Numerical Investigation on Hydrodynamic Characteristics of Landslide-Induced Impulse Waves in Narrow River-Valley Reservoirs

Abstract

Landslide-induced impulse waves in a river-valley reservoir region have become a serious threat to life and property intactness. Compared with previous studies focusing on landslides in open-water regions, this paper systematically carried out numerical investigations on the hydrodynamic characteristics of landslide-induced impulse waves in narrow river-valley reservoirs by applying software package FLOW3D. To verify the computational reliability of FLOW3D, necessary experimental work was conducted. The predicted temporal evolutions of water elevation at selected wave gauges are in good agreement with that recorded during the corresponding experiment. The effects of some prominent factors, such as the drop height of the slide, still-water depth, slide volume, and slide slope, on the propagation and magnitude of landslide-induced impulse waves are investigated in detail by systematically analyzing both simulation and experimental results. Based on simulation results, we proposed empirical formulas for predicting the landslide-induced impulse waves by performing dimensionless analysis and applying nonlinear regression methods. Then, the proposed empirical formulas were applied to predict the impulse waves induced by four landslide accidents. It is believed that the findings drawn from this paper could greatly enhance our understanding on the hydrodynamic characteristics of landslide-induced impulse waves in narrow river-valley reservoir regions, and the proposed empirical formulas can be used as quick technical support for the safe navigation of such rivers.