EXAMPLE PROBLEM II-4-1

FIND:

Wave height and water depth at incipient breaking.

GIVEN:

A beach with a 1 on 100 slope, deepwater wave height *H*o = 2 m, and period *T *= 10 sec. Assume

breaking is expected to occur.

SOLUTION:

coefficient (see Part II-3, Equation II-3-14)

Estimate the breaker height from Equation II-4-8

From Equations II-4-6 and II-4-7, determine *a *and *b *used in Equation II-4-5, tan *β *= 1/100

Breaker height is approximately 2.7 m and breaker depth is 3.2 m. The initial value selected for the

refraction coefficient would now be checked to determine if it is correct for the actual breaker

location. If necessary, a corrected refraction coefficient should be used to recompute breaker height

and depth.

(2) Energy flux method.

(a) A more general method for predicting wave height through the surf zone for a long, straight coast

is to solve the steady-state energy balance equation

' &δ

(II-4-13)

II-4-6

Surf Zone Hydrodynamics

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