WIND-INDUCED SEDIMENT RESUSPENSION - A LAKE-WIDE MODEL

A lake-wide suspended sediment model has been developed and subsequent ly coupled with a horizontal circulation model to predict depth-averag ed suspended sediment concentrations throughout a lake. Resuspension i s induced by shear stresses at the sediment-water interface which are considered to be a result of wave action. These shear stresses are cal culated using linear wave theory. The model allows for winds from any direction to generate the waves and associated stresses. Sediment depo sition is characterised by a formulation which describes the change in suspended sediment concentration with time rather than relying on one or more representative settling velocities. Sediment resuspension is modelled as being independent of deposition. The processes of advectio n and diffusion in redistributing resuspended sediments horizontally a re accounted for in the hydrodynamic model. The result is a general, p rocess based model for predicting depth-averaged suspended sediment co ncentrations throughout a shallow lake. The model was tested against d ata collected during 1993 and 1994 from Thomsons Lake, Western Austral ia. (C) 1997 Elsevier Science B.V.