Tidal and Freshwater induced Circulation in the Tay Estuary.

An understanding of the movement of a body of water can be considered a prerequisite to any other study whether it be physical or biological. This is particularly so in the case of an estuary where the water movements are complex. The movement of water in an estuary is primarily governed by the tidal and freshwater inputs, the resulting flow being modified by bed and channel configurations, salinity, and siltload variations. The tidal and freshwater inputs are themselves variables, the tidal range varying with the lunar cycle, and the freshwater input varying with the season or rainfall. The salinity variations within an estuary are interlinked with the tidal and freshwater fluctuating inputs. In addition the local and regional weather can modify the tidal response.