aDcp measurements Rhône river confluences, Switzerland

The focus of the data collection is three junctions of the Swiss River Rhône.1- Avançon-Rhône confluence (16.10.2017)2-Lizerne-Rhône confluence (07.08.2017)3- Grande Eau-Rhône confluence (23.05.2018)The three tributaries were chosen on the basis of: (1) having low flow momentum ratios for most of the time (< 0.05); (2) having high sediment supply rates in two cases, the third having a gravel trap and sediment extraction upstream, negligible sediment supply and thereby providing a controlled comparison; (3) high junction angles; and (4) suitability for sediment provenance analyses so the origins of the sediment that comprised the tributary mouth bars could be determined. At each confluence, the measurement of the bathymetry and the time-averaged flow velocities and flow discharge at several cross sections through the confluence was performed using a moving boat acoustic Doppler current profiler (aDcp) system (Sontek RiverSurveyor M9).