广州市主城区地面塌陷灾害危险性评价研究

Study on Ground Collapse Risk Evaluation in Main Urban Area of Guangzhou City

人类工程活动诱发地面塌陷是城市地质灾害的主要类型之一。广州市主城区地面塌陷灾害频发且损失特别严重。本文采用信息量数学模型与GIS技术结合对其地面塌陷灾害进行危险性评价;选取了断裂构造、地壳稳定性、第四系覆盖层厚度、基岩岩性、地下水动力条件、地表人类活动强度和地下活动强度等7个指标中的21个变量构建了危险性评价指标体系;应用ArcGIS9.0软件参与了数据的采集、管理、分析和评价结果表达等过程,将广州市地面塌陷灾害危险性分为极不稳定级、不稳定级、次不稳定级、基本稳定级和稳定级等五个等级,极不稳定级主要分布在主城区西北角,次不稳定级分布面积最广。

Ground collapse is one of the major types of geological disasters.The Information-value model and GIS are used for the risk evaluation of ground collapse in main urban area of Guangzhou city.7 evaluation indices are conceived through choosing factors such as fault,stability of the earth＇s crust,thickness of quaternary sedimentary,bedrock lithology,groundwater dynamics conditions,surface and underground intensity of human activities.ArcGIS software is applied involving data collection,data management,data analysis and evaluation express.Finally,the danger classification chart of grade about ground collapse in Guangzhou is produced.The results of study show that there are five danger grades in main urban area,the most dangerous zone lies in the south of Guang-hua basin,the secondly most dangerous zone lies in the west-north of main urban,in Guangcong fault or in the intersection of subway,and the marginally stable zone is located in the center of main urban area.