Data from: Sediment transport and bed topography for realistic unsteady flow hydrographs of varying length in a laboratory flume

This is the dataset that was used to make the figures for the publication entitled "Sediment transport and bed topography for realistic unsteady flow hydrographs of varying length in a laboratory flume."The citation for the publication is: Wren, D. G., Kuhnle, R. A., McAlpin, T. O., Langendoen, E. L. Sediment transport and bed topography for realistic unsteady flow hydrographs of varying length in a laboratory flume. Journal of Hydraulic Engineering. 10.1061/JHEND8/HYENG-13769How the dataset was generated: Experiments were conducted at the USDA-ARS National Sedimentation Laboratory in a 30-meters long x 1.22-meters wide x 0.61-meter-deep flume channel with a frequency-controlled pump motor and adjustable slope. The sand for the bed was purchased from a local source and had a median particle size of 0.43 mm. The bed load transport rate was measured by a Sedflux system that operated at 1 Hz (Hertz, cycles per second) using two drums suspended from load cells over 1.2 meters wide by 0.57 meters long sediment trap that was 28.5 meters from the channel origin. The mass of sand accumulated in the drums was recorded continuously, and the drums were dumped after the mass of sediment reached 30 kilograms. After leaving the drums, the sand particles were circulated through a 0.152-meter diameter pipeline and re-entered the flume at the upstream end. Material that bypassed the trap entered the main return pipe and was sampled from the center of the return pipe just downstream of the pump impellor using a 10.6-millimeter diameter sampling nozzle. Flow velocity into the nozzle was matched to the mean return line flow velocity to avoid biasing the concentration measurements. Discharge in the sampling line was checked by measuring the mass of water accumulated over time. Sediment-laden water was passed through a 0.062 mm sieve that retained sand particles and allowed the water to return to the flume channel. The mean sediment concentration from the physical samples was used to calculate the load that bypassed the Sedflux system. Bed surface elevations were measured acoustically at a rate of 10 Hertz using 32 transducers with an acoustic frequency of 5-million cycles per second, fired sequentially. The transducers were spaced at 3.7-centimeter intervals in a PVC bar with a blunt face and narrow trailing edge to minimize flow separation and drag. The transducers were held at a constant distance from the bottom of the flume and were always in contact with the water surface.