杭州市滑坡地质灾害危险性区划与评价

基于证据权法构建滑坡地质灾害评价模型，进行杭州市滑坡地质灾害危险性区划研究。主要数据源包括1930－2009年杭州市域采集到的1 905个地质灾害个例以及杭州市地质图、土地利用数据及数字高程模型（DEM）等。利用Arcgis空间分析及信息提取功能，筛选强降水、地层岩性、坡度、坡向、坡高、河网与道路缓冲等证据因子，并运用证据权法客观确定各因子权重, 最后通过Arc-WofE扩展模块对多种优选因子的叠加，计算任意格网单元的滑坡发生概率，实现对潜在滑坡点位的空间预测。经分离样本法验证，区划准确率为88.3%，分析结果与现有滑坡的分布情况比较吻合。据此表明证据权法在多指标评价及其权重确定等方面具有普适性，值得在滑坡地质灾害危险性区划等方面推广应用。

Risk zonation and evaluation of landslide geohazards in Hangzhou

The evidence weights model based on the weights of evidence method was applied to study the zonation of the landslide geohazards in Hangzhou.The main data sources consisted of geological maps,digital elevation model(DEM),land use data and 1905 specical cases of geohazards collected from 1930 to 2009 in Hangzhou city.The evidence factors involve heavy rain,types and structure of rock,slope,slope direction and high slope,river network and Path buffer,which were derived from maps using Arcgis spatial analysis and information extraction.The weights for each evidence map were calculated using the frequency of known landslides in the classes of causative parameters;then the probability of landslide for arbitrary grid was produced by summation of assigned weight values using Arc-WofE extended module,achieving the goal of spatial prediction for potential landslide points.The accuracy verified by the spilt-sample validation method was 88.3%.The obtained results were well coincident with the occurrence of the known landslides in the study area.It is shown that the weights of evidence method could be evaluated objectively and quantitatively for multivariate analysis,as a basis of the choice of factors for landslide geohazards zonation.So the methodology is very useful and accurate,and it is worth popularizing and applying to the risk zonation and evaluation of landslide geohazards.