integrate operations cost effectively in linking dredging, sand bypassing, breach-
contingency plans, and protection of beaches vulnerable to erosion by storms. Because of
the natural regional movement of sediment, the coastal influence of individual projects can
far exceed their formal dimensions. As an example, recent placement of beach fill along
the Village of West Hampton Dunes, located to the east (updrift) of Moriches Inlet, has
increased dredging requirements for that inlet. Inlets and adjacent beaches must be
connected through regional models to account for multiple and cumulative interactions
along the coast. In this manner, individual projects can be managed within a single
framework that accounts for wide-area benefits, as well as adverse impacts. A regional
modeling system encompassing waves, currents, and longshore and cross-shore sediment
transport is the backbone of the planned Long Island south shore regional sediment
management system.
The New York District, State of New York, and Coastal Inlets Research Program of the
U.S. Army Corps of Engineers are supporting the monitoring and modeling system, with
logistical assistance from counties and communities. The monitoring program began in
April 1998 with a dense array of instruments (nine separate instrument packages for waves,
water level, current, and wind) placed at Shinnecock Inlet for one year to validate the
circulation and wave models. Instruments are being relocated westward at yearly intervals
and are presently deployed at Shinnecock Inlet, Westhampton (near Moriches Inlet), Fire
Island Inlet, Jones Inlet, and Coney Island. Most instruments provide the data in near-real
time (within 15 min or 2 hr, depending on instrument see http://www.lishore.org/).
This paper describes the wave component of the comprehensive regional monitoring
and modeling system. A regional modeling system for tidal circulation in the complex bay,
inlet, and coastal system of Long Island was developed concurrently with the monitoring
program (Militello, Kraus, and Brown 2000). The present paper, focusing on the wave
measurements and modeling and the work to date, substantiates the following:
Quantifiable estimates and/or predictions of nearshore coastal processes (for example,
sediment transport) require accurate knowledge of local wave energy levels, wave
directionality, tidal current, and wind.
Reliable and properly validated boundary conditions are required, such as offshore
wave directional spectra, time- and space-varying wind fields, and tide to model local
wave, tide, and wind conditions. For example, wind and boundary spectra for this work
were taken from a new Atlantic Coast wind and wave hindcast (Swail, Ceccacci, and
Cox, 2000).
Establishment of a method for developing appropriate boundary conditions sets the
stage for future automation for forecasting, operational applications, and other
engineering and environmental uses of the system.
Modeling of local wave transformation, in particular accurately describing wave
transformation over an ebb shoal and channel, as well as the wave-current interaction near
inlets, requires dense local bathymetric surveys and the associated gridded representations.
Along the coast of Long Island, the reliability of wave and circulation modeling at inlets
has been greatly improved through almost-annual bathymetric surveys at the inlets by
SHOALS LIDAR (Lillycrop, Parson, and Irish 1996), supplemented by conventional
surveys as necessary.
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