Author(s): Eric M. Valentine
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Keywords: Sediment transport; Hydrodynamic modelling; Tropical river; Morphology
Abstract: The rivers of tropical northern Australia constitute a unique set of largely un-impacted systems. These rivers and associated aquifers are estimated to contain 70%of Australia’s fresh water resources. There is, therefore, a long history of interest in developing northern Australia for agriculture and this is presently being further influenced by increasing pressure on water supply and river systems in southern Australia. The Daly River of tropical Northern Australia has the highest base-flow of all rivers in the Northern Territory, and potentially the highest of any perennial free-flowing river in Australia’s wet-dry tropics. There is considerable interest in the sediment budget and recent observations of the channel indicate that there may be instabilities in the channel cross-section. There is also concern that further irrigation abstraction will alter the flow conditions, particularly during the dry season. This study deals with reach-scale modelling of a selected 20 km long reach of the Daly River with its associated floodplains. Hydrodynamic and morphological models are being used to study steady and unsteady flows and associated sediment transport. This paper is a progress report on this work which will provide insights into contemporary and recent historical bed material transport rates and which will be used as a basis for management decisions.
Year: 2010