Author(s): Weipeng Hou; Chendi Zhang; Guo-An Yu; Yang Zhao
Linked Author(s): Chendi Zhang
Keywords: Debris flows; River blockage; Sediment transport; Alpine environment
Abstract: Debris flows are one of the dominating natural hazards that threaten the security of communities living in alpine environments. Debris flows provide high-intensity abrupt sediment supply to the main river, significantly affecting sediment transport processes throughout the river network. However, the interaction between hydraulics and geomorphology in the complex physical processes when a debris flow enters the main river has not been fully addressed. To quantify the impact of an abrupt debris flow on sediment transport processes in the main river, a theoretical model consisting of four modules was established: (i) estimating debris flow volume and velocity; (ii) analyzing debris flow movement in the flowing reach; (iii) quantifying debris flow entering the main river; and (iv) calculating sediment transport rate in the main river. The threshold for blocking the main river was revealed by defining the block coefficient, which is the ratio of debris flow deposition width to the main river width. The results highlight the debris flow discharge, main river flow velocity, and channel width as the primary influencing factors on the blockage of the main river.
Year: 2024