Geomorphology and Sedimentation Patterns of Tidal Inlets: A Review

Tidal inlets are generally formed by either of two mechanisms: storm generated scour channels, and closure of estuarine entrances by growth of sand spits. On depositional, coastal plain shorelines that have achieved steady state or grade conditions, inlet morphology folllows a predictable pattern based on the interaction of tidal energy and wave energy flux. On microtidal, wave dominated coasts, inlets are widely spaced and have large flood-tidal deltas. On mesotidal coasts with moderate waves, tidal inlets are closely spaced and ebb tidal deltas are considerably larger than flood tidal deltas. On mixed energy shorelines, large volumes of sand are stored in ebb tidal deltas. Many property losses occur on developed barrier islands, particularly mixed energy barrier islands, as a result of inlet migration and/or expansion. Because of the abundance of sand and the depth of channels associated with tidal inlets, they are highly preservable in stratigraphic sequences in the rock record, even those formed during major transgressions.