多年冻土区活动层土壤粒度垂向分异的冻融驱动机制：研究进展与展望

Freeze-Thaw Driving Mechanism of Vertical Differentiation of Soil Particle Size in the Active Layer of Permafrost Regions: Research Progress and Prospects

摘要: 冻融循环是塑造多年冻土区地表过程的核心物理营力，活动层土壤粒度垂向分异直接决定寒区土壤水热与力学特性，深刻影响区域水文过程、生态系统稳定性及工程基础设施安全。针对当前冻融驱动土壤粒度垂向分异的研究成果分散、缺乏多尺度多过程系统整合框架的问题，本文系统梳理了国内外相关野外观测、室内模拟的研究进展，厘清了该过程的典型现象、分异模式、核心驱动机制与关键控制因素。当前学界已形成一些核心共识，但在微观机制主导性权重、微观界面过程定量描述、多过程耦合模型构建、长期演化规律预测等方面仍存在显著争议与认知瓶颈。本文构建了冻融驱动粒度垂向分异的多尺度多过程整合分析框架，阐述了未来研究需突破的核心难题，以期为寒区冻土退化风险评估、生态环境保护及工程安全维护提供理论支撑。

Abstract: Freeze-thaw cycle is the core physical agent that shapes surface processes in permafrost regions. The vertical differentiation of soil particle size in the active layer directly determines the hydrothermal and mechanical properties of soil in cold regions, and exerts a profound impact on regional hydrological processes, ecosystem stability, and the safety of engineering infrastructure. Aiming at the current problems that the research results on freeze-thaw-driven vertical differentiation of soil particle size are scattered and lack a systematic multi-scale and multi-process integrated framework, this paper systematically reviews the research progress of relevant field observations and laboratory simulations at home and abroad, and clarifies the typical phenomena, differentiation patterns, core driving mechanisms and key controlling factors of this process. At present, the academic community has reached some core consensuses, but there are still prominent controversies and cognitive bottlenecks in aspects including the dominance weight of microscopic mechanisms, quantitative description of microscopic interface processes, construction of multi-process coupling models, and prediction of long-term evolution laws. This paper constructs a multi-scale and multi-process integrated analytical framework for freeze-thaw-driven vertical differentiation of soil particle size, and elaborates the core scientific problems to be broken through in future research, so as to provide theoretical support for risk assessment of permafrost degradation, ecological environment protection, and engineering safety maintenance in cold regions.