Suspended sediment transport dynamics in the sub-tropical micro-tidal Richmond River estuary, Australia

Suspended sediment transport and sedimentation dynamics in the sub-tropical Richmond River estuary were investigated between July 1994 and June 1996. During low flow months the estuary received net sediment inputs from the co ntinental shelf; during high flow the estuary exported sediment to the cont inental shelf depending on the magnitude of floods. Flow-weighted sampling along with a one-dimensional unsteady flow hydrodynamic model of the estuar y estimated that about fifty percent of the flood-borne suspended sediment was transported through the estuary to the continental shelf during two min or floods (with a 2-year return period), whereas, one hundred percent of th e flood-borne sediment was transported to the continental shelf during a mo derate flood (with a 5-year return period). Marker horizons confirmed a net accumulation of sediment in the Richmond River estuary at the salt-fresh w ater interface during all post flood recovery stages. (C) 2001 Academic Pre ss.