A Note on Burst Event Detection in Unsteady Natural Flows

Turbulent bursting events play a major role in natural systems in terms of sediment scour, transport and accretion as well as contaminant mixing and dispersion. The "bursts" were extensively studied in laboratory experiments under steady flow conditions, but rarely tested in unsteady natural flows. Herein a technique is described for the detection and analysis of turbulent events within large continuous data sets collected in unsteady natural flows, in particular natural estuaries. This study highlights and addresses several key issues related to burst event analysis in unsteady flows. These issues include the selection of individual sample size and event threshold value, the effect of flow reversal, and a comparison of individual samples over the entire data set. Some initial findings are presented as part of a broader investigation aimed to optimise the turbulent burst event detection technique for unsteady geophysical flows.