极地冻融风蚀机理与定量分析研究

全球变暖与人类活动增加影响下，极地季节性冻土区冻融作用导致的风蚀灾害问题日益加剧，严重影响生态环境乃至区域气候变化。现有的研究有些集中在冻融作用对土壤结构影响的微观机理方面，或冻融条件下土壤风蚀量动态变化的宏观测量方面。本项目拟在野外样本分析与风洞实验的基础上，研究冻融作用下土壤结构变化规律；以此为基础构建土壤颗粒从地表释放的流体起动与冲击起动函数，实现冻融环境下粒-床相互作用过程的描述；进一步结合模拟复杂空气流动的大涡模拟算法与颗粒轨道模型，研究冻融风蚀近地表颗粒运动，探究冻融对土壤风蚀的影响规律，搭建连接土壤结构参数与风蚀量的桥梁，为区域与全球尺度土壤风蚀预报模式提供参数化方案，也为季节性冻土区风蚀过程的模拟、预测、风险评估以及灾害防治提供参考与工具。

Under the influence of global warming and the increase of human activities, wind erosion disasters caused by the freeze-thaw of seasonal tundra are increasingly serious in polar areas, affecting regional ecology and even climate change. Most of the related researches focus on the microscopic study of the effects of freeze-thaw on the physical and chemical properties of soil, or the macroscopic measurement of the dynamic changes of soil wind erosion under freeze-thaw conditions.On the basis of field sample analysis and wind tunnel.experiment, this project plans to construct a description scheme of soil structure changes under the action of freeze-thaw by combining the rod-bead model.Based on this, the fluid start and impact start functions of soil particles were constructed to describe the granular-bed interaction process in the freeze-thaw environment.Combining with large eddy simulation algorithm to simulate complex air movement and particle track model to calculate the movement of soil particles, we plan to study freeze-thaw wind erosion near surface, and research the interaction process of freeze-thaw and wind erosion, build the bridge links for soil physical and chemical properties and wind erosion rate, provide a parameterized scheme for soil wind erosion prediction model in regional and global scale, also provide the reference and tool for in seasonal frozen wind erosion process simulation and prediction, risk assessment, and disaster prevention and control.