A test of the ADV-based Reynolds flux method for in situ estimation of sediment settling velocity in a muddy estuary

摘要: Under conditions common in muddy coastal and estuarine environments, acoustic Doppler velocimeters (ADVs) can serve to estimate sediment settling velocity (w s) by assuming a balance between upward turbulent Reynolds flux downward gravitational settling. Advantages of this method include simple instrument deployment, lack flow disturbance, relative insensitivity biofouling water column stratification. Although is being used with increasing frequency date it has received little direct ground truthing. This study compared situ estimates w s inferred 5-MHz ADV independent observations from high-definition video over the course flood tide bottom boundary layer York River estuary, Virginia, USA. The ADV-based measurements were found agree those when current speed at about 40 cm above bed was greater than 20 cm/s. corresponded periods estimated magnitude term suspended continuity equation four or more times larger time rate change concentration. For restricted these conditions, (mean 0.48±0.04 mm/s) highly consistent observed 0.45±0.02 mm/s). However, for estimating sensitive prescribed concentration non-settling washload, C wash. In an objective operational definition, wash be set equal lowest solids around slack water.