九寨沟景区“8·8”震后崩塌灾害发育特征及影响因素

Development Characteristics and Influencing Factors of“8·8”Jiuzhaigou Earthquake Collapse Disasters in Scenic Area

2017年8月8日四川省阿坝州九寨沟县发生里氏(M s)7.0级地震,震中据九寨沟景区仅5 km,地震诱发大量崩塌、滑坡、泥石流等次生地质灾害,严重威胁景区正常运营。通过对景区则查哇沟两岸8处重大崩塌灾害点深入调查,统计分析崩塌(危岩)规模、分布及变形破坏特征,并结合景区的地质环境,研究地形地貌、地质构造、岩性及地震对崩塌发育的影响。结果表明:该区多发育中、高位崩塌,低位较少;中、高位崩塌具有“归槽效应”,形成的崩塌流呈面状破坏,危害性较大。研究结果对防治景区震后崩塌灾害有借鉴价值。

On August 8,2017,an M s 7.0 earthquake occurred in Jiuzhaigou County,Aba Prefecture,Sichuan Province.The epicenter of the earthquake was only 5 km from the Jiuzhaigou scenic area.The earthquake induced a large number of secondary geological disasters such as collapse,landslides and debris flows,which seriously threatened the normal operation of the scenic area.Based on the in-depth investigation of 8 major collapse on both sides of Zechawa gully,the author analyzed the scale,distribution and deformation and destruction characteristics of collapsse(dangerous rocks).Combining with the geological environment of the scenic area,the author also studied the collapse development influence by topography,geological structure,lithology,and revealed that there are more middle and high collapse in this area,but fewer low-level ones.It is pointed out that the middle and high-level collapses have the“channel effect”and are more destructive and covers a wider area.The results of the study provide a reference value for the collapse disaster prevention in scenic spots.