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Migração lateral da desembocadura do Rio Itapocú, SC, Brasil: evolução morfológica e condicionantes físicas

CASSIANO, Gabriela Freire; SIEGLE, Eduardo
Fonte: Sociedade Brasileira de Geofísica Publicador: Sociedade Brasileira de Geofísica
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
26.81%
Desembocaduras são ambientes bastante dinâmicos e sujeitos à complexa interação entre fatores estabilizadores e desestabilizadores. Dependendo dessa interação, desembocaduras podem apresentar a tendência de migração ao longo de barreiras arenosas. Um dos mecanismos mais eficientes de transporte de sedimento paralelo à costa, e consequentemente migração de canais, são as correntes longitudinais geradas pelas ondas se aproximando obliquamente à costa. A motivação do presente trabalho é entender o comportamento morfodinâmico do sistema de desembocadura do rio Itapocú, localizado no centro-norte de Santa Catarina (SC), frente aos processos forçantes que atuam na sua migração ao longo da linha de costa. A morfologia dos pontais arenosos foi obtida a partir de levantamentos morfológicos com o uso de DGPS. Para analisar a refração de ondas foi utilizado o modelo numérico MIKE 21 SW, sendo considerados como condições de contorno os dados de ondas referentes ao ano de 2002 e os dados de ondas previstos referentes ao período de coleta. Os dados de saída do modelo foram utilizados para estimar a deriva litorânea potencial na região. Os resultados morfológicos obtidos demonstraram uma migração da desembocadura para o norte durante o período analisado...

Migração lateral da desembocadura do Rio Itapocú, Santa Catarina - Brasil: evolução morfológica e condicionantes físicas; Lateral migratin of the Itapocú Inlt, SC -Brazil: morphological evolution and forcing conditions

Cassiano, Gabriela Freire
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 29/10/2008 PT
Relevância na Pesquisa
26.81%
Desembocaduras são ambientes bastante dinâmicos e sujeitos à complexa interação entre fatores estabilizadores e desestabilizadores. Dependendo dessa interação, desembocaduras podem apresentar a tendência de migração ao longo de barreiras arenosas. Um dos mecanismos mais eficientes de transporte de sedimento paralelo à costa, e conseqüentemente migração de canais, são as correntes longitudinais geradas pelas ondas se aproximando obliquamente a costa. A motivação do presente trabalho é entender o comportamento morfodinâmico do sistema de desembocadura do rio Itapocú, localizado no centro-norte de Santa Catarina, frente aos processos forçantes que atuam na sua migração ao longo da linha de costa. A morfologia dos pontais arenosos foi obtida a partir de levantamentos morfológicos com o uso de DGPS. Para analisar a refração de ondas foi utilizado o modelo numérico MIKE 21 - SW, sendo considerados como condições de contorno dados de ondas referentes ao ano de 2002 e dados de ondas previstos referentes ao período de coleta. Os dados de saída do modelo foram utilizados para estimar a deriva litorânea potencial na região. Os resultados morfológicos obtidos demonstraram uma migração da desembocadura para o norte durante o período analisado...

A dinâmica sedimentar e a caracterização de Zonas de Erosão Acentuada (ZEA) ao longo do arco praial de Massaguaçu, SP; The sediment dynamics and the characterization of erosional Hot Spot (EHS) in Massaguaçu beach, SP

Rogacheski, Carlos Eduardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/11/2010 PT
Relevância na Pesquisa
27.02%
Nas últimas décadas, a praia de Massaguaçu vem sofrendo processos erosivos intensos, cujos segmentos possuem taxas de recuo acentuadas, denominadas Zonas de Erosão Acentuada (ZEAs). Partindo deste problema este trabalho se propôs a entender a dinâmica sedimentar do arco praial de Massaguaçu e das possíveis causas de formação e manutenção das ZEAs. A coleta de dados se baseou no levantamento batimétrico e do clima de ondas, bem como no levantamento sonográfico de varredura lateral e na coleta de amostras de sedimento de superfície da antepraia de Massaguaçu. Para processar os dados se optou pela aplicação da modelagem numérica utilizando o modelo SWAN (propagação de ondas em águas profundas) e o modelo SMC (módulos OLUCA, COPLA e EROS, que trabalham, respectivamente, com propagação de ondas em águas rasas, simulação de correntes e simulação de transporte sedimentar). Para a formulação da discussão foram selecionados os 6 (seis) casos que apresentaram as condições de ondas mais representativas. Tais casos mostraram que a dinâmica sedimentar e os processos costeiros responsáveis pela formação e manutenção das ZEAs são controlados por dois padrões distintos de ondas incidentes. O primeiro padrão está relacionado às ondas vindas de NE - E...

