土壤风蚀对表层土壤粒度特征的影响  

The effect of wind erosion on the surface particle size

作　　者：张正偲[1] 董治宝[1] 

机构地区：[1]中国科学院沙漠与沙漠化重点实验室,兰州730000

出　　处：《干旱区资源与环境》2012年第12期86-89,共4页Journal of Arid Land Resources and Environment

基　　金：国家自然科学基金项目(批准号:41101007;41130533;41171010)资助

摘　　要：土壤风蚀是一种严重的环境问题。文中选择我国西北干旱及半干旱区,风蚀严重的盐池县风沙土地为研究对象,利用Marven2000粒度分析仪对不同风蚀强度的表层土壤粒度进行分析,探讨土壤风蚀过程对地表粒度的影响,研究表明:随着风蚀程度的增加,表层土壤粒度逐渐变粗,由灌丛-推平耕地-草地-吹蚀地,地表中的细沙,粉沙和粘土的含量逐渐降低,而中沙和粗沙的含量逐渐增加。灌丛表面以细沙为主,占34.9%;推平耕地和草地以中沙为主,占32.7和39.1%;吹蚀地以粗沙为主,占44.2%;土壤平均粒径逐渐变粗,分别为2.48,2.08,1.91,1.12φ。土壤风蚀过程,地表的细沙,粉沙和粘土大量损失,灌丛的细沙,粉沙和粘土分别占34.86,20.01和10.98%,但在严重风蚀的吹蚀地,细沙,粉沙和粘土仅占6.09,3.72和2.52%。由此可见,土壤风蚀造成地表细颗粒物质损失,形成沙漠化土地。不同地表沙粒的分维数不同,随平均粒径增加,分维数总体降低。wind erosion is the serious environmental problem.In this paper,wind erosion samplers in Yanchi County in arid and semi arid region were selected to analyze the effect of wind erosion on the particle size characters.Results indicate that surface material trend to coarser with wind erosion stronger.The amount of silt and clay material decreases,and sand material increases from shrubbery land to cultivated land,grass land and wind erosion land.In the shrubbery land,surface particle is mainly fine sand and about 34.9%,in the cultivated land and grass land,surface particle is mainly medium sand and about 32.7 and 39.1%,respectively.In the wind erosion land,surface particle is mainly coarse sand and about 44.2%.The mean diameters increased from shrubbery land to cultivated land,grass land and wind erosion land,and are 2.48,208,1.91 and 1.12φ,respectively.In the course of wind erosion processes,the amount of fine sand,very fine sand and silt material obviously loosed,fine sand,very fine sand and silt are 34.86,20.01 and 10.98%,respectively.In shrubbery land,they are only 6.09,3.72 and 2.52% respectively.So,wind erosion causes surface land fine material losses and forms desertification.Grain size fractal dimensions in different lands are different,fractal dimension decreases with average particle size increase.

关 键 词：土壤风蚀 粒度 粒度参数 

分 类 号：S152.3[农业科学—土壤学]