基于改进的ArcGIS对石台县地质灾害易发性评价探讨

Evaluation of geological hazard susceptibility in Shitai County based on improved ArcGIS

石台县地质灾害易发性评价通过地质灾害综合调查,考虑区内地灾发育现状、孕灾背景条件,选用坡度、地形起伏度、工程地质岩组、与断层缓冲距离、斜坡结构5个因素作为评价因子,建立石台县地质灾害易发性评价指标体系。基于ArcGIS将计算分析得到5个因子图层的信息量,再用层次分析法来校正、完善信息量模型,结合层次分析法得到各因子权重,进行叠加得到每个单元格的总信息量值,即为地质灾害易发指数。经过层次分析法校正与单一信息量法结果上的差异,可知前者更符合实际,易发性评价结果更加准确合理。

The evaluation index system of geological hazard susceptibility in Shitai County was established on the basis of comprehensive geological hazard investigation,with the hazard development status and hazard background conditions in the area being taken into consideration,and with five factors of topographic slope,relief degree,slope structure,buffer distance from fault and engineering geological rock formation being selected as evaluation factors.Based on ArcGIS,the information content of the five factor layers was obtained by analysis and calculation,and then the analytic hierarchy process was used to correct and improve the information content model.The weight of each factor is obtained by using the analytic hierarchy process,and the value of total information content of each cell was obtained by superposition of the weight of each factor,which is the vulnerability index of geological hazard.The difference between the result of analytic hierarchy process(AHP)correction and that of single information content method indicates that the former is more in line with reality and more accurate and reasonable.