Sedimentação Quaternária na Planície Costeira de Peruíbe-Itanhaém (SP)

Giannini, Paulo Cesar Fonseca
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/06/1987 PT
Relevância na Pesquisa
27.11%
Este trabalho contém uma caracterização sedimentológica dos depósitos marinhos, com ênfase aos sedimentos arenosos, aflorantes ao longo da planície costeira de Peruíbe - Itanhaém, envolvendo basicamente distribuição granulométrica, mineralogia e morfometria. A planície costeira de Peruíbe-Itanhaém constitui-se numa faixa de cerca de 25 km de extensão contínua de sedimentos quaternários regressivos situada no litoral sudoeste do Estado de São Paulo, apresentando largura variável desde 4 até 14 km e altitudes entre 0 e 14 m. Tem como fronteiras naturais a Serra do Peruíbe (subsidiária da Serra do Itatins), a SW, o Morro do Poço de Anchieta e os morros Botoruçu, Araraú, e Novo Mundo, a NE, e a Serra das Laranjeiras (subsidiária da Serra do Mar), na parte interior. Entre o flanco norte da Serra do Peruíbe e a porção meridional da Serra das Laranjeiras, define-se, parcialmente controlado por lineamentos associados à Falha de Itariri, o sistema flúvio-paleolagunar dos rios Preto e Branco de Peruíbe, enquanto na extremidade oposta da planície (NE), ocorre outro sistema semelhante, compreendendo os rios homônimos de Itanhaém. Estes dois sistemas flúvio-paleolagunares constituem as únicas zonas de sedimentação areno-lamosa aflorantes na planície...

Dinâmica sedimentar quaternária no litoral sul paulista; Not available.

Tessler, Moyses Gonsalez
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/09/1988 PT
Relevância na Pesquisa
27.05%
A origem e evolução das feições arenosas holocênicas, presentes no litoral sul paulista, estão vinculadas à ação da dinâmica litorânea atual, bem como ao papel representado pelos processos dinâmicos pretéritos. Esta dinâmica atual, fortemente condicionada pelos mecanismos de circulação atmosférica do continente sul-americano tem, nas correntes de deriva litorânea geradas a partir da interação dos trens de ondas incidentes com alinha de costa, o principal mecanismo de movimentação de sedimentos arenosos, junto ao fundo, no litoral sul paulista. A interação entre os mecanismos de circulação atmosférica do continente sul-americano e os trens de ondas incidentes constitui a base para a compreensão da origem e do sentido de deslocamento das correntes litorâneas de fundo, a partir dos trens de onda provenientes de S e SE são geradas correntes de deriva litorânea que se propagam no litoral sul rumo ao litoral centro-sul paulista, NE. Por outro lado, as correntes litorâneas de sentido inverso (SW), são geradas a partir dos trens de onda incidentes dos quadrantes NE - E. Esses sistemas de correntes litorâneas, de sentidos opostos, são responsáveis pela redistribuição dos sedimentos provenientes da cobertura sedimentar atual da plataforma continental próxima bem como dos sedimentos de origem continental...

