北川县地震次生滑坡空间分布特征研究

Research on Spatial Distribution Characteristics of Secondary Landslide Induced by Earthquake in Beichuan County

在已解译的遥感影像资料基础上,利用MAPGIS空间分析方法对汶川地震次生滑坡在北川县的空间分布特征进行研究.结果表明,由于断层效应、烈度效应、水系侵蚀作用、岩性控制作用等内外力因子的影响,在北川县境内,距发震断层4km范围区域、发震断层上盘区域、距水系1km的沿河两岸、Ⅺ级和X级地震烈度区、砂页岩分布区是五类地震次生滑坡的强发育区.将五类区域进行空间叠加,并据此对研究区进行地震滑坡危险性区划,可以看出,在发震断层上盘,汶川地震次生滑坡的高危区分布于沿断层4km范围内的整个区域及X级、Ⅺ烈度区内的沿河两岸地区;在发震断层下盘,高危区分布于沿断层4km范围内的沿河两岸地区.

The spatial distribution characteristics of secondary landslide induced by earthquake in Beichuan county was studied by utilizing remote sensing image data and the space analysis function of MAPGIS,the results showed that the region in the range of 4kilometres＇ distance from causative fault and the hanging wall of causative fault and two banks along river in the range of 1kilometres＇ distance from water system and the seismic intensity zones ofⅪ,Ⅹand the distribution area of sandstone and shale are the strong developed areas of secondary landslide because of fault effect and intensity effect and erosion action by river water and lithology.According to Landslide risk level the regions were divided by spatial overlay analysis,the landslide danger areas on the hanging wall of the fault are all region in the range of4kilometres＇ distance from causative fault and two banks along river in the range of seismic intensity zones of Ⅺ and Ⅹ,the landslide danger area on the footwall of the fault is two banks along river in the range of4kilometres＇ distance from causative fault.