Correlation Study between Modelled Bed Shear Stress and Fine Sediment Suspension from Dredging Operation Using MODIS Images

Lack in function in the well-known MIKE 21 Sediment Plume modelling for simulation of dredging scenarios had brought to a level of discrepancies between the model results and MODIS TSS measurement. This paper aims to determine the suspension of passive plume from dredging using MODIS images, in relation to the bed shear stress (BSS). MODIS images with 250m resolutions were used as standard for TSS measurement while BSS was derived from a calibrated model of the study area. Correlation study was conducted between MODIS and In-situ TSS and it shows an acceptable correlation of r^2=0.5258 and r^2=0.2256 at Seagrass and Paroo stations. Lower correlation between sediment suspension and modelled bed shear stress was achieved at r^2=0.2519, for BSS ranging from 0 to 0.3N/m2 for BHD loading operation. However, strong correlation was observed for smaller bed shear stress range (from 0 N/m2 up to 0.08 N/m2) for TSHD loading operation with r^2=0.9194. It was found that the concerns due to the lower correlation coefficients achieved are because of factors such as MODIS resolution and the limitations to separate the long-term and short term sources.