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This paper exploits triggered lightning as a point source for the basin‐scale electromagnetic tomographic survey to image 3‐D subsurface electrical properties in basins. This paper further develops a new temporal moment approach, overcoming the difficulties in forward and inverse modeling of 3‐D Maxwell’s equations with heterogeneous parameter fields. Using this approach, we find that the influence of a single triggered lightning strike covers a radius of 20–70 km with detectable signals. The cross‐correlation analysis between the moment difference of the electric and electric/magnetic property field indicates that the approach is suitable for mapping subsurface electric conductivity () heterogeneity. A numerical experiment with 3‐D spatially random parameter fields demonstrates that the method captures the spatial distribution of electric conductivity over large areas with a sparse monitoring network. It reveals the potential of using triggered lightning as a basin‐scale electric/magnetic tomography survey.

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 betterTestimates 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.