Abstract
SUMMARY: The water turbidity measured with optical methods (transmittance and backscattering) is usually expressed as beam attenuation coefficient (BAC) or formazin turbidity units (FTU). The transformation of these units to volumetric suspended sediment concentration (SSC) units is not straightforward, and accurate calibrations are required in order to obtain valuable information on suspended sediment distributions and fluxes. In this paper, data from field calibrations between BAC, FTU and SSC are presented and “best-fit” calibration curves are shown. These calibrations represent an “average” from different marine environments of the western Mediterranean (from estuary to continental slope). However, the general curves can only be applied for descriptive or semi-quantitative purposes. Comparison of turbidity measurements using the same sensor with different calibration ranges shows the advantage of simultaneously combining two instruments calibrated in different ranges when significant changes in suspended sediment concentrations are expected.
Highlights
Suspended sediment concentration (SSC) in the marine environment must be measured to study the distribution patterns of suspended sediment and its associated components, including contaminants and living organisms
Calibration of the beam attenuation coefficient (BAC) was carried out using data from six field campaigns conducted in different areas of the western Mediterranean Sea
Specific calibration curves for each instrument and for each environmental condition are required in order to obtain accurate transformations
Summary
Suspended sediment concentration (SSC) in the marine environment must be measured to study the distribution patterns of suspended sediment and its associated components, including contaminants and living organisms. These measurements are necessary to quantify sediment fluxes across and along continental margins. Whereas the gravimetric technique involves the direct measure of the particle concentration, the indirect methods consist in the measurement of different water properties related to the suspended sediment concentration. Measurement with optical instruments depends greatly upon a variety of parameters such as particle size, composition, and shape, as well as environmental characteristics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
