闪电

The accurate quantification of infiltration processes in cold regions is essential for predicting hydrological responses to climate change and developing effective water management strategies. Current infiltration models are developed for stable, temperate conditions and constant soil properties, which contrast sharply with the thermal and hydraulic conditions in freeze-thaw environments. This study proposed a Horton-RCCC formula specifically designed for the freeze-thaw environment in cold regions, which are achieved by several terms of innovation as follows. A large-size undisturbed soil sampling and restoration method to enable laboratory simulation of soil freeze-thaw processes. The soil freeze-thaw state is innovatively described using the ratio of current freeze-thaw depth to maximum freeze-thaw depth. The calculation equations for soil water initial infiltration rate and stable infiltration rate are developed, shifting from the traditional approach of using a single parameter set for entire watersheds and improving distributed characterization of soil infiltration capacity under varying underlying surface conditions. The Horton-RCCC formula is calibrated and validated in permafrost and seasonally frozen ground regions. In complete thawing stage, the Horton-RCCC formula demonstrates comparable accuracy with that of Horton equation on a condition of zero slope, and shows its advantage to calculation infiltration under sloped conditions. In freeze-thaw period, the Horton-RCCC formula effectively addresses the dynamics of underlying surface infiltration conditions, and shows a significant improvement in accuracy. This formula breaks away from the conventional research paradigm of directly applying infiltration formulas for temperate conditions, could stimulate improvements in hydrological modeling, water resource management and climate change adaptation in cold regions.精准量化寒区入渗过程，是预测气候变化下流域水文响应、制定高效水资源管理策略的核心基础。现有入渗模型多针对稳定温带环境与恒定土壤属性开发，与冻融环境下的热学与水力学条件存在显著差异。本研究针对寒区冻融环境，开发了专属的Horton-RCCC入渗公式，该公式通过以下多项创新得以构建：其一，提出大尺寸原状土取样与复现方法，可在实验室中模拟土壤冻融过程；其二，创新性地以当前冻深与最大冻深的比值表征土壤冻融状态；其三，构建了土壤初始入渗率与稳定入渗率的计算方程，摒弃了传统全流域统一参数集的研究思路，提升了变化下垫面条件下土壤入渗能力的分布式表征精度。本研究在多年冻土与季节冻土区对Horton-RCCC公式进行了率定与验证。在完全解冻阶段，该公式在零坡度条件下的计算精度与经典Horton方程相当，且在坡面入渗计算中展现出更优性能；在冻融周期内，该公式可有效刻画下垫面入渗条件的动态变化，计算精度得到显著提升。该公式突破了直接套用温带入渗公式的传统研究范式，有望推动寒区水文模拟、水资源管理与气候变化适应领域的研究发展。