Characteristics of Earthquake-Triggered Landslides and Post-Earthquake Debris Flows in Beichuan County  

作　　者：ZHUANG Jianqi CUI Peng HU Kaiheng CHEN Xiaoqing GE Yonggang 

机构地区：[1]Key Laboratory of Mountain Hazards and Land Surface Processes and Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China [2]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Journal of Mountain Science》2010年第3期246-254,共9页山地科学学报（英文）

基　　金：supported by the National Key Fundamental Research Program of China (973) (2008CB425802);The Project Group of Knowledge Innovation Program of Chinese Academy Sciences (KZCX2-YW-Q03-5)

摘　　要：Field investigations and aerial photography after the earthquake of May 12, 2008 show a large number of geo-hazards in the zone of extreme earthquake effects. In particular, landslides and debris flows, the geo-hazards that most threaten post-disaster reconstruction, are widely distributed. We describe the characteristics of these geo-hazards in Beichuan County using high-resolution remote sensing of landslide distribution, and the relationships between the area and volume of landslides and the peak-discharges of debris flows both pre- and post-earthquake. The results show： 1） The concentration （defined as the number of landslide sources per unit area： Lc） of earthquake- triggered landslides is inversely correlated with distance from the earthquake （DF） fault. The relationship is described by the following equation： Lc = 3.2264exp（-0.0831DF） （R2 = 0.9246）; 2） 87 % of the earthquake-triggered landslides were less than 15× 10^4 m2 in area, and these accounted only for 5o% of the total area; 84% of the landslide volumes were less than 60×10^4 m3, and these accounted only for 50% of the total volume. The probability densities of the area and volume distributions are correlated： landslide abundance increases with landslide area and volume up to maximum values of 5 ×10^4m2 and 30 ×10^4 m3, respectively, and then decreases exponentially. 3） The area （AL） and volume （VL） of earthquake-triggered landslides are correlated as described with the following equation： VL=6.5138AL1.0227 （R2 = 0.9231）; 4）Characteristics of the debris flows changed after the earthquake because of the large amount of landslide material deposited in the gullies. Consequently, debris flow peak-discharge increased following the earthquake as described with the following equation： Vpost = 0.8421Vprel-0972 （R2 = 0.9821） （Vpre is the peak discharge ofpre-earthquake flows and the Vpost is the peak discharge of post-earthquake flows）. We obtained the distribution of the landslides based on th

关 键 词：5.12 earthquake Landslide Debris flow MAGNITUDE Beiehuan County 

分 类 号：P642.22[天文地球—工程地质学] P315.9[天文地球—地质矿产勘探]