摘要
选取丹江鹦鹉沟流域78个不同土壤剖面,应用分形理论研究不同土地利用类型的土壤颗粒分形特征和空间变异性以及与土壤养分的相关关系。结果表明:(1)研究区的土壤粒径分布中,粉粒含量占主导地位,粉粒含量百分比在45.41%～66.19%之间,粘粒含量和极粗砂粒含量相对较低。(2)小流域土壤颗粒的分形维数不能用半方差模型和Kriging插值来模拟。表层土壤颗粒分形维数受土壤侵蚀影响较大。(3)陡坡以下,土层较厚且质量较好的地块往往被用作农地,致使相同坡度下,土壤颗粒分形维数表现为农地>林草地。(4)分形维数与不同粒级含量的相关性具有明显差异,其中,分形维数与粉粘粒含量呈显著线性正相关,与细砂粒、中粗砂粒和极粗砂粒含量呈线性负相关。(5)农地和草地0-10cm土壤颗粒的分形维数随坡度的增加呈降低趋势,但坡度对林地的分形维数影响很小。(6)分形维数在4个土层均与土壤含水量呈显著正相关,在0-10cm与有机质含量呈显著负相关。
There were 78 soil samples chosen in different profiles in Yingwugou watershed. Using fractal theory, the fractal features of soil particle-size distribution（PSD） under different types of land use, the spatial distribution of fractal dimension and the relationship between fractal dimension and soil nutrients were studied. The results indicated that： （1）The predominant soil particle sizes were found to be silt in studied area. The percentages of silt were between 45. 41% and 66. 19%. The contents of clay and gravel were relatively lower. （2）The soil fractal dimension of particle-size distribution could not be simulated by semi variance model and the Kriging simulation in small watershed. The soil fractal dimension in topsoil was largely affected by soil erosion. （3）The plots with thick soil and good conditions were often used as farmland under steep slope, causing the soil fractal dimension in the same slope to show： Farmland ）woodland and grassland. （4）The fractal dimension showed distinct difference according to the content of different particle-sizes. The fractal dimension of PSD had a strong positive correlation with silt-clay content, a negative correlation with the content of fine sand, coarse sand and gravel. （5）The fractal dimensions of cropland and grassland in 0--10 cm came to be smaller as the slope increased, but the slope showed a small influence on the fractal dimension of forest land. （6）The fractal dimension had strong positive relationship with soil water content in the four soil layers, but negative relationship with soil organic matter in 0--10 cm soil layer.
出处
《水土保持学报》
CSCD
北大核心
2013年第2期244-249,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目“植被格局对坡沟水蚀过程调控机理研究”(41071182)
博士点基金资助项目“退耕生态系统植被根系行为与土壤水环境响应”(20096118110006)
国家重点基础研究发展计划“973”计划项目“黄土坡面土壤养分流失特征与控制机理”(2011CB411903)
陕西省自然科学基金项目“自然-人工植被对非点源污染过程调控机理”(2011JE008)
关键词
土地利用方式
分形维数
小流域
丹江
land use types
fractal dimension
small watershed
Dan river
