Hydraulic Condition of Breaking Waves

Iribarren number, which is a non-dimensional physical number of combing wave height, wave length and beach or breakwater slope, is widely used by many researchers and coastal engineers for classifying the type of breaking waves and for estimating armor weight and run-up height. But it does not represent the hydraulic condition of breaking waves sufficiently well, because it implies the offshore wave condition and insufficient shoaling effect. In the present paper new surf parameters, 1st order wave action slope and 2nd order wave action slope, are suggested for the same purpose. The new surf parameters use the values of wave length as well as wave height at the local points or at the breaking points. The accurate estimation of local value of wave length may be very difficult, but the use of linear wave theory might be sufficient enough for characterizing the breaking waves at the breaking points.