汶川地震驱动的滑坡灾害空间发育规律研究—以四川省安县为例

Research on Spatial Development Rules of Landslide Hazards Induced by Wenchuan Earthquake: A Case of An County in Sichuan Province

利用遥感影像数据和MAPGIS空间分析功能,对汶川地震驱动的滑坡灾害在四川省安县的发育规律进行研究,结果表明：1）逆冲断层发震时上下盘加速度峰值的差异导致上盘滑坡灾害点密度远大于下盘;2）由于北川-映秀断裂和彭县-灌县断裂的双重影响及锁固段效应的作用,安县滑坡点高密度区位于距发震断层2~6 km处,表现出与其他研究区域不同的特征;3）河流的侧蚀、下蚀作用为滑坡的形成提供了破碎岩土体和有效临空面,滑坡灾害多沿水系呈带状分布;4）滑坡灾害点高密度区与地震高烈度区基本重合;5）滑坡点密度值随岩性硬度的减弱而增强.

The spatial development rules of landslide hazards induced by Wenchuan earthquake in An county were studied by utilizing remote sensing image data and the space analysis function of MAPGIS. The main results of this research can be summarized as follows： 1） There was difference in the peak acceleration of hanging and lower walls of fault,the density of landslide sites on the hanging wall of the fault was higher than that of landslide sites on the the foot wall. 2） The high density region of the landslide hazards was located at location spacing 2-6 km from causative fault because of the dual influence of Beichuan-Yingxiu fault＇Pengxian-Guanxian fault and the effect of locked segment; the density of landslide sites in An county showed different characteristics from other regions. 3） The crushing rock and soil and effective freeing surface formed from lateral erosion and downcutting of rivers with the landslide hazards distributed in belts along the rivers. 4） The high density region of landslide hazards was basically in coincidence with high intensity seismic region. 5） The density of landslide hazards was decreased with the addition of rock hardness.