摘要
基于风洞实验数据 ,对砂质壤土与壤质砂土短期吹蚀的粒度分形结构及其分维变化进行了探讨。结果表明 :( 1)在砂质壤土与壤质砂土的不同吹蚀时段 ,各自床面的粒度组成是具有分形结构特征的 ,在风洞里不同风速与时间下的吹蚀并未改变两种土壤所具有的分形结构 ,改变的只是分形结构的定量描述参数分维 ;( 2 )无论是在初始状态还是在一定的风速和时间下 ,砂质壤土的分维都小于壤质砂土的分维 ;( 3)两种不同质地的土壤在不同的吹蚀时段床面粒度分维与 <0 0 5mm的颗粒 (即粉粘粒 )含量之间都存在着显著的正相关性 ;( 4 )两种土壤在吹蚀的过程中由于土壤性状的差异 。
Based on the fractal theory and experimental data in wind tunnel,the fractal character of soil particle size in a short period was preliminarily discussed in this paper. Also,the trend of fractal dimension on soil surface during different deflation periods was analyzed. Some conclusions can be drawn as follows: (1) During the different blowing intervals,fractal structure exists in the grain size distributions of sandy loam and loamy sand. Furthermore,fractal characters of two soils don't change with the different wind speeds and time in the wind tunnel. But their fractal dimensions change as the time gone. (2) Whether the initial stage of deflation or the consequent stage with definite wind speed and time,the fractal dimensions of sandy loam are all smaller than that of loamy sand. (3) During the different soil deflation process,regression analysis indicated that there was significant positive correlation between the fractal dimensions of the grain sizes of the two soils with different texture and the content of the clay(<0.05 mm),but the correlations between the fractal dimensions and the contents of the rest grain size are different. In generally,the more the content of clay is,the larger the fractal dimension of grain size is. (4) Because of the different situation of the two soils with different texture during the deflation process,correspondingly the fractal dimensions of grain size had different process of variation with the different wind speed and time.
出处
《土壤学报》
CAS
CSCD
北大核心
2004年第2期176-182,共7页
Acta Pedologica Sinica
基金
国家科技攻关项目 ( 2 0 0 2BA5 17A0 4)
国家自然科学基金项目 ( 40 0 710 18)资助
