The method of distributions for dispersive transport in porous media with uncertain hydraulic properties
The method of distributions for dispersive transport in porous media with uncertain hydraulic properties
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DOI：
10.1002/2016wr018745
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发表时间：
2016-06
影响因子：
5.4
通讯作者：
F. Boso;D. Tartakovsky
中科院分区：
文献类型：
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作者：
F. Boso;D. Tartakovsky
由于含水层的不均匀性和水力参数值的不确定性，地下环境中溶质运移的预测是众所周知的不可靠。概率框架，将相关参数和溶质浓度作为随机场，允许量化这种预测的不确定性。通过为预测浓度的概率密度函数或累积分布函数（CDF）提供确定性方程，分布方法使人们能够估计，例如，污染物浓度超过安全剂量的可能性。我们推导出一个确定性方程的CDF的溶质浓度，占流速和初始条件的不确定性。该方程中的系数以浓度的平均值和方差表示。CDF方程的准确性和鲁棒性进行了分析，通过比较他们的预测与Monte Carlo模拟和假设的β CDF。
Predictions of solute transport in subsurface environments are notoriously unreliable due to aquifer heterogeneity and uncertainty about the values of hydraulic parameters. Probabilistic framework, which treats the relevant parameters and solute concentrations as random fields, allows for quantification of this predictive uncertainty. By providing deterministic equations for either probability density function or cumulative distribution function (CDF) of predicted concentrations, the method of distributions enables one to estimate, e.g., the probability of a contaminant's concentration exceeding a safe dose. We derive a deterministic equation for the CDF of solute concentration, which accounts for uncertainty in flow velocity and initial conditions. The coefficients in this equation are expressed in terms of the mean and variance of concentration. The accuracy and robustness of the CDF equations are analyzed by comparing their predictions with those obtained with Monte Carlo simulations and an assumed beta CDF.