(3) Data requirements for RCPWAVE.

(a) Primary input to the RCPWAVE model includes the following: parameters describing the domain

to be modeled, such as the number of computational grid cells in each direction and the cell dimensions;

definition of the water depth at each cell; and definition of the incident wave height, period, and direction

along the offshore domain boundary for each wave condition to be simulated. Model output includes wave

height, period, and direction at each cell of the computational domain, and an indication of whether or not

the wave is calculated to be a broken wave.

(b) Typically the first step in the model application process is to discretize the model domain into a

rectangular mesh. The grid mesh that is created can be overlaid on a bathymetric chart, assuming the grid

and chart are plotted to the same horizontal scale, and depths at each cell can be digitized for use as model

input. A constant correction to the depths, representing a datum change or a specific water level change, can

be included in the input data set. An arbitrary number of wave conditions, each defined by a unique

combination of height, period and direction, can be simulated. Wave conditions to be simulated are usually

defined after a statistical analysis of the wave climate in the region being studied. Bathymetry specification

and incident wave conditions comprise the bulk of the effort to create the input data set.

(1) Introduction. The model REF/DIF 1, which has been developed for practical application, is based

on the mild-slope, wave-current model equation developed by Kirby (1984), which may be written as

& L @ (*C C*g L φ) % (σ2 & *k * 2 C Cg ) φ ' 0

%L@*U*

(II-3-27)

where φ is the velocity potential at the free surface, and where

M

%*U*@L

(II-3-28)

'

M*t*

M

M

L'

(II-3-29)

,

M*x*

M*y*

(II-3-30)

σ'ω&*k*@*U*

(II-3-31)

σ

(II-3-32)

Mσ

(II-3-33)

M*k*

σ2 ' *g k *tanh (*kh*)

(II-3-34)

Several additional features are included in the model in order to increase its range of application and

accuracy.

II-3-24

Estimation of Nearshore Waves

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