The Wenchuan earthquake triggered lots of high-speed and long-range landslides

and under the super-strong ground motions

the slope was easily torn and ejected

then the sliding mass was crashed and transferred into debris flow for long-range movement because of the terrain and its potential energy.This type of rock-fragment flow had great kinematic velocity and extraordinary running out distance which caused great disasters and losses to the stricken region people.Based on lots of field investigations of large-scale typical high-speed and long-range landslides induced by the Wenchuan earthquake

this paper summarizes and analyzes the initial flight velocity

maximum kinematic velocity and debris flow velocity

comparatively calculates the movement velocity and motility of Donghekou landslide by different simplified methods.Results show that the movement characteristic value of Donghekou landslide is 0.2292

maximum kinematic velocity is 63.40 m/s

and average velocity exceeds 25 m/s

which belongs to superhigh speed landslide and has strong debris flow characteristics.