Temporal moments of solute transport through porous media are calculated to analyze the time average spatial distribution of solute plume. Simulation of spatially and temporally distributed breakthrough curves (BTCs) is computationally rigorous and lacking the explanation about overall plume evolution within porous media. However, temporal moment provides an attractive and simple solution to study the plume behavior. In this study, temporal moments are presented to interpret solute plume behavior in heterogeneous porous media such as hydraulically coupled stratified porous media with different time-dependent dispersion models. Governing equations of solute transport have been solved numerically using Crank-Nicolson scheme, and further solute concentration data has been utilized to calculate moments of solute concentration using numerical integration. The effect of various parameters such as mass-transfer coefficient, pore-water velocity, time-dependent dispersion coefficients, and porosity of mobile region on the transport of solute has been studied through sensitivity analyses. Temporal moment analysis revealed that the mass recovery, mean residence time, and variance are sensitive to the estimated parameters. Numerical results suggested that the asymptotic time-dependent dispersion function with mobile–immobile model represents the plume spreading through heterogeneous porous media in a more realistic manner.

计算通过多孔介质的溶质运移的瞬时矩，以分析溶质羽流的时间平均空间分布。时空分布的突破曲线（BTC）的模拟在计算上十分严格，并且缺乏对多孔介质内总体羽流演化的解释。但是，瞬时力矩为研究羽流行为提供了一种有吸引力且简单的解决方案。在这项研究中，提出了瞬时矩来解释非均质多孔介质（如液压耦合分层多孔介质）中的溶质羽流行为，这些介质具有不同的时变离散模型。使用Crank-Nicolson方案对溶质运移的控制方程进行了数值求解，进一步的溶质浓度数据已被用于通过数值积分计算溶质浓度的矩。通过敏感性分析，研究了传质系数，孔隙水速度，随时间变化的弥散系数以及可移动区域的孔隙度等各种参数对溶质运移的影响。时间矩分析表明，质量回收率，平均停留时间和方差对估计的参数敏感。数值结果表明，带有移动-不动模型的渐近时间相关色散函数以更现实的方式表示了通过非均质多孔介质扩散的羽状流。通过敏感性分析研究了流动区对溶质运移的孔隙度。时间矩分析表明，质量回收率，平均停留时间和方差对估计的参数敏感。数值结果表明，带有移动-不动模型的渐近时间相关色散函数以更现实的方式表示了通过非均质多孔介质扩散的羽状流。通过敏感性分析研究了流动区对溶质运移的孔隙度。时间矩分析表明，质量回收率，平均停留时间和方差对估计的参数敏感。数值结果表明，带有移动-不动模型的渐近时间相关色散函数以更现实的方式表示了通过非均质多孔介质扩散的羽状流。