EM 1110-2-1100 (Part II)
30 Apr 02
Figure II-3-12.
Spectral model results compared to laboratory measurements for broad directional
spectrum
(3) Data requirements for STWAVE. In STWAVE, a square grid mesh covers the computational
domain. Water depth must be supplied at each node. If currents are included, a current must be supplied at
each point. Wave characteristics are computed at each of these grid points. The model requires an input
directional spectrum for the outer boundary and information about wind speed and direction and bottom
friction coefficients.
e. Limitations.
(1) Each model has natural limitations reflecting its theoretical basis. The references provided discuss
these in some detail. If strictly interpreted, each model has a narrow range over which it is valid. Almost all
of these models are regularly used to simulate conditions outside a strict interpretation of limits, with the
results often effectively accurate. Considerable judgement and experience are required to determine if the
simulation is valid.
(2) The following limitations indicate where the model may or may not be useful. RCPWAVE may be
inaccurate for waves crossing behind shoals, or in the vicinity of structures. Wave approach directions should
not be too oblique relative to the offshore boundary. REF/DIF1 can allow for some structures and islands
but again should not use waves with highly oblique wave angles (In both RCPWAVE and REF/DIF1,
II-3-30
Estimation of Nearshore Waves
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