The Debris Flow Development Trend of in Xiaogangjian Gully in Mianzhu County, Wenchuan Earthquake Zone
详细信息
- 责任者：Yang Dongxu (Key Laboratory of Mountain Hazards and Earth Surface Processes ; Institute of Mountain Hazards and Environment ; CAS ; Chengdu 610041 ; China) ; Chen Xiaoqing
- 刊名：Journal of Mountain Research
- 出版年：2012
- 卷期：30(6)
- 关键词：泥石流 ; debris flows ; 四川 ; Sichuan Province
- 页码：p.701-708
- 图表：3 illus., 1 table, 13 refs.
- 分类号：1800
- issnNo：ISSN1008-2786
- isbnNo：CN51-1516/P
摘要
The Xiaogangjian Gully is typical for debris flow in the earthquake zone.Located in the left of Mianyuan River,it has a drainage area of 1.36 km2 and an average longitudinal slope of 412‰.After Wenchuan earthquake,many debris flow occurred in this gully,causing great disasters to the reconstruction of Qingping Town,The debris flow formation process is as follows: torrents→ torrent scourage → small-scale debris flow → debris flow in mainstream channel,with powerful energy and strong capacity of scouring →,incision of streambed sediment and old deposit platform → large-scale debris flow.At the outlet, there were 10 debris flows in the following 4 years after the earthquake,which cut the gully up to the depth of 35 m,and brought 50 × 104 m3 of solid mass out of the gully.Debris flows buried the Hanwang-Qingping road,blocked the river and formed a dam lake,carried a huge volume of sediment to the downstream,uplifting the water level and silting the highway.At present,the gully still has 334.3×104 m3 of solid material,of which about 156.8×104 m is prone to debris flow in the future when it encounters great rainstorms.The development trends of the debris flow in Xiaogangjian gully are as follows: 1) its strength of activity will keep reducing with the decrease of loose granular materials and total amounts of debris flow; 2) the debris-flow’s activity is transport-limited system right after the earthquake,followed by the transitional type between transport-limited system and weathering-limited system and ultimately is weathering-limited system.