Hydraulic conductivity exhibits a high spatial variability due to the heterogeneity and discontinuity of the geologic environments and their constituent materials. Representing such variability is problematic when implementing groundwater flow models, especially in geological media such as fractured rocks, fractured porous media, and karstic media, where the scale of observation is important when defining the heterogeneity of the media. In those cases, hydraulic tests performed locally in the fractures measure hydraulic conductivity at a fine scale. Nevertheless, groundwater flow models usually deal with problems involving a regional scale, with a grid cell size much greater than the cell in the fine scale. Modeling groundwater flow in fractured media using the Discrete Fracture Network (DFN) method at the regional scale is still challenging due to the difficulty of hydraulically characterizing the entire fracture network using the limited available data. Instead, methods such as Equivalent Porous Media (EPM) represent the fractured media as a continuous media, making it more practical to represent fractured rocks as a continuous equivalent media in regional models than the DFN method. However, in approaches such as EPM, choosing the block size adequately is critical because, at large scales, it can considerably affect the simulated flow patterns. Accordingly, upscaling hydraulic conductivities of fracture networks at the fine scale into equivalent parameters at the scale of the model's block is still a relevant question in practical groundwater modeling. This paper reviews the most widely used hydraulic conductivity scaling techniques to identify methods that consistently represent fractured media groundwater flow dynamics in regional models.

中文翻译：

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连续模型中多孔和裂隙介质中水力传导率的缩放：综述


由于地质环境及其组成材料的异质性和不连续性，水力传导率表现出高度的空间可变性。在实施地下水流模型时，表示这种可变性是有问题的，尤其是在裂隙岩石、裂隙多孔介质和岩溶介质等地质介质中，在定义介质的非均质性时，观测尺度很重要。在这些情况下，在裂缝中局部进行的水力测试可以精细测量水力传导率。然而，地下水流模型通常处理涉及区域尺度的问题，其中网格像元的大小远大于精细尺度上的像元。由于使用有限的可用数据难以对整个裂缝网络进行水力表征，因此在区域尺度上使用离散裂缝网络 （DFN） 方法对裂隙介质中的地下水流进行建模仍然具有挑战性。相反，等效多孔介质 （EPM） 等方法将裂隙介质表示为连续介质，这使得在区域模型中将裂隙岩石表示为连续等效介质比 DFN 方法更实用。但是，在 EPM 等方法中，适当选择块大小至关重要，因为在大尺度上，它会极大地影响模拟的流型。因此，将裂缝网络的精细尺度的水力传导率放大为模型块规模的等效参数仍然是实际地下水建模中的一个相关问题。本文回顾了最广泛使用的水力传导率缩放技术，以确定在区域模型中一致表示裂隙介质地下水流动力学的方法。