CETN II-28
(12/91)
efficiency of the program is due to the assumption that only wave energy
directed into the computational grid is significant, i.e. wave energy not
directed into the grid is neglected.
The program also assumes that wave
conditions vary sufficiently slowly such that the variation of waves at a
given point over time may be neglected relative to the time required for waves
to pass across the computational grid.
While these assumptions minimize
c o m p u t a t i o n s , they also limit the model to nearcoast applications in which
waves are generally directed into the grid and move quickly across it (within
30 minutes). Model output includes the energy-based significant wave height,
peak spectral period, and mean spectral direction for each point on the
computational grid for each output interval specified.
In addition, the
frequency and frequency-direction wave energy spectra at-user-specified grid
locations along with the energy-based wave height, peak spectral period, and
mean spectral propagation direction for the total energy spectrum at these
same user-specified locations are computed by the model.
Model HARBD is a two-dimensional, steady-state, finite-element model for
studying wave oscillations in and around harbors,
and is applicable to harbors
having arbitrary depths and geometric configurations. This model is based on
linear wave theory, and solves a boundary value problem of harbor resonance
and wave scattering which include the effects of bottom friction.
The model
may also be applied to weakly nonlinear waves, though great care must be
exercised while interpreting results.
Model output includes wave height
amplification factors and wave phases.
Model SBEACH is an empirically-based two-dimensional model for predicting
Input requirements
storm-induced beach erosion and post-storm recovery.
include a time series of deepwater wave height and period, a time series of
water level, median beach grain size, and initial profile shape.
Model output
is the beach profile at all user-specified timesteps.
Model GENESIS is a one-dimensional model for simulating long-term
shoreline change.
It can predict shoreline change and longshore transport
rates under a wide range of beach, coastal structure, wave, initial and
boundary conditions, which may vary in space and time, as appropriate.
Input
data include the initial shoreline position, measured shoreline position for
calibration purposes, seawall positions, depths along the nearshore reference
line, and the wave height, period, and direction for every timestep.
Model
output includes the shoreline position and longshore transport rates at user-
specified timesteps.
Software packages for supporting these models include:
Grid generation software.
Post-processing software to display model results.
a.
Utility software to supplement data used by models.
C.
Automated Job Control Language (JCL) procedures to execute items
d.
(a) through (c)
The grid generation package presently contains software for creating
stretched rectilinear computational grids used by several models in CMS. This
software allows square or rectangular grid systems to be-generated; but also
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