关键词: 库姆塔格沙漠, 羽毛状沙垄, 风沙活动特征

Abstract:

Through on-the-spot observation in windy season and data analysis a study on the wind regime, grain size characteristics and wind-sand flux structure near sand bed of feather-shaped sand ridge in the Kumtag Desert was conducted. The wind regime was seasonally changing, the E-dominated wind blew in winter and the N-E dominated wind blew in the other seasons. The annual average wind speed was 5.94 m·s-1 in the area, and the frequency of sand-blowing threshold wind was 46.76%. The grain size of barchan ridge was within 1.22—1.86, belonging to better rating, and the grain size between sandy ridges was within 1.35—2.11, belonging to weaker rating. With the increasing of wind speed, the sand content in wind-sand flux aboveground 0—2 cm reduced obviously; the content within 2—20 cm tended to increase, occupying more than 92.28% of the total. The sand-transporting rate of 0—40 cm height had power function relation with the average wind speed per minute at 2 m, in addition it was influenced strongly by different landforms. The wind regime over feather-shaped sand ridges appeared on the wind-speeding and wind-slowing in different positions of barchan and lowland, also on the variation of wind direction angle between that faced sand ridges.

Key words: Kumtag Desert, feather-shaped sand ridge, characteristics of sand-blown activity近30 a