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Rapid landslides into water bodies may generate massive water waves posing a threat to riparian settlements and infrastructure. These waves are referred to as impulse waves and exhibit tsunami-like characteristics. The generation and in particular the spatial propagation of impulse waves was studied in a hydraulic laboratory wave basin. A videometric measurement system was applied to track the water surface displacement. Compared to fixed wave gauges typically applied in previous studies, this technique yields a quasi-continuous representation of the water surface allowing for a detailed analysis of spatial propagation patterns. In total 74 experiments with deformable mesh-packed slides were conducted thereby varying the slide impact velocity, the slide mass, the slide thickness, the slide width, the slide impact angle, and the stillwater depth. Empirically derived prediction equations are presented and discussed for key wave characteristics including wave amplitudes and celerities. In the context of a preliminary hazard assessment, these equations allow for the estimation of wave magnitudes at prototype-scale.

Large subaerial mass wasting into water may generate large waves along coast lines and in bays. Hazard assessment of such an events is based on the decay rate of these impulse waves along their propagation path to populated areas and infrastructure along the shoreline. The spatial propagation processes of impulse waves generated by deformable slides was investigated in a wave basin. A videometric measurement approach allowed for a detailed tracking of the free water surface and key wave characteristics during the experimental runs including the wave height. Based on selected tests, the slide width effect on spatial wave propagation is discussed.

Impulse waves are generated by landslides or avalanches impacting oceans, lakes or reservoirs, for example. Non-breaking impulse wave runup on slope angles ranging from 10° to 90° (V/H: 1/5.7 to 1/0) is investigated. The prediction of runup heights induced by these waves is an important parameter for hazard assessment and mitigation. An experimental dataset containing 359 runup heights by impulse and solitary waves is compiled from several published sources. Existing equations, both empirical and analytical, are then applied to this dataset to assess their prediction quality on an extended parameter range. Based on this analysis, a new prediction equation is proposed. The main findings are: (1) solitary waves are a suitable proxy for modelling impulse wave runup; (2) commonly applied equations from the literature may underestimate the runup height of small wave amplitudes; (3) the proposed semi-empirical equations predict the overall dataset within ±20% scatter for relative wave crest amplitudes ε, i.e., the wave crest amplitude normalised with the stillwater depth, between 0.007 and 0.69.