Assessing the risks associated with transport of contaminants in hydrogeological systems requires the characterization of multiple sources of uncertainty. This paper examines the impact of the uncertainty in the source zone mass release rate, aquifer recharge, and the spatial structure of the hydraulic conductivity on transport predictions. Through the use of the Lagrangian framework, we develop semianalytical solutions for the first two moments of the total solute discharge through a control plane while accounting for source zone release conditions and recharge. We employ global sensitivity analysis (GSA) to investigate how the predictive uncertainty of the mass discharge is affected by uncertainty in source zone mass release rate, recharge, and the variance of the log‐conductivity field. The semianalytical solutions are employed with the polynomial chaos expansion technique to perform a GSA. Our results reveal the relative influence of each source of uncertainty on the robustness of model predictions, which is critical for site managers to allocate resources and design mitigation strategies.

中文翻译：

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拉格朗日随机公式内表征多个不确定性对地下水污染物排放预测的影响

评估与污染物在水文地质系统中的运输相关的风险需要表征多种不确定性。本文研究了源区质量释放速率，含水层补给以及水力传导率空间结构的不确定性对输运预测的影响。通过使用拉格朗日框架，我们为通过控制平面排放的总溶质的前两个时刻开发了半解析解，同时考虑了源区释放条件和补给。我们采用全局敏感性分析（GSA）来研究质量排放的预测不确定性如何受到源区质量释放速率，补给和对数电导率场的不确定性的影响。半解析解与多项式混沌扩展技术一起使用来执行GSA。我们的结果揭示了每个不确定性源对模型预测的稳健性的相对影响，这对于站点管理者分配资源和设计缓解策略至关重要。