Quantification of Uncertainties for Risk Management of Landslide Dam Break Emergency

Abstract

The break of large landslide dam will trigger catastrophic flood hazard to the downstream area. To manage the flood risk, multiple mitigation measures are required, such as evacuation and removal of obstacles in the river channel. Design of these mitigation measures relies on the estimation of critical flood parameters, namely, peak discharges and stages along the river. However, uncertainties in outburst flood prediction and flood routing analysis have significant influence on the estimation of these flood parameters. Ignoring these uncertainties will undermine the reliability of the estimated flood parameters, which might lead to insufficient design of risk mitigation measures. To enhance the reliability of landslide dam break risk management, we quantify the influence of uncertainties in both landslide dam material erodibility and river channel roughness on the estimation of flood parameters. Successive Baige landslide dams on the Jinsha River in 2018 are investigated to show how the uncertainty quantification facilitates robust decision making for risk management.