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Imaging the spatial distribution and variability of the physical properties controlling subsurface fluid flow remains a fundamental geophysical challenge. Oscillatory hydraulic tomography is a minimally invasive hydraulic testing approach to image these hydraulic properties; however, the resolution and uncertainty associated with this tomographic method remains an open question. Using linearized and non-linear approaches, we show that multi-frequency oscillatory hydraulic tomography provides additional information content that improves imaging resolution and reduces estimated parameter uncertainty.
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Aquifer Characterization and Uncertainty in Multi‐Frequency Oscillatory Flow Tests: Approach and Insights
Abstract Characterizing aquifer properties and their associated uncertainty remains a fundamental challenge in hydrogeology. Recent studies demonstrate the use of oscillatory flow interference testing to characterize effective aquifer flow properties. These characterization efforts relate the relative amplitude and phase of an observation signal with a single frequency component to aquifer diffusivity and transmissivity. Here, we present a generalized workflow that relates extracted Fourier coefficients for observation signals with single and multiple frequency components to aquifer flow properties and their associated uncertainty. Through synthetic analytical modeling we show that multi‐frequency oscillatory flow interference testing adds information that improves inversion performance and decreases parameter uncertainty. We show increased observation signal length, sampling frequency, and pressure sensor accuracy all produce decreased parameter uncertainty. This work represents the first attempt we are aware of to quantify effective aquifer parameters and their associated uncertainty using multi‐frequency oscillatory flow interference testing.
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- Award ID(s):
- 1654649
- PAR ID:
- 10367914
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Groundwater
- Volume:
- 60
- Issue:
- 2
- ISSN:
- 0017-467X
- Format(s):
- Medium: X Size: p. 180-191
- Size(s):
- p. 180-191
- Sponsoring Org:
- National Science Foundation
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