Comparison between the first and second wave crest amplitude generated by landslides

The landslide-generated wave which is largest is of particular interest due to hazard prevention. Among all wave trains, the first or second wave crest has the maximum amplitude. Whether the first wave crest amplitude is larger or not is undoubtedly affected by the landslide dimension and impact velocity. This paper presents a criterion for comparison between the first and second wave crest amplitude. 49 test runs are carried out based on an orthogonal design array, and in 39 runs wave crest amplitudes of the second waves are larger than those of the first waves. This study systematically investigates the effects of dimensionless front area, dimensionless top area, dimensionless two-dimensional volume and dimensionless three-dimensional volume on wave crest amplitude and wave amplitude ratio. An optimal criterion, including slide Froude number and dimensionless two-dimensional volume of slide, is proposed to determine which wave crest has the larger amplitude. The criterion is well verified by 157 test runs of two previous experiments.