Sediment Transport using Grain Size Trend Analysis: A Case Study in SW of Portugal

Du, XIAOQIN; Gama, Cristina; Liu, James
Fonte: Asia Oceania Geosciences Society- AOGS 2011 Publicador: Asia Oceania Geosciences Society- AOGS 2011
Tipo: Aula
ENG
Relevância na Pesquisa
26.61%
As a embayed coast, the main sediment sources are fluvial discharges, sea-cliff erosion and sand carried by longshore currents [1]. The particles are transported in suspended load or bedload pattern under the coactions of tidal currents and waves. In response to sediment transport processes, the spatial variations in the grain-size parameters exist, that reflect the net particles transport trend and the dynamic conditions. Thus, the grain size trend analysis was developed to study the net sediment transport. The study area is an embayed coast from Troia to Sines in SW of Portugal. There is a cape in the south end while the north end is a mountain belt with 35 km in length and 500 m in height [2]. A river with small discharge lies in the north. The tidal range varies between 1.5~3.5 m while the swell and winds from the west and northwest are dominant [3]. Therefore, the study area is sheltered from persist winds from north in summer and exposed to the storm waves from southwest in winter. The surfical sediment was sampled in the shallow water in 1980, 1983 and 1985, respectively. In order to obtain the important sediment source and sediment transport trend, three approaches were used: (1) the EOF (Empirical Orthogonal Function) analysis technique; (2) the McLaren Model; (3) grain size trend analysis. The wave is dominant in the study area. The result of EOF analysis shows that the most important sediment source is cliff erosion. The sediment eroded from cliffs during storms and high waves was transported off-shore and southward in the south part during high energy effect...

Dinâmica Costeira dos Campos petrolíferos Macau/Serra, litoral setentrional do Estado do Rio Grande do Norte

Chaves, Marcelo dos Santos
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Geodinâmica e Geofísica; Geodinâmica; Geofísica Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Geodinâmica e Geofísica; Geodinâmica; Geofísica
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
26.87%
This thesis describes the general behavior of the northern shore of the State of Rio Grande do Norte relating beach profile morphology with hydrodynamic and sedimentological parameters. The Macau and Serra Oil Field are inserted on this area and are under accelerated coastal erosion. At these oil fields are installed oil wells from PETROBRAS, nowadays located directly in the shoreline, under constant attacks of coastal processes (e.g. waves, tides and currents), which promote an intense morphodynamic variability of this sandy coast. The area was monitored for 24 months in three different stations (P01, P02 and P03). The methodology applied involved current techniques of beach profiles, hydrodynamical processes, remote sensing and geophysics. A synthesis of results obtained through the use of different time scales (monthly, lunar cycle, seasonal, annual) from a coastal dynamics study is presented. The average wind direction corresponded to 77ºAz (NE). The steepness of the berm and of the shoreface, as well as coastal current direction, do not present major changes, with an average of 36º for the steepness of the berm, 15º for the shoreface and 15º for the coastal current direction. This data set allows us to infer that the months of larger coastal erosion were November/2000 and April/2001...

Morfodin?mica costeira e o uso da orla oce?nica de Salin?polis (Nordeste do Par?)

RANIERI, Leilanhe Almeida
Fonte: Universidade Federal do Pará Publicador: Universidade Federal do Pará
Tipo: Tese de Doutorado
POR
Relevância na Pesquisa
26.84%
Os aspectos morfodin?micos relacionados ? eros?o ou acres??o da linha de costa s?o alguns dos assuntos analisados na gest?o das zonas costeiras que v?em sendo tratada em todo mundo no sentido de monitorar e proteger essas zonas. Esta tese objetiva analisar o comportamento da morfodin?mica costeira de Salin?polis, relacionando-o ao uso da orla oce?nica. A ?rea de estudo foi compartimentada em tr?s setores: Oeste (praias da Corvina e do Ma?arico), Central (praia do Farol Velho) e Leste (praia do Atalaia). A metodologia consistiu na: (a) aquisi??o e tratamento de imagens multitemporais (1988-2001-2013) do sat?lite Landsat 5 TM, 7 ETM e 8 OLI; (b) aplica??o de entrevistas/question?rios com banhistas, (c) aquisi??o de dados de campo durante as esta??es chuvosa (26, 27, 28/04/2013) e menos chuvosa (04, 05, 06/10/2013); e (d) an?lise laboratorial para o tratamento dos dados adquiridos em campo (topografia das praias estudadas, amostragem de sedimentos superficiais das mesmas e com o uso de armadilhas, e medi??es oceanogr?ficas de ondas, mar?s, correntes e turbidez). Foram feitas as representa??es gr?ficas dos perfis topogr?ficos das praias, calculados os par?metros estat?sticos granulom?tricos de Folk & Ward (1957), as taxas do transporte sedimentar nas praias e os par?metros morfom?tricos de Short & Hesp (1982)...

