Vincent Leys, Moritz Lehmann


In New Brunswick, Atlantic Canada, Tabusintac Bay’s multiple tidal inlets meander through narrow barrier islands and are prone to large storm-induced shifts, making navigation hazardous. A multi-evidence assessment comprised of air-photo analysis, field observations and modeling was undertaken to understand the system and recommend sustainable dredging strategies and/or engineering alternatives. The modeling relied on a combination of simple analytical methods for tidal inlet stability, and complex morphological modeling to project the evolution of the nearshore bathymetry. The study recommended reassigning dredging efforts to a new inlet projected to grow and have better stability. Observations two years after the initial modeling effort indicate that the morphological evolution is consistent with the simulation results, and allowed lowered maintenance dredging requirements. This study illustrates how such a multi-evidence assessment of complex coastal dynamics can concretely guide efforts to reduce maintenance dredging and improve safety at sea.


dredging; tidal inlets; morphological modeling

Full Text:



Dean, R.G., and Dalrymple, R.A. 2002. Coastal processes with engineering applications. Cambridge U. Press, 475p

FitzGerald, D. M., Origin and Stability of Tidal Inlets in Massachusetts in Formation and evolution of multiple tidal inlets. D. G. Aubrey and S. Giese, eds., Washington DC, 1993.

Forbes D.L., Parkes G.S., Manson G.K., and Ketch L.A., 2004. Storms and Shoreline Retreat in the Southern Gulf of St. Lawrence. Marine Geology 210 (pp 169‐204).

Jarrett, J.T. (1976). Tidal Prism-Inlet Area Relationships. GITI Report 3, U.S. Army Waterways Experiment Station, Vicksburg, MS.

Jones O.P., Petersen O.S., Kofoed-Hansen H. 2007. Modelling of complex coastal environments: Some considerations for best practice. Coastal Engineering 54 (2007) 717-733, Elseveier B.V.

Kamphuis J. W. 2000. Introduction to Coastal Engineering and Management. World Scientific. ISBN 981-02-3830-4

Kraus N.C, 2008. Engineering of Tidal Inlets and Morphologic Consequences, USACE Research and Development Centre. In: Kim Y.C. Handbook of Coastal and Ocean Engineering. World Scientific ISBN-10 981-281-929-0.

McCulloch M. M., Forbes D.R., Shaw R.W. and A041 Scientific Team. 2002. Coastal Impacts of Climate Change and Sea Level Rise on Prince Edward Island. Geological Survey of Canada. Open File 4261.

Pacheco A., Ferreira O., Williams J.J., Garel E., Vila-Concejo A., Dias J.A. 2010. Hydrodynamics and equilibrium of a multiple-inlet system. Marine Geology 274 (20100 32-42.

Reinson G.E. 1980. Variations in Tidal Inlet Morphology and Stability, Northeast New Brunswick. In: The Coastline of Canada, S.B. McCann, editor; Geological Survey of Canada, Paper 80-10, p. 23-39, 1980.

Reinson G.E., Frobel D. 1980. Effects of Dredging Activities on Shoreline Morphology and Stability, Northeast New Brunswick. Atlantic Geoscience Centre, Geological Survey of Canada, Bedford Institute of Oceanography, Dartmouth Nova Scotia.

Swail V.R, Cardone V.J., Ferguson M., Gummer D.J., Harris E.L., Orelup E.A. and Cox A.T. 2006. The MSC50 Wind and Wave Reanalysis. 9th International Workshop On Wave Hindcasting and Forecasting September 25-29, 2006 Victoria, B.C. Canada.

Weidman, C. R. and J. R. Ebert, Cyclic Spit Morphology in a Developing Inlet System in Formation and evolution of multiple tidal inlets. D. G. Aubrey and S. Giese, eds., Washington DC, 1993.