[A-HW25] Near Surface Investigation and Modeling for Groundwater Resources Assessment and Conservation

[AHW25-P01] Application of Fiber Grating Multilevel Monitoring System on Hydraulic Tomography in a Contaminated Site in Taiwan

*Jui-Pin Tsai¹, YU-LI WANG¹, YEN-TE HO¹, Liang-Cheng Chang², Tien-Hsing Dong³ (1.National Taiwan University, Taiwan, 2.National Chiao-Tung University, Taiwan, 3.APOLLO TECHNOLOGY CO., LTD)

Keywords:Groundwater monitoring, Optical sensor, Hydraulic test

Hydraulic tomography (HT) is a new hydraulic test method for characterizing heterogeneous aquifer properties. For the HT test, we need to perform sequential pumping/injection tests using a group of wells and simultaneously measure the groundwater pressure variations during the test. The pressure variations are then transformed into hydraulic heterogeneity using the geostatistics approach. For the traditional HT test, the conventional wells for collecting pressure data often open screens at the single target depth. In other words, a single well can only measure the pressure data in one depth range. On the contrary, a multilevel well monitoring system (MLMS) has several open-screen at the target depths, and each monitoring zone is separated by the packer to interrupt the connection of vertical flow inside the well. Thus, the amount of pressure data from a MLMS can be several times more than that from a traditional well. Accordingly, this study employed a new multilevel well system, developed by fiber Bragg grating technology, to conduct HT at a contaminated site. We then compare the image profile of hydraulic conductivity with that of electrical resistivity to validate the practice of using FBG MLMS to conduct HT. Results reveal that HT with an FBG multilevel well system is reliable and practical.