Analysis of nearshore currents near a submarine canyon

Cushanick, Matthew Stephan
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Relevância na Pesquisa
36.86%
Accurate prediction of nearshore waves and currents is of critical importance in littoral naval operations. This study examines the effects of complex bathymetry on nearshore currents. Data collected by an array of 12 pressure and velocity sensors in the Nearshore Canyon Experiment (NCEX), conducted near La Jolla, California in 2003, were analyzed to investigate the variability of nearshore currents near a submarine canyon. Time series of pressure, 3-component velocity, and wave heights along the 10 meter depth contour were analyzed to determine the relative importance of tides, waves, and winds in the forcing of nearshore currents outside the surf zone. Additionally, the spatial variability of the observed currents was investigated in relation to the nearby canyon head. Case studies are examined to determine how different wave and tide conditions affect the currents near the canyon. In low-moderate wave conditions, tides dominate longshore currents, whereas cross-shore currents show the passage of irregular bore-like features. The currents are coherent away from the submarine canyon and decay towards the canyon head. Strong longshore currents were observed near the canyon head during a large wave event that were likely driven by an alongshore pressure gradient associated with wave set-up variations.

Small-scale morphology related to wave and current parameters across the surf zone

Swayne, Jeffrey Lynn
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
26.69%
Small-scale beach morphology (scales < 5 m) height variations were measured by combining the CRAB survey with bed elevation acquired from a 1 MHZ sonic altimeter mounted on the CRAB during the October phase of the DUCK94 experiment. Bedform types were observed using a 500kHZ side-scan sonar also mounted on the CRAB. Corollary waves and currents were measured. Three cases were examined in detail: mild waves and weak longshore currents resulting in wave ripples everywhere; storm waves with strong longshore currents resulting in lunate and straight crested megaripples in the trough of the barred beach; and narrow banded, normally incident waves with a strong rip current resulting in a relatively planar bed everywhere except in the throat of the rip where magaripples were measured. The predictive wave ripple height and length equations of Nielsen (1981) worked reasonably well for mild wave conditions, but did not predict ripples during moderate wave conditions. The wavenumber spectra were generally broad, indicating that newly formed ripples coexisted with residual ripples from the past to form complex, multi-scaled ripple patterns. (MM)

Nearshore currents over a barred beach

Faria, Garcez; Fernando, Antonio
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
ENG
Relevância na Pesquisa
27%
Approved for public release; distribution is unlimited.; The objective of this dissertation is to develop numerical models and compare their predictions with data acquired during the DUCK94 experiment in order to improve our physical understanding of the hydrodynamic processes governing the vertical and cross shore distributions of both longshore and cross shore currents over a barred beach. The vertical structure of the mean longshore current is found to be well described by a logarithmic profile and a relationship between bed shear stress and bottom roughness, including the influence of ripples and mega-ripples, was also found. The vertical structure of the mean cross shore current (undertow) is modeled using an eddy viscosity closure scheme to solve for the turbulent shear stress and includes contributions from breaking wave rollers. These models of the vertical profiles of longshore and cross shore mean currents are combined to formulate a quasi three dimensional model to describe the cross shore distribution of the longshore current. This model includes turbulent mixing due to the cross shore advection of mean momentum of the longshore current by the mean cross shore current and contributions from wave rollers

A simple quasi-three dimensional model of longshore currents over arbitrary profile

