Application of Cascade to the south shore of Long Island, New York demonstrated its
capability to simulate regional sediment transport and coastal evolution for complex
conditions. The simulations included two inlets that opened and evolvied through
significant changes in cross-sectional area, changing the equilibrium volumes of the ebb
shoal complex. Eroded and accreted volumes updrift and downdrift the inlets, respectively,
were well predicted, whereas the calculated and measured shoreline shape differed
somewhat downdrift of the inlets. This discrepancy is attributed to the algorithm for
releasing sediment from the attachment bar to the adjacent beach. Work is underway to
enhance the model as well as to include other features at the regional scale, such as spit
evolution, sediment storage and transfer in the flood shoal and channels of an inlet, and
barrier-island migration due to overwash.
This paper was prepared under the Regional Sediment Management Program and the
Coastal Inlets Research Program, U.S. Army Corps of Engineers (USACE). We appreciate
reviews by Dr. Jack Davis and Julie Dean Rosati. Permission was granted by
Headquarters, USACE, to publish this information.
Czerniak, M.T. 1977. Inlet interaction and stability theory verification. Proc. Coastal
Sediments '77, ASCE, 754-773.
Kana, T. W. 1995. A mesoscale sediment budget for Long Island, New York Marine
Geology, 126, 87-110.
Kraus, N.C. 2000. Reservoir model of ebb-tidal shoal evolution and sand bypassing. J.
Waterway, Port, Coastal, and Ocean Engineering, 126(6), 305-313.
Kriebel, D.L., Kraus, N.C., and Larson, M. 1991. Engineering methods for predicting
beach profile response. Proc. Coastal Sediments '91, ASCE, 557-571.
Larson, M. 1995. Model for decay of random waves in the surf zone. J. Waterway, Port,
Coastal and Ocean Engineering, 121(1), 1-12.
Larson, M., and Bayram, A. 2002. Calculating cross-shore distribution of longshore
sediment transport. In: Port Engineering. Ed. Per Bruun, Butterworth (in press).
Larson, M., and Hanson, H. 1996. Schematized numerical model of three-dimensional
beach change. Proc. 10th Congress of the Asia and Pacific Division, IAHR, Langkawi,
Larson, M., Rosati, J.D., and Kraus, N.C. 2002. Overview of regional coastal processes
and controls. Coastal and Hydraulics Engineering Technical Note CHETN XIV-4, U.S.
Army Engineer Research and Development Center, Vicksburg, MS.
Morang, A. 1999. Shinnecock Inlet, New York, Site investigation, Report 1: Morphology
and historical behavior. Tech. Rep. CHL-98-32, U.S. Army Corps of Engineers,
Waterways Experiment Station, Vicksburg, MS.
Rosati, J.D., Gravens, M.B., and Smith W.G. 1999. Regional sediment budget for Fire
Island to Montauk Point, New York, USA. Proc. Coastal Sediments 99, ASCE, 802-
Walton, T.L., and Adams, W.D. 1976. Capacity of inlet outer bars to store sand. Proc.
15th Coastal Eng. Conf., ASCE, 1919-1937.
Larson, Kraus, and Hanson