贡嘎山东坡磨西河流域泥石流暴发的临界雨量值初探

在实地调查和前人研究的基础上,查明了贡嘎山东坡磨西河流域内泥石流沟的分布状况、暴发规律及危害特征等;并根据近20年来流域内发生的典型泥石流灾害,分析了泥石流发生前的降雨过程,发现磨西河流域内泥石流发生的当日雨量和前6 d有效雨量之间具有明显的幂函数关系,据此以泥石流发生的当日雨量和前6 d有效雨量为指标,初步探讨了磨西河流域内泥石流暴发的雨量值。

Preliminary Study on the Critical Rainfall Condition of Debris Flows along Moxi River in the East Slopes of the Mount Gongga

On the basis of field investigation and former researches,35 typical debris flow gullies were found out,which threat the local residents,vistors,farmlands,electric power stations,water resource facilities,roads,cableways and other tourism equiments along Moxi river,Sichuan province,Southwest China.The debris flows mainly occurred in the following years including 1989,1990,1995,2003 and 2005 and furthermore the occurrence of debris flows is obviously associated with rainfall.Then according to the typical debris flow occurrence events during the passed 20 years,corressponding rainfall process were analyzed and relationship between antecedent effective rainfall and the 24 h rainfall was discussed.It was found that the 24 h rainfall when debris flows occurred was associated obviously with the antecedent effective rainfall accumulated for 6 days before debris flows occurred and their quantitative equation was established.Based on this relationship,the critical rainfall condition was discussed in this paper.This research is of certain theoretical and actual significance for the prediction and mitigation on debris flow disasters.