Faria, Antonio Fernando Garcez
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
36.99%
The long shore current maximum observed in the trough of a barred beach during the nearshore dynamics experiment DELILAH at Duck, North Carolina, is not predicted by present theory. The simplest longshore curren models balance cross-shore changes in the alongshore wave momentum (radiation stress) with the alongshore bottom shear stress. Waves break over the bar, reform in the trough and again break on the foreshore resulting in changes in the radiation stress, which predicts two jets, one over the bar and the other at the foreshore, which does not agree with the observed current maximum in the trough. The advection of the momentum of the longshore current by mean cross-shore currents as a source of momentum mixing is investigated. The longshore current is strongest toward the surface and decreasing to zero at the bottom. The cross-shore mean current has an onshore transport in the wave crest/trough region and an offshore transport beneath (undertow). The net interaction can induce significant lateral mixing of the alongshore momentum of the mean currents, which is shown using a simplified three- dimension model of nearshore currents to explain much of the differences with observations.

Vertical profiles of longshore currents

Soares Costa Ventura, Carlos Manuel da.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
46.76%
The vertical structure of the mean longshore current is examined on three strong current days during the DUCK94 experiment and it is found well described by a logarithmic profile (mean correlation coefficient for all 22 profiles, 0.98). This hypothesis works better in the trough where turbulent bottom boundary layer processes are predominant than over the bar, where breaking wave induced turbulence generated at the surface modifies the profile. A relationship between near bottom vertical velocity profiles and bottom roughness was found. The bed shear stress coefficient varied by an order of magnitude across the surf zone (0.001-0.05). For the three days considered, it is concluded that the bed shear stress coefficient increased with increasing bottom roughness, and therefore is an important parameter to characterize the bottom boundary layer. The influence of the wind is parameterized by an exponential approximation that works well in 50% of the analyzed profiles. This parameterization assumes that the residual Data Normal distribution of data is only due to the wind and does not consider the alongshore component of mass transport velocity, which is assumed small. These results should be treated carefully since there were obtained for only three days over a barred beach with strong longshore currents and cannot be generalized without further studies.

Topics in longshore currents

Church, John Casey.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: 124 p.
EN_US
Relevância na Pesquisa
57.08%
Approved for public release; distribution is unlimited.; The momentum equation governing mean longshore currents on straight beaches is a balance of forcing from the momentum transfer of the oscillatory wave motion, turbulent momentum transfer (mixing), and bottom stress. Of these, the wave's contribution is well understood, but the remaining two are not, principally due to the complicated hydrodynamics of the surf-zone. Addressing the bottom stress term, a longshore current model is developed which includes a modification of the bottom stress due to the effects of breaking-wave induced turbulence. A one-dimensional turbulent kinetic energy equation is used to model this breaking-wave induced turbulence, producing a spatially varying bottom friction coefficient. The modeled longshore current cross-shore profiles show improved agreement with field observations. In a second bottom stress study, vertical profiles of mean longshore currents are examined using field data obtained with vertically stacked electromagnetic current meters with the goal of measuring the bottom stress and its associated drag coefficient. The profiles are observed to become vertically uniform whenever the ratio of wave height to depth exceeds 0.3, indicating that nearly all of the waves passing a given location are breaking. Finally...

Estudo de agitação, correntes induzidas por ondas e balanço sedimentar da região do Porto de Tubarão e Praia de Camburi, Vitória/ES; Study of wave clima, wave induced currents and sedimentary balance in the region of the region of the Tubarão harbour, Vitória-ES

Marquez, André Lanfer
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/02/2010 PT
Relevância na Pesquisa
46.51%
Os ambientes costeiros podem ser caracterizados por sua grade dinâmica, onde existe o embate entre o continente e o mar. A dinâmica sedimentar da linha de costa constitui conhecimento básico em obras de engenharia e na compreensão do ambiente costeiro. Buscou-se compreender os mecanismos do funcionamento dinâmico da região em torno do Porto de Tubarão, Vitória-ES, através de análises de marés, de clima de ondas, agitação marítima, de correntes induzidas por ondas e transporte sedimentar. Os resultados permitiram algumas interpretações tanto de curtíssimo prazo como de longo prazo. As correntes de marés são particularmente importantes, sobretudo próximo as bocas dos canais de Vitória e da Passagem atingindo valores de até 0,.7m/s. As ondas atingem a área com alturas significativas variadas, dependendo do grau de exposição. Na praia de Camburi as ondas dificilmente ultrapassam 1 metro de altura significativa, enquanto na praia Mole ondas de 2.5m de altura significativa ocorrem com certa freqüência. A direção da corrente na praia Mole está diretamente relacionadas com as direções de incidência das ondas variando de NE até SW, enquanto sua intensidade está relacionada com as alturas e períodos, variando de 0 até 0.44 m/s. A praia de Camburi...

