Accurate representation of groundwater flow and solute transport requires a sound representation of the underlying geometry of aquifers. Faults can have a significant influence on the structure and connectivity of aquifers, which may allow permeable units to connect, and aquifers to seal when juxtaposed against lower permeability units. Robust representation of groundwater flow around faults remains challenging despite the significance of faults for flow and transport. We present a methodology for the inclusion of faults utilizing the unstructured grid features of MODFLOW-USG and MODFLOW 6. The method focuses on the representation of fault geometries using non-neighbor connections between juxtaposed layers. We present an illustration of the method for a synthetic fluvial aquifer. The combined impact of the heterogeneous aquifer and fault offset is clearly visible where channel features at different depths in the aquifer were connected at the fault. These results highlight the importance of representing fault features in groundwater flow models.

中文翻译：

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在分层地下水流模型中包括垂直断层结构

地下水流和溶质迁移的准确表示需要对含水层的基本几何结构进行合理的表示。断层可以对含水层的结构和连通性产生重大影响，这可能允许渗透性单元连接，并且当含水层与低渗透性单元并列时，含水层可以密封。尽管断层对流动和运输具有重要意义，但断层周围地下水流的稳健表示仍然具有挑战性。我们提出了一种利用 MODFLOW-USG 和 MODFLOW 6 的非结构化网格特征来包含断层的方法。该方法侧重于使用并列层之间的非相邻连接来表示断层几何。我们展示了合成河流含水层的方法。在含水层中不同深度的通道特征在断层处连接的地方，异质含水层和断层偏移的综合影响清晰可见。这些结果突出了在地下水流模型中表示断层特征的重要性。