
So if a stream fines after a big flood and then coarsens again over time as it winnows... what is the appropriate stage to use to represent it for effective discharge calculations?
The fine stage may represent the Qe in terms of maximum sediment transported, but the coarse stage undoubtedly represents the channel forming discharge as it is this being moved that will reshape the channel itself instead of moving sediment through it.
Photo: channel of Ambusten Creek - large immobile clasts not well represented in the sediment photos.