垄状微地形表面剪应力概率分布及其在风蚀计算中的应用

耕作土垄作为农田地表的主要粗糙元类型，对农田风蚀有显著影响。风对地表的剪应力是产生风蚀的直接动力，土垄对剪应力强烈的分解作用及土垄本身的可蚀性，增大了垄作地表土壤风蚀过程的复杂性，但目前综合考虑垄体表面和垄间地表剪应力分布的相关研究十分缺乏。因而完整测定垄体及垄间地表的剪应力分布，是从本质上认识垄作农田土壤风蚀过程与机理的重要突破口，而对其进行量化表达则是构建农田风蚀理论模型的重要探索。本项目以垄作条件下的地表剪应力分布为切入点，采用风洞实验方法，通过精细测量垄体表面和垄间地表剪应力的空间分布，分析垄结构对地表剪应力空间分布的影响机制，建立包含风速和垄结构参数的垄作地表剪应力概率分布函数和基于该函数的农田土壤风蚀模型。本项目独辟蹊径地从可蚀性粗糙元剪应力分解的角度深入开展农田风蚀机理与模型研究，思路新颖，前期工作铺垫扎实，预期能够取得创新成果，为促进我国土壤风蚀研究发展做出贡献。

Tillage ridge, as the main roughness element of farmland surface, has a significant influence on soil wind erosion on farmland. The shear stress on the surface by wind is the direct driving force of wind erosion. Soil ridge has a strong partitioning effect on the shear stress. At the same time, due to the erodibility of soil ridge itself, the process of soil wind erosion becomes more complex, and it is rare on the study comprehensively consider the shear stress distribution on the surface of ridges and between ridges. Therefore, the complete measure of the shear stress distribution on the surface of ridge and shear stress between ridges is an essential breakthrough to recognize the process and mechanism of soil wind erosion in ridge farmland. It is an important exploration to construct the theoretical model of wind erosion on farmland. In this study, the distribution of surface shear stress on ridge tillage farmland will be taken as the breakthrough issue, and the spatial distribution of surface shear stress on the ridge and between ridges will be studied by wind tunnel experiment. The influence mechanism of ridge structure parameter on the spatial distribution of surface shear stress and the influence of ridge-shaped microtopography on the shear stress partitioning will be revealed, and eventually, the probability distribution function of surface shear stress on ridge tillage and the soil wind erosion model of ridge farmland including the function will be established. In this study, the mechanism and model of farmland wind erosion will be deeply studied from the perspective of erodible roughness element shear stress partitioning. The idea is novel and the preliminary work is solid. It is expected to achieve innovative results and make contributions to promote the research and development of soil wind erosion in China.