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为了探讨绿洲-沙漠过渡带对绿洲可持续发展的环境效应,本研究对策勒绿洲西缘绿洲-沙漠过渡带、防护林带和绿洲内部的各种风成沉积物及策勒河谷沉积物粒度特征进行比较.结果表明:绿洲-沙漠过渡带风成沉积物粒度特征(包括粒度分布特征、粒度参数、各粒级含量等)在空间上基本一致,其粒度范围为0.3~200μm,分选性良好,主峰众数为67μm,主要为悬浮组分和变性跃移组分,未出现>200μm的跃移和蠕移组分,表现出典型的大气沙尘近距离传输沉积的特点.与外围(上风向)的策勒河谷(粒度范围0.3~800μm)和沙漠地区的沉积物比较,过渡带粒度明显偏细,但与过渡带、防护林带和绿洲内部现代尘暴降尘(下风向)各种粒度特征基本一致.策勒绿洲-沙漠过渡带由于存在较高植被覆盖度,能够有效地抑制沙漠地区较粗颗粒组分(>200μm)通过变性跃移或蠕移方式输送进入过渡带和绿洲内部.绿洲-沙漠过渡带与防护林体系一样,可有效抑制沙漠入侵绿洲,二者形成一个整体,共同维护策勒绿洲生态环境的稳定.
In order to investigate the environmental effects of the oasis-desert transitional zone on the sustainable development of oasis, this paper studied the characteristics of various aeolian deposits in the oasis-desert transitional belt, shelterbelts and oases in the western edge of Le Oasis and the grain size distribution in the Cele Valley The results show that the grain size characteristics of the aeolian sediments in the oasis-desert transitional zone (including the grain size distribution characteristics, grain size parameters, grain size, etc.) are basically the same in space, with a grain size range of 0.3-200 μm, The main peak mode is 67μm, mainly composed of suspended component and denatured jump component, and there is no transition and creep component> 200μm, showing typical characteristics of atmospheric dust deposition at near distance. ) In the Cele Valley (0.3 ~ 800 μm in size) compared with the sediments in the desert area, the grain size of the transitional area was obviously thinner but basically consistent with the grain size characteristics of dustfall (downwind) in the modern dust storm in the transition zone, shelterbelts and oasis Due to the high vegetation coverage, the Cele Oasis-desert transition zone can effectively inhibit the transmission of coarse particles (> 200μm) in the desert region into the transitional zone and oasis through denaturation or creep Internal.The oasis-desert transitional zone, like the shelterbelt system, can effectively restrain the invasion of desert from the oasis, and the two form a whole to jointly safeguard the ecological stability of Cele Oasis.