(Erosion and Sediment Transport Measurement in Rivers: Technological and Methodological Advances (Proceedings of the Oslo Workshop, June 2002), IAHS Publication 283, 2003, pp. 37–44).
During two inundation periods in Spring 2002, we deployed a combined particle sizer and settling tube on an embanked flood plain along the River Waal (mean discharge = 2400 m3 s–1) in the eastern part of The Netherlands. This so-called LISST-ST device uses laser diffraction principles to measure in situ grain size distribution, settling velocities and concentrations of the suspended matter in the inundation water. To verify these measurements, we manually collected water samples and deployed an optical backscatter sensor to measure total sediment concentration and turbidity, respectively. The measurements revealed that the grain size distribution and suspended sediment concentration depend on the discharge, while the settling velocity does not vary with discharge, but depends on flocculation processes. In the near future, in situmeasured sediment characteristics will be compared to those from sediment retained in sediment traps located in the same flood plain.
Flocculation, Flood plain, Grain size, Laser diffraction, River Rhine, Settling velocity, Suspended sediment
