Fig. 4: The possible fate of clay in rivers.
a Capturing of flocs in a bedform, in which five regimes are indicated, I: suspension, II: recent deposition, III: drapes within a dune, IV: drapes below the active surface (remnant), V: homogeneously mixed conditions (initial experiment conditions). The image is taken seconds after the flow has halted. In this time a depositions layer of flocs has formed on the dunes. The image is slightly adjusted to reduce reflections. b Schematic of the suspended and bed load transport of clay particles and flocs, and the subsequent trapping in the sediment bed. Velocity profiles (u indicates the flow velocity, dotted line indicates zero m s−1) are schematised based on the measurements in ref. 38.
