四川安宁河流域姑巴沟泥石流动力学特征与减灾对策

Dynamic Characteristics and Mitigation of Guba Debris Flow in Anning Valley in Sichuan Province

姑巴沟是四川安宁河流域内最具代表性的典型低频泥石流之一。基于野外调查的基础上,对姑巴沟泥石流的动力学特征进行了计算,并对2011年泥石流的成因机制进行了分析。研究认为,姑巴沟泥石流的触发原因是由持续强降雨引发的沟道径流与上游冰湖溢水的综合作用,水动力补给过程具有复合特征。针对姑巴沟泥石流爆发突然、流体流量大流速高及其威胁对象的分布特征,提出了针对性的防灾减灾建议,对揭示姑巴沟泥石流的形成过程及动力学特征具有实际意义,并可为安宁河流域内其它具有相似孕灾背景的低频泥石流形成机理的认识提供参考。

Guba debris flow is one of the most typical debris flows with low return period in Anning Valley,Sichuan Province. Based on the field survey,we calculate the dynamic properties and analyze the genetic mechanism of Guba debris flow occurred in 2011. Results show that,combined effect of gully runoff from sustained heavy rainfall and overflow from glacial lakes upstream triggered the disaster. The water power supply processes show complex features. According to the characteristics of sudden outbreak,heavy flow,high speed and particular position of the affected targets in Guba debris flow,proposals are put forward for prevention and reduction. It has practical significance to reveal forming process and dynamic properties of Guba debris flow,which could also be a reference to understanding the formation mechanism of low frequency debris flow with similar backgrounds in Anning Valley.