Debris Flows and Landslides - River Dynamics and Integrated River Management - page 239

4.3.4.2 Slope Debris Flows after the Wenchuan Earthquake
A lot of slope debris flows occurred after the Wenchuan Earthquake because thousands of avalanches and
landslides triggered by the earthquake resulted in a huge amount of loose solid materials on slopes. An
investigation of slope debris flows and measurements of 19 slope debris flows were performed from June
to August 2009 (Li et al., 2010). Figure 4.60 shows the earthquake area and the location of the 19 slope
debris flows in the Mianyuan and Minjiang river basins. Figure 4.61 shows a slope debris flow that
occurred at Xiaogangjian on August 26, which blocked the only highway from Hanwang to Qingping.
During the rainfall with an intensity of about 90 mm/d on July 17, 2009, several tens of slope debris
Fig. 4.60 Wenchuan Earthquake area and the locations of the 19 slope debris flows
(a) (b)
Fig. 4.61 (a) Slope debris flow at Xiaogangjian along the Mianyuan River; (b) Slope debris flow at Xiaomuling
along the Mianyuan River (See color figure at the end of this topic)