裂隙介质精确地定量刻画及其溶质运移理论研究已经成为裂隙含水层地下水污染防治的关键。目前裂隙含水层通常被概化为水平裂隙，而忽视管道裂隙几何特征以及基质扩散对溶质运移的影响。

基于此，建立单裂隙管道−基质系统的溶质运移模型，并利用Laplace变换以及数值逆变换获得模型的半解析解，同时通过COMSOL Multiphysics软件建立数值模型进行验证。定量分析水动力弥散系数、迟滞因子等参数对溶质运移规律的影响，并计算溶质扩散质量通量以及存储量来反映溶质运移的时空规律。

结果表明：(1)管道裂隙水动力弥散系数越大，穿透曲线早期浓度越高，而所达到的峰值越低，且裂隙中溶质浓度随着迟滞因子增大而降低。(2)扩散质量通量峰值随着裂隙弥散系数的增加而减小，并通过分析不同位置的穿透曲线以及扩散质量通量的空间分布曲线可得反向扩散是导致穿透曲线产生明显拖尾现象的主要原因。(3)脉冲注入条件下，裂隙作为主要的存储空间，其存储总量表现出快速增加后不断降低的趋势，而基质中存储量表现出不断增加的过程。总之，通过理论模型计算分析表明在管道裂隙−基质系统中，基质存储与反向扩散过程对裂隙系统中溶质运移规律的影响不容忽视。

The accurate quantitative characterization of fractured media and the theoretical research on solute transport in fractured media have become the key to the prevention and control of groundwater contamination in fractured aquifers. Currently, fractured aquifers are generalized to horizontal fractures, ignoring the geometric characteristics of the open parts of fractures, called channels, and the impacts of matrix diffusion on solute transport.

A model for solute transport in a single channel-matrix system was established, obtaining the semi-analytical solutions using Laplace and numerical inverse transforms. The COMSOL Multiphysics software was employed to construct a numerical model for verification. Furthermore, the impacts of parameters like hydrodynamic dispersion coefficient and retardation factor on the solute transport pattern were quantitatively analyzed, and the spatio-temporal patterns of solute transport were revealed by calculating the solute diffusion flux and storage.

The results indicate that: (1) A higher hydrodynamic dispersion coefficient of the channel was associated with a higher early solute concentration and a lower peak concentration in the breakthrough curves. Moreover, the solute concentration in the fracture decreased with an increase in the retardation factor. The peak diffusion flux decreased with an increase in the dispersion coefficient in the fracture. (2) By analyzing the breakthrough curves at different positions and the spatial distribution curves of diffusion flux, this study posits that back diffusion is the main cause of the significant tailing of the breakthrough curves. (3) Under the boundary condition of pulsed injection, the total amount of solute stored in the fracture—the primary storage space—rapidly increased and then gradually decreased, while that in the matrix increased. Overall, the calculation and analysis of the theoretical model necessitate emphasizing the impacts of the solute storage capacity of the matrix and back diffusion on the solute transport patterns in the channel-matrix system.