A rapid method for settling velocity and flocculation measurement within high suspended sediment concentration rivers.

International audienceIn headwater catchments, fine sediment transport is a main issue with regard to monitoringerosion, pollutant fluxes, and reservoir siltation. In these environments, suspended sedimentconcentrations exhibit high temporal variations during runoff events and commonly exceed10 g/l. The settling velocity of suspended sediment is a key variable to understand and modelsediment transport. For such concentrated events, hindered settling and flocculation processesincrease the difficulty to model sediment transport. Currently, no automated method for themeasurement of settling velocity and propensity to flocculate within high concentrationsediment environments exists. Methods used to measure individual particle settling velocity(e.g., LISST, video) are limited to low concentrations (