Forward Waveform Transfer of Rotational Cliff Collapse-Induced Waves for Early Warning Assessment of Wave Hazards in Water Bodies

Rotational collapse of a cliff into a confined water body can generate a high-energy leading wave group that reaches exposed shores within a short time. Improved hazard assessment therefore requires a practical link between an earlier near-source water level observation and the evolving downstream wave response. This study quantifies that link by reconstructing the downstream leading wave group generated by rotational cliff collapse from an earlier upstream waveform. Paired gauge records from 79 physical experiments were analyzed over a 0.50 m propagation interval. A forward waveform transfer model was evaluated using nested source-configuration-grouped validation, with the downstream evaluation window defined independently of the measured downstream response. The median aligned waveform correlation was 0.989, while the median apparent celerity ratio, amplitude gain, and time-integrated squared wave elevation transmission ratio were 0.867, 0.578, and 0.412, respectively. Out-of-fold R2 values reached 0.840 for downstream waveform reconstruction and 0.915 for peak amplitude prediction, with positive performance across intact and fragmented source states. These findings establish a time-ordered hydrodynamic relation between near-source and downstream wave conditions, providing a basis for faster interpretation of developing cliff-collapse wave hazards and strengthening early warning assessment in reservoirs, lakes, fjords, and confined coastal inlets.