摘要
利用体积分形维数模型对塔克拉玛干沙漠和田河西侧胡杨沙堆的粒度特征进行分析,探讨了沉积物分形维数与粒度参数的相关关系,结果显示:(1)胡杨沙堆表层土壤沉积物砂含量高达98.7%,有超过82%的土壤颗粒的粒级在32~250μm的细砂范围内,平均粒径为258μm。(2)在胡杨沙堆不同部位表层土壤的粒级表现出有规律的变化,平均粒径从迎风坡坡脚至背风坡坡中逐渐变细,从背风坡坡中至背风坡坡脚逐渐变粗。(3)沙堆表层土壤整体分选性较差,偏度整体属于负偏;胡杨沙堆表层土壤呈现出从中等到较窄的峰度变化。(4)沉积物体积分形维数介于0.68~2.47,平均值为1.66。沙堆表层土壤的分形维数与各粒度特征参数均呈显著线性相关,与平均粒径拟合程度一般,R^(2)=0.403;与分选系数拟合中等,R^(2)=0.623;与偏度值拟合程度一般,R^(2)=0.353;与峰度值拟合中等偏上,R^(2)=0.737。
The fractal characteristics of grain size of Populus euphratica sandpile on the west side of the Taklimakan Desert and Hotan River are analyzed by using the volume fractal dimension model,and the correlation between the fractal dimension of sediment and grain size parameters is discussed. The results show that:(1)the sand content in the surface soil of Populus euphratica sandpile is as high as98.7%,more than 82% of the soil particles are fine sand,ranging from 32 μm to 250 μm,with an average grain size of 258.0 μm;(2)The grain sizes of the surface soil in different parts of the Populus euphratica sandpile show regular changes,with the average grain size gradually decreasing from the foot of the windward slope to the leeward slope,and gradually increasing from the leeward slope to the foot of the leeward slope.(3) The overall sorting of the surface soil of the sandpile is poor,and the overall skewness is negative. The surface soil sandpile shows a kurtosis which changes from medium to narrow.(4)The fractal dimension of sediment volume ranges from 0.68 to 2.47,with an average value of 1.66. The fractal dimension of the surface soil of the sandpile is significantly linearly related to each grain size characteristic parameter,is generally fitted to the average particle size,with R^(2)= 0.388;the fitting with sorting coefficient is medium,R^(2)= 0.403;the degree of fitting with the deviation value is general,R^(2)= 0.353;the fitting to the peak value is moderately higher,R^(2)= 0.737.
作者
马倩雯
来风兵
MA Qianwen;LAI Fengbing(College of Geography and Tourism,Xinjiang Normal University,Urumqi 830054,China)
出处
《沙漠与绿洲气象》
2020年第6期114-120,共7页
Desert and Oasis Meteorology
基金
国家自然科学基金(46061003)。
关键词
胡杨沙堆
粒径
分形维数
Populus euphratica sandpile
grain size
fractal dimension
