Suspended sediment transport in the North Esk River

This thesis investigated the suspended sediment transportation of the North Esk River, Tasmania. The investigation was divided into two sections, the origins and the quantity of sediment transported. With respect to the origins, it was found that the main contributors to the suspended sediment load were recently denuded areas, i.e. recently logged areas and ploughed farmland. For example, 761t of sediment was estimated to have come from a 50ha logging coupe in only 320 hours. A single beam turbidity meter, based on light attenuation, was designed and constructed to monitor the sediment concentrations of the river. The results from.this turbidity meter were used in conjunction with discharge data to derive a sediment rating curve. This curve was applied to daily discharge records to derive long term estimates of sediment transport. The mean annual suspended sediment transport of the North Esk River was estimated to be 7225t. This estimate was extrapolated to the whole Tamar River catchment. It was estimated that the average annual suspended sediment input to the Tamar Estuary from its tributaries is 56,900 t/year.