The key objectives of Project 3.2:
(1) Characterize the physical/optical properties of sediment suspensions;
(2) Map the dredge-generated plume;
(3) Provide data to optimize and validate plume modelling;
(5) Assess the spatial and temporal variability (~10 years) of background suspended sediment loads using archived remote sensing data;
(6) To estimate the benthic light field with respect to TSS;
In this study we investigated various common turbidity sensors, including optical scattering and acoustic scattering instrumentation, and compared and contrasted their effectiveness in estimating particle load (TSS concentration), and/or Particle Size Distributions (PSDs). Studies were conducted in a controlled laboratory-based setting with a range of different sediment types primarily obtained from the Pilbara coast.
More specifically we:
• determined the particle size (PS) of sediment samples from Pilbara coastal waters using a sequoia scientific LISST 100X submersible particle size analyser and related PS to the particulate backscattering slope (γbp parameter) of HobiLabs HydroScat-6 and the particulate scattering slope (γb parameter) of WETLabs acs-176;
• Established the relationship between Turb and TSS concentration using the optical properties of particulate backscattering coefficient (bbp), scattering coefficient (bb) and total absorptions (a) from HydroScat-6 and acs-176; Wetlabs ECO NTU and Campbell Scientific OBS3+.