On the importance of considering specific storage heterogeneity in hydraulic tomography: Laboratory sandbox and synthetic studies

•THT analysis treating Ss to be homogeneous yields less accurate results.•Ss heterogeneity should be considered in THT for improved mapping of K and Ss fields.•Reliable geological data helps THT to improve not only K, but also Ss estimates. Over the last two decades, various studies on Transient Hyd...

Full description

Saved in:
Bibliographic Details
Published in:Journal of hydrology (Amsterdam) Vol. 593; p. 125874
Main Authors: Zhao, Zhanfeng, Illman, Walter A.
Format: Journal Article
Language:English
Published: Elsevier B.V 01.02.2021
Subjects:
Aquifer heterogeneity
drawdown
geostatistics
hydraulic conductivity
Hydraulic tomography
Model calibration and validation
prediction
Specific storage
tomography
Specific storage
Aquifer heterogeneity
Hydraulic tomography
Model calibration and validation
ISSN:0022-1694, 1879-2707
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•THT analysis treating Ss to be homogeneous yields less accurate results.•Ss heterogeneity should be considered in THT for improved mapping of K and Ss fields.•Reliable geological data helps THT to improve not only K, but also Ss estimates. Over the last two decades, various studies on Transient Hydraulic Tomography (THT) have shown that it is an effective approach to characterize subsurface heterogeneity. Typically, high-resolution hydraulic conductivity (K) distributions were recovered, while the spatial variability of specific storage (Ss) was found to be smooth. In some studies, Ss heterogeneity has been intentionally ignored due to the belief that Ss is less variable than K. Therefore, one may question the importance of considering Ss heterogeneity during THT and its impact on the reliability of estimated hydraulic parameters. To investigate these issues, three modeling approaches (i.e., effective parameters, geological, and geostatistics-based) were used to obtain K and Ss estimates of varying spatial resolutions. The reliability of K and Ss estimates were evaluated by comparing their drawdown prediction performances. The values of using different prior K and Ss information for THT analyses were investigated. Our results revealed that: (1) the K distribution estimated from the geostatistics-based steady-state HT analysis accurately predicted the late time drawdowns, while further improvements in transient drawdowns were obtained only after jointly treating the Ss field as heterogeneous; (2) Ss heterogeneity should be considered in addition to K for THT inversions, even when the estimated Ss field is smooth; and (3) using K and Ss estimates from the calibrated geological model as initial mean distributions for the geostatistical inversion approach were helpful in capturing both interlayer and intralayer heterogeneity of K and Ss. These findings suggested that Ss heterogeneity should be properly considered during the implementation of THT.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0022-1694
1879-2707
DOI:10.1016/j.jhydrol.2020.125874