Abstract: The dam site of Wudongde Hydropower Station is threatened by a number of debris flow gullies. In this article, some prevention and control measures are presented to avoid huge losses caused by debris flow disasters. The static and dynamic characteristics of debris flows in Zhugongdi Gully were analyzed by means of field investigation and laboratory model test. In view of the particularity of terrain, geological conditions and project layout, the countermeasures of debris flow were proposed. In addition, the effect of the countermeasures in Zhugongdi Gully was tracked and evaluated. Results show that block dam could effectively prevent large particles of solid matter from being involved in debris flow activity and reduce the erosion degree of upstream gully. Silting field could detain some small particles of solid matter, and as a consequence only a small amount of solid substances and the flood are discharged through the drainage canal. Triangular drainage canal has the characteristics of three dimensional beam current, so the draining effect is significant. The outlet of drainage canal is located in hard bedrock with strong anti-scouring ability, conducive to the stability of drainage canal. The control system composed of block dam, silting field and drainage canal has good control effect. This research can be used as a reference for debris flow treatment in the future.

Key words: Wudongde hydropower station, Zhugongdi Gully, debris-flow, static and dynamic characteristics, countermeasure, treatment effect