Accurate characterization of heterogeneity in groundwater basins is crucial to the sustainable management of groundwater resources. This study explores the temporal sampling issues and the role of flux measurements in the characterization of heterogeneity in groundwater basins using numerical experiments. The experiments involve a digital basin imitating the groundwater basin of the North China Plain (NCP), where the groundwater exploitation reduction program is ongoing. Using the experiments, we champion that the reduction program could collect groundwater level information induced by operational variations of existing pumping wells at different locations in the basin. Such a dataset could serve as a basin-scale hydraulic tomography (HT) to characterize the basin-scale heterogeneity cost-effectively. Both steady-state and transient-state inversion experiments demonstrate the advantage of HT surveys in characterizing basin-scale heterogeneity over conventional pumping tests at fixed well locations. Additionally, head data at the early, intermediate, and late time from well hydrographs should be selected for the HT analysis to maximize HT's power and save computational costs. When accurate geological zones are incorporated in prior information, flux measurements significantly improve parameter estimates based on conventional pumping tests. However, their effects are less noticeable for long-term HT surveys in such basin-scale aquifers without fissures or fractures. This basin-scale tomographic survey example serves a guide for field data collection and optimization of the analysis of future basin-scale HT.

中文翻译：

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使用水力层析成像技术对地下水盆地地下异质特征进行时间采样和通量测量的作用

地下水流域异质性的准确表征对于地下水资源的可持续管理至关重要。本研究使用数值实验探讨了时间采样问题和通量测量在表征地下水流域异质性中的作用。实验涉及模拟华北平原 (NCP) 地下水流域的数字流域，该地区的地下水开采削减计划正在进行中。通过实验，我们支持减少计划可以收集由盆地不同位置现有抽水井的操作变化引起的地下水位信息。这样的数据集可以用作盆地尺度的水力层析成像 (HT)，以经济高效地表征盆地尺度的异质性。稳态和瞬态反演实验都证明了 HT 调查在表征盆地尺度非均质性方面优于固定井位的常规抽水试验。此外，应选择来自井水位线的早期、中期和晚期水头数据进行 HT 分析，以最大限度地提高 HT 的功率并节省计算成本。当准确的地质区域被纳入先验信息时，通量测量显着改善了基于传统抽水测试的参数估计。然而，对于在这种没有裂缝或裂缝的盆地尺度含水层中进行长期 HT 调查，它们的影响不太明显。此流域尺度层析成像调查示例为现场数据收集和未来流域尺度 HT 分析的优化提供了指导。