Xiaojia Gully is a typical debris flow gully in the earthquake zone near Yingxiu town which located in the left of Yuzi River

and has a drainage area of 7.19 km2 and an average longitudinal slope of 485‰. Many debris flows occurred in this gully after Wenchuan earthquake. In August 14

2010

a large scale debris flow(the volume is about 6.50×105 m3) was triggered by heavy rainstorm

blocked the Yuzi River and caused dam-breaking disaster. Xiaojia Gully was risky because of its large amount of loose materials and abundant rainfall. The Yingxiu part of S303 highway would be interrupted if the debris flow occurs. The Yuzi River would be blocked in the condition of large scale debris flow

and the dam-breaking flood could potentially cause damage to the newly constructed Yingxiu Town. At present

the gully still had 5.22×106 m3 of solid materials

of which about 2.02×106 m3 was prone to debris flow in the future when it encounters great rainstorms. Analyzing the activity characteristics of Xiaojia Gully debris flow after the earthquake based on formation conditions

the brief ideas for Xiaojia Gully debris flow control were discussed.