4.3 Estimating sediment deposition fields

Description

Environmental guidelines associated with dredging in Western Australia encourages dredging proponents to make scientifically sound predictions of the likely areal extent of any environmental effects associated with any turbidity-generating activities (EPA 2016). Smothering of benthic organisms by high levels of sediment deposition is known to be one of the key cause-effect pathways associated with dredging activities (Jones et al. 2016). The problem is that there are currently no reliable techniques to measure sedimentation over appropriate scales.

Aims

To assess an alternative approach – a statistical turbidity model – to estimate sediment deposition  and the size of a sediment deposition zone around a dredging project. The underlying principle  is based on the difference in the likely deposition rates or accumulation magnitude that would occur  between turbidity caused by natural sediment resuspension events and turbidity caused by dredging activities.