Hazard Mechanism Analysis of Taoguan Giant Debris Flow in Wenchuan Earthquake Area on July 10th, 2013

For the giant debris flow caused by heavy rainfall in Taoguan gully, in Wenchuan earthquake area on July 10th, 2013. Field investigation and experiments were made to analyze the loose materials, rainfall, and terrain conditions of the Taoguan gully, and study the process of startup flow and deposition of the debris flow. The result shows that the damage of the rock mass triggered by earthquake in the gully is the root cause of such frequent debris flow after the earthquake. Its mechanism is actually the startup and superposition of loose materials from collapse and landslides, and deposits on slopes and in the gully. From the development trend, the Taoguan debris flow is now on a high-frequency developmental stage, and the possibility of breakout of large scale debris flows still exists.