【作者】 郭冬梅；

【导师】 白英；

【作者基本信息】 内蒙古农业大学 ， 农业水土工程， 2005， 硕士

【摘要】 本文对内蒙古阴山北部四子王旗境内西北部的耕地、普通草地和围封草地土壤颗粒机械组成和有机质含量进行了分析。利用分形模型,计算了土壤颗粒的分形维数,对土壤颗粒的分形特征进行了研究,得出以下结论:(1)土壤颗粒分布的分形维数与土壤粒度组成有密切的关系。耕地土壤中细砂粒含量越多,分形维数越小;粘粒含量越多,其分形维数越大。草地土壤中粗砂粒含量越多,分形维数越小;粘粒含量越多,分形维数越大。并且分形维数与粒径小于 0.001mm 颗粒含量相关性最好,建立了分形维数与粘粒含量关系的数学模型,并对模型进行了实验验证。(2)土壤颗粒分形维数与有机质含量呈极显著正相关。土壤有机质含量越多,分形维数越大;反之,有机质含量越少,土壤颗粒的分形维数越低。(3)土壤粘粒含量和均匀指数对不同植被覆盖度地表土壤的分形维数均有显著影响。表土颗粒分形维数与粘粒含量呈显著正相关,与均匀指数呈显著负相关。(4)　土壤植被的覆盖度对分形维数也有影响,植被覆盖度越高,风蚀强度越小,土壤分形维数越大。土壤植被覆盖度能有效地改善土壤的质地状况,从而影响土壤颗粒分形维数的大小。(5)　在土壤剖面上,耕地土壤颗粒分形维数随土层深度的增加而增大;草地深部土壤分形维数比表层土壤分形维数要小。并且围封草地分形维数的变化幅度要比普通草地大。在土壤表层,草地的分形维数明显高于耕地。更多还原

【Abstract】 In this paper,fractal model was applied to calculate fractal dimensions of soil particle distribution based on the analysis of soil particle contents in cultivable land and grassland of Siziwangqi,the north-western part of Inner Mongolia.And the fractal characteristics of soil particle was studied,the results as follow:(1)There are the close relationship between the fractal dimensions of soil and granulometric composition of soil.Lower the content of thin sand and higher the content of clay,higher the fractal dimensions in cultivable land.In grassland,higher the content of thick sand,smaller the fractal dimensions.And higher the content of clay,higher the fractal dimensions. Moreover the fractal dimensions are best line-relative with soil particle,when the diameter of soil particle is smaller than 0.001 millimetre.The mathematical model was created between the fractal dimensions and the content of clay and verified.(2)In addition,the fractal dimensions of soil particle are positively relative with the content of organic matter.Higher the content of organic matter,higher the fractal dimension of soil particle.(3)the effect of the content of clay and even index on the fractal dimensions of surface soil particle was discussed under different land coverage.The dimensions are positively relative with clay content,and significantly negative with even index.(4)the fractal dimensions of soil particle increase with land coverage but decrease with soil erosion degree.Soil coverage can effectively improve soil structure and texture,it has an effect on the fractal dimensions of soil particle.(5)In cultivable soil profile,deeper the soil layer, higher the fractal dimensions of soil particle,but in grassland the fractal dimensions of soil depth are smaller than surface soil.In addition the fractal dimensions of grassland are highter than cultivable land in surface soil.更多还原