四川攀枝花仁和区大箐沟泥石流调查及危险性评价

Daqinggou Debris Flow Hazard Investigation and Evaluation in Renhe,Panzhihua of Sichuan

四川攀枝花仁和区大箐沟泥石流是一条沟谷型泥石流沟,在水动力侵蚀作用下时常发生泥石流并产生危害。通过野外勘察、测绘等研究方法,论述了大箐沟泥石流基本特征和形成条件,并通过选取泥石流10个特征因子,定量判定该泥石流危险度。泥石流综合判断结果为中度危险泥石流,危险等级为Ⅳ级。在形成条件方面,沟谷型泥石流汇水面积广且物源丰富,发生过程主要为降雨-崩滑-河道侵蚀-河道堆积,因此河道侵蚀、水动力强度是泥石流发生的关键因素。针对成因和特征,提出了以护坡、固床和导流等相关工程措施为主,以边坡植被恢复为辅的防治措施。

Daqinggou was a valley-type debris flow ditch,where debris flow with an incision process frequently caused serious damages.This paper discussed the basic characteristics and formation conditions of the debris flow in Daqinggou on the basis of field survey,investigation and other comprehensive methods.Meanwhile,the debris flow risk assessment has been given through the score analysis of 10 debris flow factors,which result was moderately dangerous as IV grade.In terms of debris flow forming condition,the valley-type debris flow had a wide catchment area and abundant provenance,and its occurrence process was mainly a complex process,namely rainfall-collapse-erosion or accumulation,the key process of which were river erosion and slope instability.In view of the causes and characteristics,corresponding countermeasures were put forward at the end of this paper,including main engineering controls such as slope blocking,gull-bed fixing,flow diversion and slope vegetation restoration.