SPATIAL DISTRIBUTION ANALYSIS OF SEISMIC LANDSLIDES ALONG LUHUO SEGMENT OF XIANSHUIHE FAULT ZONE

Massive landslides can be induced by earthquake because of the strong earthquake activity and fragile geological environment in Luhuo segment of the Xianshuihe fault zone. 179 landslides in 1973 and 62 landslides before 1973 are obtained through data collection and geological investigation. This paper is based on the 62 landslides before 1973 and 179 landslides in 1973. It makes a statistical analysis of the characteristic parameters of Luhuo earthquake-triggered landslides in 1973 and before. Seven characteristic parameters of the seismic landslides are analyzed. They are seismic intensity, epicentral distance, slip direction, formation lithology, slope angle, height, distribution in NW part and SE part. This study supports the following views. (1)The most landslides have a small scale; (2)Seismic intensity zones are between Ⅸ and Ⅹ; (3)Epicentral distance between 0km to 5km and 10km to 15km are high-incidence zones; (4)Angle of slip direction and fault is between 35and 75; (5)Landslides in SE part of the fault is more than those in NW part. The NE foot of NW part has larger area; (6)Formation lithology that have the most landslides is T2-3r; (7)Heights are between 30m to 60m. Major are distributed in the lower slope; (8)Slope angles are between 30to 45.The larger landslides always have lower angles.