策勒绿洲-荒漠过渡带风沙前沿近地面不同方向的输沙特征

Study on Wind-blown Sand Characteristics at Different Directions near the Surface in the Frontier of an Oasis-desert Ecotone in Qira County,Xinjiang

利用策勒绿洲-荒漠过渡带风沙前沿输沙资料及风速风向资料,分析这一区域近地面输沙的方向分布特征。结果表明:①风沙前沿起沙风风向以W、WNW为主,风向变化比较单一;②观测点输沙量集中于NW、WNW、W、SW、WSW 5个方位,合计占总输沙量的68.3%;0～40 cm高度年输沙量为96.0 kg,年合成输沙量为45.9 kg,合成输沙方向为102.5°;③观测点年输沙势为43.2 VU,年合成输沙势为31.04 VU,输沙势的方向分布与实测输沙量存在较大差异。

Aeolian sand transport is serious in many arid regions in the world,and it is considered to be as a significant part of global biogeochemical cycles.Furthermore,wind-blown sand brings often disasters.Therefore,widespread attention has been paid to the significance of aeolian sand transport in many fields,such as geomorphology,climatology,meteorology,ecology and environmental science.Wind-blown sand direction is a base for both studying the formation and evolution of aeolian geomorphology and carrying out the sand damage control measures.In this study,a statistical analysis on wind-blown sand direction in an oasis-desert ecotone in Qira County,located in the south marginal zone of the Tarim Basin,was carried out during the period from 2010 to 2011.Some preliminary conclusions are as follows：（1） In the study area,the wind directions of sand-driving wind are mainly W and WNW,and the change of wind direction is comparatively simple;（2） In the study area,the wind directions at which the values of sediment discharge are high are dominated by NW,WNW,W,SW and WSW,and the occurring frequency is as high as 68.3%.An aeolian sediment discharge of 96 kg passing through a height extent of 0-40 cm and 1-cm width occurred.The annual resultant wind-blown sand amount is 45.9 kg,and the resultant wind-blown sand direction is 102.5°;（3） In the study area,the wind-blown sand potential and resultant wind-blown sand potential are 43.2 VU and 31.04 VU respectively.There is a considerable difference between the direction of wind-blown sand potential and the measured sediment discharge.It is recognized that wind-blown sand is a complex process,and various factors affecting wind-blow sand,such as wind speed,wind direction and underlying surface,should be comprehensively considered and researched.