Beaches Produced by Waves of Low Phase Difference

A theoretical and experimental study of the action of swell waves on model beaches shows that the beach slope and the distance from the shore to the breakers correlate with the breaker height, wave period and grain diameter. The experiments were carried out using quartz sands and wave periods in the range of 0.8 sec to 1.34 sec. Wave heights were used up to a maximum breaker height of 6 cm. The waves employed were of low phase difference, i.e., the ratio of time of uprush to wave period being less than 0.7. When this ratio is exceeded, the wave period ceases to be important. Using a continuity approach it is shown that the energy lost in breaking, friction and turbulence and in moving material, amounts to about 25% of the incident wave energy when the beach angle is highest, to about 50% when the beach is at its lowest level within the range considered.