School of Earth Sciences, University of Western Australia, Crawley, WA, 6009, Australia.
College of Science and Engineering, Flinders University, Adelaide, SA, 5000, Australia.
Ground Water. 2021 Nov;59(6):799-807. doi: 10.1111/gwat.13120. Epub 2021 Jul 23.
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.
准确表示地下水流动和溶质运移需要对含水层的基础几何形状进行合理的描述。断层对含水层的结构和连通性有重大影响，可能会使渗透单元连接，并在与低渗透单元相邻时使含水层封闭。尽管断层对水流和传输很重要，但在地下水绕断层流动的稳健表示方面仍然具有挑战性。我们提出了一种利用 MODFLOW-USG 和 MODFLOW 6 的非结构网格功能来包含断层的方法。该方法侧重于使用相邻层之间的非邻接连接来表示断层几何形状。我们为一个合成河流含水层展示了该方法。在含水层中不同深度的河道特征在断层处连接的地方，可以明显看到非均匀含水层和断层偏移的综合影响。这些结果突出了在地下水流动模型中表示断层特征的重要性。
