scientific observation, which is often still appreciated scientifically today, such as in biological taxonomy. Often observation, interpretation and reporting were geared towards functional aspects, a resourcist view on the environment in the wake of the colonial enterprise. This entailed that focus could be biased towards aspects of mercantile, political or strategic interest. Landscape vision is no exception for the possible biases. The Dutch painter Frans Post during his 7 year stay in the New World (Brazil) in the 17th century was the first to depict mangroves as a very characteristic tropical vegetation, unfamiliar to Europeans, in spite of its limited interest in the context of colonial economy. He did this in the strong and developing tradition of Dutch landscape painting.

Vertical hydraulic gradient research in hyporheic zone of Beberibe river in Pernambuco State (Brazil)

The interaction between groundwater and surface water occurs naturally and is dependent on the dynamics in the hyporheic zone. The hyporheic zone is the interface between the surface water source and the phreatic aquifer and it’s a system that also influences the water quality. An important feature is the ability to flux in this zone. This work aimed to evaluate the vertical hydraulic gradient in the hyporheic zone at two points in Beberibe river, Olinda-PE, to understand the hyporheic environment characteristics and water flow dynamics in experimental area, in addition to identify the existence of hydraulic connection between surface water and groundwater. The experimental phase consisted of infiltration tests in riverbed with cylinder infiltrometer and vertical hydraulic gradients readings with differential piezometer, complemented with grain size information, for an assessment of the water budget between the river and the aquifer. Analyzing the behavior of the interaction over the period of 10 months, it was observed that the Beberibe river (middle course) contributes to the groundwater recharge in most of the time. The average infiltration rate was 1.02 mm/min in point 1 and 0.85 mm/min in point 2. It was concluded that there is a variability in flow direction, which often is top-down, but may undergo change in the stream showing upstream after long periods of rainfall. Another conclusion is that grain size distribution of bed sediment, that is predominantly sandy, influences hydraulic conductivity of hyporheic zone and influences consequently the vertical flow rates.