汶川地震甘肃省文县地震地质灾害遥感分析

Analysis on the Geo-hazards Triggered by Wenchuan Earthquake in Wenxian County,Gansu Province,Based on Remote Sensing Information

摘要:

2008年汶川地震诱发了大量的次生山地灾害。本文以多源、多时相的遥感影像(TM、AS-TER、SPOT)作为信息源,基于地学知识,采用图像增强、人机交互的方式对甘肃省文县地区汶川地震引发的次生山地灾害进行解译。以ArcGIS软件为处理平台,运用空间分析技术,将解译结果与海拔高度、坡度、植被覆盖度和地震烈度进行空间分析,获得了研究区次生山地灾害的分布规律,其特点为:文县境内的次生山地灾害主要分布在20°～60°的边坡;多发生在1 000～2 500m的海拔高程范围内;主要分布在地震烈度Ⅶ度及以上区域。

Abstract:

The great Wenchuan earthquake in 2008 induced a large number of secondary mountain hazards.In this paper,the earthquake-induced mountain hazards in Wenxian County,Gansu province,are interpreted using the image enhancement technology and human-computer interaction technology based on the multi-type and multi-temporal remote sensing images（TM,ASTER,SPOT,etc.） and the geoscience knowledge.Based on GIS spatial analysis function,the analysis of the relationship between mountain disaster and elevation,slope,vegetation coverage and earthquake intensity,as well as the rules of development and distribution of mountain disaster reveals the following characteristics in the study area.The geo-hazard mainly generated in the slope varying from 20 to 60 degrees,mainly occur in slopes with the altitude from 1 000 m to 2 500 m;developed in the area where the earthquake intensity is Ⅶ or exceeding Ⅶ.The result should be significant in reconstruction.