2016年9月5日北川县陈家坝乡发生突发性滑坡,堆积体堵塞河道形成堰塞湖.该滑坡为2008年“5.12”汶川8.0级特大地震诱发的同震滑坡的局部复活.文章利用GIS和遥感技术,基于多期高精度遥感影像和数字高程模型(DEM),分析了滑坡的变形特征及历史,测算了滑坡和堰塞湖的范围及规模.根据水位监测数据,计算两次事件水位库容对应关系曲线.同时,结合野外调查分析了该滑坡两次失稳的主控因素和形成机制.结果显示研究区在历史上共发生三次滑动,其中2008年同震滑坡主要是由于龙门山中央断裂带,映秀—北川断裂横跨滑源区,地震时强烈的断层逆冲错动,导致位于断层上盘的坡体瞬间失稳;而2016年滑坡局部复活主要是由于2008年地震造成坡体结构破碎解体,松散的同震滑坡物质堆积于斜坡上,坡体自身稳定性大大降低,加之近期地震活动和河流侵蚀坡脚等内外动力地质作用的影响,导致滑坡复活.%The Tangjiawan landslide occurred twice on September 5,2016 and May 12,2008,respectively,and blocked the Tongkou river and created a barrier lake.This landslide is of important significance as it presents a good example for the evolution of a coseismic landslide.In this paper,the volume of the Tangjiawan landslide and the barrier lake is calculated accurately by comparing pre-and post-DEMs of the landslide.The deformation evolution history of the Tangjiawan landslide is analyzed by using the multi-temporal remote sensing images.Based on the field investigation,the mechanism is also analyzed.The results show that there are three times of sliding at the study area.For the coseismic landslide,the source area of the landslide is traversed by the Yingxiu—Beichuan fault,and the oblique-thrusting of the fault apparently triggered the initial failure of the coseismic landslide.However,the revival landslide of 2016 is the result of combined geological function of inner and outer powers.
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