“4·20”芦山地震灾区次生山地灾害易发性评价

Susceptibility Assessment on Secondary Mountain Hazards in “4·20”Lushan Earthquake-stricken Area

选择"4·20"芦山地震灾区为研究区,在野外实地考察的基础上,结合高精度遥感影像解译分析,针对地震灾区滑坡、崩塌和泥石流等次生山地灾害的形成条件展开系统分析;在ArcGIS 9.3软件支持下,采用信息量模型,选择坡向、坡度、地层岩性、断裂带、河流冲刷作用、地震烈度和降水量7个影响因子作为芦山地震灾区次生山地灾害易发性评价的指标参数,将其划分为高易发区、中易发区和低易发区,该评价结果与实地考察结果基本吻合。基于GIS的信息量模型能够很好地为芦山地震灾区次生山地灾害易发性区划研究提供指导,其结果可以用来解决次生山地灾害易发性评价中效率低、精度差、费时费力等问题,从而实现次生山地灾害易发性评价的信息化和科学化。

With Lushan earthquake-stricken area as the study area,field survey as the foundation,and the high resolution remote sensing visual interpretation as the method,a systematic analysis on the forming conditions of secondary mountain hazards in Lushan earthquake-stricken area is launched in this study.Employing the ArcGIS Software and the Information Model,and taking the 7 influencing factors including slope aspect,slope gradient,stratum lithology,fault belts,river scouring action,seismic intensity,and precipitation as the parameters of susceptibility assessment,the susceptibility area has been divided into three zones：high,middle,and low zones.Furthermore,the assessment result is in conformity with that of the field survey,indicating that GIS-based information model will effectively provide parameter reference for the study of susceptibility zoning of secondary mountain hazards in Lushan earthquake-stricken area,and that such assessment result will help resolve the existing problems such as poor efficiency,low resolution,painstaking and time-consuming process so as to realize the informative and scientific susceptibility assessment.