An experimental investigation of sediment kinematics and multi‐scale propagation for laboratory bed‐load dunes

The dynamics of river bedforms is still not well understood and detailed experimental investigation may provide significant insight into the process mechanisms. In this study, results are presented for a laboratory experiment that returned long time series sediment kinematics bed-load dunes. run was performed in closed conduit but, light prior literature, also representative dunes under open-channel flows. A flow rate 1.4 times threshold transport used, lasted enough to measure four full This enabled stability mean values be obtained key properties; concentration moving sediment, velocity rate, were measured over Eulerian grid. At measuring location, all properties present an oscillation pattern resembles passage dunes, including higher-frequency oscillations (due turbulence) superimposed onto low-frequency ones related evolution more similar than velocity, which varies comparatively less. multi-scale propagation demonstrated considering grains, quick ‘sediment gusts’ triggered by field. Taking advantage Taylor-like hypothesis, assumed valid as first-order approximation, temporal sediment–kinematics determined. Although limited single hydro-dynamic condition, thus need further testing, interest number applications, bedform analysis, live-bed scour processes, quantification rates surrogate quantities.