A model for the settling of nonuniform cohesive sediment in a laboratory flume and an estuarine field setting

Lancaster Environment Centre

Keywords

COHESIVE SEDIMENT, DEPOSITION, LABORATORY TESTS, FIELD MEASUREMENTS, CRITICAL SHEAR STRESS, SETTLING VELOCITY, NONUNIFORM SEDIMENT, NUMERICAL MODEL, FLOC SIZE DISTRIBUTION, ANNULAR FLUME, MERSEY ESTUARY

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Published

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A model for the settling of nonuniform cohesive sediment in a laboratory flume and an estuarine field setting. / OCKENDEN, M C .
In: Journal of Coastal Research, Vol. 9, No. 4, 1993, p. 1094-1105.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Bibtex

@article{e82a801a1d7646df9f25c5462ffe2a14,

title = "A model for the settling of nonuniform cohesive sediment in a laboratory flume and an estuarine field setting",

abstract = "A numerical model for deposition of non-uniform cohesive sediment at a point was applied to laboratory and field settings. The results were compared with those from a uniform sediment model applied to the same settings. In the non-uniform (distributed) model, classes of sediment (representing different floc sizes) each had a corresponding settling velocity and critical shear stress for deposition. The models were applied to laboratory deposition tests in an annular flume. Tests with steady and slowly decelerating flow were both modelled. The distributed sediment model was shown to be a much better model of deposition in decelerating flow in the closed system of the annular flume. The model was shown to be sensitive to the settling velocity of the class corresponding to the largest flocs. The importance of more accurate methods of determining floc size and settling velocity distributions was recognised. Both models were also applied to field measurements of deposition during a tide made in the Mersey Estuary. Both models gave a reasonable fit to the data, but the distributed sediment model did not significantly improve the uniform sediment model for field use. External influences and advection of sediment from outside the immediate area were shown to affect the field measurements.",

keywords = "COHESIVE SEDIMENT, DEPOSITION, LABORATORY TESTS, FIELD MEASUREMENTS, CRITICAL SHEAR STRESS, SETTLING VELOCITY, NONUNIFORM SEDIMENT, NUMERICAL MODEL, FLOC SIZE DISTRIBUTION, ANNULAR FLUME, MERSEY ESTUARY",

author = "OCKENDEN, {M C}",

year = "1993",

language = "English",

volume = "9",

pages = "1094--1105",

journal = "Journal of Coastal Research",

issn = "0749-0208",

publisher = "Coastal Education Research Foundation Inc.",

number = "4",

}

RIS

TY - JOUR

T1 - A model for the settling of nonuniform cohesive sediment in a laboratory flume and an estuarine field setting

AU - OCKENDEN, M C

PY - 1993

Y1 - 1993

N2 - A numerical model for deposition of non-uniform cohesive sediment at a point was applied to laboratory and field settings. The results were compared with those from a uniform sediment model applied to the same settings. In the non-uniform (distributed) model, classes of sediment (representing different floc sizes) each had a corresponding settling velocity and critical shear stress for deposition. The models were applied to laboratory deposition tests in an annular flume. Tests with steady and slowly decelerating flow were both modelled. The distributed sediment model was shown to be a much better model of deposition in decelerating flow in the closed system of the annular flume. The model was shown to be sensitive to the settling velocity of the class corresponding to the largest flocs. The importance of more accurate methods of determining floc size and settling velocity distributions was recognised. Both models were also applied to field measurements of deposition during a tide made in the Mersey Estuary. Both models gave a reasonable fit to the data, but the distributed sediment model did not significantly improve the uniform sediment model for field use. External influences and advection of sediment from outside the immediate area were shown to affect the field measurements.

AB - A numerical model for deposition of non-uniform cohesive sediment at a point was applied to laboratory and field settings. The results were compared with those from a uniform sediment model applied to the same settings. In the non-uniform (distributed) model, classes of sediment (representing different floc sizes) each had a corresponding settling velocity and critical shear stress for deposition. The models were applied to laboratory deposition tests in an annular flume. Tests with steady and slowly decelerating flow were both modelled. The distributed sediment model was shown to be a much better model of deposition in decelerating flow in the closed system of the annular flume. The model was shown to be sensitive to the settling velocity of the class corresponding to the largest flocs. The importance of more accurate methods of determining floc size and settling velocity distributions was recognised. Both models were also applied to field measurements of deposition during a tide made in the Mersey Estuary. Both models gave a reasonable fit to the data, but the distributed sediment model did not significantly improve the uniform sediment model for field use. External influences and advection of sediment from outside the immediate area were shown to affect the field measurements.

KW - COHESIVE SEDIMENT

KW - DEPOSITION

KW - LABORATORY TESTS

KW - FIELD MEASUREMENTS

KW - CRITICAL SHEAR STRESS

KW - SETTLING VELOCITY

KW - NONUNIFORM SEDIMENT

KW - NUMERICAL MODEL

KW - FLOC SIZE DISTRIBUTION

KW - ANNULAR FLUME

KW - MERSEY ESTUARY

M3 - Journal article

VL - 9

SP - 1094

EP - 1105

JO - Journal of Coastal Research

JF - Journal of Coastal Research

SN - 0749-0208

IS - 4

ER -

Research

Keywords