Author(s): Yonghui Zhu, Dong Chen, Jianyin Zhou, Dechao Hu

Linked Author(s): Yonghui Zhu, Dong Chen, Dechao Hu

Keywords: Barrier lake; Landslide dam; Breaching; Dam-breach flood; Emergency treatment;

Abstract: Devastating disasters may occur in case of breaching of a barrier lake, which therefore have to be rapidly assessed and urgently treated in order to reduce the potential risk. A giant and dangerous barrier lake was formed in the upper reach of the Changjiang River (known as the Jinsha River) by a landslide close to the Baige Village in Tibet, China, on the 3rd Nov. 2018. According to the continuous accumulated and updated measured or inferred data transmitted from the site which is very remote and quite inaccessible, simulation of a large number of possible scenarios of the dam-breach flood of the Baige Barrier Lake was conducted to predict the flood peak outflow and hydrograph, and help to evaluate the severity of the threat to the downstream area, providing basis for the emergency evacuation of the population at risk. To reduce the water volume of the barrier lake and the flood peak outflow, and consequently the flood risk to the downstream area, ten days later after formation the Baige landslide dam was artificially breached by a manual excavated drainage channel, and the lake was successfully drained. After that back analysis of the draining process of the Baige barrier lake was also conducted to reproduce the well-monitored flood hydrograph obtained during the dam breaching process of the barrier lake.

DOI: https://doi.org/10.3850/38WC092019-1071

Year: 2019