The infiltrability of frozen soils modulates the partitioning of snowmelt between infiltration and runoff in cold regions. Preferential flow in macropores may enhance infiltration, but flow dynamics in frozen soil are complicated by soil heat transfer processes. We developed a dual‐permeability model that considers the interacting effects of freeze–thaw and preferential flow on infiltration and runoff generation in structured soils. This formulation was incorporated into the fully integrated groundwater–surface water model HydroGeoSphere, to represent water–ice phase change in macropores such that porewater freezing is governed by macropore–matrix heat exchange. Model performance was evaluated against laboratory experiments and synthetic test cases designed to examine the effects of preferential flow on snowmelt partitioning between infiltration, runoff, and drainage. Simulations were able to reproduce experimental observations of rapid infiltration and drainage behavior due to macropores very well, and approximated soil thaw to an acceptable degree. Simulation of measured data highlighted the importance of macropore hydraulic conductivity, as well as macropore–matrix heat and water transfer, on controlling preferential flow dynamics. Test cases replicated a range of snowmelt partitioning behavior commonly observed in frozen soils, including subsurface conditions that produce rapid infiltration and deeper drainage, the contrast between limited vs. unlimited infiltration responses to snowmelt, and the temporal evolution of runoff generation. This study demonstrates the important influence that water freezing along preferential flowpaths can have on infiltrability and runoff characteristics in frozen soils and provides a physically based description of this mechanism that links infiltration behavior to hydraulic and thermal properties of structured soils.

中文翻译：

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冻土中优先流动和融雪分配的双重渗透模型

冻土的渗透性调节了融雪在寒冷地区渗透与径流之间的分配。大孔中的优先流动可能会增强渗透作用，但土壤传热过程会使冻结土壤中的流动动力学复杂化。我们开发了一个双渗透率模型，该模型考虑了冻融和优先流动对结构性土壤入渗和径流产生的相互作用。该公式被并入完全集成的地下水-地表水模型HydroGeoSphere中，以表示大孔隙中水与冰的相变，从而使孔隙水冻结受大孔隙-基质热交换控制。模型性能是根据实验室实验和综合测试案例进行评估的，这些案例旨在检查优先流量对入渗之间融雪分配的影响，径流和排水。模拟能够很好地重现由于大孔引起的快速渗透和排水行为的实验观察结果，并且近似的土壤融化程度可以接受。实测数据的模拟突出了大孔水力传导率以及大孔-基质传热和水传递对控制优先流动动力学的重要性。测试案例复制了在冻土中通常观察到的一系列融雪分配行为，包括产生快速渗透和更深排水的地下条件，对融雪的有限和无限渗透响应之间的对比以及径流产生的时间演变。