- 责任者：Xie Hong (Key Laboratory of Mountain Hazards and Surface Process ; Chinese Academy of Sciences ; Chengdu 610041 ; China) ; Liu Weiming
- 刊名：Journal of Earth Sciences and Environment
- 出版年：2013
- 卷期：35(4)
- 页码：p.90-97
- issnNo：ISSN1672-6561
- isbnNo：CN61-1423/P
Debris flow happened in Tangjiagou of Tianwan river basin of Shimian, Sichuan in July 14, 2012, and resulted in two people death, five missing and huge economic loss. Characteristics of debris flow include that it is caused by the rainstorm in the partial middle and upper reaches of gully, formation mechanism is the type of start of the ditch bed, lasting process is approximately 1 h, total volume is approximately 85X 104 m3, and it is low-frequency and very large-scale; the relative height of Tangjiagou is 3 139 m, and gully, which is steep with some elbows and bayonets, results in reiterative block-outburst when debris flow moves, and block coefficients are 2.5-3.0; debris flow is supplied by the initial ditch bed debris in the middle and lower reaches of gully and enlarges the range and scale of solid matter supplement, so that its hazard potential is stronger; fluid contains 2%-4. 4% clay, viscosity is great, bulk weight is 20.6 kN • m-3, transport capacity is strong, and the maximum volume of stones, which are carried to the mouth of gully, is about 235 m3 with the weight of about 645 t; the straight-forward of fluid is strong, and the height of bend ultra-high is more than 11 m; debris flow blocks Tianwan river and forms the outburst disaster, and the mountain disaster chain of debris flow-dammed lake-mountain torrent is built, and the hazard extends from gully to the both sides of main river with wide range. Forest vegetation flourishes, but debris flow develops popularly; low disaster awareness increases the hazard of debris flow, and bend ultra-high of debris flow movement increases the casualties. In general, debris flow hazard should be prevented more in the mountains with good ecological environment.