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dc.contributor.authorZhao, Zhanfeng
dc.contributor.authorIllman, Walter A.
dc.contributor.authorZha, Yuanyuan
dc.contributor.authorYeh, Tian-Chyi Jim
dc.contributor.authorMok, Chin Man Bill
dc.contributor.authorBerg, Steven J.
dc.contributor.authorHan, Dongmei
dc.date.accessioned2019-11-07T01:34:49Z
dc.date.available2019-11-07T01:34:49Z
dc.date.issued2019-09-08
dc.identifier.citationZhao, Z., Illman, W. A., Zha, Y., Yeh, T. C. J., Mok, C. M. B., Berg, S. J., & Han, D. (2019). Transient Hydraulic Tomography Analysis of Fourteen Pumping Tests at a Highly Heterogeneous Multiple Aquifer–Aquitard System. Water, 11(9), 1864.en_US
dc.identifier.issn2073-4441
dc.identifier.doi10.3390/w11091864
dc.identifier.urihttp://hdl.handle.net/10150/634973
dc.description.abstractHydraulic tomography based on geostatistics has proven to be robust in characterizing subsurface heterogeneity in hydraulic conductivity (K) and specific storage (S-s) through the joint inversion of drawdown records from multiple pumping tests. However, the spatially variable estimates can be smooth or even erroneous for areas where pumping/observation data densities are not high. Previous hydraulic tomography surveys conducted at the North Campus Research Site (NCRS) on the University of Waterloo campus in Waterloo, Canada, revealed that the estimated hydraulic parameters were smooth and the known aquitard was erroneously identified as a high K zone. This was likely the consequence of the site being highly heterogeneous, while only utilizing four pumping tests and not having measurable drawdowns in the low K aquitard for inverse modeling. Here, we investigate whether improved K and S-s estimates could be obtained through the inclusion of additional pumping test data by stressing both aquifer and aquitard zones for a sufficiently long period. Specifically, six additional pumping/injection tests were conducted at the site, and a transient hydraulic tomography analysis with 14 tests was completed. Results reveal that there is a significant improvement to the K and S-s tomograms in terms of the visual correspondence with various geologic units, including its connectivity. More importantly, with the availability of additional data, we found that the inverse model now can better capture the high and low K features for nine boreholes when compared with K values obtained from permeameter tests. The estimated K and S-s tomograms are then used for the forward simulation of one additional pumping test not used for model calibration, revealing reasonable predictions. While encouraging results are obtained by including a large number of pumping tests to the transient hydraulic tomography analysis, stratigraphic boundaries are still smoothed, which is a direct consequence of utilizing a geostatistics-based inversion approach that assumes stationarity in statistical properties. To capture such sharp boundaries, incorporation of additional data types, such as geological and geophysical information, may be necessary when data densities are not sufficiently high.en_US
dc.description.sponsorshipEnvironmental Security and Technology Certification Program (ESTCP) [ER201212]; National Natural Science Foundation of China (NSFC)National Natural Science Foundation of China [41807202]; National Natural Science Foundation of ChinaNational Natural Science Foundation of Chinaen_US
dc.language.isoenen_US
dc.publisherMDPIen_US
dc.rightsCopyright © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).en_US
dc.subjecthydraulic tomographyen_US
dc.subjectsubsurface heterogeneityen_US
dc.subjecthydraulic conductivityen_US
dc.subjectspecific storageen_US
dc.subjectgeostatistical inverse modelingen_US
dc.subjectconnectivityen_US
dc.subjectaquitardsen_US
dc.titleTransient Hydraulic Tomography Analysis of Fourteen Pumping Tests at a Highly Heterogeneous Multiple Aquifer–Aquitard Systemen_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizona, Dept Hydrol & Atmospher Scien_US
dc.identifier.journalWATERen_US
dc.description.noteOpen access journalen_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal published versionen_US
dc.source.volume11
dc.source.issue9
dc.source.beginpage1864
refterms.dateFOA2019-11-07T01:34:50Z


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