Source characteristics of long runout rock avalanches triggered by the 2008 Wenchuan earthquake,China

作     者：Shengwen Qi~(a,b,*),Qiang Xu~b,Bing Zhang~c,Yuande Zhou~(d,1),Hengxing Lan~e,Lihui Li~(a,2) a Key Lab.of Engineering Geomechanics,Institute of Geology and Geophysics,Chinese Academy of Sciences,P.O.Box 9825,Chaoyang Area,Beijing 100029,China b State Key Lab.of Geo-hard Prevention and Geo-environment Protection,Chengdu University of Technology,Chengdu 610059,China c Centre for Earth Observation and Digital Earth,Chinese Academy of Sciences,Beijing 100190,China d Department of Civil Engineering,The University of Hong Kong,Pokfulam Road,Hongkong,China e State Key Laboratory of Resources and Environmental System,Institute of Geographic Science and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China 

会议名称：《中国科学院地质与地球物理研究所第11届（2011年度）学术年会》

会议日期：2012年

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supports from Chinese Academy of Sciences under grants of KKCX1-YW-01 and KKCX1-YW-04 State Key Laboratory of Geohazard Prevention & Geoenvironment Protection under grant of DZKJ-0802 

关 键 词：2008.5.12 Wenchuan earthquake Rock avalanche Landslide 

摘      要：The May 12,2008 Wenchuan,China Earthquake which measured M = 8.3 according to Chinese Earthquake Administration - CEA(M= 7.9 according to the USGS) directly triggered many landslides,which caused about 20,000 deaths,a quarter of the *** avalanches were among the most destructive landslides triggered by this seismic event,and have killed more people than any other type of landslide in this *** Donghekou rock avalanche,one example of a catastrophic avalanche triggered by the Wenchuan earthquake,occurred in Qingchuan and buried one primary school and 184 houses,resulting in more than 780 deaths,and in addition,caused the formation of two landslide dams,which formed barrier lakes. Combining aerial images(resolution of 0.5 m) with field investigations,this paper lists some parameters of 66 cases in one table,and details source characteristics of six typical *** has been found that most of the long runout rock avalanches have source areas with high relief and steep inclination,causing the debris in the travel courses to *** was also a large amount of saturated Holocene-age loose deposits formed by a river or gully that existed in the travel *** studies indicate that saturated Holocene loose deposits in the travel courses could be the most important factor for the causes of the long runout characteristic of the rock avalanches especially when they traveled over gentle or even flat ground surfaces. Furthermore,the relationships among the relief slope gradient,runout and covered area are investigated, and a threshold line for predicting the maximum horizontal runout distance under certain change in elevation is presented.