地下水溶质运移是复杂的跨尺度过程，相关研究对解决例如污染治理等环境和生态系统问题具有重要意义。其中，含水层小尺度非均质性是影响溶质运移的关键性因素，亟需对其展开定量研究。基于多尺度模型的地下水溶质运移数值模拟可有效建立微观过程-宏观运移间的关系，进而剖析小尺度非均质性对宏观动力学和反应机理的影响。本项目拟构建新颖、准确、高效的多尺度集成模型，基于多尺度通用界面模型框架，拓展尺度转换和松弛耦合模型，集成单一尺度溶质运移模型，将难以刻画的微观尺度机理融入宏观尺度的模拟预测中；通过对均质/非均质多孔介质内反应流的模拟，将多尺度集成模型与室内沙箱实验和传统模型进行对比和交叉验证，定量分析微观尺度机理与宏观过程参数的跨尺度关系；开展多尺度集成模型的野外场地应用，阐明含水层（重点：冲积层）小尺度非均质性对地下水溶质运移的影响规律。

Flow and solute transport processes in the subsurface are complex and highly coupled across scales. Micro-scale heterogeneity has been found to play an important role in such processes. This project aims to develop an integrated hybrid multi-scale model (IHMM) to investigate the kinetics and reaction mechanism induced by micro-scale heterogeneity, so as to provide advanced understanding of macroscopic transport processes, which is of great significance to a serious of environmental and ecosystem applications such as contaminant remediation. By integrating at-scale flow and transport simulators through a multiscale universal interface with upscaling and loose-coupling method, the IHMM becomes a feasible tool to link the transport processes and parameters between scales. The validation cases include mixing-controlled reaction (with mineral dissolution/precipitation) in homogeneous/heterogeneous porous media. The IHMM is intercompared with sandbox experiments and other at-scale/multiscale simulations before utilized to analyze the impacts of the microscopic incomplete mixing and dissolution/precipitation-induced small-scale heterogeneities on the macroscopic processes. The IHMM is further extended to simulate flow and solute transport in a field site to study the impact of alluvium heterogeneities on the coupled processes in the hyporheic zone.