广州、佛山和肇庆市(广佛肇地区)作为经济发达地区,岩溶塌陷时有发生,给当地人民群众和经济发展带来较大威胁.依托区域地质调查成果,根据岩溶地质条件情况,选择岩溶塌陷分布特征、岩溶发育条件、覆盖层特征、地质构造、水文地质条件和土地利用类型6个因素,系统研究各个因素对岩溶塌陷形成的作用和各个因素之间的权重关系.在此基础上,运用地理信息系统技术和多元统计方法(层次分析法),建立岩溶塌陷发育的多因素判别模型,进而对广佛肇地区划分出高、中等和低易发区域,并根据岩溶塌陷易发区划,编制广佛肇地区重大基础设施岩溶塌陷易发区划应用图集,统计出重大基础设施所在易发区范围.%With the rapid development of social economy,the problems associated with karst environment and geology in China are becoming more and more prominent.Karst collapse is one of the main geologic haz-ards in the southern covered karst areas in China.The karst collapse frequently occurred in Guangdong Prov-ince,especially in Guangzhou,Foshan and Zhaoqing City (Guang-Fo-Zhao regions),where covered karst is widely distributed.The karst collapse history in the Guang-Fo-Zhao regions is closely related to the social and economic development,which can be divided into three stages,the first stage is from 1970s to 1980s, with shallow groundwater intensive extraction.During the period,a large number of karst groundwater was extracted,which induces karst collapse in many water sources.The second stage is from the 1990s to the be-ginning of this century,with a large number of limestone mines mined in the open pit.The balance of groundwater is severely damaged by excessive drainage in limestone mining,which leads to the frequent oc-currence of ground collapse.The third stage is from 2003 to the present,with the leap-forward development of urban construction.The constructions of underground space and building foundation have been carried out in an all-round way.In view of the great threat of karst collapse to the lives and property of the local people, it is necessary to evaluate the susceptibility of karst collapse in Guang-fo-Zhao regions,so as to provide sup-port for land planning and disaster prevention,then so as to avoid casualties and economic losses caused by karst collapse.Based on the results of regional geological survey,according to the geological conditions of karst collapse,9 evaluation factors are selected including density of karst collapse,karst rock stratum type, the average rate of karst,soil thickness,soil structure,groundwater type,hydrous quality,fault density and land utilization,and the susceptibility evaluation prediction model is established.The analytic hierarchy process (AHP)is used to establish the weight of the evaluation factors.The evaluation factors are classified according to influence on karst collapse.Furthermore,the susceptibility of karst collapse in Guang-Fo-Zhao regions is evaluated.The results show that the high susceptibility areas are mainly distributed in Guanghua basin,Sanshui basin and Zhaoqing area karst area,which is 1,231.96 km2,accounting for 54.48% of the to-tal area of karst.Human engineering activity is intense in this area.Medium susceptibility areas are account-ing for 15.04% of the total karst area;low susceptibility areas are accounting for 30.48% of the total karst area.According to the karst collapse zoning susceptibility areas,the karst collapse susceptibility zoning atlas of major infrastructure has been compiled.The distribution of the highway,high speed railway,the oil pipe-line,the gas line and other important infrastructure in the high susceptibility areas are counted.
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