摘要
贵州省望谟县2011年6月6日暴发了特大山洪泥石流,其中暴雨中心所在的打易镇多处暴发泥石流。短历时强降雨激发了沟床起动类型的泥石流。本文通过对贵州望谟河流域群发泥石流的调查,得出该流域的66条沟中,22条沟无沟床起动类型泥石流暴发,25条沟暴发沟床起动类型泥石流,还有19条沟无法确定是否有沟床起动类型泥石流暴发。在前期工作基础上,提出了地质条件和降水条件因子的改进方法;并在前期工作的3大条件(地形条件、地质条件和降水条件)之间的关系基础上,由贵州望谟群发泥石流数据得出改进沟床起动类型泥石流的临界值,提出了泥石流的预报模型。本文模型在我国西南地区的泥石流验证中非常成功,为泥石流的预报提供了一个新方法。预报模型中的地形因子和地质因子还可以判断泥石流流域的暴发频率,为正确地判断泥石流流域的特征打下了基础。预报模型也可以估算泥石流的暴发规模,为定量地预测泥石流危害范围提供了依据。
Many debris flows were triggered in and around the Dayi area of the Guizhou province,China during a rainstorm in 2011.High-intensity short duration rainfall was the main triggering factor for these gully type debris flows.They are probably triggered by a runoff induced mechanism.A revised prediction model is introduced for this kind of gully type debris flows.The factors are related to the topography,geology and hydrology（rainfall）,and the model is applied to the Wangmo river catchment.Regarding the geological factor,the“soft lithology”and “loose sediments”in the channel are added to the list of the average firmness coefficient for the lithology.Also the chemical weathering is taken into account for the revised geological factor.Concerning the hydrological factor,a coefficient of variation of rainfall is introduced for the normalization of the rainfall factor.The prediction model for debris flows proposed in this paper,delivers three classes of the probability of debris flow occurrence.The model is successfully validated in debris flow gullies with the same initiation mechanism in other areas of southwest China. The generic character of the model is explained by the fact that its factors are based on the initiation mechanisms and the statistical analyses of an unique variety of local factors.The result provides a new way to predict the occurrence of debris flows initiated by a runoff induced mechanism.
出处
《工程地质学报》
CSCD
北大核心
2014年第3期450-455,共6页
Journal of Engineering Geology
基金
贵州省地质灾害监测预警与决策支持平台研究子项目贵州省泥石流启动机理及预警预报研究(ZG0064)资助
关键词
预报模型
泥石流
沟床起动
Prediction model
Debris flow
Initiated in channel
作者简介
余斌，男，博士，教授，主要从事泥石流灾害防治与研究工作．Email：drbinyu@yahoo.com
