地理与地理信息科学

8·8九寨沟地震诱发大量地质灾害,对川九公路造成严重危害。该文基于地质灾害遥感解译数据,从地质灾害的空间分布特征出发,分析强震驱动下公路沿线地质灾害暴发的诱因,结果表明:1)断层间相互作用为公路沿线灾害形成提供动力条件,其中,控震构造断层F1主控公路沿线地质灾害分布,距其越近,灾害数量越多、规模越大;2)受工程地质条件、地形地貌等因素共同影响,公路两侧坡体越陡,地形高差越大,坡体为坚硬岩类且SE坡向区域更易形成大规模地质灾害(群)。利用公路沿线灾害启动区位置进行分析,且剔除了环境背景特征影响,结果具有较高可信度,可为川九公路灾后重建提供技术参考。

On August 8,2017,a Ms 7.0 earthquake in Jiuzhaigou county,Sichuan,China,with a large number of geohazards,caused serious damage to the Chuanzhusi-Jiuzhaigou highway.Based on the high-resolution satellite images,more than 1 600 coseismal geohazards along the Chuanzhusi-Jiuzhaigou highway were obtained.This paper analyzes the geographic conditions at the formation region of these geohazards and the results show that:1)hard rocks are more conducive to the occurrence of geohazards than other types of rocks,and these geohazards are generally prone to occur at the position closer to mountain ridges;2)the fault F1,the central fault zone of Jiuzhaigou earthquake,provided strong dynamic conditions for geohazard occurrence by horizontal and opposite movement on both sides,which made the large magnitude and quantity of geohazards distribute near fault F1;3)influenced by the comprehensive effects of seismic wave motion,geology,topography and geomorphology,huge geohazards prone to occur at the position with steeper slope and greater altitude difference,and the aspect is generally consistent with the direction of seismic wave motion,in which it is also easy to form geohazard-group under the action of large earthquake such as Jiuzhaigou earthquake.This paper analyzes multiple factors in geohazard formation area by eliminating the influence of regional background characteristics,which have high credibility and can provide reference for regional evaluation of geohazards.