大气-雪被-冻融土壤系统水热协同效应及能量传递机理研究

Study ever ignore atmosphere, snow, freezing and thawing soil water heat transfer and energy transfer between the synergy effect, it is difficult to give full play to the frozen soil water storage keep moisture, atmosphere, and snow, freezing and thawing soil is regarded as a big system, through the field experiment in winter, identification and snow between the atmosphere and the sense of heat and latent heat exchange process, the screening of accumulated snow - melting process dynamic simulation characteristic parameters of improved physical model and the establishment of snow accumulation and ablation procedures, the calculated parameters sensitivity index, parameterization scheme is to reveal the response mechanism of the accumulation of snow - melting process.And then on the basis of the theory of complexity diagnosis and snow - hydrothermal complexity characteristics of frozen soil interface, snow - freezing and thawing soil water thermal energy transfer model is put forward, and the dynamic simulation of water thermal energy transfer process, reveals between snow and freezing and thawing soil hydrothermal migration patterns and energy transfer mechanism.Finally, analysis the atmosphere - and snow - freezing and thawing soil infiltration law of snowmelt water evaporation system, identify critical driving factor, snow melt water infiltration evaporation reveal water evaporation infiltration mechanism, melting period suitable soil soil conservaton technology is put forward.Research results to solve the identification, accumulation of snow - melting process parameters and snow - interface energy transfer model parameters calibration and permafrost melt water infiltration activities of freezing and thawing soil layer response to determine the critical depth of the problem is of great significance.

针对以往研究忽略大气、雪被、冻融土壤之间水热迁移和能量传递的协同影响，难以充分发挥冻土蓄水保墒作用，将大气、雪被、冻融土壤视为一个大系统，通过冬季大田试验，识别雪被与大气间的感热和潜热交换过程，筛选雪积累-消融过程动态模拟特征参数，改进和建立雪积累和消融过程物理模型，计算各参数化方案的敏感性指数，揭示参数化方案对雪积累-消融过程的响应机制。进而运用复杂性理论诊断雪被-冻土界面水热复杂性特征，提出积雪-冻融土壤水热能量传递模型，动态模拟水热能量迁移过程，揭示积雪-冻融土壤间水热迁移规律与能量传递机理。最后，分析大气-雪被-冻融土壤系统融雪水蒸发入渗规律，识别融雪水入渗蒸发关键驱动因子，揭示雪水蒸发入渗机制，提出融化期适宜的农田土壤保墒技术。研究成果对于解决雪积累-消融过程参数化方案识别、雪被-冻土界面能量传递模型特征参数率定和融雪水入渗对冻融土壤活动层响应的临界深度确定等问题具有重要意义。

黑龙江省是我国最大的商品粮基地，是高纬度冻土区典型代表，冬季降水形式多为降雪，受环境驱动作用的影响，土壤在冻融循环过程中伴随着水热的运移及能量的交换传递作用，同时在不同的下垫面下，冻融格局的转变也存在差异。为充分利用充足的融雪水资源，使农田土壤维持可持续性，本项目将大气、雪被、冻融土壤视为一个联合体，采用野外田间试验、室内冻融模拟试验以及模型参数化方案等研究手段，深入探究了大气-雪被-冻融土壤之间的水热协同效应及能量传递机理，并拓展研究了不同调控模式下农田土壤的养分迁移转化规律，研究成果对于揭示大气-雪被-冻融土壤系统水热迁移规律，准确预测春播期土壤温度和墒情，高效合理的利用寒区冻土资源具有重要的理论价值和现实意义，其主要成果如下：.（1）揭示了不同下垫面积雪特征参数的时间演变规律及其对气象因子的响应机理，筛选出积雪积累-消融过程主要影响参数，解析了雪积累-消融过程的物理机制。.（2）识别了影响积雪水热及土壤水热的关键环境因子，探明了土层与环境之间的热量交换关系，求解出土壤水热活动分界层范围，揭示了积雪-冻融土壤间水热能量传递机理，拓展了季冻区土壤水动力学技术理论研究体系。.（3）得出了季节性冻土区冻融土壤在不同下垫面的蒸发入渗规律，揭示了大气-雪被-冻融土壤系统融雪水蒸发入渗机制，提出了适宜于季节性冻土区的农田土壤适应性保墒技术。.（4）探明了冻融循环条件下土壤水热迁移和土壤氮转化过程，阐述了不同调控模式下土样养分迁移及土壤环境变化特征，为维持农田生态系统可持续性提供了理论依据。