汶川地震强震区震后10年泥石流活动特征遥感动态分析——以平武县石坎河流域为例  

Remote Sensing Dynamic Analysis of Debris Flow Activity Characteristics in Strong Earthquake Area of Wenchuan Earthquake 10 Years after Earthquake——A Case Study of Shikan River Watershed of Pingwu County

作　　者：赵聪 梁京涛[1] 谢忠胜[2] 佘涛 张肃[1] ZHAO Cong;LIANG Jingtao;XIE Zhongsheng;SHE Tao;ZHANG Su(Evaluation and Utilization of Strategic Rare Metals and Rare Earth Resource Key Laboratory of Sichuan Province,Sichuan Geological Survey, Chengdu 610081, China;Institute of Exploration Technology,CAGS, Technical Center for Geological Hazard Prevention and Contral, CGS, Chengdu 611734, China)

机构地区：[1]四川省地质调查院稀有稀土战略资源评价与利用四川省重点实验室,四川成都610081 [2]中国地质科学院探矿工艺研究所中国地质调查局地质灾害防治技术中心,四川成都611734

出　　处：《灾害学》2019年第4期222-227,共6页Journal of Catastrophology

基　　金：中国地质调查局项目“涪江流域1:5万环境地质调查”(DD20160251);西南地区重大地质灾害隐患遥感综合调查评价(12120113010000)

摘　　要：为研究汶川8级地震震后10年内灾区地质灾害的发育演变状况,选取极重灾区平武县石坎河流域作为研究对象,采用多期遥感解译以及地面调查相结合的方式,对汶川地震重灾区震后10年泥石流发育概况以及其发展演变规律进行研究分析。研究结果表明:①石坎河流域沿主河道分布了众多支沟,每年雨季石坎河流域泥石流暴发呈现明显的群发性。在震后10年间,石坎河流域内崩滑堆积体数量及面积总体均呈下降趋势,但残余物源方量仍较高,泥石流仍具有发生频率高、冲出量大、破坏性强的特点。②汶川震区的高密度物源发育特征导致区内部分洪水沟或常年流水沟转化为泥石流沟,以及某些处于停歇期的老泥石流沟重新复活,进入发展期。③受地形坡度以及汛期影响,地震所形成的崩塌、滑坡物源,在震后10年间大量进入沟道,转变为沟道堆积物,或以泥石流堆积物的形式沿主沟堆积。④在工程约束条件下,部分泥石流沟的启动物源分布位置以及物源类型发生较大改变,泥石流形成机制和运移过程也相应发生变化。⑤震区泥石流在主沟与主河交汇处形成大量泥石流扇形堆积,进入主河堆积体进一步抬升河床,给主河两岸或沟口人民生产生活造成不便,影响该区域地质环境。In order to study the development and evolution of geological hazards in Wenchuan M8 earthquake area within 10 years after the earthquake, the Shikan river watershed in Pingwu County, a very serious disaster area, is selected as the research object. The development and evolution of debris flow in Wenchuan earthquake-stricken area in the past ten years are studied and analyzed by means of multi-stage remote sensing interpretation and ground survey. The results show that:① There are many tributaries along Shikan river, the debris flow outbreaks in Shikan river watershed show obvious group occurrence in rainy season every year. In the 10 years after the earthquake, the number and area of landslides and avalanches in Shikan River Basin showed a downward trend, but the volume of residual material sources was still high, and debris flow still had the characteristics of high frequency, large amount of washout and strong destructiveness.② The characteristics of high-density provenance development in Wenchuan earthquake area lead to the transformation of some flood ditches or perennial flow ditches into debris flow ditches, and the revival of some old debris flow ditches in the pause period.③ Influenced by topographic gradient and flood season, the source of collapse and landslide caused by earthquake entered trenches in large quantities in 10 years after the earthquake, transformed into trench deposits, or accumulated along the main trench in the form of debris flow deposits.④ Under engineering constraints, the origin, distribution and source types of some debris flow gullies have changed greatly, and the formation mechanism and migration process of debris flow have also changed accordingly.⑤ Debris flow fan-shaped deposits are formed at the intersection of the main channel and the main river in the seismic area, which further uplift the river bed into the main stream deposit body, causing inconvenience to people’s production and life on both sides of the main river or at the mouth of the gully, and affecting

关 键 词：泥石流 汶川地震 地震灾区 石坎河流域 遥感调查 

分 类 号：P642.23[天文地球—工程地质学] X43[天文地球—地质矿产勘探]