Monitoring aquifer system compaction and land subsidence using DOFS technique in Suzhou, China
Suzhou is located at the lower reaches of the Yangtze River in southeastern Jiangsu, China.Extracting groundwater has caused large-scale land subsidence that has damaged buildings, roads and pipelines.The distributed optical fiber sensing (DOFS) technologies has a high potential for large civil engineering and hydraulic engineering monitoring.In this paper the potential of DOFS technique for monitoring aquifer system compaction due to land subsidence has been investigated.Brillouin Optical Time Domain Reflectometry (BOTDR) and Fibre Bragg Grating (FBG) were applied in a 200m drilling to monitor land subsidence and its mechanism in Suzhou.Data from the monitoring system shows a cumulative compaction from December 2012 to December 2013, occurring mainly at two thick aquitards adjacent to the main pumping aquifer.In addition, the shorter the distance between the aquitard and the pumping aquifer is, the greater the degree of compression of the aquitard is.The compression of the main strata from 42.35m to 115.5m is strongly influenced by groundwater drawdown in the second confined aquifer.Groundwater level declines sharply due to increasing water pumping in summer while rises slowly in winter.The main strata reach the maximum compression of 10.8mm in summer while a small rebound occurs in winter, showing the conformance with the groundwater level.The monitoring results provide some reasonable advice about groundwater exploitation and land subsidence control in the future.
land subsidence aquifer system compaction groundwater withdrawal distributed monitoring
J.H.Wu B.Shil H.J.Tong Y.L.Shi
Department of Earth Science,Nanjing University,Nanjing 210046,China
国际会议
南京
英文
221-225
2014-10-12（万方平台首次上网日期，不代表论文的发表时间）