TRIAL MONITORING OF DREDGER PLUMES USING A MULTIBEAM ECHOSOUNDER

摘要

The measurement of sediment plumes arising from dredging activity is important for the validation of predicted environmental impacts. A number of different approaches to measuring sediment plumes exist, which traditionally include the calibration of backscatter from Acoustic Doppler Profilers (ADPs) and the use of turbidity sensors. Measurements can be vessel based or the instrumentation can be deployed on moorings. During dredging projects it is usual to undertake a considerable amount of bathymetric survey work and presently Multi Beam Echo Sounders (MBES) tend to be used for this purpose. Projects would benefit in terms of time and cost savings if the echo sounders employed could be used for the measurement and ultimately for the quantification of sediment plumes as well as bathymetry. This paper describes a trial use of MBES technology for the detection of suspended sediment plumes. A number of scenarios were replicated in order to study the nature of the backscatter observed. Initial results are presented as qualitative and quantitative observations, along with suggestions for further work, and the potential advantages offered by the approach.