汶川、芦山和鲁甸地震滑坡分布规律对比研究  

COMPARISON OF DISTRIBUTION OF LANDSLIDES TRIGGERED BY WENCHUAN,LUSHAN,AND LUDIAN EARTHQUAKES

作　　者：陈成[1,2,3] 胡凯衡[1,2] 

机构地区：[1]中国科学院山地灾害与地表过程重点实验室,成都610041 [2]中国科学院水利部成都山地灾害与环境研究所,成都610041 [3]中国科学院大学,北京100049

出　　处：《工程地质学报》2017年第3期806-814,共9页Journal of Engineering Geology

基　　金：国家重点基础研究发展计划(2015CB452704);国家自然科学基金面上项目(41371039);中国科学院山地灾害与地表过程重点实验室开放基金资助

摘　　要：汶川MS8.0级地震、芦山MS7.0级地震和鲁甸MS6.5级地震均引发了大量的滑坡灾害。由于震级差异和地质地形条件的不同,地震滑坡分布情况有较大区别。本文综合已有的研究成果,从地震、地质和地貌3个方面,对比分析了地震滑坡的分布规律。结果表明:(1)3次地震滑坡数量和密度随着PGA和震级的增加而增加。汶川和鲁甸地震随烈度的增加,滑坡数量呈现递增的趋势。但芦山地震在较低烈度区也发育着大量滑坡。(2)断层影响滑坡分布的最大距离随着震级的增加而增加。在最大影响距离0.2倍的范围内,汶川地震分布有80%的滑坡,而其他两次地震仅30%。此外,汶川地震滑坡数量随断层距离呈指数衰减关系。(3)地震滑坡的分布受到地形的强烈影响。Ⅶ度及以上烈度区地形切割深度越大,地震触发的滑坡集中分布区域相对高差越大。同时,滑坡集中发育的坡度会随之增加。切割深度越大,地震滑坡更易发生在地势较陡的山脊或者上坡处,这可能与地形放大效应有关。All of the M_S8. 0 Wenchuan,M_S7. 0 Lushan,and M_S6. 5 Ludian earthquakes have triggered a large number of landslides. Due to differences in magnitude,geology,and topographical conditions,the distribution of seismic landslides vary widely. In this study,existing research results are combined to perform a contrastive analysis of seismic landslide distribution patterns based on three aspects： earthquake characteristics, geology, and topography. The following results are obtained.（ 1） The number and density of landslides due to the three earthquakes increase with the increase of peak ground acceleration（ PGA） and magnitude. The number of landslides shows an increasing trend following an increase of intensity during the Wenchuan and Ludian earthquakes.However,the area affected by the relatively low-intensity Lushan earthquake also develops numerous landslides.（ 2） The maximum distance of influence of a geological fault on landslide distribution increases with the increase of magnitude. Within the range of 0. 2 times of the maximum distance of influence,the Wenchuan earthquake has an80% landslide distribution,whereas the other two earthquakes have only 30%. Moreover,the number of landslides decreases exponentially with distance of the Wenchuan earthquake from geological faults.（ 3） The distribution of seismic landslides is strongly influenced by topography. In the Ⅶ or higher intensity regions,the relief depth increases and earthquake-triggered landslides in high concentration areas have relatively higher relief. Furthermore,the slopes gradient with concentrated landslides can subsequently increase. Seismic landslides occur more frequently along mountain ridges and deep slopes in areas of higher relief, which may be related to the topographic amplification effect.

关 键 词：地震滑坡 汶川地震 芦山地震 鲁甸地震 分布规律 

分 类 号：P642.22[天文地球—工程地质学]