摘要
楼梯石沟位于章江源头江西省崇义县聂都乡境内,为典型降雨型泥石流沟谷。该沟于2009年7月3日晨暴发泥石流灾害,堆积方量约5.14×10~4 m^3,造成直接经济损失约100万元。通过对楼梯石泥石流沟流域地形条件、物源条件及水源条件的特征分析,得出该沟形成泥石流的条件充分:1)主沟平均纵比降126‰,相对高差759.3 m,易发生浅层滑坡的山体(表面坡度25～45°)面积较大,约1.63 km^2;2)泥石流松散固体物源主要为浅层滑坡堆积体,总方量达26.15×10~4 m^3。楼梯石沟"7·3"泥石流为浅层滑坡启动类型,大量滑坡体进入沟道后被洪水启动形成泥石流。预测在50年一遇或大于50年一遇的强降雨条件下,楼梯石沟还可能发生新的泥石流。
The Loutishi gully is located at the source of Zhangjiang river in the Niedu town, Chongyi County, Jiangxi province. It is a typical rainfall-type debris flow valley.In the morning of July 3, 2009, the debris flow disaster broke out in the ditch, and the accumulated volume was about 5.14×10^4 m^3, resulting in a direct economic loss of about 1 million yuan.Based on the analysis of the topographic conditions, material source conditions and water source conditions of the stairway debris flow valley, it is concluded that the formation conditions of debris flow in the valley are adequate: 1) the average longitudinal ratio drop of the main ditch is 126‰, and the relative height difference is 759.3 m, the area of the mountain body (surface slope 25~45°) prone to shallow landslides is larger, which is about 1.63 km 2;2)The loose solid source of debris flow is mainly shallow landslide deposits with a total volume of 26.15×10^4 m^3. The "7.3" debris flow in the stairway is a shallow landslide initiation type. After a large number of landslides enter the channel, they are triggered by floods to form debris flow. It is predicted that a new debris flow may occur in the stairway ditch under the condition of heavy rainfall once in 50 years or once in 50 years.
作者
吴雨夫
WU Yufu(Emergent Geohazards Center of Jiangxi Province, 330025, Nanchang, PRC)
出处
《江西科学》
2019年第2期251-253,286,共4页
Jiangxi Science
关键词
崇义
泥石流
特征
降雨
成因机制
Chongyi
debris flow
feature
rainfall
formation mechanism
