Numerical study on near-field characteristics of landslide-generated impulse waves in channel reservoirs

Abstract

Landslide-generated impulse waves (LGIWs) in channel reservoirs of mountainous regions exhibit essential differences to those in lacustrine reservoirs. We used a soil–water coupling smoothed particle hydrodynamics model to study the near-field characteristics of LGIWs in channel reservoirs. Results show that wave formation and propagation are strongly affected by the opposite bank. A three-dimensional first wave in the near field gradually transforms into a two-dimensional leading wave that travels along the channel in far field. We classify the channel reservoir into wide or narrow according to whether the first wave is visibly affected by the opposite bank. The relations between parameters of first wave and landslide parameters in the near field are obtained from a series of numerical computations. We also provide estimation formulae for the amplitude of a leading wave in a channel reservoir which is beyond the capability of former empirical relations in lacustrine reservoir. The leading wave can be used later as initial conditions for a wave propagation model. These findings are helpful for engineering estimates of LGIWs in channel reservoirs.