强震区泥石流堵江-洪水灾害链式过程模拟研究——以汶川县下庄沟为例  

Modelling of Chain Process of Debris Flow Blocking River and Induced Flood Disaster in Meizoseismal Area——A Case of Xiazhuang Gully in Wenchuan County

作　　者：罗玉婷 王立娟 马松[1,2,3] 唐尧 LUO Yuting;WANG Lijuan;MA Song;TANG Yao(Major Hazard Measurement and Control Key Laboratory of Sichuan Province,Chengdu 610045,China;Sichuan Anxin Kechuang Technology Co.,Ltd.,Chengdu 610045,China;Sichuan Academy of Safety Science and Technology,Chengdu 610045,China)

机构地区：[1]重大危险源测控四川省重点实验室,四川成都610045 [2]四川安信科创科技有限公司,四川成都610045 [3]四川省安全科学技术研究院,四川成都610045

出　　处：《人民珠江》2023年第4期63-70,102,共9页Pearl River

基　　金：四川省省级科研院所基本科研业务费项目(2022JDKY0009-01,2022JDKY0009-02)。

摘　　要：汶川地震发生后,泥石流活动频率急剧增强,具有降雨阈值低、暴发频率高、影响范围广、破坏能力强的特征,危害方式主要包括淤埋、冲击、堵江及淹没等,其中泥石流堵江灾害效应尤为突出,严重威胁山区基础设施建设和居民生命财产安全,对泥石流堵江灾害链动态全过程的研究可为泥石流灾害防治和预警提供科学参考。基于对典型流域的野外调查与物理试验,并结合遥感影像与降雨数据,对下庄沟泥石流堵江灾害链的动态过程进行数值模拟研究。模拟结果表明:在t=120 step时泥石流到达流域出口;t=130 step时泥石流向前推进,堵塞部分主河;t=140、150 step时泥石流完全堵塞主河,分别形成了长、宽、厚为236.0、74.0、6.2 m和312.0、79.0、7.1 m的堰塞体,造成上游水位抬升,上游居民区淹没深度在3~5 m。通过将模拟结果与野外实测数据对比,模拟的准确度达84.9%,表明该模型对滑坡—泥石流—洪水的灾害链过程模拟具有较好的适用性。After the Wenchuan earthquake,there has been a sharp increase in the frequency of debris flow activity,which is featured by low rainfall threshold,frequent occurrence,wide impact and strong destruction.The hazards mainly include siltation,impact,river blocking and inundation.Among them,the mudslide blocking river shows particularly prominent disaster effect,seriously threatening the improvement of mountain infrastructure,and residents life and property safety.The research of the dynamic process of river blocking disaster chain of debris flow can provide scientific reference for debris flow hazard prevention and early warning.Based on field surveys,physical tests,remote sensing images and rainfall data for a typical watershed,a numerical simulation was conducted to study the dynamic process of the river blocking disaster chain of debris flow in Xiazhuang Gully.The simulation results show that the debris flow r eaches the outlet of the basin at t=120 step;and at t=130 step the debris flow pushes forward and blocks part of the main river;at t=140 and 150 step the debris flow completely blocks the main river,forming a debris-dam with a length,width and thickness of 236.0 m,74.0 m,6.2 m and 312.0 m,79.0 m,and 7.1 m,respectively,which causes the upstream water level to rise,with an inundation depth of the upstream residential area of 3-5 m.By comparing the simulation results with the field measured data,the accuracy of the simulation reaches up to 84.9%,which indicates that the model is of good applicability to simulating the disaster chain process of landslide-debris flow-flood.

关 键 词：强震区 泥石流 堵江 灾害链 数值模拟 

分 类 号：P642.23[天文地球—工程地质学] TV87[天文地球—地质矿产勘探]