Potential of Hydraulic Tomography in Identifying Boundary Conditions of Groundwater Basins

Abstract

This study investigates the potential of hydraulic tomography (HT) in identifying the boundary conditions of groundwater basins using numerical experiments. The experiment mimics the scenario of groundwater exploitation reduction in a pilot area of groundwater overexploitation control in the North China Plain. In this study, we propose an approach that integrates the HT concept and readily available groundwater monitoring data to identify the constant head and impermeable boundaries by mapping anomalously high-and low-permeability zones from HT surveys in a large-scale domain that encompasses the true groundwater basin. The resulting boundaries and conditions were then used in inversion of steady-state and transient-state simultaneous pumping tests and HT surveys of heterogeneity within the groundwater basin. The inversion results demonstrated significant advantages of HT surveys over multiple simultaneous pumping tests to identify boundary conditions and heterogeneity in the groundwater basin. Moreover, steady HT inversion outperforms transient HT inversion in capturing the true boundary conditions, leading to the better T estimates from steady HT inversion than those from transient HT inversion. Additionally, the study shows that accurate geological zonation information can significantly improve HT parameter estimations.

Multiscale Hydraulic Conductivity Characterization in a Fractured Granitic Aquifer: The Evaluation of Scale Effect

“…Additionally, we notice that two abnormal “high‐ D zones” appear at the model's upper left and right side boundaries, where the constant head was assigned. These anomalies may indicate the existence of inflow and outflow boundaries (Daranond et al., 2020; Liu et al., 2020; Sun et al., 2013). Flinchum et al.…”

“…Likewise, Liu et al. (2020) showed that THT yielded a high‐conductivity zone near the boundary if a constant head boundary is used for the actual flux boundary. Interestingly, the THT analysis of this field data confirms their findings, supported by the regional flow map (Flinchum et al., 2018).…”

“…(2020), Liu et al. (2020), and Sun et al. (2013), recommended the constant head boundaries for THT analysis.…”

“…All other inversion parameters were held the 2020) demonstrated that THT can identify actual no-flux boundaries as zones of low conductivities at the boundaries if a constant head BC was assigned. Likewise, Liu et al (2020) showed that THT yielded a high-conductivity zone near the boundary if a constant head boundary is used for the actual flux boundary. Interestingly, the THT analysis of this field data confirms their findings, supported by the regional flow map (Flinchum et al, 2018).…”

Temporal sampling and role of flux measurements for subsurface heterogeneous characterization in groundwater basins using hydraulic tomography

“…Previous studies on synthetic HT surveys at the NCP have proven that the feasibility of utilizing head data induced by groundwater exploitation reduction to enhance basin‐scale aquifer characterization (Liu, Yeh, Wang, Hao, et al, 2020), as well as the potential of HT in identifying the boundary conditions of groundwater basins (Daranond et al, 2020; Liu, Yeh, Wang, Song, et al, 2020). However, these studies did not consider the temporal sampling issues and the role of flux data for subsurface characterization.…”