Turbulent Mixing and Sediment Processes in Peri-Urban Estuaries in South-East Queensland (Australia)

Abstract

An estuary is formed at the mouth of a river where the tides meet a freshwater flow and it may be classified as a function of the salinity distribution and density stratification. An overview of the broad characteristics of the estuaries of South-East Queensland (Australia) is presented herein, where the small peri-urban estuaries may provide an useful indicator of potential changes which might occur in larger systems with growing urbanisation. Small peri-urban estuaries exhibit many key hydrological features and associated ecosystemtypes of larger estuaries, albeit at smaller scales, often with a greater extent of urban development as a proportion of catchment area. We explore the potential for some smaller peri-urban estuaries to be used as ‘natural laboratories’ to gain some much needed information on the estuarine processes, although any dynamic similarity is presently limited by a critical absence of in-depth physical investigations in larger estuarine systems. The absence of detailed turbulence and sedimentary data hampers the understanding and modelling of the estuarine zones. The interactions between the various stakeholders are likely to define the vision for the future of South-East Queensland’s peri-urban estuaries. This will require a solid understanding of the bio-physical function and capacity of the peri-urban estuaries. Based upon the current knowledge gap, it is recommended that an adaptive trial and error approach be adopted for their future investigation and management strategies.