OCCURRENCE，GEOLOGY AND GEOMORPHY CHARACTERISTICS AND ORIGIN OF QIANJIANGPING LANDSLIDE IN THREE GORGES RESERVOIR AREA AND STUDY ON ANCIENT LANDSLIDE CRITERION
Abstract：Qianjiangping landslide (2.4×107 m3)，which occurred in the Three Gorges Reservoir area on July 13，2003，is one of the serious landslide disasters in this area after impounding. Also，it caused a serious loss of lives and property. According to the tracking survey on this landslide，quite a number of information about the landslide is obtained. This paper，firstly，introduces the location，geological background，occurrence and the emergency monitoring of the landslide，and elucidates its typical geologic and geomorphic characteristics，such as its plane shape of dust pan，boundary，longitudinal tensile crack in landslide body and geological structure and so on. Secondly，combined with the first-hand data，the origin of Qianjiangping landslide is analyzed by utilizing the theories of geomorphy and engineering geology mechanics. The result shows that the vulnerable geological structure of landslide body and concentrated rainfall mainly cause this landslide，while the rise of Qingganhe River and excavation accelerate the occurrence to some degree. Finally，the methods of field identifying of ancient (or old) landslide in reservoir area are discussed in term of the geologic and geomorphic characteristics of Qianjiangping landslide.
