Rivers flowing into the sea
Estuaries and firths
These mud, silt and sand bed rivers move sediment out to the sea through both river flow and tidal current processes. The stages of the tide determine the direction and strength of water flow, and the ability of the water to move and deposit sediment. Salt marshes formed along natural shorelines help to regulate flood water, and capture flood borne nutrients. Flooding can occur due to tidal and storm surges (determined by tidal stage, wind direction and strength and tide time the sea), and also from inland floodwaters. The biggest floods occur when all these factors coincide.
Dunbarton Rock and the inner Firth of Clyde (Photo Pat MacDonald / SNH) 