基于GIS技术的汶川8.0级地震诱发地质灾害危险性评价——以四川省安县为例

通过汶川8．0级地震后对绵阳市安县地震诱发地质灾害的应急调查和遥感解译，共获得地质灾害点187处。在此基础上，利用GIS技术对地震诱发地质灾害分布与发震断裂距离、坡度、岩性、水系等因素的关系进行统计分析。结果表明，地震诱发地质灾害在区域上沿断裂带呈带状分布和沿水系呈线状分布的特点；地震诱发的地质灾害与地形坡度有很大的关系，绝大部分的灾害点集中在15°-45°的范围内；地震诱发的地质灾害与地形有很好的对应关系，北部高山地区地质灾害数量明显高于南部平原区；滑坡多发生在千枚岩、泥页岩等软岩中且多为土质滑坡，而岩浆岩等硬岩中多发生崩塌。

Evaluation on Geological Disasters Triggered by the 5. 12 Wenchuan Earthquake Based on GIS Technology——A Case Study in Anxian County of Sichuan Province

187 locations of geological disasters were identified in Anxian County, Mianyang, based on an emergency field investigation and remote sensing interpretation after the Wenchuan earthquake of magnitude 8.0. By use of GIS technology, a statistical analysis is made on the relation between distribution of seismic geological disasters and other related factors, such as distance to earthquake fault, slope, lithology and rivers. The results show that the earthquake geological disasters in the region are on the zonal distribution along the fault zone and along the river are on the linear distribution. Earthquake geological disasters are closely related to terrain slope. The majority of disaster points concentrate within the range of 15°～ 45°. Earthquake geological disasters and terrain have a close correlation. Geological disasters in the northern mountain areas are significantly higher than that in the southern plain areas. Most landslides occur in soft rock such as phyllite and shale, many of which are soil landslides. While, most collapses occur in hard rocks such as magmatic rock.