WAMSI 2 - Dredging Node - 3.1.1 - Review of Plume Characteristics

Predicting the distribution and fate for suspended sediment plumes associated with dredge operations may be achieved by advanced hydrodynamic modelling (REFS). The accuracy of the model outputs, or the level of confidence we associate with the modelled forecasts, depend to some degree on the model inputs, including parameters such as particle size distributions, particle densities, and particle settling rates. There is potential to infer optical products from the modelled 3 dimensional plume distribution, including spectral light attenuation, and spectral light intensity at the substrate. One of the approaches to testing or monitoring the accuracy of plume distribution models is to compare the modelled distributions to observed plume distributions. Optical remote sensing methods can provide reliable “maps” of plume extent, and reasonable estimates of various in-water geophysical parameters. Examples of remote sensing products include suspended sediment concentration, particle backscattering, and spectral light attenuation coefficients. This review encompasses two main components: 1) Satellite and in situ observations used to monitor sediment plumes and assess the suitability of the different sensor platforms to provide the spatial and temporal resolution needed for model validation and calibration in WAMSI Dredging Theme 3.4. Remote sensing platforms will include MODIS data and high resolution products such as WorldView and RapidEye; 2) Available water quality data (such as TSS levels, light levels, sediment deposition rate, particle size distribution etc.) collected in Western Australia and associated with different types of dredges working in different geotechnical settings and metocean conditions.