Objective This study investigates the distribution characteristics of debris flow in Jinsha River and conducts a hazard assessment to provide data support and a scientific basis for understanding regional variations in debris flow and disaster prevention in the Hengduan Mountain area.

Methods Based on the field investigation and GIS spatial analysis, 2551 debris flows in the Jinsha River were identified. Hazard assessment was performed based on the activity characteristics of these debris flows. Using ROC analysis and spatial clustering, the debris flow hazard zoning in the Jinsha River was established.

Results ① Debris flows in the upper reaches of Jinsha River are not active, predominantly of low to medium frequency, while high−frequency debris flows are concentrated in the lower reaches, especially between Yarmou and Qiaojia. ② The primary factors influencing debris flow formation include slopes ranging from 15° to 35°, frequent seismic activity, and the presence of both soft and hard clastic rocks. ③ Medium− and high−hazard debris flows cover 47.48% of the area, nearly half of the studied region. ④ The high−hazard zone in the Dongchuan−Qiaojia section shows high concentration, closely correlating with active faults and abundant sediment supply, largely controlled by tectonic activity.

Conclusions High−hazard debris flow zones are concentrated in the downstream of Jinsha River. The hazard zoning map provides a reference for risk mitigation in hydropower development and transportation infrastructure planning.