冻融条件下不同覆盖度土壤物理结皮的风蚀特征  

Wind Erosion Characteristics of Soil Physical Crust with Different Coverage Under Freeze-Thaw Conditions

作　　者：钟志强 郝连安 马波[1,3] 张秀梅[1] 代骋 Zhong Zhiqiang;Hao Lianan;Ma Bo;Zhang Xiumei;Dai Cheng(College of Soil and Water Conservation Science and Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China;Power China Zhongnan Engineering Corporation Limited,Changsha,Hunan 410014,China;Institute of Soil and Water Conservation,Ministry of Water Resources,Chinese Academy of Sciences,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学水土保持科学与工程学院,陕西杨凌712100 [2]中国电建集团中南勘测设计研究院有限公司,湖南长沙410014 [3]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《水土保持通报》2024年第5期48-57,共10页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“黄土高原北部冻融作用下物理结皮特性变化对风蚀的影响机理”(42277342);“黄土高原冻融对水蚀过程的作用机理研究”(41771311)。

摘　　要：[目的]研究冻融条件下物理结皮的风蚀特征变化,为冻融风蚀相关研究提供理论参考。[方法]以黄土高原北部风水复合侵蚀区内神木市六道沟小流域的沙黄土为研究对象,采用室内模拟冻融、风洞试验相结合的方式,设计不同覆盖度(0%,20%,40%,60%,80%,100%)的物理结皮进行风洞吹蚀试验,探究冻融作用对不同盖度结皮的风蚀强度、输沙率和输沙高度以及摩阻风速、空气动力学粗糙度等动力学参数的影响。[结果]①风蚀强度随风速的增加显著增大(p<0.05)、随结皮盖度的增加显著减小(p<0.05),且结皮盖度越高,风蚀减蚀率越强,最高可达96.07%;冻融后物理结皮的风蚀强度较冻融前均显著增加,冻融后风蚀强度可增加0.02~1.27倍。②物理结皮覆盖显著减小了近地表的输沙率,且近地表输沙率随结皮覆盖度的增加而减小,随风速的增加而增加;冻融后近地表输沙率增加了0.7~4.3倍,输沙高度增加了2~10 cm。③摩阻风速和空气动力学粗糙度随结皮盖度变化差异不显著,冻融前摩阻风速介于0.84~1.35 m/s之间,冻融后摩阻风速在0.80~1.51 m/s内变化,冻融后物理结皮摩阻风速有所减小,但空气动力学粗糙度变化不大。[结论]黄土高原北部的冻融作用增加了土壤风蚀程度,削弱了物理结皮对风蚀的抑制作用;随着结皮盖度增加,冻融作用后风蚀强度和近地表输沙强度明显增大;物理结皮覆盖度、冻融作用对空气动力学粗糙度的影响不显著。[Objective]The change of wind erosion characteristics of physical crust under freeze-thaw conditions was studied to provide theoretical reference for the study of freeze-thaw wind erosion.[Methods]The study examined sandy loess of the Liudaogou sub-watershed in Shenmu City,Shaanxi Province,situated within the wind and water erosion crisscross region of the northern Loess Plateau.The synergistic approaches of indoor freeze-thaw simulation and wind tunnel testing were used to assess the impact of freeze-thaw cycles on wind erosion intensity,sand transport rate,and kinetic parameters such as friction wind speed and aerodynamic roughness across varying soil physical crust coverage levels(0%,20%,40%,60%,80%and 100%).[Results]①Wind erosion intensity was found to increase significantly with increasing wind speed(p<0.05)and decrease with increasing incrust coverage(p<0.05),and the maximum reduction in erosion rate was up to 96.07%.Compared to that under pre-freeze-thaw condition,there was a significant rise in the wind erosion intensity of physical crusts under post-freeze-thaw condition,and the increase ranged from 0.02 to 1.27 times.②Physical crust coverage significantly reduced the near-surface sand transport,which decreased with increasing crust coverage and increased with increasing wind speeds.After freeze-thaw cycles,the near-surface sand transport rates increased by 0.7 to 4.3 times,and the transport height increased by 2 to 10 cm.③Changes in friction wind speed and aerodynamic roughness in response to variations in crust coverage were not statistically significant.The friction wind speed before freeze-thaw was between 0.84 and 1.35 m/s,and post-freeze-thaw varied from 0.80 to 1.51 m/s.Although the friction wind speed was slightly reduced after freeze-thaw,the aerodynamic roughness exhibited minimal variation.[Conclusion]In the northern part of the Loess Plateau,the protective effects of physical crusts against wind erosion reduced and soil wind erosion was intensified by freeze-thaw processes.With increase

关 键 词：土壤物理结皮 冻融作用 风洞试验 风蚀 黄土高原 

分 类 号：S157.1[农业科学—土壤学]