THE RUN-UP AND BACK-WASH PROCESSES OF SINGLE AND DOUBLE SOLITARY WAVES

The run-up and back-wash processes of single and double solitary waves on a slope were studied experimentally. Experiments were conducted in three dif-ferent wave flumes with four different slopes. For single solitary wave, new ex-perimental data were acquired and, based on the theoretical breaking criterion, a new surf parameter specifically for breaking solitary waves was proposed. An equation to estimate maximum fractional run-up height on a given slope was also proposed. For double solitary waves, new experiments were performed by using two successive solitary waves with equal wave heights; these waves were separated by various durations. The run-up heights of the second wave were found to vary with respect to the separation time. Particle image velocimetry measurements revealed that the intensity of the back-wash flow generated by the first wave strongly affected the run-up height of the second wave. Showing trends similar to that of the second wave run-up heights, both the back-wash breaking process of the first wave and the reflected waves were strongly af-fected by the wave-wave interaction. Empirical run-up formula for the second solitary wave was also introduced