The most probable maximum waves can be obtained by using
r. ft
H„ = 0.707 Ho
/ loge - .
(3-39)
H1 = 0.707 (59.4)
The most probable maximum wave is obtained by setting n
1, and
using Equation 3-39
303'
—j— = 100.4 feet, say 100 feet.
Assuming that the 100-foot wave occurred, then the most probable
second highest wave is obtained by setting n = 2, the third from n = 3, etc
H3 = 0.707 (59.4)
- 94.1 feet, say 94 feet;
H3 = 0.707 (59.4) -Jtage ~y = 90.2 feet, say 90 feet.
The problem now is to détermine the changes in the deepwater waves as
they cross the Continental Shelf, taking into account the combined effects
of bottom friction, refraction, the continued action of the wind, and the
forward speed of the hurricane. This requires numerical intégration, using
Table 3-3, Figure 3-35, and refraction diagrams. It is also necessary to
obtain an effective fetch length, by use of
where
and
0.0555 UR
Fg is the effective fetch in nautical miles,
Ho is the deepwater significant wave height in feet,
Up is the maximum sustained wind speed in knots.
For this example, using Equation 3-40
59.4
0.0555(91.6)
- (11.69) = 137 nautical miles.
(3-40)
3-62