HR: 1330h
AN: OS23A-13    [Abstracts]
TI: Quantifying Sediment Transport Determined From Grain-Size Distributions
AU: * De Almeida, R A
EM: roberto@dealmeida.net
AF: USP Instituto Oceanografico, Praça do Oceanográfico 191, São Paulo, SP 05508-120 Brazil
AU: Möller, O O
EM: dfsomj@furg.br
AF: FURG Laboratório de Oceanografia Física, Av. Itália km 8, Rio Grande, RS 96201-900 Brazil
AU: Lentini, C A
EM: lentini@io.usp.br
AF: USP Instituto Oceanografico, Praça do Oceanográfico 191, São Paulo, SP 05508-120 Brazil
AU: Campos, E J
EM: edmo@io.usp.br
AF: USP Instituto Oceanografico, Praça do Oceanográfico 191, São Paulo, SP 05508-120 Brazil
AB: A technique derived from McLaren & Bowles (1985) has been applied to investigate sediment dynamics in the Patos Lagoon estuary (Brazil). Qualitative sediment transport in the access channel of the estuary was inferred from changes in statistical properties describing grain-size distributions. Assuming the influence of a single transport function, the spatial gradient of particle mean size, sorting and skewness was used to determine the transport direction along the channel. A long-average net sediment deposition rate in the area was estimated using digitalized historical nautical charts. This deposition rate was used to quantify the sediment transport inside the estuary, through a simple application of Green's Theorem. Results show a net seaward transport in the deep channel of approximately 50 m³ day^-1, accompanied by a net inward transport in the shallower channel margin of similar intensity. The estimated net sediment transport was validated against a numerical model output, with good agreement in terms of direction and intensity.
DE: 4235 Estuarine processes
DE: 4558 Sediment transport
SC: Ocean Sciences [OS]
MN: 2005 Joint Assembly