乌兰布和沙漠不同土地利用类型粒度特征分析

Grain Size Characteristics of Different Land Use Types in Ulan Buh Desert

以乌兰布和沙漠段流动沙丘、沙丘前草地、沙丘前农田为研究对象,对沙丘各部位和草地、农田不同深度（0~1m）土壤粒度特征的变化规律进行了分析。结果表明：流动沙丘土壤以细砂为主,农田以粉粒为主,草地以细砂和中砂为主;随着土层深度的增加农田土壤粒径增大,草地粒径减小,沙丘无明显变化;流动沙丘粒度分布曲线为单峰,而草地和农田为双峰。农田偏度呈现近对称到极正偏态的分布趋势,分选较差;草地则呈近对称到正偏态再到极正偏态分布的趋势,分选较好到很差;沙丘分选很好,分选性差异不大。

The paper analyzed the variation law of grain size characteristics at different depths( 0 ~ 1 m) of each location of dunes,grassland and farmland by taking moving dunes,grassland and farmland in front of the dunes as an object of study. The outcomes show that a) the moving dunes are mainly fine sands,farmland mainly silt and grassland mainly fine sand and medium-sized sand; b) the particle size of farmland increases,grassland decreases and sand dunes have no remarkable changes along with the increase of soil depth and; c) the particle size distribution curve of moving dunes shows single peak and that grassland and farmland shows double peak. The skewness of farmland shows the tendency from negative bias to very positive bias and poor sorting. The skewness of grassland shows the tendency from nearly symmetrical to positive skewness to extremely positive skewness and sorting coefficients are from better to poor. Sorting of sand dunes is good and had little difference.