Experimental study on the characterization of landslide-generated waves in water bodies with rigid vegetation

Considering the severe hazards posed by landslide-generated waves, the development of effective mitigation strategies is of utmost importance. This study employed physical modeling in a wave flume to investigate the characteristics of impulse waves generated by landslides in water bodies with rigid vegetation. The entry of a block slide into water produced nonlinear impulse waves within the intermediate water depth region. The results obtained validate the accuracy of the Heller and Spinneken model in predicting maximum wave amplitude and height, thereby extending its applicability to a relative slide thickness of 0.83. A novel dispersion relationship, which accounts for wave nonlinearity, is introduced in this study, offering a precise representation of the entire wave evolution process. Empirical formulas are derived to quantify the reduction in wave amplitude and height in both emergent and submerged vegetation scenarios. The study underscores the unique role of vegetation dissipation in wave attenuation, with maximum attenuation accounting for over 80% of the total reduction in emergent vegetation, in contrast to less than 67% in submerged vegetation. Furthermore, the maximum runup height of landslide-generated waves is primarily dependent on the incident wave momentum flux parameter, regardless of the vegetation arrangement patterns.