Browsing by Author "Miller, BM"

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    Evolving role of radiotracers in coastal zone studies
    (Pergamon-Elsevier Science Ltd., 2003-03-01) Airey, PL; Hughes, CE; Kluss, T; Duran, EB; Miller, BM; Chiuenta, S; Nielsen, AF; Hollins, SE
    Recent advances in the off-shore radiotracing program in the Asia Pacific region are described with examples from the Philippines, Thailand, Hong Kong and Australia. Advances are driven by changing requirements from the user community which include: (1) the need to experimentally evaluate the output of numerical models underpinning engineering and environmental investigations; (2) the need to address increasingly sophisticated questions posed by researchers into coastal ecosystems; and (3) the need to respond to pressures from regulators to minimise the level of tracer released to the environment. Four stages in the recent evolution of tracer technology are identified. Crown Copyright © 2003 2003 Published by Elsevier Science Ltd.
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    Three dimensional numerical modelling of circulation patterns in Manila Bay, Philippines
    (Institution of Engineers, Australia, 2001-10-05) Miller, BM; Chadwick, MJ; Kluss, T; Hughes, CE; Duran, EB
    Flow processes found in Manila Bay, Philippines are dominated by complex wind driven currents. Flow circulation within the bay has a significant impact upon the water quality and sediment transport processes occurring in the bay. This paper presents the outcomes of a study, funded by the International Atomic Energy Agency, which used a combination of field data collection and numerical modelling techniques to assess the distribution of Red Tide algal blooms within Manila Bay. This paper presents the model verification against nuclear tracer experiments and the three dimensional hydrodynamics of Manila Bay. Field experiments were undertaken using radioactive isotope tracers to track flow currents at selected locations in the bay. The data from the field experiments were used to validate a threedimensional hydrodynamic (RMA-10) model of the bay. The methods of presenting the radioactive isotope tracers results and comparison of model results and experimental data are presented in this paper. The outcomes of the field data collection and numerical modelling work clearly demonstrate the importance of representing three-dimensional flow processes in defining the hydrodynamic behaviour of the bay. The significance of wind generated currents and the resulting three-dimensional flow patterns is indicated by both field data and model results. A comparison against model results obtained using a two-dimensional depth-averaged flow approximation is presented to further highlight this point. © 2021 Institution of Engineers, Australia
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    Using radiotracer techniques for coastal hydrodynamic model evaluation
    (Elsevier Science Ltd., 2004) Hughes, CE; Airey, PL; Duran, EB; Miller, BM; Sombrito, E
    A three-dimensional (313) water circulation and contaminant transport model of Manila Bay has been developed with the aim of better understanding the formation and movement of harmful algal blooms. Radiotracer techniques were used to evaluate the model by recording the dispersion of a tracer at depths of 2 and 15 m near the injection point. The selected tracer was Tc-99m eluted from a molybdenum/technetium medical generator. The rationale for the choice of the tracer and the location of the injection is discussed. At 2 m the transport was dominated by the prevailing winds, and at 15 m by tidally induced currents. The development of the hydrodynamic model and its experimental evaluation were iterative processes. The experimental study confirmed the need for full 3D modelling of Manila Bay; quantified the impact of the prevailing wind field on contaminant dispersion near the injection point; and allowed the calculation of transverse dispersivity to guide the selection of parameter values used in the overall model. Crown Copyright © 2004 Elsevier Ltd.