VISUALIZATION OF THE TURBULENT-FLOW STRUCTURE IN A GRAVEL-BED RIVER

A novel technique for visualizing turbulent flow data from a gravel-be d river is presented. The time development of flow velocity and shear stress at three heights is displayed using a computer program. This ca n be used to observe how the fluctuations of velocity and shear stress interact both spatially and temporally. We highlight examples of flow events which are important for the understanding of flow dynamics. Th e visualization suggests that the turbulent flow-field is characterize d not only by coherence over time at a point, but also by spatial inte rdependence between points. We suggest that this new visualization app roach will assist further interpretation of statistical analyses of tu rbulent signals, as well as focusing future measurement strategies by providing a clearer spatio-temporal picture of the flow structure.