Contribution of Strata Lithology and Slope Gradient to Landslides Triggered by Wenchuan M_s8 Earthquake, Sichuan Province, China

• 责任者：Yao Xin (Key Laboratory of Neotectonic Movement and Geohazard ; Ministry of Land Resources ; Institute of Geomechanics ; Chinese Academy of Geological Sciences ; Beijing 100081 ; China) ; Xu Chong
• 刊名：Geological Bulletin of China
• 出版年：2009
• 卷期：28(8)
• 关键词：滑坡 ; landslides ; 四川 ; Sichuan Province
• 页码：p.1156-1162
• 图表：6 illus., 1 table, 22 refs.
• 分类号：1800
• issnNo：ISSN1671-2552
• isbnNo：CN11-4648/P

It’s indicated by remote sensing images interpretation and field investigations that within an area of 48 678 km², there are more than 48 000 landslides geo-hazards triggered by Wenchuan earthquake. The purpose of this study was to detect correlation between landslide occurrences and strata lithology and slope gradient based on Geographic Information System (GIS) by using two parameters: namely landslide-area ration (LAR) and landslide concentration (LC). Within the studied area, LAR was defined at 1.462 2 % and LC was defined at 0.986 2 landslides/km². The results of statistical analyses show that LAR and LC have a positive correlation with slope gradient and most of the slides occur with slope between 25° and 50°.  It is also indicated by comprehensive research of slope, lithology and landslide spatial distribution that in strongly fractured rocks most landslides occur at where the slope angle is less than 30°, in weakly fractured rocks, most landslides occur at where the slope angle is more than 40°.