Coastal hydrodynamics and longshore transport of sand on Cassino beach and Mar Grosso beach, southern Brazil

Fontoura, Jose Antonio Scotti; Almeida, Luiz Emilio Sa Brito de; Calliari, Lauro Julio; Cavalcanti, Augusto Muniz; Möller Junior, Osmar Olinto; Romeu, Marco Antônio Rígola; Christófaro, Bruno Ramos
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.61%
The hydrodynamic and morphodynamic parameters of a region in southern Brazil were determined by collecting sediments with stream traps (bedload and suspended load) in the surfzone and capturing images, studying topography, and researching sedimentology with the help of a movie camera, a total station, and laboratory work. Data on deep-water waves were garnered with a CPTEC/INPE model. Field work was carried out in 50 field trips during a 1-year period; 42 out of 50 trips focused exclusively on hydrodynamic and morphodynamic data, whereas eight of the trips were also used for collecting sediments. In addition, data on wind direction and velocity and on the longshore currents were also collected. All data were obtained in normal atmospheric conditions. Field work was carried out in six cross-shore profiles along Cassino Beach and Mar Grosso Beach (three profiles on each side of the estuary of Patos Lagoon).

Do mud deposition events on sandy beaches affect surf zone ichthyofauna? A southern Brazilian case study

Giovanini, Renata Mont'Alverne Bretz; Moraes, Leonardo Evangelista; Rodrigues, Fábio Lameiro; Vieira, João Paes
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.61%
Using fluid mud deposition events which occur regularly at Cassino Beach in south Brazil, we evaluated the influence of such events on the structure of the ichthyofauna inhabiting its shallow surf zone. Wave action was the dominant factor in differentiating between sampling sites, being lower or even absent at the mud-influenced sectors compared to beach area without mud. Samples were collected using a beach seine net at two control locations (A1 and A2), and at three locations influenced by mud deposition (B1, B2, and B3). During the study period (21 Aprile04 August 2009), 15,245 fishes were captured and separated into 26 taxonomic groups, from species to family. Individuals of a total length (TL) up to 50 mm accounted for 65% of the catch, while individuals of TL < 30 mm were the most numerous and more responsible for the total abundance spatial pattern. The area with higher wave action (A2) had the lowest relative species abundance and greatest diversity, whereas the areas with mud-forced lowest wave action (B2 and B3) had the highest species abundance values. Three hypotheses were proposed to explain the higher concentration and capture of juvenile fishes at mud locations. First, longshore currents may be responsible for the displacement of juvenile aggregations toward areas of lower energy. Second...

COASTAL CURRENTS AND SEDIMENT TRANSPORT IN PARANAGUA ESTUARY COMPLEX NAVIGATION CHANNEL; CORRENTES COSTEIRAS E TRANSPORTE DE SEDIMENTOS NOS CANAIS DE NAVEGAÇÃO DO ESTUÁRIO DA BAÍA DE PARANAGUÁ

