干旱区生态环境知识资源中心

Sand samplers were laid out in the grassland in the northern foot of Yinshan Mountain for collecting soil flux samples from 0 to 1.5m height above the surface from Mar, 1, 2008 to Feb, 29,2009. Grain size parameters proposed by Folk and Ward, including average, SD, skewness and kurtosis of grain size were used. The vertical distribution of grain size characteristic of sediments trapped by sand samplers in different seasons was analyzed by using electrical mirror technology. The results indicated that size of aeolian sand in desert steppe is mainly sand and silt. The content of coarse silt, very fine sand and medium sand are 20 similar to 60%, 10 similar to 30% and 10 similar to 20%, respectively, in the sediment-for all seasons. As height increased, the content of sand decreased while silt increased and the mean size of particle changed from fine sand to very fine sand. The mean diameter of particle ranged from 2.4 similar to 4.2 phi and standard deviation ranged from 0.7 similar to 1.5 phi Skewness is positive with the value ranges from 0 to 0.2, while Kurtosis mainly concentrated on 0.7 to 1.3.