ICCE 2018 Cover Image

Supplementary Files

Conference Presentation File

How to Cite

Larson, M., Nunes, A., Tanaka, H., & Hanson, H. (2018). A SEMI-ANALYTIC MODEL OF TIDAL INLETS AND THEIR EVOLUTION. Coastal Engineering Proceedings, 1(36), sediment.62. https://doi.org/10.9753/icce.v36.sediment.62


The water exchange between the sea and a lagoon or bay through an inlet due to tides is a classical topic that has been investigated in a large number of studies (Keulegan, 1967; O'Brien and Dean, 1972; O'Brien and Clark, 1974; Escoffier, 1977). In this paper, a simple semi-analytic model of the flow induced by tides through an inlet connecting the sea to a lagoon or bay is developed. The model is employed to derive explicit expressions for key parameters associated with inlet flows such as bay water level amplitude, tidal prism, maximum inlet velocity, and mixing (retention) time. Also, the inlet flow model is combined with a sediment transport model to determine the conditions for equilibrium as well as the evolution of the inlet cross-sectional area towards equilibrium or closure.


Escoffier (1940): The stability of tidal inlets, Shore and Beach, 8(4), 114-115.

Escoffier (1977): Hydraulics and stability of tidal inlets, GITI Report 13, US Army Corps of Engineers, Waterways Experiment Station,Vicksburg, MS.

Keulegan (1967): Tidal flow in entrances, Water-level fluctuations of basins in communication with seas, Technical Bulletin No. 14, US Army Corps of Engineers, Vicksburg, MS.

Kraus (1998): Inlet cross-sectional area calculated by process-based model, Proceedings 26th International Coastal Engineering Conference, ASCE, 3265-3278.

Larson, Hanson, Kraus and Hoan (2011): Analytical model for the evolution of coastal inlet cross-sectional area, Proceedings of Coastal Sediments '11, World Scientific, 444-457.

Mota-Oliveira (1970): Natural flushing ability in tidal inlets, Proceedings of the 12th Coastal Engineering Conference, ASCE, 1827-1845.

O'Brien and Clark (1974): Hydraulic constants of tidal entrances, Proceedings of the 14th Coastal Engineering Conference, ASCE, 1546-1565.

O'Brien and Dean (1972): Hydraulics and sedimentary stability of tidal inlets, Proceedings of the 13th International Coastal Engineering Conference, ASCE, 761-780.

Seabergh (2003): Long-term coastal inlet channel area stability, Proceedings Coastal Sediments '03, World Scientific (on CD).

Authors retain copyright and grant the Proceedings right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this Proceedings.