Assessment of local outburst flood risk from successive landslides: Case study of Baige landslide-dammed lake, upper Jinsha river, eastern Tibet

•Baige landslides induced dam breaches were back-analyzed.•Two parameters (Effective dam height and Narrowing rate) were proposed to analyze geometry that influences the successive dam breaches and outburst floods.•Effective dam height dominates peak discharge with linear rate of 1009.4 m3/s/m.•Locally narrowing and lifting effects both promote to form subsequent dam with high effective dam height with high flood risk.