Alternate, more precise, methods of determining the wave height and period by using shallow
water wave forecasting equations are given in U. S. Army Corps of Engineers (1977c) (1981b) and
(1981c). The two later references will eventually supersede the first and are preferred by many coastal
engineering specialists. Their use, however, involves more elaborate procedures so, for the sake of
brevity and simplicity, only the equations from the first reference will be given. Either the tables or the
equations are adequate for design of low cost shore protection.
The wave height, H. is,
H = (0.283U2 /g) tanh [0.530 (gd/U2)0.75] tanh {(0.0125(gF/U2)0.42)/(tanh[0.530(gd/U2)0.75])}
(5)
And the period, T, is
T = 2.40 (πU/g) tanh [0.833(gd/U2)0.375] tanh {(0.077(gF/U2)0.25)/(tanh[0.833(gd/U2)0.375])}
(6)
Where U = the wind speed in feet/second;
F = the fetch length in feet;
D = the depth in feet:
g= 32.2 ft/sec2.
And
Note: The above equations are in dimensionless form and can be used with any consistent set of units.
44
Previous Page