Noernberg, Mauricio Almeida; UFPR; Marone, Eduardo; UFPR; Angulo, Rodolfo José; UFPR
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 23/04/2009 POR
Relevância na Pesquisa
46.49%
The coastal currents variability and ability to carry sediment by bed load transport at the external area of thenavigation channel of Paranaguá’s estuary complex were analyzed from data obtained from two type L mooringslocated about 3.5 km from the coast, taken between 4/16/1997 and 6/17/1997. The local dynamics, as well asthe bottom transport of sandy sediments are ruled mainly by tidal currents which work mostly perpendicular andoutward from the coast. However, in a high energy situation associated to increased ocean wave energy, theparallel component to the coast gains prominence in the residual circulation, enhancing the sediment transport towards and along the coast.; A variabilidade das correntes costeiras e a capacidade dessas correntes em transportar sedimentos por traçãoforam analisadas, na área externa do canal de acesso marítimo do Complexo Estuarino de Paranaguá, a partirde dados de dois fundeios do tipo L, localizados a aproximadamente 3,5 km da costa, e realizados entre os dias16/04/97 e 17/06/97. A dinâmica local, bem como o transporte dos sedimentos arenosos do fundo, é governadaprincipalmente pelas correntes de maré, as quais agem preferencialmente transversalmente à costa e no sentidocosta afora. Contudo...

NET SEDIMENTS TRANSPORT PATHS BASED ON THREE GRAIN-SIZE TRENDS ANALYSIS PROGRAMS IN THE SOUTH SECTOR OF THE PARANAGUÁ ESTUARINE COMPLEX OUTLET DELTA - SOUTH BRAZIL; PADRÕES DE TRANSPORTE DE SEDIMENTOS BASEADO EM TRÊS PROGRAMAS GERADORES DE VETORES DE TENDÊNCIAS DE TRANSPORTE A PARTIR DE PARÂMETROS GRANULOMÉTRICOS NA PORÇÃO SUL DO DELTA DE DESEMBOCADURA DO COMPLEXO ESTUARINO DE PARANAGUÁ - SUL DO BRASIL

Veiga, Fernando Alvim; Angulo, Rodolfo José; Marone, Eduardo; Brandini, Frederico Pereira; Soares, Carlos Roberto
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 25/09/2006 POR
Relevância na Pesquisa
26.89%
This work presents the results of GSTA, GSTAST and TRANSVEC grain size trend analysis programs based in mean size, standard deviation and skewness parameters of bottom sediments at the south portion of the Paranaguá Estuarine Complex Outlet Delta. The longshore sediment transport is from southwest to northeast in the area, ruled by episodically high-energy frontal systems events. Consequently, the sediments are trapped by the hydraulic dam formed by tidal currents and the south part of the outlet is quite large that the north portion. Thus, an extended breaking wave field from 1.5 to 5 meters water depth named Galheta Bank is formed. Currents and wave action in this bank sediments cause spit formation that moves landward into the bay mouth. The result suggests that the trends generated by GSTA program fits with the bathymetry. They are according to the expectations in the southern and center sector of the area, but they are not in the NE and NW sectors. The TRANSVEC program identifies the transport path to the marginal channel of the delta and the tendency of this channel to export sediments during strong ebb tide currents in the NW sector, but the vectors also indicate SW preferential transport that contradicts field observations. The most consistent result was obtained by GSTAST program that generates empiric data and a significant test with 95% confidence before validating or not the resultant vectors. The eastern vectors reflect wave sediment transport on the Galheta bank...

Sand Characteristics and Beach Profiles of the Coast of Gaza Strip, Palestine

Ubeid,Khalid Fathi
Fonte: Serie correlación geológica Publicador: Serie correlación geológica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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The Gaza Strip's coastline forms a small section of the south-eastern corner of the Levantine Basin. The Strip is 45 km long and from 6 to 12 km wide. Its coastal zone covers approximately 74 km², of which 2.7 km² is beach. This study first describes the coastal zone's profile from observations and the literature. This study also collected 36 sandy sediment samples from 12 sites along its beaches and performed a textural study and statistical analysis of grain-size distribution. The beach tends to be narrower in the north and center and wider in the south and its northernmost stretches and in some sites in the center. The narrower stretches tend to be due to the effects of the seaport and other human construction activity on the sedimentation and erosion rates. The beach profile's slope varies from a few degrees to 90 degrees. At some sites actions of the waves and tides have caused the sea cliff to erode and mix with the beach sands. Longshore currents bring sands to the beaches from the Nile delta and then northward along the shore. The sand grains become segregated as they move from south to north, being finer as they move north. In general, this study's analysis of the surface samples found medium-grained sands to predominate...