土壤学报2017，Vol.54Issue(4)：854-863,10.DOI:10.11766/trxb201611280500
祁连山区土壤砂粒含量剖面分布模式及其影响因素
Mode of Profile Distribution of Soil Sand Content and Its Affecting Factors in the Qilian Mountains
摘要
Abstract
[Objective] The Qilian Mountains is the main water head of the Heihe River Valley in Northwest China.To balance the need of water between socio-economic development and natural ecology protection,it is very important to understand the hydrology and other scientific basis of water management.Situated at the headwater area of the basin,soil properties especially soil physical properties such as particle size distribution in the Qilian Mountains have significant impacts on hydrological processes.Mode of profile distribution (PDM) of soil particle size composition and its relationships with various environmental factors were discussed in an attempt to further understand quantitatively the transport of water,nutrient,gas and heat in soil and to develop 3D predication and mapping of soil particle size distribution.[Method] A total of sixty-nine soil profiles ≥ lm in depth typical of the Qilian Mountains were investigated and soil samples collected from layers of the profiles for fractionation of clay,silt and sand fractions with the laser diffraction method.Sand fraction,the most variable one,was selected to study mode of its vertical distribution in the profile and its relationships with environmental factors,including elevation,slope,aspect,annual mean precipitation,plan curvature,profile curvature,terrain wetness index,land use and parent materials.[Result] Results show that the sand fraction in that region had 6 PDMs,i.e.,uniform,increasing,decreasing,increasing-decreasing,decreasing-increasing and irregular,which were little related to any quantifiable environmental factors.We predicted the PDM with random forest,the accuracy was low.It is difficult to predict the PDM with quantifiable environmental information.[Conclusion] Because of the diversity of soil forming parent materials and complex landform and land relief in the Qilian Mountains,migration and discontinuity of parent materials often occurs as a result of land use.So it is difficult to predict PDM quantitatively only with single environmental variables,and therefore,its essential to explore in depth the issue from the angle of composite environmental variables.关键词
土壤颗粒组成/砂粒含量/剖面垂直分布/环境变量/祁连山Key words
Soil particle size composition/Sand content/Profile vertical distribution/Environmental factor/the Qilian Mountains分类
农业科技引用本文复制引用
李璇,杨帆,李德成,张甘霖..祁连山区土壤砂粒含量剖面分布模式及其影响因素[J].土壤学报,2017,54(4):854-863,10.基金项目
国家自然科学基金(41371224和41130530)资助 Supported by the National Natural Science Foundation of China(Nos.41371224,41130530) （41371224和41130530）
