Author(s): Bart Vermeulen; Toine Heus; Anouk Boon; Ton Hoitink
Linked Author(s): Bart Vermeulen
Keywords: No Keywords
Abstract: Estimating sediment concentration from Acoustic Doppler Current Profilers (ADCPs) is often challenging due to the combined effect of backscatter and attenuation caused by sediments. This combined effect can make the relation between backscatter and sediment concentration ambiguous. In this study, an existing method is used to estimate sediment concentrations that assumes the specific attenuation (i. e. per unit of concentration) to be constant over depth. The method is applied to measurements collected in the hyperturbid Ems Estuary. A tidally varying specific attenuation is included in the inversion to account for tidal variation in grain size distribution. This variation is confirmed by in-situ measurements of the grain size distribution. The obtained sediment concentration are validated with samples and show an improvement of the method including temporal variation in specific attenuation. Eventually we explore the possibility to use bottom backscatter to estimate attenuation.
Year: 2022