基于证据权方法的玉树地震滑坡危险性评价

THE YUSHU EARTHQUAKE TRIGGERED LANDSLIDE HAZARD EVALUATION BASED ON WEIGHT OF EVIDENCE METHOD

玉树地震诱发了2036处滑坡。应用地理信息系统与遥感技术,选取与地表破裂距离、峰值加速度(PGA)、高程、坡度、坡向、曲率、坡位、与水系距离、岩性、与断裂距离、与公路距离、归一化植被指数(NDVI)等12个因素作为玉树地震滑坡危险性评价因子,采用加法与减法2种证据权方法,开展玉树地震滑坡危险性评价研究工作。结果表明:基于加法证据权方法得到评价结果的正确率为80.32%,基于减法证据权方法得到结果的正确率为80.19%。将滑坡危险性评价结果图分为极高危险区、高危险区、中危险区、低危险区与极低危险区5类。这一成果可划分出滑坡危险区,为灾后滑坡防治、基础设施重建与自然环境保护提供参考。

2036 landslides were triggered by the 2010 Yushu earthquake from aerial photographs and remote sensing images interpreting, verified by selected field checking. In this paper, twelve factors that influence landslide occurrence, including distance from main co-seismic surface ruptures, peak ground acceleration （PGA） , elevation, slope angle, slope aspect, slope curvature, slope position, distance from drainages,lithology, distance from faults, distance from roads, normalized difference vegetation index （NDVI） , are selected as landslide hazard evaluation factors. Two types of landslide hazard index map are derived using two ＂ weight of evidence＂ methods based on Geographical Information Systems （GIS） technology. The success rate of Add-＂ weight of evidence＂ method is 80.32% , and the success rate of Subtract-＂ weight of evidence＂ method is 80.19% , both are satisfactory. The resulting hazard evaluation maps are divided into five categories, i. e. extremely high, high, moderate, low, and extremely low, respectively. The landslide hazard maps can be used to identify and delineate unstable hazard-prone areas. It can also help planners to choose favourable locations for development schemes, such as infrastructures, buildings, road construction, and environmental protection.