Detailed bed topography and sediment load measurements for two stepdown flows in a laboratory flume

Streams and rivers, particularly smaller ones, often do not maintain steady flow rates for long enough to reach equilibrium conditions sediment transport bed topography. In particular, streams in small watersheds may be subject rapidly changing hydrographs, relict bedforms from previous high flows can cause further disequilibrium that complicates the prediction of rates. order advance understanding how respond rapid changes rate, a series flume experiments were performed where was reduced conditions. Sediment elevation data across over 15-meter-long test section collected during allow detailed examination evolving bedform dynamics. It found stopped moving completely after reductions, mode shifted arose dune stoss sections throughout section. The with time as sand adjusted new rate agree predictions based on relations proposed Wren et al. (2020). Wavelet analysis is used visualize length amplitude scales transition process.