Author(s): Wei Huang; Zhiyuan Yue; Zhixian Cao; Gareth Pender
Linked Author(s): Gareth Pender, Zhixian Cao
Keywords: Tangjiashan; Dam breach; Mathematic model; Landslide dam
Abstract: The Tangjiashan landslide dam, generated by the 2008 Wenchuan earthquake in Sichuan Province, is composed of heterogeneous sediments. Simplified mathematical models have been used to model the dam breach and the flood. However, it remains hard to identify the errors due to simplifications in the models, rendering the agreement between modelling and observations open to question. Here a physically enhanced, coupled 2D mathematical model is extended by implementing a multiple-sized sediment transport model for graded sediments in order to resolve the Tangjiashan landslide dam breach and the flood. The model is built upon the complete shallow water hydrodynamic equations and the HLLC approximate Riemann solver. Both erosion and mass collapse are accounted for. In comparison with the observed data, the widening and deepening of the breach as well as the flood hydrographs are reproduced rather well by the present model when the heterogeneity of the dam material is properly incorporated.
Year: 2011