Work

Landslide-lake outburst floods accelerate downstream hillslope slippage

Year: 2021

Type: article

Abstract: . The Jinsha River, carving a 2–4 km deep gorge, is one of the largest SE Asian rivers. Two successive landslide-lake outburst floods (LLFs) occurred after the 2018 Baige landslides along the river. Using Sentinel-2 images, we examined the LLFs' impacts on downstream river channel and adjacent hillslopes over a 100 km distance. The floods increased the width of the active river channel by 54 %. Subsequently, major landslides persisted for 15 months in at least nine locations for displacements > 2 m. Among them, three moving hillslopes, ~80 km downstream from the Baige landslides, slumped more than 10 m one year after the floods. Extensive undercuts by the floods probably removed hillslope buttresses and triggered deformation response, suggesting a strong and dynamic channel-hillslope coupling. Our findings indicate that infrequent catastrophic outburst flooding plays an important role in landscape evolution. Persistent post-flood hillslope movement should be considered in disaster mitigation in high-relief mountainous regions.

Source: Earth Surface Dynamics

DOI: 10.5194/esurf-9-1251-2021

Authors: Wentao Yang, Jian Fang, Jing Liu-Zeng

Institutions: Beijing Forestry University, Central China Normal University, Tianjin University

Language: English

Topic: Landslides and related hazards

Subfield: Management, Monitoring, Policy and Law

Field: Environmental Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,682

Funders: National Natural Science Foundation of China, Ministry of Science and Technology of the People's Republic of China, Japan Aerospace Exploration Agency