STUDY ON CATASTROPHIC LANDSLIDES TRIGGERED BY 2008 GREAT WENCHUAN EARTHQUAKE,SICHUAN,CHINA

In order to analyze the intensity and influence of landslides triggered by the great Wenchuan earthquake,a central idea in this paper is to focus on the first 3 extreme landslide events among the first 10 landslides with the largest volume,the longest sliding runout,the most serious hazard and the largest landslidedammed lake. The followings are revealed: (1)the extreme landslides are mainly distributed along the Longmenshan central fault and in the areas with high intensity of Ⅹ-Ⅺ; the strong vibration force,the main propagation direction of earthquake and the NE expansion of seismic fault are the major reasons for the initiation of extreme landslide events; (2)generally,the first 10 landslides both have the largest volume and the longest sliding long runout,among them,the Daguangbao landslide,located at Anxian county,Mianzhu city,is the first one,with the volume of 742 million m3 and the sliding long runout of 35 km; the second one is the Wenjiagou landslide in Qingping county,Mianzhu city,with the volume of 150 million m3 and the sliding runout of 42 km. The above two landslides are all rare rapid and long runout landslides with high energy in the world; (3)the first 10 catastrophic landslides totally caused 3751 deaths,and over 100 deaths are due to individual event,with the maximum of 1600; (4)the first 10 landslidedammed lakes with potential risk had threatened the lives safety for hundreds of thousands of people; among them,the Tangjiashan dammed lake is the largest one,which had imperiled 03 million peoples life of Mianyang city; fortunately,timely measures such as artificial excavation had been taken for removing of potential risk．