四川甘洛县黑西洛沟“8·31”泥石流动力过程  

Dynamic process of the“8·31”debris flow in Luoxi gulley of Ganluo County,Sichuan Province

作　　者：史继帅 姜亮 翟胜强 SHI Jishuai;JIANG Liang;ZHAI Shengqiang(Sichuan Geological Environment Suervey and Research Center,Chengdu,Sichuan 610081,China;Sichuan Province Engineering Technology Research Center of Geohazard Prevention,Chengdu,Sichuan 610081,China)

机构地区：[1]四川省地质环境调查研究中心,四川成都610081 [2]四川省地质灾害防治工程技术研究中心,四川成都610081

出　　处：《中国地质灾害与防治学报》2024年第3期52-60,共9页The Chinese Journal of Geological Hazard and Control

摘　　要：黑西洛沟位于四川省甘洛县苏雄镇,该沟于2020年8月31日上午8时暴发特大型泥石流灾害,对当地居民、成昆铁路桥梁及基础设施等造成了极大的损失。为研究黑西洛沟泥石流的活动特征与动力特征,综合利用野外实地调查、现场观测及研究区高精度DEM数据等,并利用Massflow软件对该次泥石流进行模拟验证,模拟反演黑西洛沟泥石流的动力演化过程,定量评价“8·31”泥石流动力特征。研究表明:“8·31”泥石流主要经历了“降雨汇流—下切侧蚀—一级平台淤积分选—平台后下切侵蚀—二级平台进一步淤积分选—平台后进一步下切侧蚀—岸坡崩滑堵溃—堵河形成堰塞湖、溃决泄流”等“滚雪球式”的循环加剧过程。基于Massflow的泥石流动力过程分析,模拟各沟段的洪峰流量、流速、流深、侵蚀沉积深度等均与实测数据相匹配,证实了该方法的可靠性。通过该手段,可更加直观地分析泥石流的动力特征,为后续的防灾减灾工作提供理论依据。Heixiluo gully,located in Suxiong Town,Ganluo County of Sichuan Province,experienced a catastrophic debris flow disaster at 8:00 a.m.on August 31,2020,causing significant losses to local residents,as well as to the Chengdu–Kunming railway bridges and infrastructure.To Study the activity and dynamic characteristics of the debris flow in Heixiluo gully,a comprehensive analysis was conducted using field investigations,on-site observations,and high-precision DEM data from the study area.The formation conditions and activity characteristics of the“8·31”debris flow were studied,and the Massflow software was utilized to simulate and verify the debris flow,inversely simulating the dynamic evolution process of the debris flow in Heixiluo Gully,and quantitatively evaluating the dynamic characteristics of the“8·31”debris flow.The study indicates that the“8·31”debris flow mainly underwent a“snowballing”cycle of processes,including“rainfall runoff convergence-,incision and erosion on the sides,sedimentation and selection on the first-level platform,erosion on the rear side of the platform,further sedimentation and selection on the second-level platform,further incision and erosion on the rear side of the platform,bank slope collapse,blockage and collapse,river blockage,formation of barrier lakes,and dam breach discharge.”Based on the Massflow analysis of the dynamic process of the debris flow,the simulated peak discharge,flow velocity,flow depth,erosion,and sedimentation depths in each gully segment match the measured data,confirming the reliability of this method.Through this method,the dynamic characteristics of debris flow can be more intuitively analyzed,providing a theoretical basis for subsequent disaster prevention and mitigation works.

关 键 词：泥石流 Massflow 动力演化过程 活动特征 动力特征 

分 类 号：P642.23[天文地球—工程地质学]