Characteristics of aeolian sediment under different underlying surfaces in oasis-desert transitional region of Minqin

Based on the practical observation materials of three sand storms in Minqin county, the characteristics of aeolian sediment under different underlying surfaces in the oasis-desert transitional region of this area were studied. The sand storms were occurred on April 19, 22 – 23 and 30 in 2009. The results showed that the upper segment of the sediment discharge line of the vertical distribution fit in with exponential rule, and the real sediment near the soil surface (beneath 35 cm) was larger than that of calculated with the exponential function. 90% sediment discharge of the sand surface was beneath 15 cm. 80% sediment discharge of soil surfaces with Nitraria bushes, straw checkerboard barrier and reed were in the height of 35 cm from the soil surface. The effects of underlying surface with different conditions on sediment particles diameter mainly focus on the near surface at 15 cm range from soil surface, and the effects on the particle size of aeolian sediment at 35 cm to 125 cm range mainly focus on the percentage of different particles. The straw checkerboard barrier is a best way for reducing the wind erosion, which can lower the sediment transport capacity of wind. The function of soil surface with Nitraria bushes takes the second place, and the soil surface with reeds is the third. The surface covered by sand has the biggest sediment discharge.