四川泸定M_(S) 6.8级地震区湾东河流域泥石流活动性预测  

Characteristics and risk assessment of debris flows in the Wandong catchment after the M_(S) 6.8 Luding earthquake

作　　者：张宪政 铁永波[1,2,3] 李光辉 杨昶 卢佳燕[1,4,5] 鲁拓 ZHANG Xianzheng;TIE Yongbo;LI Guanghui;YANG Chang;LU Jiayan;LU Tuo(Chengdu Center of China Geological Survey,Chengdu 610081,Sichuan,China;Technology Innovation Center for Risk Prevention and Mitication of Geohazard,Ministry of Nature Resources,Chengdu 611734,Sichuan,China;Observation and Research Station of Chengdu Geological Harzards,Ministry of Natural Resources,Chengdu 610000,Sichuan,China;Graduate School of Chinese Academy of Geological Sciences,Beijing 100083,China;China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国地质调查局成都地质调查中心,四川成都610081 [2]自然资源部地质灾害风险防控工程技术创新中心,四川成都611734 [3]自然资源部成都地质灾害野外科学观测研究站,四川成都610000 [4]中国地质科学院研究生院,北京100083 [5]中国地质大学(北京),北京100083

出　　处：《地质力学学报》2022年第6期1035-1045,共11页Journal of Geomechanics

基　　金：国家自然科学基金(U20A20110-01);中国地质调查局地质调查项目(DD20221746)。

摘　　要：2022年9月5日四川泸定县发生M_(S) 6.8级地震,地震诱发大量同震崩滑体,并导致湾东河断流。基于现场调查、影像解译和区域地质资料分析,采用空间统计和水文计算的方法,对湾东河流域同震崩滑体分布特征和潜在泥石流危险性进行了研究。结果表明:湾东河流域内同震崩滑体主要分布在地震烈度Ⅸ度区,规模以中小型为主,主要沿沟道两侧展布,尤其是单薄山脊两侧临空面发育密度较大,距断层距离和坡度对其分布具有明显的控灾效应;未来湾东河流域暴发溃决型泥石流的冲出量可能为同等触发条件下震前泥石流的约两倍。依此提出了加强流域内溃决型泥石流风险防范,尽快通过综合监测预警获取泥石流发生的临界雨量值,在泥石流防治工程设计中应充分考虑泥石流规模放大系数等防灾减灾建议,为泸定地震后泥石流灾害防灾减灾提供科学参考。On Sep.5,2022,an M_(S) 6.8 earthquake struck Luding County.The earthquake triggered large amounts of co-seismic landslides,which blocked the Wandong River for nearly 24 hours.Field surveys,image interpretation,spatial statistics,and hydro-logical calculations were used to investigate the characteristics of coseismic landslides and the risk of debris flow following the earthquake.According to the findings,co-seismic landslides are primarily found in areas of earthquake intensity IX,and their sizes are typically small and medium.They are distributed along both sides of the channel,particularly on both sides of the thin ridge facing the air.The distance from the fault and slope controls the distribution of co-seismic landslides.The volume of debris flow runout in the Wandong catchment may be twice that of the debris flow prior to the earthquake.On this basis,the following disaster prevention and mitigation suggestions were put forward.The risk of runout debris flow in the catchment should be strengthened;The value of triggering rainfall of debris flow should be obtained as soon as possible through comprehensive monitoring and early warning;The scale amplification factor of debris flow should be fully considered in the design of debris flow prevention and control projects.This research can be used as a scientific reference for disaster prevention and mitigation of post-earthquake debris flows.

关 键 词：泸定地震 震后泥石流 同震崩滑体 溃决放大 危险性预测 

分 类 号：P642.23[天文地球—工程地质学]