ORIGINAL ARTICLE A technique for quantifying groundwater pumping and land subsidence using a nonlinear stochastic poroelastic model Shih-Jung Wang • Cheng-Haw Lee • Kuo-Chin Hsu Received: 5 January 2013 / Accepted: 17 December 2014 Ó Springer-Verlag Berlin Heidelberg 2015 Abstract Subsidence in Yunlin County, Taiwan, is seri- ous and continuous. The Taiwan High Speed Rail (THSR) route crosses the subsidence area and might be affected by differential settlements. It is important to evaluate the pumping quantity for water resource management and to predict the subsidence for land resource management to mitigate the subsidence problem in Taiwan. This study combines first-order second-moment (FOSM) stochastic poroelastic theory with nonlinear parameters to develop a FOSM nonlinear stochastic poroelastic model and applies it to quantify groundwater pumping and future subsidence with uncertainty. The additional loading and discharge are evaluated by fitting the subsidence historical data to the numerical model. The results show that the proposed model well describes the subsidence behavior and quantifies groundwater pumping. However, the numerical results are larger than the monitoring data at various depths, which might be due to the different compaction situations in individual formations of the aquifer system. The predicted subsidence at the Yuanchang monitoring well is the largest (0.32 ± 0.52 m in 2020) with consideration of the climate change effects, achieved by adding an additional discharge of 31.7 %. The large uncertainty is caused by the large variation of hydraulic conductivity caused by the hetero- geneity of the aquifer system, which could be improved by doing more experiments or using a conditioned model. The information provided in this study is useful for the safety of THSR and for land and groundwater resource management in Yunlin County, Taiwan. Keywords Subsidence  Pumping  Stochastic poroelastic model  Nonlinear  Uncertainty Introduction Land subsidence is serious and continuous in Yunlin County, Taiwan, due to groundwater withdrawal via over- pumping. The main reason is the lack of strict enforcement of groundwater rights in Taiwan. Thus, the total number of pumping wells in Yunlin County exceeds 100,000, most of which are private and located in the middle and distal fan sections of the Jhuoshuei River Alluvial Fan (Hung et al. 2010). The main use of the pumped groundwater is for aquaculture and irrigation due to the lack of surface water in the area. From core samples of drilling wells, the hydrogeology in the Jhuoshuei River Alluvial Fan can be approximately separated into four aquifers and three intercalation aquitards at a depth of 300 m (Taiwan Central Geology Survey 1999). The lithology in this area also includes several clayey interbeds (Hung et al. 2010). Both aquitards and interbeds can be easily compacted to induce subsidence (Liu et al. 2001). The Taiwan High Speed Rail (THSR) route passes through the subsidence area in Yunlin County and might be affected by differential settlements (Hwang et al. 2008). To mitigate the subsidence problem, it is important to quantify groundwater pumping for water resource management and to predict the subsidence for various scenarios for land resource management. Land subsidence caused by groundwater withdrawal and external loading can be well explained by poroelastic theory, which couples soil and fluid behavior (Biot 1941). S.-J. Wang  C.-H. Lee  K.-C. Hsu (&) Georesources Research Center, National Cheng Kung University, Tainan, Taiwan, ROC e-mail: kchsu@mail.ncku.edu.tw C.-H. Lee  K.-C. Hsu Department of Resources Engineering, National Cheng Kung University, Tainan, Taiwan, ROC 123 Environ Earth Sci DOI 10.1007/s12665-014-3970-6