© 2020 Elsevier Ltd There are increasing evidences that probability distributions and associated statistical moments of a variety of hydrogeological and soil science variables and their spatial increments display distinctive scale-dependent features that are not captured by a typical Gaussian model. A Generalized Sub-Gaussian (GSG) model is able to capture key aspects of this pattern. We present the results of a suite of computational analyses set in a Monte Carlo framework and aimed at assessing the impact of a GSG structure of log hydraulic conductivity (Y) on transport of a conservative solute through a three-dimensional bounded porous medium under steady-state saturated Darcy flow. Our results indicate that the longitudinal spreading of a plume is on average significantly smaller for Sub-Gaussian than for Gaussian Y fields. Otherwise, the velocity field arising from a Sub-Gaussian Y field induces enhanced plume stretching with respect to what can be observed in a Gaussian Y setting, this aspect potentially influencing the strength of solute mixing within these two types of conductivity domains. We also find that, in some cases, it may be difficult to identify the nature of the underlying conductivity field relying solely on observations of solute concentrations migrating within the system. In this regard, we show that the action of local dispersion tends to mask the influence of Sub-Gaussianity on major transport metrics.

中文翻译：

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以广义亚高斯对数电导率分布为特征的有界多孔介质中的溶质输运

© 2020 Elsevier Ltd 越来越多的证据表明，各种水文地质和土壤科学变量的概率分布和相关统计矩及其空间增量显示出典型的高斯模型无法捕获的独特的尺度相关特征。广义亚高斯 (GSG) 模型能够捕获此模式的关键方面。我们展示了一套在蒙特卡罗框架中设置的计算分析的结果，旨在评估对数水力传导率 (Y) 的 GSG 结构对保守溶质在稳定条件下通过三维有界多孔介质传输的影响。状态饱和达西流。我们的结果表明，与高斯 Y 场相比，次高斯场的羽流纵向扩散平均要小得多。除此以外，相对于在高斯 Y 设置中观察到的情况，亚高斯 Y 场产生的速度场会引起增强的羽流拉伸，这方面可能会影响这两种类型的电导率域内的溶质混合强度。我们还发现，在某些情况下，仅依靠对系统内溶质浓度迁移的观察可能难以确定潜在电导率场的性质。在这方面，我们表明局部分散的作用往往会掩盖亚高斯性对主要传输指标的影响。我们还发现，在某些情况下，仅依靠对系统内溶质浓度迁移的观察可能难以确定潜在电导率场的性质。在这方面，我们表明局部分散的作用往往会掩盖亚高斯性对主要传输指标的影响。我们还发现，在某些情况下，仅依靠对系统内溶质浓度迁移的观察可能难以确定潜在电导率场的性质。在这方面，我们表明局部分散的作用往往会掩盖亚高斯性对主要传输指标的影响。