2013年4月20日,中国四川省芦山县发生一次Ms7.0级强烈地震。地震触发了大量的山体滑坡并造成了严重的灾害。本研究选取地震动峰值加速度、高程、坡度、坡向、斜坡曲率、地层岩性6个地震滑坡影响因子,基于GIS技术开展芦山地震滑坡易发性快速评价工作。基于专家知识与2008年汶川地震研究成果,按照0~9的分级方式,给6个因子赋予权重,给因子内部各个分类赋予滑坡易发等级。根据影响因子权重与因子内部滑坡易发分级。计算出研究区内每个栅格的地震滑坡易发性指数,得到地震滑坡易发性指数索引图。基于3878处芦山地震滑坡开展易发性指数索引图的合理性检验。结果表明正确率超过75%,表明本研究的滑坡易发性评价方法与易发性索引图成果的合理性。将研究区按易发性指数分为5类。分别为极低易发区、低易发区、中易发区、高易发区、极高易发区.得到研究区滑坡易发性分区图。
On April 20, 2013, a strong earthquake of Ms7.0 occurred at Lushan County, Sichuan Province of China. Tile earthquake triggered many landslides and some of the landslides resulted in serious hazards. In this paper, six earthquake-triggered landside impact factors, including the peak ground acceleration (PGA), the elevation, the slope angle; the slope aspect, the slope curvature, and the strata and lithology were selected for a GIS-based quick landslide susceptibility evaluation for the Lushan earthquake. The weights of the six factors and the landslide susceptibility ranks of each factor were assigned in an ordinal rating from 0 to 9 based on the expert knowledge and the information from my previous studies of the 2008 Wenchuan earthquake-triggered landslides. Then, the landslide susceptibility indexes of each grid were calculated and the landslide susceptibility index map of the study area was produced, which was validated based on 3878 landslides triggered by the Lushan earthquake with a success rate of the index map over 75%. This indicates that the method of the quick landslide susceptibility evaluation is reasonable and the result is useful. Finally, based on the landslide susceptibility index values, the study area was divided into five classes, namely the very low susceptibility, the low susceptibility, the moderate susceptibility, the high susceptibility, and the very high susceptibility, and the landslide susceptibility map was produced.